SPEAKER ABSTRACTS

Effect of Sediment Impacts of Opportunistic Multi-disciplinary Accumulation on the Algae on the Early Life Approach to Study Larval Productivity of Habitat- History of a Habitat- Development forming Seaweeds forming Fucoid

Edwin Ainley // The University of Tommaso Alestra // University of Andrea Alfaro // Auckland Auckland Canterbury University of Technology

Dr Nick Shears, Dr Alwyn Rees // The David Schiel // University of Canterbury Tim Young, Annapoorna Ganesan, University of Auckland Adam Rusk, Le Viet Dung, Neil de Jong, A decline of extensive populations of Colleen Higgins, John Brooks, Chris Pook Increasing human population, coastal fucoid macroalgae has been reported // Auckland University of Technology development, infrastructure and land use worldwide as a result of human-driven changes are causing large amounts of coastal habitat degradation. Contributing One of the most enigmatic processes in sediment to be transported into adjacent to such declines may be the influence the lives of marine invertebrates is the marine ecosystems. Macroalgae are of opportunistic algae which respond development of larvae into juveniles. A often at the heart of these ecosystems, quickly to stresses such as nutrient wide range of strategies exists among and yet there is little information on the loading and warmer sea temperatures, species, which involve morphological, effect that sediment has on subtidal thereby outcompeting the early life physiological and behavioural changes macroalgal stands in New Zealand. This stages of fucoids. Here we examine the geared to enhance survival and study monitored the temporal and spatial interactions between early life stages of recruitment into adult populations. variability in sediment accumulation the intertidal fucoid Hormosira banksii and These rapid and complex changes are on Ecklonia radiata and Carpophyllum fast-growing, opportunistic green algae, associated with high energy requirements flexuosum at a range of sites throughout Ulva spp. Through a series of laboratory and elaborate sensory mechanisms that 2011, and determined the primary experiments, we test: 1) the impact of allow larvae to respond to their immediate environmental drivers responsible Ulva on the settlement of H. banksii environment. Even with these adapted for this. In addition we examined the zygotes; 2) the impact of Ulva on the rates evolutionary strategies, exceedingly effects of experimentally simulated of post-settlement survival and growth of high larval mortalities are a common sediment accumulation on the growth H. banksii germlings, under both normal occurrence in the marine environment and photosynthetic rates of E. radiata and increased levels of temperature and and within aquaculture settings. The and C. flexuosum for up to 11 days. nutrient concentration; 3) the interactions consequences of these high early larval The results showed that the amount of between the two species under grazing mortalities are vast, since they may sediment accumulating on seaweeds pressure of the abundant intertidal snail directly impact on the persistence and was temporally and spatially variable, and Lunella smaragdus. Ulva was facilitated by structure of wild populations and/or may primarily related to two environmental increased temperature and nutrients and result in significant financial constraints drivers: wave action and rainfall. The it negatively affected H. banksii by both for hatchery production. Thus, great maximum amount of sediment recorded impairing the settlement of the zygotes scientific interest has been placed on on E. radiata was 4.5mg cm-2 which was and by limiting the growth of germlings. the understanding of developmental estimated to reduce light levels by more Post-settlement survival of germlings was processes and the mechanisms that than 75%. Not surprisingly sediment not affected by competition with Ulva, underpin these dramatic changes. Within addition to E. radiata in the laboratory but there was an indication that this may the Aquaculture Biotechnology Group caused plants to lose weight, and caused decline with warmer waters. Both species at AUT, we have used traditional and bleaching, rotting and perforations on the were consumed by L. smaragdus, but a new techniques to investigate larval thalli. Subsequently this had detrimental preference for Ulva indirectly facilitated H. developmental processes for a range effects on photosynthesis, considerably banksii. These findings augment extensive of marine invertebrate species. Herein, reducing oxygen production of the plant. field-based research showing the effects we present some of the advances we Conversely, C. flexuosum was slightly of small, ephemeral understory species have achieved with this multi-disciplinary more tolerant of sediment accumulation. on biogenic habitat-formers and highlight approach. Furthermore, the results from By better understanding the the threat posed by their synergisms with these studies have been used to derive consequences that increased terrestrial degraded physical conditions, which are comparative analyses of strategies among sedimentation is having on natural now occurring in coastal ecosystems taxa. marine systems we can emphasise the throughout the world. importance of improved policies and land management practices to ensure the maintenance of this important life- supporting habitat.

58 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Overview of Current Fine-scale Data Present & Future Research on New Zealand Management of the New Applications of Remote Mangrove Ecosystems Zealand Commercial Paua Sensing of Water Quality in Fishery Rotorua Lakes

Andrea Alfaro // Auckland Edward Abraham // Dragonfly Mathew Allan // The University of University of Technology Science Waikato

Kathy Campbell, Melissa Bowen, Christopher Knox David Hamilton, Brendan Hicks // The Lorna Strachan // The University of University of Waikato Auckland Management of the commercial paua Lars Brabyn Sebastian Leuzinger, Mark Duxbury // fishery has been hampered by lack of Auckland University of Technology information at an appropriate scale. The high spatial resolution of Landsat Cyril Marchand, Audrey Leopold // IRD, Since 2009/10, commercial fishers have satellite data and free availability of a New Caledonia begun using GPS loggers that record large image archive spanning more than their position when they are on the 40 years have made Landsat the sensor surface, and depth profiles when thay choice for monitoring inland water Temperate mangroves occupy large are underwater. These loggers provide a areas of northern coastal New Zealand. quality in small lakes. We developed an view of the fishery with unprecedented automated procedure for the retrieval Their ecological role is substantially spatial resolution. In this talk, we show different from their tropical counterparts, of chlorophyll a concentrations from preliminary results from the logger Landsat Enhanced Thematic Mapper which the great majority of mangrove programme and discuss how these data studies have focused on in the past. To imagery of Rotorua lakes. A total of may be used to indicate the status of the 106 Landsat 7 satellite images were alleviate this imbalance, the goal of the paua fishery. Mangrove Research Group supported by captured from 1999 to 2011. Image the Auckland University of Technology, processing routines included radiative Auckland University and the ‘Institut de transfer-based atmospheric correction, Recherche pour le développement’ in using 6sv (Second Simulation of the New Caledonia is to establish a highly Satellite in the Solar Spectrum). A novel interdisciplinary, long-term study site at algorithm was developed using symbolic Mangawhai Harbour Estuary. We will regression to predict chlorophyll a from provide comprehensive data covering visible reflectance of Landsat satellite all aspects of this temperate mangrove imagery. Bio-optical models were applied ecosystem, reaching from detailed to quantify the physical processes habitat mapping, hydrodynamics, responsible for the relationships between sedimentology, geochemistry to food web the reflectance used in regression analysis and mangrove ecophysiology. algorithms, and to examine possible For example, habitat maps will be sources of error. Results from this study established using ultralight aerial vehicles suggest that remote sensing provides with hyperspectral cameras. Further, the a valuable tool to assess temporal and nutrient-, water- and carbon cycles will spatial distributions of chlorophyll a. be characterised, using classic (C, N, P Estimated chlorophyll a concentrations analysis, stable isotope analysis) as well displayed considerable intra- and as state-of-the-art plant physiological inter-lake spatial variability, associated measurements (continuous stem with differences in lake morphology, radius, sap flow and leaf water potential hydrodynamics and chemistry. The future monitoring), and detailed studies of of the NASA Landsat series satellites had carbon pools and fluxes (e.g., eddy flux been assured with the recent launch of an tower, quantification of biomass and litter improved sensor known as Landsat 8. fall/decomposition). Food-web analysis will include detailed studies of diversity and abundance of meiofauna and fish. The results are expected to provide a solid scientific basis for future management decisions as well as detailed insight into all scientific aspects of temperate mangrove ecology.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 59 SPEAKER ABSTRACTS

Benthic Enhancement Management of Water In a Mess with Models Trial for the Hydro-electric Abstraction to Manage Storage Lake – Lake Effects on the Endangered Mahinerangi Central Otago Roundhead Galaxias

Richard Allibone // Golder Richard Allibone // Golder Chris Arbuckel // Aspiring Associates (NZ) Ltd Associates (NZ) Ltd Environmental Ltd

Greg Burrell, Ian Boothroyd, The Otago region is home to a number Whether you think the policies held within Duncan Gray // Golder Associates (NZ) of threatened freshwater fish including the water reform package, Freshwater Ltd the Central Otago Roundhead Galaxias reform 2013 and beyond launched in (CORG). This species is of increasing March this year, or closer to my home, Resource consents for the operation of conservation concern as populations are the Otago Regional Councils Plan Change Waipori hydro-electric scheme required continuing to be lost. Populations persist 6A and Environment Southland’s “Water an assessment of benthic enhancement today in streams abstracted for irrigation and Land 2020 & Beyond” are doing techniques for Lake Mahinerangi, the water and in relatively unmodified, but too much or too little to protect our scheme’s storage lake. The consent disturbance prone, low gradient systems waterways, the effectiveness of these required that leaf litter inputs and rock where introduced salmonids are present. policies ultimately lays in the hands of the substrates be trialled to determine if Both water abstraction and salmonids people who just use water and land to these habitat enhancements improved have been implicated in the extirpation make a living. Rural water users are being invertebrate populations and forage fish of CORG populations. It has also found compelled to manage to environmental abundance. Initial short-term trials with that water abstraction can moderate limits; with the hope that restrictions on rock substrates and leaf packs were the effects of salmonids on CORG in substances like nitrogen, phosphorus, encouraging and a full five year trial streams where water abstraction causes bacteria and sediment entering water, will was initiated in 2008. A small riparian intermittent flow during summer. Many swiftly improve degraded waterways. One planting programme was undertaken to of these water abstractions that have of the biggest challenges at present is investigate the establishment of leafy been active for up to 100 years are for convincing a community or a water user plants to provide leaf litter to the lake. Six large water volumes and are exempt from facing restrictions on hard to manage rock pile transects were established in the Otago Regional Plan Water rules. These substances, that numbers generated by varial zone of the lake bed. Invertebrate abstractions, known as deemed permits many of our environmental models for and fish communities on the lake bed will all expire in 2021. It is expected that limit setting are factual. The defensibility and rock piles were assessed each winter any new consents granted for abstraction of many of our key models have been and summer for five years. The rock piles will have to comply with Regional Plan called in to question and over the next 5 were rapidly colonised and the fauna conditions. This will include minimum to 10 years huge pressure will be placed differed from the adjacent lake bed. flow provisions and it is therefore possible on the science underpinning these so However, the invertebrate communities that summer low flows will be increased called “black boxes”. A further challenge were still dominated by small bodied in some streams with CORG populations. for water managers is that New Zealand organisms such as Diptera larvae. The However, to date no method has been lacks any framework to address model CPUE for common bully and koura was developed to assess change in stream use in environmental management. My significantly greater on the rock piles flow and how whether improvements talk will examine how important some than on the soft sediment lake bed. to summer flows will assist CORG or sort of framework is needed, especially However, as the rock piles offer refuge allow salmonids to permanently invade as resource manager’s lunge for at a from predation it is unlikely the rock piles CORG populated areas. A habitat and grab bag of models to set limits, and the significantly increased the availability flow based assessment method is being effectiveness of their limit setting relies of forage fish for predator sports fish. developed from non-abstracted streams on a virtual number; for both the water Survival of the lake shore planting with CORG and salmonid populations that user and manager. was very low and showed there were can be applied to abstracted streams to significant difficulties establishing a leaf assess the likelihood that salmonids will litter source on the lake shore. The final permanently establish. success of the rock piles also appeared limited as the majority of rock piles were smothered by fine sediment by the end of the five year trial.

60 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Codium fragile: Modelling of Dual Smelt Life Histories Within An Assessment of the Land & Water the Lower Waikato River Morphological & Genetic Discharge Systems Catchment Variation in Native & Introduced Subspecies

Phoebe Armitage // The University Olivier Ausseil // Aquanet Cindy Baker // NIWA of Auckland Consulting Limited Joshua Smith, Brenda Bartels // NIWA Nina von Westernhagen // Hawke’s Bay Dual land and water systems, where Regional Council wastewater is discharged to land at Within the Waikato River basin both Kit Rutherford // NIWA certain times of the year and to water at diadromous and lacustrine smelt Olivier Ausseil // Aquanet Consulting Ltd other times are becoming increasingly populations exist. To determine the common. These allow in principle for degree of diadromy and mobility of The green alga Codium fragile (Sur.) a more rational utilisation of the land’s smelt within the lower river catchment Hariot is a cosmopolitan species wastewater treatment functions and the otolith microchemistry was undertaken. appearing along temperate coasts in waterbody’s assimilative capacity. The In total, 100 smelt were collected from both hemispheres. The finger-like fronds development and optimisation of dual Huntly during their spawning migration branch dichotomously from a basal discharge systems generally involves in autumn. To determine the elemental holdfast and are coenocytic, composed multiple and complex scenarios, which signature of different rearing habitats of interlacing filaments that terminate in generally require detailed modelling, within the catchment, at monthly a pointed utricle. A native subspecies, interpretation and communication. A intervals smelt were also collected from Codium fragile ssp. novae-zelandiae daily time-step model was developed 19 sites between Lake Karapiro and Port (J. Ag.) Silva is found throughout New to assess the potential effects of dual Waikato. To accommodate temporal Zealand, and is abundant on the west discharge scenarios on river water quality. changes in ambient water chemistry that coast of Auckland. A second subspecies, Model development and calibration may influence otolith signatures during Codium fragile ssp. fragile is regarded involves the development of daily data smelt growth, water samples were also as highly invasive. It has spread widely series of discharge and river quantity collected during each fish collection. from its native range in Japan, and and quality covering a significant period Overall, 98% of the smelt captured, has been known in New Zealand since of time. Clear data summaries are also including those captured from the lower 1973, when it was reported from required in order to communicate the Waikato River lakes, were diadromous. the Waitemata Harbour in Auckland. results to the different parties involved Analysis of the outer (freshwater) region The current distribution of C. fragile in the resource consenting process. The of otoliths from ripe smelt captured at subspecies in Auckland is unknown, in model has been applied to several small Huntly found 20% of fish had signatures part due to a lack of reliable diagnostic and medium-sized communities in the that matched the signatures of smelt field characters. Previous identifications Manawatu Region and has been found rearing in nine locations within the lower based on morphology distinguish the to provide robust and useful support to Waikato River catchment. Of the nine invasive subspecies by the presence system development, decision making sites, eight were located between 16 and of a cinched and pointed utricle, and and assessment of future compliance 117 km upstream of Huntly. In addition, fewer fronds per thallus than the native with specific Regional Plan water quality several distinct elemental signatures subspecies. We aim to test the reliability targets or limits. Real-life examples of were found within the freshwater growth of these morphological characters, model development and application will phase of many smelt. These data show using the plastid marker rps3-rpl16 be presented. that during their freshwater growth to to distinguish between subspecies of adulthood, diadromous smelt are highly C. fragile. We will focus primarily on mobile with regard to distance and material from the Auckland region, and frequency of movements. test whether it is possible to develop a sound morphological basis for distinguishing between ssp. fragile and ssp. novae-zelandiae, thereby allowing effective monitoring of the spread of the introduced subspecies.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 61 SPEAKER ABSTRACTS

Like Sands Through the Using Environmental DNA On ‘Bloomin’ Seaweeds Hourglass, These are the to Detect the Presence of & ‘Bloody’ Earthquakes Days of Piharau Lives Brown Trout (Salmo trutta) – Changes in Nitrogen in New Zealand Streams Biochemical Indicators in Ulva from the Avon Heathcote Estuary, Christchurch, Set in a National Context

Cindy Baker // NIWA Jonathan Banks // The University Neill Barr // NIWA of Waikato, Cawthron Institute Shannan Crow, Don Jellyman, Nina von Westernhagen // University of Michael Stewart, Erica Williams // NIWA Nick Demetras, Ian Hogg, Canterbury Matthew Knox , Philip Ross // The Kit Rutherford // NIWA Although adult piharau (lamprey) spend University of Waikato extended periods of time in freshwater Adam Daniel // Fish & Game New Historically, massive blooms of Ulva in (up to 16 months) during their upstream Zealand the eutrophic Avon-Heathcote Estuary of migration to spawning grounds, lampreys Dave West // Department of Conservation Christchurch, have significantly affected are rarely seen, except where their both the estuary’s aesthetic value and its migration is hindered or prevented at The Lake Ecosystem Restoration ecosystem function. With the diversion of obstructions. As such, little is known (LERNZ) programme aims to restore Christchurch City’s wastewater discharge about the cues lamprey use for migration, New Zealand’s freshwater ecosystems away from the estuary in March 2010 it and the habitats utilised during this by removing introduced pest fish from was expected there would be close to a extended period in freshwater. This study selected lakes and their tributaries. Part 10-fold reduction in nitrogen(N)-loading, is using Passive Integrated Transponder of this programme was to develop a which in turn promised a reduction in (PIT) technology to monitor the spawning simple method for the detection of pest algal biomass. A 5-year MBIE-funded migrations of adult lamprey within the fish using environmental DNA (eDNA). partnership between NIWA and University Okuti River catchment. In total, 142 To assess the feasibility of the eDNA of Canterbury is examining, amongst adult lamprey have been tagged after technique, we chose brown trout, Salmo other ecosystem components, macroalgal entering the catchment. Close to 100 trutta, that were targeted for eradication biochemical indicators of N-loading. of those fish have been re-located by from streams within a mainland reserve Following the March 2010 diversion of the either fixed or hand-held antennae as (Karori Sanctuary). We collected water wastewater from the estuary there was a they migrate upstream. This project is samples before and after the eradication significant reduction in tissue-N, tissue- currently on-going, however, results efforts and extracted eDNA to determine chlorophyll, and in particular tissue-free to date have shown that the upriver Ulva if we could detect the presence of brown amino acid content in . However, the spawning migration of adult lamprey trout DNA in the water column. From series of earthquakes that have rocked is closely linked with increased river these water samples, we successfully Christchurch since September 2010 flows. The micro-habitats utilised by amplified a segment of the brown trout caused substantial breakdown of the lamprey during this migration, and the d-loop region. Electrofishing surveys city’s wastewater infrastructure resulting timing of movements have also been taken before and two months after the in overflows of untreated sewage into the identified. This knowledge is fundamental eradication have thus far confirmed the estuary. This return to elevated N-loading to rehabilitation and restoration of presence (or absence) of trout inferred and corresponding qualitative shifts in lamprey populations and has important Ulva from our eDNA analyses. The next steps tissue N-isotopes (δ15N) reflected implications for ensuring lamprey in our programme are to develop: changes in the nitrogen sources (treated populations are retained within rivers and 1) quantitative, real time polymerase vs untreated sewage) that affected the streams utilised as water take sources. chain reactions (qrtPCR) to increase the estuary. We place all of these changes Ulva sensitivity of the method and to provide seen in nitrogen indicators in the an indication of brown trout abundances; Avon-Heathcote within the context Ulva 2) extend the range of fish that can be of a National estuarine survey of detected from eDNA, and 3) develop conducted in 2002. This study proves non-species-specific methods (e.g. using the validity and utility of biochemical Ulva next generation sequencing) that will properties of extant populations of enable the detection of a range of pest as indicators of relative shifts in both fish species from environmental samples. the amount and the source of nitrogen loading to New Zealand’s estuaries.

62 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Aquatic Fate of The CV Rena Incident: Don’t Shoot Herbicides in a Planted A Warning Shot Across the Messenger: Forest Catchment the Bow for Environmental Communicating Science to Preparedness an Audience That Wants Your Blood

Brenda Baillie // Scion Chris Battershill // The Chris Battershill // The University of Waikato University of Waikato Daniel Neary // US Forest Service Stefan Gous, Loretta Garrett // Scion David Schiel // University of Canterbury Communicating tough messages, messages the audience doesn’t want to In New Zealand’s planted forests, When the CV Rena grounded on hear, messages to an angry audience, management of competing vegetation Astrolabe Reef, Bay of Plenty, the first and messages to a misinformed during the establishment phase of concerns of all stakeholders were audience is hard. Combine that with the crop rotation is critical in ensuring scientific ones. What would be the effects communicating complex science, and seedling survival and growth and of heavy fuel oil contamination along the you have a recipe for a lynching. Over maximising timber yields. Herbicides are coastline and how long would it last. In the course of years in communicating currently the most cost effective tool in the scramble for relevant ecotoxicological the science underpinning the field of New Zealand for vegetation management information pertaining to Heavy Fuel Oil biodiscovery (bioprospecting), presenters but there is increasing global pressure and the dispersants that might be used, faced audiences that were either rabid to reduce their use due to environmental it was clear that there was very little with loathing of biopiracy, or that were concerns. Hexazinone and terbuthylazine information of any relevance to a New staunch sceptics. The task of breaking are two herbicides commonly used Zealand situation. This was surprising down misconceptions was monumental. in combination to control unwanted given some of the early environmentally It was achieved by elegant science and vegetation in New Zealand’s planted oriented oil and gas industry research of through easy to understand, ethical, forests. We monitored the concentrations the 1980s, particularly relating to the Shell well founded scientific communication. of these two herbicides in two small BP and Todd Maui development program. Honest review of the history of the streams in an area of Kaingaroa Forest There both lab and field experiments discipline, warts and all, and substantive that was aerially sprayed under normal were conducted to assess likely pollution evidence underpinning the successes operational conditions in November scenarios should spills occur. Here have resulted in a new age of popular and 2012. One site was 100% sprayed we focus on early lessons learned and scientific support for this cutting edge upstream, the other 45%, with a 10m the need to focus on the synergistic biomedicinal science. In a contrasting no-spray buffer maintained around effects of contaminant mixtures and situation, that of communicating to an the stream margins. Concentrations of sublethal intergenerational effects on angry public, complex environmental spray landing on the stream channel marine organisms. In many ways, the science associated with marine disaster from drift were around 28% of the Rena event is one of the world’s most events (e.g. CV Rena), the approach prescribed rate sprayed directly onto complicated oil spills because of the had to be ruthlessly direct. This meant the treatment area. Highest herbicide highly complex contaminant streams. relaying often bad news immediately, concentrations occurred in both streams The combination of HFO, other shipping honestly and succinctly and being clinical on the day of spraying. The streams were petrochemicals, heavy metals from cargo in describing the likely environmental monitored for 8 months after spraying and antifouling paints in the ecosystem consequences. This approach garnered and herbicide concentrations remained has not previously been examined in a respect and anger soon dissipated as the low (<2 ppb for both herbicides) for the field scenario where long term effects audience had facts and could consider duration of the trial. These preliminary on important marine food species is a relevant scenarios. A consistent approach results indicate that when applied under focus. Sublethal effects are likely to be of this nature has led to a well informed standard operational conditions, these as important as toxicology in considering public that now will rationally (mostly) two herbicides posed a low threat to the ecological effects. review the ongoing development of the aquatic environment. However, the trial Rena incident. occurred during a very dry period limiting the assessment of herbicide leaching and movement into waterways during normal and high rainfall events.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 63 SPEAKER ABSTRACTS

Hydrodynamic Modelling Interactions Between Impacts of Small of the Firth of Thames & Marine Mammals & Arthropods on Algal Hauraki Gulf to Support Commercial Fisheries in Epiphytes Associated with Aquaculture Planning & New Zealand Waters Subtidal Coralline Turf Management

Brett Beamsley // MetOcean Katrin Berkenbusch // Dragonfly Anna Berthelsen // The Solutions Ltd Science University of Auckland

Ben Knight, Chris Cornelisen // Cawthron Edward Abraham // Dragonfly Science Richard Taylor // The University of Institute Leigh Torres // NIWA Auckland Hilke Giles, Vernon Pickett // Waikato Regional Council Interactions between marine mammals Small arthropods, particularly amphipod and commercial fisheries occur frequently crustaceans, are highly abundant in Economical and environmentally when their distributions overlap, with subtidal coralline algal turf. Many of sustainable development of aquaculture incidental captures affecting a range of the arthropods are herbivores, but requires a suitable understanding of the cetacean and pinniped species across nothing is known about the impact of salient hydrodynamic and atmospheric different fisheries worldwide. As bycatch their feeding on their host seaweed. drivers at both local scale and in a assessments are often hampered by In the current study, abundances of broader regional context. In order to scarcity of data of the number and arthropods in subtidal Corallina officinalis address these requirements, a 3-D identity of captured individuals, risk turf were experimentally reduced in finite-element model of the Hauraki Gulf assessments provide a systematic situ. This was achieved using plaster and Firth of Thames using open source approach to identify and evaluate blocks impregnated with the insecticide code (SELFE) has been developed for potential impacts of fishing-related carbaryl; as the blocks dissolved the the Waikato Regional Council. The model mortalities, while also accounting for carbaryl was released over 1-2 weeks. consists of element sizes ranging from 75 uncertainty. The present study forms Blocks were replaced ~weekly for 15 m in the nearshore and 3,500 m offshore, the basis for such a risk assessment weeks. The carbaryl reduced arthropod while the vertical structure is defined of the interactions between different abundances by 86.5% relative to controls. using 40 terrain-following sigma layers. commercial fisheries and marine This resulted in major changes in the Specific higher resolution areas with mammals in New Zealand waters. abundance and composition of algae element sizes of ~30 m were refined in Considering each of 10 mysticete, 23 growing epiphytically on the coralline turf. areas identified for potential aquaculture odontocete (including dolphins and The clearest response to the reduction development. Full 3-D baroclinic offshore beaked whales), and three pinniped in arthropod densities was an increase boundary conditions are sourced from a (sub)species that inhabit New Zealand in abundance of the brown seaweed multi-decadal New Zealand scale ROMS waters, existing data from New Zealand Colpomenia sp. (to a mean cover of 7% implementation, while a 4-km resolution and elsewhere identified the types of in carbaryl treatments, compared to 0% WRF implementation provides temporally interactions that may occur when these in both controls and plaster treatments and spatially variable atmospheric forcing marine mammals interact with trawl, after 6 weeks). We will run feeding within the model domain (wind, solar longline, setnet, and pot/trap fisheries. assays to identify the grazers responsible radiation, precipitation, temperature For large baleen whales, the majority of for suppressing Colpomenia sp. Our etc.). In addition, the model includes recorded incidents were entanglements results support the emerging view that temporally variable river fluxes from 52 and injuries in static gear, with few small mobile arthropods are capable of different rivers within the Firth and the records in offshore regions. In contrast, influencing the structure of their habitat, Hauraki Gulf, while satellite nudging of for smaller-sized dolphins and pinnipeds, as opposed to simply being “hangers-on”. the sea surface temperature has also direct interactions with fishing operations been implemented. The model physics often lead to acute mortality, as captured were calibrated using ~6 weeks of multi- individuals are unable to free themselves level measured temperature, salinity, and drown in fishing gear. Furthermore, and velocity data from 6 deployment the coastal distributions of many dolphin sites within the Firth of Thames. The and pinniped species mean that they co- model was shown to faithfully capture occur with intensive fishing operations, the observed variations in velocities, resulting in bycatch mortalities. Data temperatures and salinities over the reviewed here allowed the identification validation and calibration period. The of different fisheries-marine mammal calibrated model has been used to interactions, and will inform the next step generate a 2-year hindcast dataset to in the risk assessment process involving assist WRC in the on-going planning and marine mammals and commercial management of aquaculture in the Firth fisheries in New Zealand. of Thames.

64 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Threatened Fish Eye Development & Light To What Extent is Reintroductions in the Response in Deep-sea Invertebrate Community Lower Lakes of the Cranchiid Squids Composition Across New River Murray 2011–2013: Zealand’s Rivers Related to Successes, Lessons & Hydrological Regime? Prospects

Chris Bice // South Australian Kat Bolstad // Auckland University Doug Booker // NIWA Research and Development Institute of Technology Michelle Greenwood // NIWA Nick Whiterod // Aquasave – Nature Monica Acosta // The University of Ton Snelder // Aqualinc Research Glenelg Trust Auckland Michael Hammer // Museum & Art Aaron Boyd Evans // Auckland University Predictive relationships between Gallery of the Northern Territory, Aquasave of Technology hydrological regimes and ecological states – Nature Glenelg Trust are required to support environmental Cephalopods are highly visual predators flow setting decisions. Data from 1,075 Desiccation of the littoral habitats of the and possess (for the most part) well- river sites across New Zealand were Lower Lakes of the River Murray from developed eyes; their ability to perceive used in a variance decomposition 2007–2010 necessitated the rescue, and process complex images appears analysis to investigate the proportion captive maintenance and breeding similar to that of vertebrates. Many of variance explained by hydrological, of four threatened freshwater fish deep-sea species in particular possess geomorphological, land cover and species to avoid localized extinction. relatively large eyes at maturity, some of catchment characteristics for the Ex situ populations of Yarra pygmy which differ structurally from those of community matrix and each of three biotic perch, southern pygmy perch, Murray earlier, photic-zone-dwelling life stages. indices representing: taxon richness; hardyhead and southern purple-spotted These ontogenetic changes are being Macroinvertebrate Community Index; and gudgeon were maintained and bred using investigated, focusing on the family percent of species in the Ephemeroptera, various ‘housing’ and rearing techniques Cranchiidae (‘glass’ squids). Histological Plecoptera, and Trichoptera orders. including aquaria, ponds and farm dams. analysis of preserved (and fixed) Results showed that hydrological regime The success of these approaches varied specimens has revealed changes in the contributes a unique component to the with species. Following widespread retinal structure coinciding with migration explainable variation in the biotic indices flooding in the MDB and restoration of into deeper waters. These developments, and community, but this contribution is water levels in the lower lakes a project in particular a dramatic increase in overestimated if other explanatory factors was developed to guide reintroduction the length of the outer photoreceptor are not considered. A Gradient Forest of these species. The aims of the segment, suggest cellular modification model comprised of 93 Random Forest project were to: 1) identify potential to greatly increase sensitivity to light. models each predicting the probability reintroduction sites and assess their Live cranchiid squids observed at depth of occurrence of a taxon indicated that, suitability, 2) release fish and 3) assess show clear behavioural responses to the of 20 environmental predictors, low flow the success of reintroductions. Since presence of unusual bright light stimulus, magnitude, high flow magnitude and 2011, >15,000 individual fish, across the and histological examinations of the eye mid-range flow variability were among four species, have been released at a total following exposure to light are expected the top ten predictors of the community of 10 different sites. All fish were stained to reveal additional changes at the cellular as a whole. The importance of high flows with calcein prior to reintroduction to level, as has been observed in other was confirmed by the models, but the assist post-reintroduction identification. squid species. These findings provide other dimensions of hydrological variation Post-reintroduction monitoring has insight into several aspects of deep-sea were almost as important in predicting yielded >100 individual fish across the squids’ ecology and have implications for invertebrate taxa and biotic indices. four species, with ~50% likely recaptures research aiming to collect and/or observe Although many freshwater invertebrates in of released fish, indicating survival at these animals in situ. New Zealand are well adapted to a range select release locations for periods of of flow conditions through resistance 6–18 months and there is evidence of traits and/or rapid colonisation, this limited wild recruitment. Nonetheless, the study suggests that several aspects of long-term sustainability of these species the flow regime influence invertebrate in the region remains uncertain. Further communities. These results suggest that reintroductions may be necessary and environmental flows may be designed surveillance monitoring and increased to sustain or even optimise specific water security are likely required to ecological taxa, but changes along several ensure population establishment and dimensions of hydrological variability persistence into the future. are likely to disadvantage other taxa and change invertebrate community composition.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 65 SPEAKER ABSTRACTS

Taking Notice of Waikato Regional Conservation & Recovery Whitebaiting as a Value: Council Freshwater Fish of Threatened New Zealand the River Values Monitoring Programme – a Fishes Assessment System for Developmental Overview Whitebaiting

Kay Booth // Lindis Consulting Callum Bourke // Waikato Regional Sjaan Bowie // Department of Council Conservation The River Values Assessment System (RiVAS) is a tool that has been developed Bruno David, Mark Hamer // Waikato Dave West, Jane Goodman // Department to assess river values (e.g. native birds, Regional Council of Conservation whitewater kayaking, irrigation). Applying a standardised and rigorous method, Healthy and abundant fish populations In 2003, the Department of Conservation RiVAS results in a ranked list of the are essential to maintaining the value (DOC) established recovery groups and rivers, sorted by importance, for each of the Waikato region’s water bodies. formulated recovery plans for three river value under examination. RiVAS However, little is known about the key groups of freshwater fish groups; has been developed for the activity of state of fish communities and for this non-migratory galaxiids, mudfish and whitebaiting; it considers attributes of reason, a fish monitoring programme large galaxiids. Species covered by the activity such as the level of use, river was initiated in 2008/09 to develop the plans range from lowland longjaw access, and social conflict and crowding, a robust, standardised procedure for galaxias a national critical threatened amongst other things. Application of assessing assemblages in wadeable species through to freshwater fish that RiVAS to whitebaiting offers a means by streams throughout the region. This field are not threatened. These plans set out which councils, and others, can quantify season (December 2012 – end of April the strategic direction and prioritise what the relative significance of whitebaiting 2013) numerous wadeable rivers and needs to be done for the recovery and for a set of rivers. The RiVAS method for streams were sampled by way of electric conservation security of these fish and whitebaiting will be discussed. fishing, netting, and trapping. This was achieve greater coordination nationally. the second season of freshwater fish These plans are now nearing their monitoring using a probability-based completion date so a formal review has (random) site selection survey design in been begun. Alongside this options are conjunction with a reference site network. being considered on what is the best It was also the first season that sites were tool to provide DOC and others this netted utilising the newly established guidance and direction in the future. New Zealand Freshwater Fish Sampling The recovery groups associated with Protocols (Joy et al., 2013). In 2012/2013, these plans are made up of key DOC 62 wadeable river and stream sites were representatives and external specialists. sampled of which 53 were random sites The key functions of this group are to and 9 reference sites. A new electronic provide regular review, reporting and data capture system was used recording advice on the progress of the plan. These collected electric-fishing and spotlighting plans have been the driving force behind data. This has proved to be an accurate, key conservation successes including effective, and efficient means of gaining key information that has enabled recording and uploading our field data in recognition of local extinctions and better a consistent manner. In this paper we will management and protection of these fish. outline the methods used and discuss An overview of these, preliminary results findings of interest. of the review and future options will be presented.

66 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Susceptibility of Murray Systematics & Tracking Changes in the Cod (Maccullochella peelii) Ecology of Whip-lash Microbial Community Larvae to Barotrauma Squid (Cephalopoda: Composition of Toxic During River Infrastructure mastigoteuthidae) Found in Benthic Freshwater Passage New Zealand Waters Cyanobacterial Mats in the Hutt River

Craig Boys // New South Wales Heather Braid // Auckland Katie Brasell // Victoria University Department of Primary Industries University of Technology of Wellington

Wayne Robinson, Lee Baumgartner // Kathrin Bolstad // Auckland University of Mark Heath, Ken Ryan // Victoria New South Wales Department of Primary Technology University of Wellington Industries Susie Wood // Cawthron Institute Anna Navarro // Charles Sturt University Mastigoteuthids are bathypelagic Brett Pflugrath, Richard Brown // Pacific and some species have circumglobal Toxic benthic Phormidium blooms are Northwest National Laboratory distributions. They are prey to marine becoming increasingly common in Brett Miller // University of New South mammals and commercially important many of New Zealands rivers. During Wales fish species. Based on decreasing blooms, the benthic mats can cover bycatch incidence in commercial fishing large areas of substrate and extend for nets, at least one species, Idioteuthis tens of kilometres along the riverbed. Understanding what mechanisms influence cordiformis, appears to have experienced The blooms often produce a range of the survival of larval fish is critical to the significant decline within New Zealand neurotoxic compounds and consumption management of adult populations. Murray waters. Less is known on the impacts on of mats has resulted in numerous dog cod, Maccullochella peelii, is an iconic smaller, less distinctive species that are deaths. Little is known about the early species that has declined throughout less frequently encountered, but these stages of biofilm formation and how the its range in south-eastern Australia. It smaller species could be similarly affected Phormidium comes to dominate and has a downstream drifting larval phase, by human activities. Mastigoteuthid reach such high biomass in relatively which has lead to concerns that this taxonomy is notoriously controversial, low nutrient environments. The aim species may be susceptible to injury or with many species descriptions based of this study was to determine the death when passing river infrastructure on single, badly damaged specimens. microbial composition of benthic biofilms (e.g. weirs, regulators and hydropower In addition, specimens frequently lose through their succession to Phormidium- turbines). Fish can be exposed to adverse their skin and tentacles (heavily relied dominated mats. Three sites along hydraulic conditions when passing on by previous authors for identification) the Hutt River (Wellington), each with infrastructure, including elevated fluid upon capture. An integrative taxonomic different water chemistries (low, medium shear and turbulence, or rapid drops in approach has been attempted for New and high nutrients), were monitored every hydraulic pressure, but little is known of Zealand material in order to clarify the 2 to 4 days for 32 days during summer the magnitude and relative influence of local representatives of this family. 2013. Biofilm sampling began 4 days after these conditions on the injury and survival Several methods have been trialled a flushing flow. Environmental parameters of most species and life stages. In this for extracting DNA sequences from were recorded at each site and water study hypo/hyper barometric chambers formalin-fixed tissue from museum samples were taken for nutrient analysis were used to determine the susceptibility specimens and limited frozen material. throughout the sampling period. The of larval Murray cod (3 to 27 days post A morphological distinction between the biofilm was sampled for morphological hatch, DPH) to barotrauma injury and genera Mastigoteuthis and Idioteuthis has and molecular analysis of the microbial death resulting from rapid decompression been supported by genetics. Though only communities and toxin assessment. over ranges that may be experienced by three to five species of mastigoteuthid Macroscopic analysis showed a fish when drifting downstream though squid had previously been reported in succession from bacteria, to diatom river infrastructure. Larval Murray cod New Zealand, five known species have to either green algae or Phormidium demonstrated buoyancy responses to presently been identified: I. cordiformis, dominated biofilms. Phormidium decompression from 17 DPH suggesting I. hjorti, M. dentata, M. famelica, and M. coverage was highest at the low nutrient inflation of the swim bladder. After this age, psychrophila. One new Idioteuthis species site, while the medium and high nutrient the probability of swim bladder rupture was found that is genetically distinct from sites were dominated by filamentous increased as the level of decompression morphologically similar species, and two green algae. Nitrates were the increased, but did not exceed 20 % for additional, possibly new Mastigoteuthis predominant nutrient detected at all sites the most extreme conditions tested and species also occur locally. Stomach (0.075-0.23 mg/L), while phosphate levels there was little evidence of mortality contents and stable isotopes for 15N and were barely detectable (<0.008 mg/L). 24 hours post experiment. The results 13C indicate that I. cordiformis, the heavily Results from morphological, molecular suggest that mechanisms other then impacted species, is a top predator. and toxin analyses and the implications of rapid decompression and barotrauma this study will be presented. (such as fluid shear or turbulence) may be more important in causing the injury and mortality reported for larval Murray cod when passing river infrastructure.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 67 SPEAKER ABSTRACTS

Preliminary Investigation Mitigating Natural Barriers Separating Natural of White Island’s Natural to Upstream Passage of Plankton Variability from

CO2 Vents as Sites of Macquarie Perch Aquaculture-induced Future Ocean Acidification Change: New Simulation Research Modules for the Regional Ocean Model

Johanna Brinkman // University Ben Broadhurst // University of Niall Broekhuizen // NIWA of Otago Canberra Mark Hadfield // NIWA Abigail Smith // University of Otago Mark Lintermans, Rhian Clear // University of Canberra A decade ago, concerns regarding Ocean acidification is expected to affect shellfish aquaculture spurred the a variety of marine organisms. Short- The endangered Macquarie perch development of coupled hydrodynamic term studies have shown that calcifying (Macquaria australasica) requires access and nutrient-phytoplankton-zooplankton organisms, including plankton, coralline to flowing water to spawn. A remnant models to examine the influence that algae and echinoderms, may suffer as self-sustaining population of Macquarie mussel farming may have upon plankton dynamics. Now, expansion of finfish energetic costs to precipitate CaCO3 perch exist in the Cotter Reservoir, skeletons increase with decreasing Australian Capital Territory, which rely on farming activities is spurring further development of such models. NIWA uses CaCO3 saturation. It is difficult, however, passage out of the reservoir to pools in to accurately predict the response the Cotter River to spawn each spring. the open-source ROMS modelling system of these organisms based on short- Enlargement of Cotter Reservoir will for much of its coastal work. ROMS term studies that exclude complex inundate much of the current spawning ships with several models of the plankton ecosystem interactions and often involve habitat and passage to new spawning system but has node code to represent transplanting organisms directly into grounds is a high management priority. A the influences that shellfish farms and low pH environments to which they are survey of the natural barriers of the Cotter finfish farms have upon the system. We unaccustomed. In situ studies using River from the headwaters of the current have written new modules to provide that functionality. In this presentation, we will natural CO2 vents near Ischia, Italy, and Cotter Reservoir 27 km upstream to the Papua New Guinea are now being used to next reservoir was undertaken. Location give a brief overview of the ROMS system gain a more complete understanding of of potential spawning habitats (i.e. pools) and of the new modules that we have the effects of acidification. These oceanic was also recorded. A subset of the developed to enable it to represent the vents create natural environments that identified barriers was monitored during influence that mussel and fish farms have mimic projected ocean trends of lower low (10–40 ML Day-1), medium (40–80 upon plankton dynamics. We will present pH. Shallow (~10 m depth) vents have ML Day-1) and high (80–160 ML Day-1) illustrative results from artificial, test- also been found off New Zealand’s White flows to determine if natural barriers cases and, if possible, also preliminary Island with pH as low as 7.56, within the could be mitigated using flow releases results for Queen Charlotte Sound. range of predicted values for the year from the upstream Bendora Reservoir to

2100. CO2 vents with contaminants (i.e. provide the best case access to potential sulphur, methane, mercury), however, spawning grounds. This presentation would be unsuitable for acidification outlines the results, implications and research. We have analysed water management options for maintaining samples and gas chemistry around access to spawning habitat following the New Zealand’s vents to determine the filling of the enlarged reservoir. suitability of White Island’s CO2 vents for future ocean acidification research.

68 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Larval Dispersal Amongst What Have We Learnt Comparison of Potential the Cockle (Austrovenus from 14 Years of Marine Management Controls for stutchburyi) Beds Within Sediment Contaminant the White Banana Prawn Whangarei Harbour Monitoring in Auckland? Fishery in Australia’s Northern Prawn Fishery

Niall Broekhuizen // NIWA Marcus Cameron // Auckland Rik Buckworth // CSIRO Council Carolyn Lundquist // NIWA Nick Ellis, Shijie Zhou, Sean Pascoe, Ricky Eyre // Northland Regional Council Geoff Mills, Bruce Williamson // Diffuse Roy Deng // CSIRO Sources Limited Fiona Hill // Australian Fisheries Whilst the Snake Bank, McDonald Banks Melanie Vaughan // Auckland Council Management Authority regions of the outer Whangarei Harbour Michael O’Brien // Tropical Ocean Prawns support healthy cockle (Austrovenus In 1998, the Auckland Regional Council Australia Pty Ltd stutchburyi) populations, anecdotal (now Auckland Council) initiated evidence indicates substantial population a sediment chemistry monitoring Simulating a large number of annual declines within many of the beds in the programme aimed at assessing the white banana prawn fisheries, we central and inner harbour. To inform spatial distribution of, and temporal examined the economic performance cockle restoration strategies in the trends in, key chemical contaminants of individual fisheries when different harbour, we conducted field surveys to across the region’s urban estuaries, management controls were applied. map habitat-quality features and cockle harbours, and sheltered open coast. We first specified a range of fisheries population densities. The data were used Over the subsequent 14 years important consistent with historical observation, to create maps of spawn production and lessons have been learned concerning estimating fishable biomass, catchabilities cockle-habitat suitability for inputs to a factors such as QA procedures and and harvest rates, for 1987-2011, using newly developed 3D particle tracking reporting, consistency of methods and depletion analyses. A binomial model model designed to simulate the birth, the influence of analytical variability. As described effort patterns. We evaluated dispersal and fate of cockle larvae. a result the programme has recently economic performance of alternative Simulations were made for a variety of undergone significant review and management controls for the fishery, wind scenarios. The majority of those restructure and improvements have been predicting profits (losses) of pre-season virtual larvae which were able to settle achieved including the consolidation of Total Allowable Catches (TAC), TACs did so within ~ 3 km of their natal three originally separate programmes. up-dated mid-season (U-TAC), and an location. Nonetheless, a few individuals Substantial data analysis has been MEY catch rate trigger (MEYT), relative to disperse over much larger distances – carried out and results (including trends) the status quo (SQ) catch rate stopping such that all beds are (at least) weakly will be presented for copper, lead, zinc rule. Superficially, performance under connected. There is an abundant supply and polycyclic aromatic hydrocarbons the different controls was similar, (mean of allochthonous recruits to the beds of (PAHs). Of particular interest is that the annual profit, $10–11 million), but this the inner harbour. Most of these originate early patterns of linear increases in zinc was very variable (SD = $8-9 million). from the large Takahiwai bed that extends and copper (and decreases in lead) have Marked differences from within-year across the southern shoreline of the not necessarily persisted, and recent comparisons exposed potential risks, central and outer harbour. Whilst cockle data illustrate that changes over time are concealed by averaged performance, densities on Takahiwai are believed to more complex and variable than might from adoption of a particular strategy. have declined, they remain moderately have been expected. Consideration of Consistently effective, MEYT provided at high relative to those elsewhere in the other potential sources of contaminants least $1+ million in profit than SQ about central/inner harbour. We infer that the (such as marinas) and implications for the half the time, and was rarely worse. There population declines in the central and ecological health of the marine receiving was, however, substantial risk of loss in inner harbour beds reflect bed-specific environment will also be discussed. adopting TAC. In bad (low catch) years, habitat degradation rather than larval- SQ and, especially, MEYT, were clearly supply decline. The simulations suggests more profitable than TAC; U-TAC in these that habitat improvement in the inner years was not effective but tended to harbour will be followed by moderately perform well in high catch years. There rapid natural recolonization provided that is substantial risk that introduction of the Takahiwai population does not decline TAC or U-TAC would lead to poorer profit further. performance than SQ or MEYT, especially in a series of bad years – drought – in marked contrast to the small differences apparent in long-term average or total profits from the different strategies.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 69 SPEAKER ABSTRACTS

Effects of Ocean Graduated-field Fish Preliminary Validation of Acidification & Warming Barriers as Conservation MAM-PEC Modelling of on Fertilisation & Larval Tools for Managers: Copper Concentrations in Development in the Invasive Species Control Eight Auckland Marinas Antarctic Bivalve, Laternula & Downstream Guidance elliptica Applications

Christine Bylenga // Victoria Carl Burger // Smith-Root, Inc Marcus Cameron // Auckland University of Wellington Council John Parkin // Parkin Engineering Vonda Cummings, Neill Barr, Aaron Murphy // Smith-Root, Inc Jennifer Gadd, Chris Hickey // NIWA Graeme Moss // NIWA Martin O’Farrell // Smith-Root Europe Sonja Hempel , Stephanie Menashe, Ken Copper is now found in almost all Ryan // Victoria University of Wellington Fisheries managers have used non- antifouling paints in New Zealand but lethal, pulsed DC technology to control can have adverse effects on non-target Laternula elliptica is a common and highly invasive fish migrations in several areas marine organisms when at elevated stenothermic species of clam in coastal of North America and Europe. Electrode concentrations. NIWA undertook regions of the Southern Ocean. Slight arrays have also been used to deter fish modelling for the New Zealand EPA to increases in water temperature reduce from hydropower intakes. Successful predict the water column concentrations energetic activity and initiates anaerobic applications have employed an innovative of copper in ports and marinas using cellular respiration in this organism. design: the Graduated-Field Fish Barrier the MAM-PEC model. These predictions Furthermore, reduced pH increases (GFFB), a technology that intensifies suggested that in most marinas copper production of heat shock proteins voltage gradients as fish enter the field. concentrations would exceed water in adults and reduces shell integrity. There are 49 GFFBs around the world. quality guidelines by up to 7 times. Given However, little is known of the effects We provide examples from published these high predictions, a field study of both of these climate change related literature on both successes and was undertaken to measure copper processes on fertilisation success and “lessons-learned,” particularly for invasive concentrations in the water column larval development in L. elliptica. In March species control. We discuss key elements of eight Auckland marinas to provide 2013, eggs and sperm were stripped of the technology and how it works. In preliminary validation of these model from the gonads of mature clams. the Southern Hemisphere, conservation results and to assess the likelihood for Through exposure to temperatures of priorities often require downstream effects on aquatic biota. A further aim -1.6, -0.5 and 0.5°C and pH levels of 7.95, guidance technologies. Accordingly, we of this study was to estimate the export 7.80 and 7.65, the rates of fertilisation, present information on three installations of copper from Auckland marinas to malformation of larvae and timing of to guide downstream-moving fishes. the wider coastal environment. Results development through the D-larvae stage The first addresses juvenile salmon from the field study compared well to were investigated. Preliminary results entrainment at an irrigation canal on model predictions. In most marinas, suggest larval development timing was the Sacramento River, California (where copper concentrations did exceed affected by temperature and pH change. entrainment of downstream-moving, ANZECC (2000) water quality guidelines 24 days after fertilisation, 83.5% of larvae juvenile Chinook salmon was reduced by based on either 95% or 90% levels of raised at 0.5°C and pH 7.95 were at 79%). The second is a recent installation protection. Several marinas also exceeded the D-larvae stage compared to 15.3% to keep adult salmonids from entering site-specific chronic and acute water of those raised at -1.6°C and pH 7.65. a hydropower diversion in Colorado. quality guidelines based on dissolved Results are currently being analysed The third involves controlled flume trials organic carbon concentrations. Leaching on invasive sea lamprey juveniles in of antifouling paints from vessel hulls Michigan. Preliminary data show that very appears to be the major source of copper low voltage, graduated fields of pulsed in the water column for the marinas DC guided 55-74% of the downstream studied. Using the results from this study, migrants into a mock trap at end of flume and predictions of fate from the previous (depending on approach velocities). An modelling study, an estimate of the total innovative, hybrid-design is proposed for export of copper from Auckland marinas future downstream fish guidance. The due to vessel leaching was made. This concept involves graduated electric fields estimate equates to roughly double that in concert with low-frequency acoustics predicted from stormwater for the entire (to elicit fright responses and move fish Waitemata Harbour catchment. around water intakes upstream of GFFB arrays). This combination may be key to achieving high levels of conservation success in future downstream guidance applications.

70 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Dicyemid Parasites as DetectionImplications of Estimating Stock Size Biological Tags to Assess Environment Gradients, of Orange Roughy on the Population Structure of & Alternative eDNA Seamounts in the High Sepia apama Collection & Extraction Seas: What can We do Methods when We don’t know Anything?

Sarah Catalano // University of Lindsay Chadderton // The Malcolm Clark // NIWA Adelaide Nature Conservancy, Great Lakes Project Owen Anderson, Ian Doonan, Ian Whittington, Steve Donnellan // Andy McKenzie // NIWA University of Adelaide, South Australian Chris Jerde, Matt Barnes, Cameron Museum Turner, Mark Renshaw, Karen Uy, Brett Deep-sea fisheries in the High Seas Terry Bertozzi // South Australian Olds, David Lodge // University of Notre around New Zealand have occurred for Museum Dame several decades, but few have proven Bronwyn Gillanders // University of Andrew Tucker // The Nature sustainable in the long-term. In contrast Adelaide Conservancy, Great Lakes Project to fisheries inside EEZs, there is typically little research associated with such fisheries, and few data on which to base Sepia apama , the largest species of The application of reliable and effective effective fisheries management. High cuttlefish in the world, is endemic to surveillance methods is a critical Seas fisheries for orange roughy occur southern Australian waters, distributed component of invasive and threatened largely on seamount features, and in from Ningaloo in Western Australian species management. Sampling and this work we have examined whether through to Moreton Bay in southern detecting rare, cryptic and or mobile fish the physical attributes of the seamounts Queensland. A mass breeding aggregation species across large spatial scales and themselves (often relatively well known) S. apama of occurs in Upper Spencer Gulf in deep (>1 m) and or turbid waters is can inform estimation of likely biomass, (USG), South Australia (SA), Australia, particularly problematic. Environmental and hence sustainable yields. Building during the winter months each year. DNA (eDNA) monitoring methods appear on an earlier study, we have compiled However, the abundance and biomass to offer a surveillance approach that can information on 91 seamounts in the New of this mass breeding aggregation is in be applied at broad scales with high Zealand and Australian region, consisting decline. Differences in host molecular levels of sensitivity and potentially low of 15 environmental and physical data, morphology and behaviour suggests detection errors. However, many parts variables, and reported total catch of that the USG breeding aggregation may of the eDNA method are incompletely orange roughy. Regression modelling be distinct, and as such, recruitment from understood. For instance detection indicated that a number of seamount neighbouring populations may have no sensitivity is likely to be affected by rates attributes showed strong relationships impact on sustaining this aggregation. of DNA settlement and degradation with the level of orange roughy catch, Therefore, the population structure of this that will vary across environmental including depth of summit, latitude, species needs to be investigated further gradients. In addition, the two contrasting longitude, association (whether the and verified using an innovative approach. approaches (filtration vs precipitation) that seamount is oceanic or on the continental In this study, we used dicyemid parasites, have predominantly been used to collect slope), connectivity (isolated, cluster, or microscopic organisms found in the renal and extract DNA from environmental chain), and whether the seamount is a appendages of cephalopods, as biological water samples appear to offer a tradeoff spawning site. The GAM results suggest tags to assess the population structure of between sample volume and extraction that knowledge of the physical nature of S. apama in southern Australian waters. efficiency, factors that will also likely a seamount can be used to predict the Four dicyemid species were documented affect detection sensitivity. Here we use a likely total biomass of orange roughy, and S. apama from collected throughout series of mesocosm trials to quantify the hence give managers a basis on which to southern Australian waters, although all impacts of pH, Chlorophyll and biological set provisional catch limits. four species were never found together oxygen demand on eDNA degradation in the same host individual. Rather rates. We also test the relative detection patterns of dicyemid fauna composition, efficacy of a variety of collection and inferred via morphological and molecular extraction methods across a putative analyses, varied with capture locality of the Asian carp abundance gradient in the host. In particular, the dicyemid parasite Chicago Area Waterway System. Based fauna of Spencer Gulf (SG) cuttlefish on these results, recommendations that was different to the fauna found from should increase detection sensitivity and cuttlefish collected in other localities. Due interpretation of eDNA sampling methods to the highly host-specific nature of these are provided. parasites, this result gives strong support to the SG cuttlefish representing a distinct sub-set and potentially a distinct species compared to the other populations in southern Australian waters.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 71 SPEAKER ABSTRACTS

Is the Manawatu River The Science Behind The Reproductive Cycle Really the Worst in the Successful Freshwater of the Freshwater Mussel West? Biosecurity Management Echyridella menziesii in Lake Taupo, New Zealand

Maree Clark // Horizons Regional John CLAYTON // NIWA Susan Clearwater // NIWA Council In 1861 the New Zealand government David Roper, Chris Hickey, Logan Brown, Jon Roygard // Horizons promoted introduction of foreign species Michael Martin, Erica Williams // NIWA Regional Council to rehabilitate New Zealand’s depauperate fauna and flora and for c. 100 years the The seasonal cycle of reproduction of Media headlines in late 2009 dubbed the Acclimatisation Society imported a wide a population of the native freshwater Manawatu River as the worst in the west. range of species for this purpose. Today hyriid mussel Echyridella menziesii (Gray, Within the Horizons region the Manawatu population growth, globalisation, trade 1843) (previously Hyridella menziesi) in River is the most intensively monitored treaties, the pet industry & tourism have Lake Taupō is described using historic catchment. This presentation seeks to taken over as key drivers of the escalating data. Adult mussels were collected show case some of the monitoring results biosecurity problems in New Zealand from August 1993 to August 1994, from the Manawatu catchment and and around the world. The relatively and reproductive status was assessed. place this information within the national isolated location of New Zealand presents Eggs are fertilized in the brood pouch context. We will draw comparisons a unique opportunity to implement of the female mussel gill, where they between our monitoring results for the successful biosecurity management develop into a glochidia larvae which Manawatu catchment and compare strategies to help protect what remains of must parasitize on a fish to develop into with the pool of information available our unique fauna and flora. New Zealand a juvenile. Spawning commenced in late nationally via the Land and Water New has been proactive in using science austral winter (August) and brooding Zealand website to answer the question based solutions to biosecurity challenges. females peaked in abundance (23 to 30%) is the Manawatu River really the worst in Biosecurity legislation based on scientific from spring to mid summer (September New Zealand let alone the west? evidence has been instrumental in to January), decreasing to a minimum of guiding border control, regulating the 8% in early autumn (March). No brooding pet trade and nursery industry, and in females were present from mid-autumn formulating government and regional to early winter (April until June). council obligations under the National Planktonic glochidia were first detected in Interest Pest Response programme and January coinciding with a seasonal water Regional Pest Management Strategies. temperature increase to 20°C, up from Species risk modelling developed in New ~14°C in late November. Common bullies, Zealand has helped validate biosecurity Gobiomorphus cotidianus, parasitized by policy and this approach has been also glochidia were found in benthic trawls adopted in other countries. Quarantine from January to March. The presence of competitive species growth trials and spermiated male mussels and vitellogenic experimental testing facilities for pest oocytes in the females throughout the control have been critical for validating year suggests spawning is partial and biosecurity management strategies in continuous, however distinct seasonal New Zealand. Modelling the spread changes in abundance of brooding of pest species based on key drivers females indicate seasonality of successful such as population density, roads and fertilization, brooding and glochidial accessibility to freshwater resources have release. Seasonal extremes in water helped guide and prioritise surveillance temperature and photoperiod preceded strategies. Research on the application the start of both embryo brooding and refinement of pest control tools and glochidia release, suggesting has led to more cost efficient use and these environmental cues synchronise improved performance. reproduction in this population of E. menziesii. Understanding the reproductive cycle of native mussels has enabled our recent evaluation of the contaminant sensitivity of glochidia and juveniles.

72 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Seasonal Movement Variable Timing of Hatch & Are Macroinvertebrates Patterns of Macquarie Early Ontogeny in Bluegill Effective Indicators of Perch in Cotter Reservoir, Bully (Gobiomorphus Environmental Stress in Australian Capital Territory hubbsi) Large Rivers?

Rhian Clear // University of Gerard Closs // University of Otago Kevin Collier // The University of Canberra Waikato Jonathan Wright, Manna Warburton, Jason Thiem // University of Canberra, Hannah Harland // University of Otago Mark Hamer // Waikato Regional Council Carleton University Stephen Moore // Landcare Research Ben Broadhurst, Mark Lintermans, Daniel Timing of hatch from an egg is a critical Wright // University of Canberra life history stage in many organisms. Macroinvertebrate community responses Brendan Ebner // University of Canberra, Hatch too early, and insufficient to contrasting human stressors were James Cook University development has occurred for survival. measured at three locations during spring Hatch too late, and competitors have and autumn along a 45-km section of the a head start in the race for resources. Cotter Reservoir, Australian Capital Waikato River, Hamilton, New Zealand, to Amphidromous fish face unique Territory, is home to a self-sustaining determine the utility of littoral and deep- challenges in deciding when to hatch. population of the endangered Macquarie water macroinvertebrate communities Fish hatching too early may be unable to perch (Macquaria australasica). as an indicator of large river health. orientate and survive in turbulent waters Enlargement of Cotter Reservoir threatens Industrial organic discharges increased during downstream transport to the critical natural habitat (emergent phosphorus levels above recommended sea. Fish that hatch too late may have macrophytes) so provision of constructed ecological guideline values at the upper insufficient internal resources to survive habitat is crucial to long term persistence location, sediment inputs from a large downstream transport and develop of this population. Knowledge of tributary increased turbidity up to four into an independently-living juvenile movement of this species was required times above upstream levels at the middle fish. Collection of eggs of bluegill bully, to guide placement of the constructed location, and cooling water discharge a small amphidromous eleotrid that habitat. We used radio telemetry to from a thermal power station elevated spawns on large cobbles, revealed a determine seasonal diel movements and maximum summer water temperature surprising degree of flexibility in the hatch activity of adult Macquarie perch in Cotter by around 3oC over ambient at the lower timing. Movement of rocks triggered Reservoir. Macquarie perch exhibited a location. Overall, macroinvertebrate almost immediate hatch of entire egg diel range of 389 ± 46 m, a diel mobility communities comprised 89 taxa and were plaques, with emerging larvae exhibiting of 769 ± 93 m and diel area use of 24008 dominated numerically by the amphipod considerable variation in their ontogeny. ± 5595 m2 among four seasons. Diel Paracalliope fluviatilis (29% of total Development at hatch varied from being range was significantly higher in winter numbers) and naidid worms (26%) which little more than a yolk sac with a tail, to compared with other seasons. Macquarie were strongly associated with littoral and relatively well formed larvae. Analysis perch inhabited deeper water in summer deep-water benthic habitats, respectively. of the behaviour and development of across the diel cycle in comparison with Nested PERMANOVA analyses indicated these larvae indicated strong positive other seasons. Within seasons, remote that community composition was phototaxis and delayed development and manual telemetry identified that diel strongly influenced by location along in freshwater. Hatching in response to activity was predominantly crepuscular. the river, sampling habitat (littoral or movement suggests that hatching occurs Based on results of this study, deep-water) and season (spring or in response to flood-related disturbance, constructed habitats have been placed in autumn). Comparison for sites or seasons although this raises the question as to readiness for reservoir filling. when the full complement of samples what cues are used to initiate hatching was collected indicated a significant in the absence of floods. Delayed effect of stressor type (upstream vs development saves energy during the downstream), and within locations there downstream migration, but how long can was a significant effect of ranked stressor development be delayed before resources intensity for organic enrichment and are too depleted to allow further turbidity. Broadscale surveys of other development is unclear. The implications non-wadeable rivers in the region suggest of variable hatch in amphidomrous fish that the macroinvertebrate community in will be discussed. this large river did not reflect generalised land cover patterns evident in other non-wadeable rivers, reinforcing the need to characterise stressor types when interpreting macroinvertebrate responses in large rivers.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 73 SPEAKER ABSTRACTS

A Simple Method For Near Real-time Water Spatially Explicit Ecological State of The Environment Quality Monitoring in Risk Assessment to Inform Reporting & Assessing Shellfish Growing Waters Fisheries Management: Compliance Against Methods, Inferences, & Numerical Limits of Water Pitfalls Quality Standards

Jim Cooke // Streamlined Chris Cornelisen // Cawthron Martin Cryer // Ministry for Primary Environmental Ltd Institute Industries

There is wide variation in the methods Jonathan Banks, Kirsty Smith, Rohan Currey, Ben Sharp // Ministry for that Regional Councils use to report Lesley Rhodes // Cawthron Institute Primary Industries on surface water quality in State of the Kevan Yamahara // Center for Ocean Environment reports. Many of these Solutions Recent developments in ecological methods use complex metrics and are Christine Preston, Scott Jensen, Brent risk assessment offer the promise of designed to report on the state of water Roman, Chris Scholin // Monterey Bay understanding risks and threats to classes, rather than individual sites. As Aquarium Research Institute protected species in a spatially and part of a review on Southland’s surface temporally explicit framework that can water quality I developed a simple be used to identify the times, places, and method using box and whisker plots, to Excellent water quality with low risk of microbial contamination is critical activities that pose most risk. We use compare confidence intervals about the to sustaining a productive aquaculture two recent semi-quantitative, spatially median value of a contaminant measured industry. Shellfish growing waters often explicit ecological risk assessments to at individual sites with the numerical limit lie within the influence of catchment show the opportunities offered by this of the objective or standard used for the runoff and associated contaminants. To approach and some of the limitations water class in question. This enabled minimise pathogen risk and meet food and pitfalls. Risk assessment is central me to construct a ‘report card’ based on safety standards, shellfish sanitation to implementation of New Zealand’s confidence intervals about the median programmes manage harvests around recently-revised National Plan of in which sites are graded red (95% CI rainfall/river flows and monitor faecal Action to Reduce the Incidental Catch exceeds standard) through green (all indicator bacteria (Escherichia coli) for of Seabirds in New Zealand Fisheries connected data meets the standard). compliance. Prolonged closures greatly (NPOA-Seabirds). The risk assessment The method is simple, robust, and compromise farm productivity and there used is designed to assess the likelihood transparent. It readily allows comparison are lags in obtaining E. coli results, which that the biological risk objective of the of individual parameters (e.g. DRP, NNN, provide no information on sources of NPOA-Seabirds will not be met as a result black disk clarity), and for the rapid contamination. The in situ Environmental of commercial fishing in New Zealand identification of problem sites where Sample Processor (ESP) presents exciting waters. Of 70 seabird species considered, new prospects for managing aquaculture numerical limits of standards are routinely 10 were assessed as being at high or resources by providing results in near exceeded for several parameters. By very high risk and 44 were assessed real-time. We trialled an ESP in Tasman grouping sites according to water class, as being at very low risk. Another risk or catchments, visual comparisons Bay that remotely collected and analysed water samples for quantitative PCR (qPCR) assessment was used to inform the between these groups can also be made. markers specific to faecal contamination. review of the Threat Management Plan The rapidity of the data analysis means The ESP was deployed adjacent to for Maui’s dolphin (Cephalorhynchus that it is quite feasible to produce annual aquaculture areas and transmitted data hectori maui), a critically endangered report cards that report on progress to over a 30-day period. Field surveys were sub-species endemic to New Zealand. improve regional water quality, and to carried out during and after deployment to This assessment considered 23 human galvanise action where sites persistently assess the spatial extent of contamination. and non-human-induced threats likely to exceed the standard. The ESP deployment occurred during a dry affect population trends within the next 5 period and detected low levels of faecal years. An expert panel’s scores suggested pollution. Water samples collected from a median of 5.27 total human-induced rivers within the catchment and analysed mortalities per annum (0.97–8.40), a high using a lab-based ESP frequently had proportion of which was attributable to elevated levels of ruminant and human fishing. In both cases, disaggregated contamination, particularly following estimates of risk and uncertainty can rainfall. Bench-top qPCR analysis of be used to target and prioritise both mussel samples also indicated presence management responses and collection of of ruminant contamination following new information, including research. elevated river flows. The ESP represents a powerful technology for the surveillance of water quality contaminants in shellfish growing waters. When placed in “proxy” locations, ESPs also have the potential to greatly augment and strengthen operational models for forecasting water quality.

74 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Riding an Oily Wave: Mating Behaviour of Integrated Catchment Impacts of the CV Rena on Clownfish in a Tank Based Management – Striking the Bay of Plenty Surf Clams System Balance Between Sports Fisheries, Biodiversity & Community Values in the Cardrona Catchment

David Culliford // The University Norsila Daim // Universiti Teknologi Matt Dale // Otago Regional of Waikato MARA (Perlis), Malaysia Council

Rex Fairweather, Chris Battershill // The Zulkifli Hamzah // Universiti Teknologi Matt Salmon // Otago Regional Council University of Waikato MARA, Malaysia Located in the upper reaches of the During the breakup of the CV RENA, an Clownfish or anemonefish is one of the Clutha catchment, the Cardrona River is estimated 355 tonnes of fuel oil spilled famous and demanded ornamental fish in one of the most water short catchments into the sea, a large portion washing aquarium trade industry worldwide. Coral in Otago. The complex interaction ashore on Bay of Plenty beaches. As reef fish including clownfish from family between groundwater and surface water, part of the long term Rena recovery Pomacentridae live in warm water habitat. combined with a variety of instream program, we investigated the impacts of The demand of wild-caught ornamental and socioeconomic values, pose unique the spilled fuel oil on intertidal open coast fish keeps increasing and sometimes the resource management challenges. The invertebrates. Specifically, we focused supply is unable to satisfy the demand. Cardrona River supports a large spawning on the surf clam Paphies subtriangulata Captive breeding of marine ornamental run of rainbow trout and is the most (Tuatua), which is generally abundant on fish might be a solution to overcome this significant spawning tributary of the sandy open coasts in the Bay of Plenty problem and the observation on mating upper Clutha River. As well as being an characterising the open beach habitat. It behaviour of coral fishes is very crucial important source of recruits for the upper is also an important kai moana species. for a successful breeding process. In this Clutha fishery, the Cardrona River also Tuatua abundance, length frequencies, study, four pairs of false percula clownfish supports an early season recreational biomass, invertebrate diversity Amphiprion ocellaris, a pair of spinecheek fishery before the spent fish return to the and environmental variables were clownfish Premnas biaculeatus, a pair of main stem of the Clutha River. Although compared across thirteen locations from tomato clownfish Amphirion frenatus, trout have invaded most of the tributaries Bowentown to East Cape which spanned and a pair of pink clownfish Amphipirion in the Cardrona catchment, some creeks high and low oil impact areas. Chemical perideraion were reared as broodstock still support isolated populations of Clutha and demographic data was analysed in in 30 L tanks. The flat surface and hard flathead galaxias, which are one of the the context of the degree of oiling across items (tiles and live rock) were provided most threatened non-migratory galaxiids the region. No catastrophic die offs were as a suitable place for egg laying for the in New Zealand. The lower reaches of the observed, but population and PAH profile broodstock. Frozen blended fish meal Cardrona River are dewatered for much of attributes varied considerably within and consisting of fresh fish meat, squid and the irrigation season due to a combination among locations and also with degree shrimp was used to feed the broodstock of water abstraction and losses to the of beach oiling. Decreases in abundance five times a day. Frozen bloodworms underlying Wanaka-Cardrona aquifer. As and biomass were noted at the most were also included in the diet and fed to well as providing a source of groundwater heavily oiled locations. Abundance the broodstock, singularly. Water quality for domestic and agricultural use, the and biomass decreased from winter to parameters (temperature, pH, salinity, Wanaka-Cardrona Aquifer also augments summer sampling programs, believed nitrate, nitrite, ammonia, phosphate, and surface flows for the lower Cardrona to be related to environmental factors. carbonate hardness) were observed and River and the nearby Bullock Creek. Long term effects on the recovery of the maintained throughout the experimental The Otago Regional council is currently exposed soft shore were not detected period. The mating behaviour of clownfish undertaking a series of workshops with broodstock was observed day and night the aim of setting a minimum flow and around full moon and recorded between allocation limits for the Cardrona River January and June 2012. All of the and the Wanaka-Cardrona Aquifer. When broodstock pairs exhibited two distinct combined with targeted management types of courtship behaviour, which are tools such as residual flows and trout spawning rise and body scrubbing with migration barriers, it is hoped that each other. The mating behaviour was the socioeconomic, recreational and used as an indicator to observe and biodiversity values of the Cardrona predict successful breeding process. catchment will be maintained and enhanced.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 75 SPEAKER ABSTRACTS

Fish Communities of Rope Beats Slope: Mussel What is it Worth? An Shallow Waikato Lakes. Ropes Improve Fish & Exploration of Estuarine Where are the Longfins? Shrimp Passage Through Ecosystem Services & Culverts Human Well-being

Adam Daniel // Fish & Game New Bruno David // Waikato Regional Kathryn Davies // The University of Zealand Council Auckland

Brendan Hicks, Nicholas Ling // The Jonathan Tonkin, Hayden Hokianga // Bay Simon Thrush // NIWA University of Waikato of Plenty Polytechnic Mark Dickson, Karen Fisher, Richard Kris Taipeti // Waikato Regional Council LeHeron // The University of Auckland Lakes Mangahia, Kaituna, Ohinewai and Serpentine were intensively sampled We investigated the installation of Estuaries are complex social-ecological during non-native fish removal operations mussel spat ropes as a potentially rapid systems that cover a diverse cross- conducted between 2010 and 2013 and cost effective tool for improving section of habitats, support a wide range to monitor for changes in species passage of freshwater biota through of human activities and values, and are an composition of large-bodied fish. Native culvert pipes where internal barrel integral part of the New Zealand cultural [longfin eel (Anguilla dieffenbachii) conditions impede passage. We assessed identity. Estuarine systems provide a and shortfin eel (Anguilla australis)] passage success for two fish species, range of services that benefit humans; a and non-native fish [koi carp (Cyprinus juvenile Oncorhynchus mykiss (Walbaum few examples include food production, carpio), goldfish (Carassius auratus), 1972; rainbow trout) and adult Galaxias recreational opportunities, contaminant catfish (Ameiurus nebulosus) and rudd maculatus (Jenyns 1842; inanga), and processing, and storm protection. Some (Scardinius erythrophthalmus)] were one migratory shrimp, Paratya curvirostris of the services provided by estuaries, marked via fin clip to determine species (Heller 1862). We hypothesized that such as food production, can be valued biomass using a capture-mark-release- ropes would enhance passage of all three in monetary terms and incorporated recapture study design. The biomass species but that success rates would into decision-making with relative ease, of fish in lakes Mangahia, Kaituna and differ dependent on swimming ability and but many other services are difficult to Ohinewai were dominated by non-native trial combinations of culvert length (3 and express in monetary or other quantitative fish (range 104–228 kg ha-1) compared 6 m), gradient (1.5 and 3°) and flow (0.24 terms and are therefore under-valued to native fish (range 34–57 kg ha-1). and 0.75 L s-1). Ropes resulted in reduced if they are considered at all in decision Lake Serpentine, the only lake with a water velocity within culvert barrels and making. Social values of estuaries, and non-native fish control program, had a significantly improved passage success factors which underpin ecosystem low biomass of non-native fish (1 kg ha-1) for all three species. Shrimp benefited service provision such as ecosystem and a moderate biomass of eels (32 kg most by the presence of ropes, being processes, the diversity of habitats within ha-1). Longfin eels were captured in low unable to negotiate any of the pipe estuaries, and the connections between numbers (range 1–7 kg ha-1) in all four combinations in their absence, but habitats within estuaries, are particularly lakes compared to shortfin eels (range exhibiting varying rates of success across difficult to capture and incorporate into 31–55 kg ha-1) composing just 2% of the all combinations with their presence. Both decision making but are a vital part of individuals captured. G. maculatus and O. mykiss were able to any ecosystem service implementation negotiate some of the non-roped pipe process. The difficulties associated combinations but as the level of difficulty with incorporating ecosystem services increased, successful passage was into decision making combined with only achieved with ropes present. We the complex relationships governing conclude that this relatively inexpensive the delivery of services suggest that a tool has potential to substantially improve precautionary management approach passage for a range of aquatic biota is necessary to prevent critical failures through a range of culvert scenarios. in service delivery, but as yet there is no Application of ropes would be particularly regional or national stocktake of estuarine useful in situations where internal culvert ecosystem services or their associated access is difficult and where various processes. Current research using a case culvert parameters (slope, flow, length) study from Mangere Inlet, Manukau result in internal barrel hydraulics that Harbour, explores ways to identify and would normally limit or exclude passage value ecosystem services provided by of aquatic biota. estuaries.

76 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

The Many Voices of Assessing Boat Developing Freshwater Manukau: a Participatory Electrofishing Injury on Objectives from Values: an Approach to Mapping Shortfin Eels, Anguilla Example from New Zealand Ecosystem Services australis Freshwater Fisheries

Kathryn Davies // The University of Joshua de Villiers // The Neil Deans // Fish & Game New Auckland University of Waikato Zealand

Karen Fisher, Mark Dickson, Brendan Hicks, Adam Daniel // The Martin Unwin // NIWA Richard LeHeron // The University of University of Waikato Kay Booth // Lindis Consulting Auckland Simon Thrush // NIWA Electrofishing is standard practice for Giving effect to NZ’s new National Policy most freshwater fisheries monitoring Statement on Freshwater Management Ecosystem services are the benefits programmes and has been a valuable requires Regional Councils to identify that people obtain from ecosystems. sampling technique for over half freshwater values in catchments and set The development and implementation a century. However, electrofishing objectives to provide for them. Limits, of ecosystem service frameworks can potentially cause a number of targets and standards may then be is perceived as a way to cope with injuries, most commonly dermal burns, established to provide for critical values environmental problems that are haemorrhaging and spinal damage, and and enable community decisions on what characterised by high levels of complexity we examined injury rates in shortfin eels would be provided for. Deciding what and uncertainty. Ecosystem service (Anguilla australis). Eels were captured by level of significance and hence weight frameworks aim to encourage the fyke netting and boat electrofishing with to be given to particular values in each consideration of links between natural a Smith Root 5 GPP unit (60-Hz pulsed case requires a rigorous, consistent systems and human well-being; facilitate direct current, 45–60% of range, 3–4 and defensible approach towards the assessment of feedbacks and amps RSM output) from two Waikato comparing within and between values trade-offs that occur among services and lakes. The incidence and severity of in particular locations. Few national human beneficiaries; and incorporate injuries resulting from each method of datasets are available to analyse and values into decision making processes. capture was assessed by radiographic develop consistent frameworks to assess Extensive stakeholder participation imaging and bilateral filleting immediately values; one such is Fish and Game NZ’s is needed to guide the development, after capture and following a 30-day National Angler’s Survey undertaken at implementation, and maintenance of holding period; also, mortality rates seven year intervals. An approach using ecosystem service frameworks if these were determined after 30 days. Survival the River Values Assessment System ambitious goals are to be realised. of shortfin eels after 30 days was high (RiVAS) to establish relative significance This research explores the use of a for both capture methods (90% for fyke of freshwater angling values across NZ’s participatory mapping methodology netting and 94% for boat electrofishing). 1150 rivers and lakes is outlined. in an urban estuary, and shows how Rates of internal haemorrhaging the application of this methodology immediately after electrofishing were can contribute to the identification and inconsistent (0% in Lake Areare and 28% valuation of ecosystem services in areas in Lake Rotongaro); in Lake Rotongaro, where problems are complex and futures this was significantly greater than those are uncertain. Mangere Inlet, an estuary captured by fyke netting, in which only located in Manukau Harbour, is the case 8% had haemorrhages. The incidence of study for this research. haemorrhaging in electrofished eels was lower after the 30-day holding period than immediately after capture, i.e., 28% in Rotongaro eels at capture but only 4% after 30 days in captivity. Spinal injury rates in eels captured by electrofishing ranged from 8% in Lake Rotongaro eels to 12% in Lake Areare eels. In contrast, the rate of spinal injury in eels captured by fyke netting was 0% in Lake Areare eels and 4% in Lake Rotongaro eels.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 77 SPEAKER ABSTRACTS

Water Quality in Pegasus The State of the Taupo Temperature Limits to Early Bay: From the River to the Fishery & Its Impact Development of the New Sea on the Level of Angling Zealand Sea Urchin Participation Evechinus chloroticus (Valenciennes, 1846)

Fiona DEATH // Aquanet Consulting Michel Dedual // Department of Natalí Delorme // The University of Limited Conservation Auckland

Olivier Ausseil // Aquanet Consulting The level of participation in angling Mary Sewell // The University of Auckland Limited has traditionally been thought to be Lesley Bolton Ritchie // Environment strongly correlated with the state of Seawater temperature is an important Canterbury the fishery. When fishing is not good environmental factor for the early life (low catch rate and/or small fish size) stages of marine invertebrates. In this A number of freshwater bodies flow into anglers move somewhere else, the study we evaluated and described the Pegasus Bay at various points along the licence sales drop and the associated effects of temperature during early coastline. Wastewater from both the drop in fishing pressure allows for the development of E. chloroticus, identifying Waimakariri District and Christchurch fishery to recover. It is this general the optimum temperature range and City also enter the bay via ocean outfalls. observation that leads to the supposition upper thermal limit for successful Inputs of contaminants, in the form of that recreational fisheries tend towards development. The temperature range nutrients, sediment and micro-organisms self-regulation. If this supposition is true evaluated was between 15–24ºC from all of these sources have the we would expect to see a cyclical trend in which included the normal seawater potential to adversely affect the water participation following the ups and downs temperatures during the spawning quality of coastal Pegasus Bay. A survey in fish number and/or size. However, season in northern New Zealand, as well in which water quality data were collected the evidence that this is occurring in as the highest temperature projected by at locations on fourteen Canterbury rivers Taupo is not fully convincing. The trend the IPCC for this region due to global (as close to the coast as possible but in participation estimated by the number warming (1–3ºC by the year 2100). without being affected by tidal influence); of fishing licence sales has peaked in Gametes from several females and as well as at 10 beaches along Pegasus the late 1980s but has been consistently males were used in the experiment. Bay was undertaken between 1 July going down since then despite the fact Fertilization was carried out at different 2010 and 30 June 2011. Data collected that the fish caught in the late 1990s were temperatures and development was allowed an assessment of the state of on par with those from the golden years monitored at different time points after water quality at river sites that feed into of the fishery. Google Trends is used to fertilization in each temperature. The Pegasus Bay; as well as at nearshore illustrate the global decline in participation development rate of E. chloroticus and offshore water quality sites. Total to freshwater angling in New Zealand increased with an increase in seawater annual loads of nutrient (nitrogen and and in other parts of the western world. temperature. However, at temperatures phosphorus) entering Pegasus Bay were In this presentation we also explore how higher than 21.5ºC the amount of estimated using a number of methods important are the abundance and the size abnormal development reached ~30%. and the relative contribution made by of the fish to explain the current trend in The optimum temperature for early each river and outfall was quantified. participation and what this means for the development was between 15–21 ºC, Results have highlighted the contribution management of the fishery. whereas the upper thermal limit was of the Christchurch City Council ocean ~24 ºC. Therefore, early development outfall to the total loads of both TN and of E. chloroticus is negatively affected TP entering Pegasus Bay. The findings by an increase in seawater temperature of this study would assist in identifying of ~3–4ºC above current seawater key nutrient sources and prioritising their temperature levels in northern New management, should actual or potential Zealand. The thermal sensitivity of early algal growth issues be identified in life stages of E. chloroticus could affect Pegasus Bay. survival rates during early development of this species in a global warming scenario, which could impair recruitment in populations which are exposed to higher temperatures, leading to possible distributional shifts of this species.

78 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

After the Outfall (and Macrophytes & Development of Molecular fallout): Sediment Fluxes of Monitoring – What does Tools for the Detection & Nutrients & Oxygen in the LakeSPI say about New Discrimination of Potentially Avon Heathcote Estuary, Zealand Lakes? Invasive Mussel Species of Christchurch the Genus Perna

Craig Depree // NIWA Mary de Winton // NIWA Joana Dias // Western Australia Fisheries and Marine Research John Zeldis, Catherine Congol // NIWA John Clayton, Tracey Edwards // NIWA Laboratories David Schiel // University of Canterbury Use of submerged macrophytes J. P. A. Gardner // WA Fisheries & Marine Up until March 2010 when Christchurch as ecological indicators is gaining Research Laboratories City diverted its waste to a new ocean acceptance for inventory and monitoring Michael Snow // Victoria University of outfall, the Avon Heathcote Estuary purposes world-wide. LakeSPI Wellington received approximately 160,000 m3 (Submerged Plant Indicators) is a per day of effluent from the Bromley biomonitoring tool developed for New Marine mussels of the genus Perna treatment ponds, accounting for around Zealand lakes. It involves measurement include three species: Perna canalicula, 90% of the nitrogen load to the estuary. of 11 vegetation metrics at representative Perna viridis and Perna perna. While P. The legacy of nutrient discharges sites in a lake. A Native Condition canalicula appears to be greatly restricted have resulted in a eutrophic estuary Index (NCI) combines metrics for the to its endemic range of New Zealand, characterised by low species diversity and functional diversity, depth extent, cover P. perna and P.viridis introductions have excessive growth of nuisance macroalgal and occupancy of native submerged been recorded outside their native species over much of the intertidal area of plants. An Invasive Impact Index (III) ranges in several regions of the globe. the estuary. As part of a larger ecological reflects the degree of development by Such introductions have often resulted programme to track the recovery (or at invasive weeds, and ranks the perceived in significant negative ecological, least response) of the estuary, since 2007, severity of impact and habitat tolerances economic and social impacts. Perna every summer and winter, sediments of invasive species that are present. perna and P.viridis are exotic to Australia from five locations around the estuary Aspects of these are incorporated into and are listed under the Australian (including the discharge site, Avon a LakeSPI Condition Index (LSI). Indices Government National System for the and Heathcote River mouths) have are expressed as % of what the lake Prevention and Management of Marine been analysed to determine to what could or should score (pristine state). Pest Incursions as high priority species. extent, and how quickly, sediments LakeSPI results are available for c. 250 Rapid detection of marine pests such from a eutrophic system respond to an lakes, with 87 lakes surveyed on more as Perna species remains fundamental ‘overnight’ reduction in water column than one occasion. These results show to their effective containment and nitrogen. And importantly, whether the less than 15% of assessed lakes possess control. The present study reports on sediment ‘reservoir’ of organic matter a submerged vegetation close to the the development and validation of both could continue to fuel nuisance algal expected pristine state (LSI >75%). conventional and real-time PCR assays growth via nutrient fluxes to the overlying Approximately 15% of assessed lakes suited to the rapid identification and water and delay recovery. Key parameters were dominated by exotic water weeds discrimination of juvenile and adult that will be presented include a sediment (III >75%), and 25% of lakes had such a specimens of P. viridis, P. canalicula and timeline of oxygen fluxes (as proxy low abundance of submerged vegetation P. perna. The development of a sensitive for carbon respiration), trophic status they were categorised as ‘non-vegetated’. high-throughput real-time PCR assay (production/respiration ratio), and nutrient Of 87 lakes that were re-surveyed, 44% offers further potential for the efficient fluxes. Superimposed on the ‘recovery showed a significant change in LakeSPI detection of the presence of single Perna trajectory’ however are the three major Indices, deterioration was shown by specimens in mixed populations of native Christchurch earthquakes that caused 37% and an improvement in 7% of lakes. mussel species, and for early detection of significant physical upheavals (bed tilting, Changes included retraction/extension in larval stages in ballast water and plankton liquefaction) and prolonged pulses of raw the depth of plants (28%), new incursions samples. This assay offers considerable effluent discharged to the estuary via the of worse exotic weeds (17%), and shifts advantages over traditional identification Avon and Heathcote Rivers. between vegetated and non-vegetated methods and represents an important states (11%). step in developing capacity for efficient identification and management of Perna species incursions in Australian waters.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 79 SPEAKER ABSTRACTS

Length-Weight Relationship Cultural Relationship & The ‘Land & Water New in the Goby, Parapocryptes Mana of Water with & Zealand’ Web Tool – Where serperaster (Richardson, within the Maori World We’ve Come From & 1864), Caught from Where We are Heading Mekong Delta, Vietnam

Minh Quang Dinh // Flinders Ngahuia Dixon // AM2 & Associates Katharina Doehring // Cawthron University, Australia Institute The Maori world as tangata whenua of Jian Qin, Sabine Dittmann // Flinders Aotearoa has seen its relationship with Jo Bailey // Massey University University, Australia water, especially in terms of waterways, Nina von Westernhagen // Hawke’s Bay Dac Dinh Tran // Can Tho University, used in political debates by governments Regional Council Vietnam including Labour and National. Maori Kit Rutherford // NIWA relationships with water have been Olivier Ausseil // Aquanet Consulting Ltd visible since traditional times. Although Parapocryptes serperaster is one of the debate regarding its use has been two amphibious fishes of the genus Regional Councils, the Cawthron Institute, an ongoing, in-depth issue for nigh on Parapocrytpes (Gobiidae), and of Massey University and MfE are working five – six years Maori tribes still recognize commercial interest in Southeast Asia. to evolve the current Land and Water and acknowledge the mana of water A study on the goby P. serperaster was New Zealand (LAWNZ) website, which and those relationships to waterways. carried out along the muddy shoreline provides information on New Zealand’s This presentation discusses those of the Mekong Delta, Vietnam, to river water quality. Funding has been relationships and the mana of water establish some basic population biology provided by the Tindall Foundation and to Maori tribal groups, irrespective of parameters. To determine the length- design development is being undertaken the tensions imposed through colonial weight relationship of this species, a by Open Lab (Massey University). The constructs promoted by organisations total of 822 individuals were caught in vision for the project is to develop a such as central government. mud flats of the study area by dip net new ‘freshwater tool’ that is respected, and hand. After determining sex via accessible and easy to use, which will external features, total length (TL in cm) act as a hub for water information in New and body weight (W in g) of this goby Zealand. The tool should engage multiple were measured. This study ran for six user-groups with freshwater issues, months, from October 2012 to April 2013. enable the translation of scientific data so The mean lengths for total fish, male, it can be easily understood by all water female and unsexed individuals were users, and thereby increase engagement 15.84±3.47, 17.84±2.76, 15.31±3.02, and with water issues. Moreover, the tool 10.76±0.69 cm respectively. The average should facilitate the sharing of water body weights for total fish, male, female quality information between interested and unsexed individuals were 16.39±8.20, groups, support and link initiatives 20.68±7.55, 15.16±7.12, and 5.99±1.07 working to improve freshwater quality g, respectively. The length-weight and ultimately affect behavioral change relationships of male, female, unsexed in terms of how New Zealanders relate and total fish were highly correlated. to water. This presentation summarises Correlation values of b were 2.370, 2.524, the team’s progress to date, which 2.302 and 2.605 for total fish, male, mechanisms were used to get there, as female and unsexed, respectively; and well as where we are planning on taking regression coefficients of R2 share nearly the website in the future. the same pattern which were 0.974, 0.963, 0.968 and 0.826. The correlation value of unsexed was slightly higher than that of male and female, whereas the opposite was true for the regression coefficient. However, they were not significantly different (p<0.005) based on Tukey method in Minitab software package. The growth relationship of this species shows positively allometry, which means that this goby could be a potential fish for future aquaculture.

80 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Where does all the Experimental & Modelling Dynamics of Reef Strontium go? Otolith Studies of Fine Organic Communities Situated Chemistry Insights from the Particle Dynamics in Close to Salmon Farms Australian Synchrotron Streams

Zoë Doubleday // University of Jennifer Drummond // Robyn Dunmore // Cawthron Adelaide Northwestern University, NIWA Institute

Hugh Harris, Christopher Izzo, Bronwyn Aaron Packman // Northwestern Nigel Keeley // Cawthron Institute Gillanders // University of Adelaide University Rob Davies-Colley, Rebecca Stott, Sandy Salmon farming in New Zealand has Strontium (Sr) is the most extensively Elliot, Graham McBride // NIWA historically occurred over soft sediment used element in otolith chemistry habitats in low-flow environments, research and is used to reconstruct the Fine organic particle dynamics are and nearby reef communities have not movement and environmental histories important to stream biogeochemistry, been in the depositional footprint of of fish from freshwater to hypersaline ecology, and transport of contaminant waste products. Hence, the literature environments. It has long been assumed microbes. These “biocolloids” migrate pertaining to enrichment effects is that trace elements, like Sr, randomly downstream through a series of deposition strongly dominated by research on soft substitute for Ca within the aragonitic and resuspension events, which results sediment habitats and very little is known about the effects on reef communities. calcium carbonate (CaCO3) lattice of in a wide range of residence times. This otoliths; however, this has never been retention influences biogeochemical In Tory Channel, Marlborough Sounds, tested, and Sr may form Sr-rich phases processing and in-stream stores of two salmon farms in high-flow sites are situated in close proximity to potentially of the mineral strontianite (SrCO3) or contaminant microbes that may mobilise be bound within the interstitial spaces during flood events and present a sensitive rocky reef habitats. As part or organic (protein) component of hazard to downstream uses such as of their consents, New Zealand King the otolith. If this is the case, otolith water supplies and recreation. We are Salmon have monitored the sites for chemistry data may be misinterpreted, conducting studies to gain insights into any signs of effects from farm related which could have critical consequences organic particle dynamics in streams, with enrichment or sedimentation. This was for how fish and fisheries are understood a campaign of experiments and modeling. achieved by establishing permanent and managed. Using X-ray Absorption The results should improve understanding quadrats, photographing them through Spectrometry (XAS) at the Australian of nutrient (C, N, P) spiraling and fine time and analysing the images for percent Synchrotron, we explicitly tested how Sr sediment movement in streams, and cover and/or numbers of conspicuous binds within fish otoliths by examining the have particular application to microbial invertebrates, algae and triplefins. Extended X-ray Absorption Fine Structure hazards (Drummond et al., POSTER, this Multivariate analyses using (EXAFS) region of the XAS spectrum, conference). We developed a stochastic PERMANOVA showed that overall, which enabled the structural state(s) of model to describe the transport and there was no farm-related impact in Sr to be distinguished. Aragonitic otoliths retention of fine suspended particles in comparison to reference sites, but from several native Australian species, rivers, including advective delivery of there were highly significant changes representing freshwater, estuarine, particles to the streambed, transport at some sites through time and some marine and hypersaline environments, through porewaters, and reversible sites and replicate quadrats were highly and hence a range of Sr concentrations, filtration within the streambed. Because significantly different to each other. were examined. A squid statolith, coral fine particles are only episodically Examination of individual and groups of skeleton, cuttlebone and shark tooth and transported in streams, with intervening taxa generally showed high variability vertebra were also analysed for structural periods at rest in the bed, this transport through time, and no distinct trends comparison. For all otolith samples, process violates conventional advection- were observed across impact and the results consistently indicated that dispersion assumptions. Instead we reference sites. Distinct declines and Sr substitutes for Ca within aragonite adopt a stochastic mobile-immobile increases in taxa were observed over all regardless of Sr concentration, and that model formulation to describe fine sites, and these were most likely related the substitution is random, rather than particle transport. We apply this model to natural recruitment, migration and forming clusters of strontianite. This to measurements of particle transport mortality events. research further validates Sr as a useful from multiple tracer experiments in an chemical tracer in otolith chemistry, agricultural stream, and use the model to and confirms, for the first time, that Sr improve interpretation of baseflow particle replaces Ca in otolith aragonite. dynamics.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 81 SPEAKER ABSTRACTS

The Interaction Between Evaluation of the Use Management of Biodiversity Habitat & Fisheries: of Elastomer & Paint as on the High Seas – Using the Case of Deep-sea Methods to Mark Lowland Ecologically & Biologically Seamounts Longjaw Galaxias Significant Areas (EBSA) to Examine the Overlap of Values & Pressures on the High Seas

Matthew Dunn // Victoria Nicholas Dunn // Department of Piers Dunstan // CSIRO University of Wellington Conservation Nicholas Bax, Mike Fuller // CSIRO Seamounts and other underwater The purpose of this study was to evaluate features throughout the world’s oceans three products for use as subcutaneously The oceans cover 70% of the Earth’s can support diverse and exceptionally (under the skin) injected marks for surface, and the majority of this area abundant faunal communities. These individual or batch identification in studies (or half the Earth’s surface) is in Areas areas are also the focus for commercial involving the nationally critically threatened Beyond National Jurisdiction (ABNJ). fisheries. The conflict between lowland longjaw galaxias (Galaxias cobitinis: The international community provided biodiversity conservation and fisheries Galaxiidae). The three materials assessed a program of action for achieving makes management difficult. To ensure were visual implant elastomer, acrylic paint, sustainable development of the oceans, sustainable fisheries, highly precautionary and fabric paint. Over the three months coastal areas and seas at the Rio Earth feature-based catch limits, and credible of the study, survival of marked fish was Summit in 1992, however sustainable and timely stock assessment advice are high, and no mortality was attributed use of living resources on the high required. Interpretation of catches from to the presence of marks. Growth and seas has been challenging and remains commercial fisheries as indicators of relative condition of G. cobitinis were not a major concern for the international underlying stock dynamics is all that is adversely affected by the injection of community. In 2008, the Conference of available in many stock assessments, but subcutaneous elastomer or acrylic paint the Parties to the CBD adopted seven using these data is highly problematic. material, even when receiving multiple scientific criteria to identify ecologically or A better understanding of the ecology marks. All elastomer and acrylic paint biologically significant areas (EBSAs) to of seamount fishes, and their use of marks were retained, however fabric paint enhance conservation and management such habitats, is needed to better did not perform as well and its use is not measures and encouraged competent understand stock dynamics, and so the recommended. Digital image analysis was parties to conduct regional workshops. signals contained in commercial fishery used to determine mark area at monthly The first regional workshop, convened catch data. Using orange roughy, the intervals to assess absorption rates. by the Secretariat of the Convention on value of seamounts to fish populations Elastomer marks were more stable than Biological Diversity (SCBD) in November is illustrated using demographic data, acrylic paint marks. Extrapolation of these 2011 was to identify potential EBSAs and hypotheses for habitat connectivity data suggest that acrylic paint marks may in the western South Pacific region. are considered using spatially-stratified be visible for 24 months, and elastomer Subsequent workshops have been held population models. The results question marks even longer, possibly for the life-time in the Western Atlantic, Southern Indian, some hypotheses about the value and of G. cobitinis. However, elastomer marks Eastern Pacific, and Southeast Atlantic use of seamount habitats. were more likely to fragment than other and North Pacific oceans. We report materials, although this did not affect on the results of those workshops here overall visibility. In conclusion, long-term and the types of EBSA that have been marking of G. cobitinis can be achieved with identified. We discuss their progress either elastomer or acrylic paint without through the international negotiations at adversely effecting fish. These results are the 16th meeting of the CBD Subsidiary also likely applicable for use in population Body on Scientific, Technical and monitoring studies of other small galaxiid Technological Advice (SBSTTA) and species COP11. We briefly highlight some of the pressures to marine biodiversity beyond national jurisdiction and examine the potential for using EBSA to identify values on the high seas and how different pressures might interact with those EBSA. We also provide a brief summary of the current negotiations for a new implementing agreement under UNCLOS for biodiversity beyond national jurisdiction.

82 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Stunning Sicydiines in The Whitebait Population So What Now Australian Wet Tropics Dynamics in a Dynamic World

Brendan Ebner // CSIRO, James Eimear Egan // University of Janise Eketone // Maniapoto Maori Cook University Canterbury Trust Board

Recent research efforts have revealed Michael Hickford, David Schiel // The Nga Wai o Maniapoto (Waipa River) the presence of Amphidromous sicydiine University of Canterbury Act passed into legislation on 6th April gobies in short and steep coastal 2013. It took 5 years to reach this point streams of the Australian Wet Tropics. Anecdotal reports suggest that the and the legislation marked the ‘official’ Generally, earlier fish surveys in Wet whitebait fishery is in decline. A thorough beginning of the co-governance, co- Tropics catchments failed to detect this understanding of the population management and collaborative clean-up assemblage, although, occasionally dynamics of Galaxias maculatus, the journey in the Waipa River catchment. specimens were collected. I aim to most common whitebait species, is So what does this mean for Maniapoto? provide a brief background to the central to informed decision making by For those directly involved in discussions discovery and ecology of seven species managers, ecologists, policy-makers it all makes perfectly good sense. For for which published information is and whitebaiters. Recent restoration those that live with, in and alongside the available in the Australian context, and efforts have focused on rehabilitating Waipa it means...The session presents a demonstrate that the highly localised spawning habitat and increasing egg practical view of clean-up opportunities distribution of this fauna largely explains production, with little knowledge of and challenges. why they eluded us for so long. I also the consequences for larval production present the first records of an eighth and subsequent population dynamics. species in the region. Conservation Galaxias maculatus crosses multiple requirements of the group are discussed ecosystems during its life history and is amid a backdrop of peri-urban and vulnerable to the conditions experienced agricultural development as well as the in each, which can positively or negatively potential for direct harvest by aquarists. influence populations. The dynamics of a population are closely related to its age structure, spawning stock biomass and egg/larval production among other factors. In the initial phase of my PhD, I am developing techniques for gauging the larval production of waterways in relation to egg production in their spawning habitat. I intend to use a suite of field and laboratory techniques to assess the age and condition of G. maculatus. Taken together, condition indices, larval production and population parameter studies will give us a greater understanding of the processes impacting at the population and sub-population levels of this species, and aid in preserving its ecological, cultural and economic value.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 83 SPEAKER ABSTRACTS

Satellite Tagging of Blue Lessons from Applying Downstream Services in Sharks in New Zealand to Regional & National Support for the EU Marine Assess Critcal Habitat Use Contaminant Load Models Strategy Framework & Migration to Support Land-Water Directive: Combining Managment Observation Technologies for Optimal Ecosystem Mapping

Riley Elliott // The University of Dr Sandy Elliott // NIWA Anders Erichsen // Danish Auckland Hydraulic Institute Dr Annette Semadeni-Davies, This project investigates patterns in Dr Ude Shankar, Dr Chris Palliser, Ben Tuckey // Danish Hydraulic Institute habitat use and migration of blue sharks Dr Aroon Parshotam // NIWA across a range of spatial and temporal Achieving good environmental status (GES) scales within New Zealand (NZ) waters. At large catchment to national scales, of the EU’s marine waters requires detailed Large scale migration and habitat use predictive models of mean annual knowledge about the current status. Some is assessed using long term historical loads serve as a means to assess the of the key goals are mapping the current catch data, via the New Zealand fishery outcome of future land use change and environmental state as well as establishing observer program. Catch composition interventions on water quality. The CLUES monitoring programmes to measure (size/sex) is assessed for correlation catchment model, which is driven by progress towards GES. Open water with habitat type and significant marine a simplified version of Overseer and is monitoring is traditionally done sampling at systems. Satellite tagging assists in calibrated to water quality data nationally, a limited number of sites at a frequency of identifying large scale spatial/temporal has been applied in various ways for weeks to months, providing time series of trends. Small scale diurnal patterns are this purpose. This process has identified different parameters at one or few location investigated inshore (<1000 m depth) various strengths and weaknesses of in each water body. These data are used using active telemetry tracking of the approach, some of which are being for evaluation of the overall state of the acoustic tags with temperature and depth addressed. Valication against new sea. However, the accuracy of this type of sensors. Simple stomach content analysis regional datasets, is that local refinement monitoring is debatable, especially with will reveal possible foraging stimulus of model parameters is often useful to the arrival of new technologies extending for diurnal movement. Collaboration of more accurately reflect local catchment the possibilities of exhaustive monitoring the above will give a broad, baseline behaviour in a particular application programmes, e.g. earth observation, ferry understanding of the behaviour, habitat region. This requires measured loads box, continuous buoy measurements, preference and migratory cycles of the for calibration, however. Prediction of and modelling. These technologies have blue shark; a species lacking research but nutrient loads to estuaries has been different advantages and disadvantages fundamental to NZ’s marine ecosystem. used to assess estuarine eutrophication that add valuable knowledge as they Justification for this project is that impacts, but to improve such models, increase the temporal and spatial coverage sharks are apex predators, evolved over seasonality of nutrient inputs needs to be significantly. A question is: how they can be millions of years, holding trophic levels of addressed. Regional groundwater effects applied to help assessing the state of the marine ecosystems in balance. Globally, (flow bypassing surface catchments, sea? Through two FP7 projects, Aquamar however, shark populations are in reduced stream attenuation, lags) have & CoBiOS, the Danish Hydraulic Institute significant decline due to overexploitation. been identified as important effects not (DHI) is developing the infrastructure to Highly migratory species, such as blue yet captured in CLUES, so that further make use of the different technologies sharks, are inherently hard to manage modifications are required for general and integrate them into a combined and sufficient knowledge is lacking for applicability nationally. Model predictions on-line monitoring and information system effective management and awareness. of nutrient concentrations entail high providing a holistic assessment of the So far 8 blue sharks have been tagged, uncertainty; normalisation to measured state of the marine environment. Hence, returning the first ever data on these concentrations or direct empirical it addresses the past, the present, and animals in this area of the world. predictions of current concentrations has the future through different ‘products’ proven to be a useful measure to reduce presenting ‘raw’ and aggregated data, this uncertainty. Such models have been and then supports and facilitates the useful in identifying catchment level implementation of Marine Strategy responses to mitigation measures, and Framework Directive. This presentation for identifying potential limitations on will discuss advantages and disadvantages land development before minimum state related to the different technologies and levels are breached. However, more work present the status of integrating these into is required to fully leverage the benefits dynamic models. of such predictive models in collaborative catchment processes.

84 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Happy Snapper: Home is Environmental Does Fishing Selectively Where the Seagrass Sways Consequences of Remove Snapper (Pagrus Management Decisions auratus) Fish with Bold on the Footprint of Wild Personalities? Capture Seafood

Tegan Evans // The University of Anna Farmery // University of Courtney Farthing // The Auckland, NIWA Tasmania University of Auckland

Ian Tuck // NIWA, University of Auckland Caleb Gardner, Bridget Green, Sarah Swastika Lal, Neill Herbert // The Mark Morrison // NIWA Jennings // University of Tasmania University of Auckland Darren Parsons // NIWA Snapper (Pagrus auratus) are the most Maintaining the ecological foundation of important inshore commercial fish food systems is essential for achieving Previous studies at the Leigh Marine species in New Zealand. Their nursery food security. Current concepts Laboratory demonstrate that snapper grounds are known to be associated of seafood sustainability – ending (Pagrus auratus) show consistent with biogenic habitats such as seagrass overfishing of target species, protecting individual differences (CIDs), otherwise meadows, which are vulnerable to ecosystems and non-target species – known as “personality”, with respect land-based impacts. Rangaunu and can be broadened to include impacts to their physiology and behaviour. For Parengarenga harbours (upper East stemming from the energetic and example, individual P. auratus differ Northland) are heavily utilised as snapper material demands of the fish capture in willingness to take risks, and show nursery grounds. They contain extensive phase and supply chain. We used life different rates of resting metabolism seagrass and other habitats that vary cycle assessment (LCA) to measure the (standard metabolic rate, SMR). Most in their environmental and physical environmental footprint of the supply of importantly, these features of physiology characteristics, resulting in a range of Southern rock lobster, Jasus edwardsii and behaviour are correlated; P. auratus habitat qualities for juvenile fish. They (SRL). International airfreight of live with high SMR (>145 mgO2. kg-1 hr-1) are also under a range of increasing lobsters was the major contributor to are quick to explore potentially dangerous human pressures, despite being relatively the global warming potential (GWP) environments and are therefore more pristine compared to most other New and cumulative energy demand (CED) bold. Conversely, fish with low SMR Zealand estuaries. This study aims to use indicators, while the fishing stage take less risk and are more timid. The juvenile snapper (<6 months old, c. 30–60 accounted for the majority of impacts implication of personality differences mm) daily growth rates as a measure to eutrophication potential (EP), water for fisheries management and marine of juvenile snapper fitness, and link this use and marine aquatic ecotoxicity. reserves is not entirely understood, to habitat quality effects. High rates of We examined a series of management however there is concern that fishing may juvenile growth are assumed to result scenarios to determine impacts of selectively remove bold personalities first, in higher survivorship to adulthood and marine resource management decisions leaving behind timid personalities. This other fitness benefits to fish. To determine on the SRL environmental footprint. would render future fishing effort more growth rates, daily growth rings will be Changing the management objective difficult and could potentially reduce counted and measured on the snapper’s from maximum sustainable yield to biomass, as timid personalities often grow sagittae otoliths. Growth rates and maximum economic yield decreased the slower. If fishing leads to a predominance condition indices will be compared across carbon footprint by 80% or 11 kg CO2e of timid personalities within fished areas different habitat types and associated kg-1 of lobster at capture. Increasing the it is plausible that marine reserves act environmental variables, to assess coverage of marine protected areas to as a refuge for bold personalities, and juvenile snapper fitness, and how it levels applied in an adjacent jurisdiction could thus provide a buffer against fishing relates to adjacent land-based activities increased the fishery’s carbon footprint pressures. To test this, P. auratus will be -1 influences (i.e. associated sediment and by 24% or 3 kg CO2e kg of lobster at angled sequentially in the Leigh area and other inputs into the harbours). Results capture. Fisheries management decisions their behaviour and physiology assessed will be used to help identify how and can be a tool to reduce environmental within laboratory conditions to determine where negative impacts are occurring on impacts of seafood production and whether bold personalities are angled juvenile snapper production, which can maintain food supply. Given the first. A further comparison of fish angled be used to help resource managers in predicted impacts of climate change on in this way from reserve and non-reserve moving towards a more ecosystem based fisheries, the unintended consequences areas will help to resolve whether management of fisheries and marine of management changes on carbon reserves contain more bold fish. This systems. emissions suggest that marine resource study will provide important information decision making should not be made in on the effects of individual variation for isolation of these broader environmental fisheries management and conservation. impacts.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 85 SPEAKER ABSTRACTS

Progress with the Non-human Charisma Bringing Social Theory to Manawatu River Accord and its Role in Science Social-ecological Systems & Projects Funded by the Communication Research: New Zealand’s Fresh Start to Freshwater Marine Futures Clean-up Fund

Lucy Ferguson // Horizons Sophie Fern Karen Fisher // The University of Regional Council Auckland As scientists, we seek to communicate Jon Roygard, Josh Markham, our research in ways that are both Richard Le Heron, Nick Lewis // The Alesha Cooper // Horizons Regional relevant and interesting to a lay audience. University of Auckland Council The results of this communication are Simon Thrush // NIWA, University of now woven into grant and promotion Auckland The Manawatu River has been widely applications. We are given to believe that, if the public doesn’t know about our reported in the media over the last few Research utilising social-ecological research, then it cannot be important. years to have poor water quality values. systems thinking provides a framework The scholarship on non-human charisma As a result, stake holders within the that crosses social theory and ecological explores what it is about the non-human, catchment including industry, local sciences. In investigating possible marine be it animal, vegetable, landscape or authorities, iwi and interest groups futures in New Zealand, social theory rock, that attracts an audience. This formed a leaders’ forum to address the enables the complicated relationships includes work on species indices, flagship issues attributing to a decline in water between humans and the ecosystem to species, the charisma of landscape and quality. An action plan was developed be explored and diverse understandings the reasons for our attraction to certain with the goal of improving the mauri of sustainability to be revealed. This species, places and things. These ideas of the Manawatu River catchment paper reports on the approach taken are transferable to the field of science such that it sustains fish species and to engage people in a process to communication. As the communicator, is suitable for contact recreation, in investigate grounded understandings we are able to highlight the aspects of our balance with the social, cultural and of sustainability in diverse contexts. We research that will hook an audience. This economic activities of the catchment discuss the significance of conducting paper outlines some of the main findings community. The Manawatu River this research in an indigenous landscape, from the research into non-human Leaders’ Forum was successful in its and explain how institutional, investment charisma and outlines ways in which this bid to the central government’s Fresh and ecological trajectories influence information can be used to enhance the start to Freshwater Clean-up Fund in thinking about ecological and social communication of our own research. 2012, with funding going toward eight possibilities for the marine environment clean-up fund projects. The projects and the possibilities narrated through the include: (i) upgrades to sewage treatment development of future scenarios. plants in three districts within the catchment; (ii) stream fencing; (iii) native fish habitat restoration; (iv) whitebait habitat restoration; (v) environmental farm plans on dairy farms to address nutrient management issues; and (vi) community engagement. The Manawatu clean-up fund is a two-year project that commenced in July 2012. This presentation will cover progress made to date in the projects and how we have engaged with stake holders to implement these works.

86 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Oceanographic Inter-annual The Impacts of Aquaculture Applying Enrichment Stage Variability on the Campbell on Ecology in New Tools for Large Offshore Plateau Zealand; a Literature Mussel Farms Review

Aitana Forcen-Vazquez // Rich Ford // Ministry for Primary Reid Forrest // Cawthron Institute Victoria University of Wellington, Industries NIWA Dana Clark, Emma Newcombe, The Ministry of Primary Industries David Taylor, Nigel Keeley // Cawthron Michael Williams // NIWA commissioned a literature review of Institute Melissa Bowen // The University of the impacts of aquaculture on ecology; Auckland this was completed by collaboration Large-scale ‘offshore’ marine farming has Lionel Carter // Victoria University of of staff from NIWA and the Cawthron the potential for significant effects to the Wellington Institute. The review has been recently seabed environment, and therefore, the released as part of a package of work wider ecosystem. Accordingly, robust that also includes a document with Ocean water properties such as environmental monitoring is needed to guidance for Regional Councils on Temperature and Salinity over the evaluate and track the condition of the how this information can best be used. Campbell Plateau, south of New Zealand, seabed. Monitoring of such ‘offshore’ Chapters in the literature review aim to are relevant to ocean climate and may sites is expensive and produces a large cover the full range of potential impacts: have a significant impact on fluctuations amount of environmental information. pelagic, benthic, marine mammal, wild in fish and sea lions populations. Water For resource management proposes fish, seabirds, biosecurity, escapee, properties formed over the plateau that information then needs to be placed hydrodynamic, and from genetic are potentially influential in setting the in context by determining the level modification and polyploidy or additives characteristics of the Pacific Ocean ecological effect (from minor to adverse), as well as cumulative effects. This talk intermediate waters. Two data sets are a process which has also highlighted the will discuss the key findings from each investigated to identify the oceanographic need for sound environmental quality chapter and provide some insight into inter-annual variability on the Campbell standards (EQS). Benthic EQS have been relative importance of these effects Plateau. Approximately 70 CTD developed for feed-added finfish farms and how they might best be utilised by (Conductivity-Temperature-Depth) profiles using an Enrichment stage (ES) gradient Regional Councils in the aquaculture were collected in December of each year (from 1 natural, to 7 azoic). However, consenting process. from fisheries research cruises between this approach has not previously been 2002 and 2009 and were analysed and applied to mussel farms, which tend to comprised. Remotely sensed SSH (Sea be associated with less severe levels of Surface Height) data from 1992 to 2012 enrichment. Recent monitoring of two were averaged to create a time series large-scale ‘offshore’ farms included of the ocean variability. Preliminary assessments of sediment physico- results from CTD data show inter-annual chemistry, infauna communities, epifauna variability over the Campbell Plateau. and shellfish health. At the conclusion Conservative Temperature and Absolute of the first stage of development, areas Salinity profiles reveal high variability in beneath farm fell within in a relatively the upper 200 m of the water column and narrow band towards the lower end of the a homogeneous water column from 200 gradient (ES 1.5–3), with some associated to 600 m depth. Temperature variability stimulation of infauna and epifauna of about 0.7°C, on occasions between communities. Effects were constrained consecutive years, is observed down to to within 100m of the farms, and overall, 900 m depth. First inspection of the SSH differences between within and outside data reveal variability over the whole time farm areas were overshadowed by period, with a slightly increasing trend in larger bay-wide processes. Although the late 90’s. A minimum SSH anomaly of minor benthic effects were evident, the -4 cm over the mid 90’s and a maximum ecological consequences were potentially of 6.5 cm towards the end of the last positive in terms of the bays biodiversity decade are observed. and productivity.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 87 SPEAKER ABSTRACTS

Changes in the Spatial Life at the Edge or the Habitat Modification or Structure of South Best of Both Worlds: How Migration Barrier? Tide Australia’s Snapper Fishery do Pelagic Sharks & Rays Gates & their Effects – Relate to Recruitment Straddle the Interface on Freshwater Fish Between Neritic & Oceanic Communities Waters?

Anthony Fowler // South Malcolm Francis // NIWA Paul Franklin // NIWA Australian Research & Development Institute,, Aquatic Sciences Clinton Duffy // Department of Michelle Hodges // Waikato Regional Conservation Councill The latter 2000s has been a period of Mahmood Shivji // Nova Southeastern dramatic change for South Australia’s University New Zealand’s native fish fauna is (SA) snapper fishery. SA’s annual catches John Holdsworth // Bluewater Marine characterised by a high proportion of have increased to record levels, and Research diadromous species, meaning that fish now account for >50% of the national Warrick Lyon // NIWA communities are sensitive to the presence commercial catch. Concomitantly, the of migration barriers. This case study spatial structure has changed as catches describes the effects of tide gates on the Oceanic pelagic species are known to in traditional snapper regions such fish community of Kurere Stream in the migrate large distances in the open as Spencer Gulf have crashed, whilst North Island of New Zealand. Results ocean, but they also frequently encounter having increased dramatically in other indicated that the tide gates were not and enter neritic waters around islands regions, particularly Northern Gulf St. acting as a significant physical barrier to and along continental shelves. Little is Vincent. In order to manage this State upstream fish migration, with populations known about how they navigate, where fishery, it is necessary to understand of key migratory fish species present in and when they travel, and the extent the demographic processes behind suitable habitats in the upper reaches of of their presence in coastal waters. such dramatic changes. This is possible the catchment. However, the presence Electronic tagging offers the potential based on results from a market sampling of the tide gates significantly modified to unlock the secrets of their behaviour program that has provided regional, the physico-chemical characteristics and to generate hypotheses about what annual estimates of fish size and age of instream habitat in the low gradient factors drive that behaviour. Tagging data since 2000. Such data are the basis reaches immediately upstream of the tide from four pelagic shark and ray species, for regional estimates of size and age gates. Dissolved oxygen was low, water shortfin mako shark (Isurus oxyrinchus), structures, recruitment histories, growth temperatures high, aquatic macrophytes porbeagle shark (Lamna nasus), great functions and estimates of longevity. This abundant and siltation high. These white shark (Carcharodon carcharias) and presentation considers such demographic modified conditions are sub-optimal for spinetail devilray (Mobula japanica), were information in the context of the recent native species typical of lowland reaches, analysed to identify patterns of horizontal changes in the status of regional fisheries such as inanga (Galaxias maculatus) and and vertical movement behaviour in and their catches. The age structures smelt (Retropinna retropinna), and this neritic New Zealand waters and the reflect considerable variation in year class was reflected in the low abundance of south-west Pacific Ocean. At least three strength (YCS), which is the consequence these species throughout the impacted of the four species undergo extensive of inter-annual variability in recruitment. reach. Conversely, several undesirable oceanic migrations, but the four species Estimates of YCS were temporally introduced fish species including tench have varying levels of residence within correlated amongst regions, but the (Tinca tinca), catfish (Ameiurus nebulosus) neritic waters. Relationships between relative sizes of strong year classes and gambusia (Gambusia affinis) were horizontal and vertical behaviour are varied considerably amongst regions. relatively common, reflecting their greater discussed, and four quite different niches Such regional differences account for the tolerance of elevated water temperatures are identified. changes in regional catches. Therefore, and low dissolved oxygen. To investigate the spatial pattern in recruitment has the potential for mitigation of the physico- changed dramatically in recent years with chemical impacts on instream habitat, profound consequences for populations the effects of partially opening one of and local fisheries. Research can now be the tide gates was tested. Hydrological focussed on why this has occurred. effects were evident throughout the reach and improvements in dissolved oxygen and water temperatures were detected in some parts of the impacted reach.

88 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Marine Spatial Planning: eDNA Detection Development of a Sports Managing the Use of Parameters Fisheries Quality Index Marine Space through for Assessing Effects of Participation Agricultural Intensification

Greig Funnell // Department of Elise Furlan // The University of Rasmus Gabrielsson // Cawthron Conservation Canberra Institute

Carolyn Lundquist // Department of Dianne Gleeson, Richard Duncan // The Robin Holmes, John Hayes, Roger Young Conservation, NIWA University of Canberra // Cawthron Institute Chris Hardy // CSIRO Marine Spatial Planning (MSP) offers Agricultural intensification is increasingly a framework where you can maintain The utility of environmental DNA (eDNA) affecting stream ecosystems and marine biodiversity values while allowing for low-density species detection has recreational fishery values worldwide. sustainable use of marine resources. As been demonstrated in a number of Difficulty in managing cumulative a process it incorporates international studies and offers great potential for effects has resulted in a need to develop principles of ecosystem-based the control of invasive species or the science-based tools to better understand management, and increases integrated conservation of endangered species. To how multiple stressors affect recreational management of all sectors using [or determine the value of this relatively new fishery quality. This will allow concepts valuing] the marine environment. This technique as a management tool, detailed like “resource capacity” and ecosystem talk will give a brief overview of the studies are required to evaluate detection “tipping points” to be used as a vehicle Marine Spatial Planning process, and probabilities for various species under for managing cumulative effects of the application of MSP to a New Zealand a range of environmental conditions. contaminants. However fishery managers case study. We describe a web-based Controlled aquarium manipulation and regional councils first need tools geospatial tool called SeaSketch that experiments allow us to measure the that quantify the multivariate quality of the Department of Conservation is influence of variables contributing to New Zealand recreational trout fisheries developing to engage and facilitate changes in eDNA concentration and before researchers can investigate how involvement of stakeholders in MSP detection probabilities. We have selected in fact rivers and trout fishery quality is projects. The SeaSketch tool will allow several taxa that are listed as invasive affected by a gradient of agricultural land for active stakeholder participation in the in Australia and for whom low-density use/dairy stressors. We reviewed the marine spatial planning process, promote detection is likely to provide economic scientific and grey literature on fishery conflict resolution by resource [users], and/or environmental benefits. These taxa quality indices to summarise the current and ultimately result in ‘ownership’ will be used to parameterise a detection knowledge, and then used this to develop of the integrated outcomes delivered framework. I will present data from initial a New Zealand Fishery Quality Index in a mariner spatial plan. In addition, aquarium experiments on the Oriental (FQI) specifically for this purpose. Indices SeaSketch will enhance understanding of weatherlaoch, Misgurnus anguillicaudatus, of biotic integrity (IBIs) or fishery quality the marine environment and the marine that determine the relationship between (FQ) are used worldwide for assessing spatial planning process by the public, the number of individuals and eDNA ecological health or condition of fish through visualisation and quantitative production, the distribution of eDNA populations, by combining multiple reporting of marine information such as throughout the water column and eDNA variables into a single number that is habitat types, species distributions, and accumulation and degradation over time. more easily comprehended by end users. the location of various uses of the marine We aim to develop a framework for eDNA The proposed FQI offers a quantitative environment such as fishing, aquaculture, detection probabilities that will ultimately approach to assessing FQ. It defines shipping lanes, and sand extraction. provide clear information for natural fishery quality as the sum of one or more resource managers on the utility of eDNA salmonid species quality index scores, to address environmental questions. which in turn incorporate population measures of recruitment, maximum size, overall abundance, and abundance of individuals above the size of interest to recreational anglers. We intend to apply this index to fishery data collected from 50 sites around New Zealand over the next few years for identifying tipping points to agricultural intensification.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 89 SPEAKER ABSTRACTS

Reproduction & Larval Identifying Morpho- Looks DO Matter – Simple Ecology of the Toheroa functional Groups for Lake Visual Communication Paphies ventricosa in Geneva – a Key First Step Helps Sell your Science Southland, New Zealand to Model Phytoplankton Dynamic Succession

Kendall Gadomski // University of Nicole Gallina // The University of Bronwyn Gay // EOS Ecology Otago Waikato Retailers, service providers and people Miles Lamare, Henrik Moller // University Deniz Özkundakci, David Hamilton // The selling useless plastic junk spend on of Otago University of Waikato average 3–10% of their annual income Mike Beentjes // NIWA Orlane Anneville // INRA, UMR 042 ensuring their target market is aware CARRTEL of what they are up to. This spend The toheroa, Paphies ventricosa is predominantly on different forms (Bivalvia:Mesodesmatidae), has Predicting the stochastic pattern of the of visual communication (e.g., print experienced significant population phytoplankton community remains a adverts, packaging, websites etc.). declines over the past 40 years. To challenging task when modelling lake Yet within the world of science, we ecosystems due to their extremely identify possible causes of decline continue to undervalue the role good diverse behavior. Grouping phytoplankton visual communication has to play in and better manage the recovery of the into functional groups not only has project outputs. If you want others to populations, we studied the reproductive the advantage to better represent their cycle and larval development of southern ecological behavior and succession, engage with your work you need to toheroa. The reproductive cycle of the but moreover reduces the number plan for successful communication of assessing entities allowing a more toheroa was studied from February outcomes. Apportioning time and budget representative overview of the entire 2011 to December 2012 at Oreti Beach, for qualified graphic designers can be community. This study represents a first appropriate, however not all situations Southland, New Zealand. Monthly dynamic modelling approach of functional samples were obtained from a stable groups of the phytoplankton community warrant this form of investment. There toheroa bed and histological sections in deep, mesotrophic Lake Geneva are simple, but important, decisions of the gonad were analysed using light using the General Lake Model (GLM) – you can make to take advantage of the Framework for Aquatic Biogeochemical rare opportunities you have to influence microscopy. The sections were sexed Model (FABM). Lake Geneva plays an and classified into one of four stages and inform your colleagues, managers, important environmental role as it is the Ministers, funders and the general public. of gonadal development – early active; largest lake in central Europe in the peri- late active; ripe; and partially spawned Alpine region, representing an essential Topics covered include: the importance or spent. The proportion of clams per resource for drinking water supply. It is of knowing who you are really trying developmental stage present each hypothesized that climate change will to communicate with; what you want affect the phenology of the phytoplankton month was used to determine periods them to do with the information; how communities and promote an increase this knowledge lets you tailor your visual of spawning. During late 2011 and early in biomass. Furthermore, the emergence communications for maximum effect. 2012, samples of toheroa were collected of potentially toxic cyanobacteria is from the same stable bed and transported forecasted, with potential to contribute We will consider the appropriate use of back to Portobello Marine Laboratory to considerable deterioration of water typography, photography, infographics, quality. Our aim was to produce an (PML) in Dunedin. At PML the toheroa colour, iconography and other basic accurate predictive management tool for were tagged using Hallprint FPN 4 mm x design techniques, and how these Lake Geneva and to assess the ecological can be applied across any 2D medium 8 mm external shellfish tags and placed state of the lake under present as well into flowing seawater tanks containing as under future climatic conditions, with i.e., posters, reports, powerpoint sand from Oreti Beach. The kept clams focus on the phytoplankton community presentations, graphs, etc. The aim is to were conditioned with a mixed algal and its successional sequence. For this help you realise the potential and impact purpose, morpho-functional groups of culture. Adult toheroa were injected with of simple visual communication, and phytoplankton specific for Lake Geneva improve the efficacy of the media you a 2mM solution of 5- hydroxytryptamine were identified. Beforehand, a clustering currently use. Making your outputs as into the anterior adductor muscle to method was applied, based upon species induce spawning. Larvae were reared at having similar occurrence patterns. The visually accessible as possible is vital in PML and their development tracked using resulting groups were separated based todays uber-visual world...how your work light microscopy. Toheroa larvae settled on their functional ecological behavior looks DOES matter. but also on their morphology, as well as out of the water column around 21 days links to abiotic seasonal conditions. The as pediveliger larvae, and at 28 days, had groups were also compared to those yet to undergo metamorphosis. derived for similar lake ecosystems. Physiological parameters were defined for each of the groups, with morphological traits (e.g., surface area to volume ratio) being an important consideration in the selected parameter values. The simulations demonstrated the close relationship of successional sequences of functional groups with mixing and stratification in Lake Geneva, which were strongly seasonally driven. Morpho-functional groups appear to be an appropriate level of state variable representation in this type of modelling approach to enable valuable insights into emerging environmental drivers such as climate change.

90 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Biology & Behaviour for The management & pH to P Modelling – Behaviour conservation of freshwater & Swimming Ability fish and crustaceans of in Larval Black Bream Polynesian streams (Acanthopagrus butcheri)

Eleanor Gee // The University of Philippe Gerbeaux // Department Max Gibbs // NIWA Melbourne of Conservation, French Ichtyological Society Christopher Hickey, John Quinn // NIWA Stephen Swearer, Andrew Western // The University of Melbourne Philippe Keith, Gerard Marquet, Clara Lord pH is a parameter often overlooked // Museum National d’Histoire Naturelle, when monitoring lakes and rivers, yet it Coupled biophysical-hydrodynamic Paris could be the key to understanding why dispersal models are useful for testing Eric Vigneux // Onema and French cyanobacteria blooms proliferate in the hypotheses about the relative influence Ichtyological Society edge waters of a lake or as attached mats of environmental and behavioural factors in a stream bed. During the diurnal cycle, photosynthesis within the bloom or mat on the dispersal of fish eggs and larvae. Polynesia is made of 9 Pacific Island In light of recent drought and declines in removes the CO2 and carbonate from the countries and territories. The results of water column and the pH rises. At pH catches of black bream (Acanthopagrus several decades of freshwater fish and butcheri) in the Gippsland Lakes estuary values above 9.2, phosphorus (P) bound crustacean surveys in the regions have to mineral oxides of iron and manganese in southern Australia, questions were been recently compiled in our book raised about the role of dispersal in in the surficial sediments desorbs and is “Polynesian Fresh Fish and Crustaceans released as dissolved reactive P (DRP) year-class strength in black bream. of Polynesia: taxonomy, ecology, biology A dispersal modelling approach was into the water column where it can be and management”. This presentation will used by the cyanobacteria for growth. proposed, however existing information outline some of the key findings of our on the development of environmental High pH release of P may be sufficient to work in the region, with a particular focus sustain cyanobacterial growth allowing preferences and swimming abilities on conservation and management issues. in black bream larvae was insufficient the bloom or mats to persist for long to inform a dispersal model of early periods. In lakes, the phenomenon is life stages of black bream. This paper most likely to be seen in the afternoon therefore details a laboratory study because of the time lag for the pH to of developmental changes in critical rise as the CO2 is assimilated from the swimming speed, halocline response and water. In streams and rivers, the effect depth response of black bream larvae may be confined to the bottom of the mat using swimming flumes, salinity stratified in contact with the rocks and sediment. cylinders and pressure tanks. Larvae However, if large enough areas of the 35 days or older showed a barokinetic bed are covered, the pH of the whole response and could swim at speeds up water column may be affected. This to 26 cm/s. Larvae 13 days or younger presentation looks at examples of where had limited swimming abilities and were pH release of P may have occurred surface attracted. The depth response and investigates the implications for of young larvae was influenced by the the use of P-inactivation agents for the presence of a halocline. Our results show management of internal P cycling in that late stage larvae have the potential shallow lakes. It also examines the side to influence their dispersal, particularly in effects of high pH on the form of nitrogen a strongly-stratified estuary. Our results released from the sediments. suggest that including swimming ability and depth preference in a dispersal model of black bream could help predict dispersal paths. Our study demonstrates how laboratory studies can be used to develop biological and behavioural algorithms for larval dispersal models in the absence of existing information on the biology of a species.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 91 SPEAKER ABSTRACTS

Wind Forced Circulation in Towards Integrated Coastal Linking Otoliths of Fish Lake Rotorua Monitoring in the Waikato from Indigenous Middens Region to Modern Day Species: a Novel Approach Based on Otolith Morphology

Max Gibbs // NIWA Hilke Giles // Waikato Regional Bronwyn Gillanders // University Councill of Adelaide Jonathon Abell, David Hamilton // The University of Waikato Barrie Forrest, Chris Cornelisen // Christopher Izzo, Morgan Disspain, Cawthron Institute Matthew McMillan, Liangwen Xu // Wind forcing on the surface of a lake Vernon Pickett // Waikato Regional University of Adelaide can generate currents and circulation Council patterns in the water column that affect Fish ear bones (otoliths) from indigenous mixing and transport processes in the State of the environment (SOE) middens contain considerable lake. Transfer of wind energy to the lake monitoring and environmental environmental, ecological and cultural bed can suspend sediments releasing monitoring of consented activities can information. Midden otoliths can usually nutrients in the sediment pore water provide early warning of environmental be identified to a family level based on into the water column, thereby affecting problems, illustrate where environmental otolith shape, however species level the water quality of the lake. Sediment management has been effective and identification can be difficult if there are resuspension may negate the use of inform decision-making, regional planning multiple species within the family. Our sediment capping with phosphorus (P) and policy development. Under the RMA, aim was to identify the species of midden inactivation agents to reduce internal P regional councils are required to monitor otoliths using quantitative analyses of loads. Consequently, it is important to their region’s state of the environment. otolith shape. Shape of midden otoliths understand the hydrodynamics of the lake Regional councils can also require suggested that they were from the family and the depth to which wind-induced resource consent holders to carry out Sillaginidae (or whitings). Sagittal otoliths mixing currents can penetrate before environmental monitoring to provide of three species of whiting distributed implementing such a management information on the environmental effects in southern Australia were used as strategy. In this presentation we use of their activity. Our coastal marine area is baseline data of known species identity. Lake Rotorua as a case study to examine exposed to many pressures arising from a Otoliths (modern day and midden) were the circulation patterns produced by the variety of water and land-based activities. photographed and normalised elliptical different wind flows and the magnitude The effects of these pressures cannot Fourier descriptors of the outlines of of the lake currents relative to wind be managed in isolation and instead otolith shape determined. Canonical strength. The interpretations are based an integrative management approach analysis of principal coordinates was on Acoustic Doppler Current Profiler is required. To achieve integrative used to test the ability of otolith shape (ADCP) measurements and a computer environmental monitoring, Waikato to discriminate modern day species. simulation of the lake during the mixed Regional Council (WRC) is reviewing Midden otoliths were then assigned phase in winter. The results indicate and improving its approach to coastal species identifications by treating them that the circulation patterns in Lake monitoring by (1) developing a framework as unknowns. Fourier descriptors were Rotorua are strongly influenced by the for coastal monitoring that integrates SOE significantly different among the three lake bathymetry. North-easterly winds and consent monitoring; (2) improving modern day species and each species across the eastern side of the lake cause SOE monitoring by investing in new was correctly classified with a high clockwise circulation around the mid-lake technologies that will enable an increase degree of success. The majority of island (Mokoia Is) and a second counter- in spatial and temporal coverage of midden otoliths were assigned to a single clockwise gyre between Mokoia Is and monitoring information and facilitate species, although all three species were the western shore. A shift to a south- systematic prioritisation of issues; represented. This approach provides westerly wind causes these circulation and (3) improving the effectiveness of a cost-effective means of species patterns to reverse direction. Current environmental consent monitoring. This identification. By linking midden otoliths velocities vary with wind speed and were presentation will provide an overview to specific species will allow comparisons measured at up to 20 cm/s through the of the integrative coastal monitoring over long time scales to be made and the full 20 m depth of the water column approach WRC is currently developing, effects of changing environmental and during a storm event. including the conceptual approach of an anthropogenic factors to be determined. integrated SOE and consent monitoring framework, examples of numerical modelling applications (including the Waikato Marine Management Model) and plans for a coastal monitoring buoy in the Firth of Thames.

92 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

DNA Versus Microscopy – Challenges with Aquatic Response of Temperate can Molecular Techniques Weed Control: an Intertidal Benthic Replace Morphology for Operational Perspective Assemblages to Mangrove Cyanobacterial Analysis? Detrital Inputs

Gemma Gimenez Papiol // Marcus Girvan // Boffa Miskell Rebecca Gladstone-Gallagher Cawthron Institute Limited // The University of Waikato

Marcia Maier, Daniel Dietrich // University Managing aquatic weed control Carolyn Lundquist // NIWA, University of of Konstanz operations within large water bodies can Auckland Susie Wood, Xavier Pochon, be a logistical challenge where weed, Conrad Pilditch // The University of Jonathan Puddick // Cawthron Institute water and weather conditions dictate Waikato David Hamilton, Craig Cary // The when, where and how control can be University of Waikato carried out. Shrinking budgets, adverse Tropical mangroves have been shown public perception, onerous consent to deliver an important organic subsidy conditions and a lack of cost effective The intensity and regularity of toxic to coastal ecosystems through the control tools adds to the challenge of cyanobacterial blooms is escalating production, decay and export of leaf litter. effectively controlling hornwort and globally. There is a corresponding In New Zealand, mangrove (Avicennia lagarosiphon within New Zealand’s lakes. need for rapid, reliable and high- marina subsp. australasica) distribution For decades the herbicide diquat has throughput methods to identify these has shown recent increases in many been used to control aquatic weed in microorganisms and their toxins in estuaries and management plans New Zealand waterways with reasonable complex environmental samples. Recent have aimed to reduce this expansion success. However, weed and water advances in molecular technologies through tree removal. However, current conditions can reduce the effectiveness provide opportunities for the development knowledge of the services provided of diquat sometimes resulting in ‘hit- of innovative diagnostic tools. Our current by temperate mangroves to estuarine and-miss’ outcomes. Consequently, it research is focused on developing a ecosystem functioning is limited. We has been near impossible to eradicate Next-Generation Sequencing (NGS) examined the role of mangrove detritus these aquatic invaders. A new herbicide, method that will enable simultaneous in structuring benthic assemblages at Endothall, has had a positive impact in detection of multiple cyanobacterial two intertidal sites (sandy and muddy) more recent years, but is not always species. In this study contrived in the Whangamata Harbour. In late effective in larger water bodies. We communities were created using varying summer, we added mangrove leaf have found that a mixture of herbicide concentrations of DNA and PCR products detritus to surficial sediments (260 g application, and diver-based suction from 12 cultures to assess the limits DW m-2; equivalent to the measured dredging and hand weeding is effective, of detection of the methodology. The summer leaf fall) and followed changes however, due to high costs diver-based contrived communities were analysed in the macrofaunal community and methods are not always viable options for by NGS (IonTorrent platform), producing sediment properties for three months. large infestations. Grass carp have been >70,000 sequences per treatment. Additions drove subtle changes in the touted as an effective bio-control tool, but Analysis of the data demonstrated that relative abundances of a few dominant their environmental costs may outweigh this technique is semi-quantitative and taxa, rather than whole-scale shifts their benefits. It’s obvious in some water can detect species present in very low in assemblage composition. Muddy bodies that significant progress is being abundance. Additionally, during the and sandy communities responded made using traditional methods of aquatic summer of 2013 a survey of planktonic similarly with the same dominant taxa weed control, although in others this cyanobacteria from 150 lakes across (mainly polychaetes, e.g., Prionospio is less so. Under the current economic New Zealand was undertaken. Each aucklandica) changing at both sites. The climate the Crown has the mandate sample was analysed using a range of subtle responses to the relatively large of doing more with less. Collaborative molecular techniques. Samples were detrital addition suggest that temperate management initiatives aim to improve screened for genes involved in toxin mangrove detritus plays a minor role efficiencies and ensure transparency of production and results confirmed using in shaping intertidal soft-sediment aquatic weed control, however, at the chemical methods. Forty percent of the communities. Our data indicate this coal face currently available technology samples tested positive for toxins genes. may be due, in part, to relatively low is failing to effectively manage hornwort A DNA fingerprinting technique was production and slow decay rates of and lagarosiphon in all water bodies. used to explore cyanobacterial diversity temperate mangrove litter, making The aquatic weed control toolbox is among lakes and selected samples were benthic communities less reliant on well overdue for the development of analysed using NGS to obtain a snapshot this form of detritus than tropical innovative, cost effective tools! of cyanobacterial species present across counterparts. New Zealand.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 93 SPEAKER ABSTRACTS

Eradication of Invasive Linking an Otolith-based Porirua Harbour – Part 2: Species from the South Marine Biochronology with Clarity by Setting Sediment Island: are We there Yet? Environmental Parameters Limits to Explore Climate-related Changes in Coastal Upwelling Strength

Natasha Grainger // Department Gretchen Grammer // University Malcolm Green // NIWA of Conservation of Adelaide Leigh Stevens, Barry Robertson // David West, Alastair Fairweather // Christopher Izzo, Peter Hawthorne, Wriggle Coastal Management Department of Conservation Bronwyn Gillanders // University of Keith Calder // Porirua City Council Adelaide Megan Oliver, Juliet Milne // Greater In 2000, koi carp (Cyprinus carpio) and Wellington Regional Council gambusia (Gambusia affinis), were Multi-decadal growth chronologies based detected in the South Island of New on hard structures from long-lived aquatic Having decided on a target annual- Zealand for the first time. They were organisms (biochronologies) can be average sedimentation rate of 1 mm/ found associated with the Noxious used as a proxy to provide a long-term year to manage degradation of Porirua fish; rudd (Scardinius erythropthalmus) record of the seasonality of climate- Harbour (see the first of two talks on and Sports Fish tench (Tinca tinca) and growth relationships and the effects of managing Porirua Harbour), it remains to, perch (Perca fluviatilis) which were not environmental variability within a region. firstly, calculate catchment sediment load known from the Nelson/Marlborough The research presented here compares limits to achieve the target sedimentation region before this. A delimitation survey otolith chronologies based on patterns rate and, secondly, develop a suite of was undertaken before an eradication of fish growth between upwelled and mitigations to achieve the load limits. An programme commenced. non-upwelled regions along the coast obvious inclination is to uniformly reduce This programme has required of southern Australia. We constructed sediment runoff from the catchment in an intensive survey, eradication and growth-increment chronologies effort to uniformly reduce sedimentation monitoring by field staff as well as the using otoliths from the ocean perch rates throughout the estuary. However, development of tools such as rotenone, (Helicolenus percoides), a long-lived, this is bound to fail, since it will never be best practices and survey and monitoring deeper water, benthic fish found along cost-effective or even possible to reduce guidelines to support the programme the continental shelf of southern Australia sediment runoff uniformly over an entire and to ensure that these tools are and New Zealand. Sagittal otoliths were catchment and, in any case, it would effective in New Zealand conditions. extracted from the fish, thin sectioned, usually not be necessary to set a goal of Twelve years later, it is time to polished, and ages estimated. Growth uniform reduction in sedimentation to evaluate what has been achieved, what increments were further examined and achieve ecological and human-amenity remains to be done, as well as examining measured using high-resolution digital objectives. We present a method of the reasons for successes and failures at imagery in conjunction with image calculating sediment load limits that is various sites. analysis software. Annually resolved smarter than the obvious. The method chronologies were produced by assigning is based on manipulating the sediment the correct calendar year to each budget and takes advantage of the growth increment in the otolith through inherent complexity of the estuary and crossdating; this dendrochronological its connections to different sediment (tree-ring dating) method cross-matches source regions in the catchment. Results synchronous patterns of growth show explicitly that there is never just increment widths among multiple one way of achieving any given estuary samples at a given time and place. A sedimentation target or targets, which mixed-model approach was also used to management can exploit to its advantage. compliment the crossdating. The resultant We will describe how this is presently master chronology was correlated with playing out in Porirua Harbour, where various environmental climate indices targets, load limits and mitigation to examine climate-growth relationships strategies are being juggled to find an in relation to upwelling strength along optimum way of managing the catchment southern Australia as well as the effects to deliver objectives in the harbour. of climate variability on fish growth.

94 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Marine Spaces: Unravelling the Mystery of Influences of Hydrological Thought for Food Hutt River Cyanobacterial Regime on Traits & Blooms: Nutrient Inputs & Availability of Adult Aquatic Management Insects to Terrestrial Consumers

Bridget Green // University of Summer Greenfield // Greater Michelle Greenwood // NIWA Tasmania Wellington Regional Council Doug Booker // NIWA Reg Watson, Robert Parker, Caleb Gardner, Mark Heath // Victoria University of Colin Buxton, Klaas Hartmann, Sean Wellington Adult aquatic insects emerging from Tracey, Sarah Jennings // University of waterways provide an important food Tasmania Susie Wood // Cawthron Institute resource for many terrestrial consumers. Ray Hilborn // University of Washington Understanding how river flow and Tony Smith, Beth Fulton // CSIRO The Hutt River is one of the most catchment land-use affect the identity, Nathan Pelletier // JRC Institute for popular rivers for recreational use in New supply and availability of these potential prey to terrestrial consumers is an Environmentand Sustainability, Italy Zealand. However, in recent years risks important step in understanding when Brett Molony // Western Australian Fisheries to recreational users from blooms of the anthropogenic alterations to rivers may Jake Kritzer // Environmental Defense benthic cyanobacterium Phormidium autumnale have become increasingly have impacts on terrestrial communities. Adrian Kitchingman // Department of prevalent. Since 2005, 11 dog deaths Changes to aquatic larval communities Environment & Sustainability, Victoria have been reported following contact alter the taxonomic identity and thus with cyanobacteria in the Hutt River. abundance, frequency and timing of Concurrent with the goal to achieve 10% During the summer months, signs along adult aquatic insect emergence into global marine protected area coverage of the river bank warning people not to the terrestrial environment. As adults all marine and coastal ecological regions walk dogs near or swim in the river have of different aquatic taxa vary in their by 2020 are goals to maintain fisheries become a common occurrence. Over dispersal ability and flight height, the production as a vital part of global food the last five years Greater Wellington ability of terrestrial consumer taxa to security. Motivation to create MPAs is Regional Council in partnership with benefit from the aquatic food resource partly based on the expectation that they Victoria University, the Cawthron Institute may also vary. We used a large national are the best solution to conserve the and, more recently, Upper Hutt City dataset that incorporated multiple visits marine environment while protecting and Council, have undertaken research to per site to investigate whether river even expanding fish stocks. Some present flow regime and catchment land-use MPA networks are enormous in scale and understand the environmental drivers of benthic cyanobacterial blooms. Recently are likely to affect the supply of adult multinational in nature, indicating wide aquatic insects to terrestrial consumers. belief that there will be significant future it has been suggested that nutrients, in Specifically we hypothesised that the benefits. Notwithstanding this, a billion particular the relative concentrations of abundance of larval aquatic insects people depend on fisheries for protein, and nitrogen and phosphorus, may be a key and their taxonomic identity (and thus concerns over food security continue to factor driving the occurrence of benthic mount, with global population projections cyanobacteria blooms in the Hutt River dispersal behaviour as an adult) would of 9 billion by 2050. Closing marine spaces and other New Zealand rivers. Work be affected by hydrological regime and need a wide base of national and local undertaken to quantify nutrient sources by the intensity of catchment land-use. support, and areas are often selected to within the Hutt River catchment, which For example, aquatic insect communities minimise current conflicts including those include both rural and urban inputs in flood-prone streams were predicted with fishing operations. Fishing fleets are, via both surface water and shallow to have a higher proportion of taxa with however, expanding their fishing ranges groundwater, will be presented. We will smaller adult sizes, multiple generations and target species. Areas currently unfished also briefly discuss the implications for per year and relatively poor flight abilities, could be tomorrow’s fishing grounds, future management of cyanobacterial thus providing terrestrial consumers with contributing to the sustainable supply blooms – both for the Hutt River and an abundant supply of small prey items of marine protein. We examine potential other rivers in New Zealand. close to the river. We provide evidence conflict in the use of marine spaces by that the larval supply, adult size and looking at overlaps between MPAs and ‘catchability’ of adult aquatic insects fisheries production. We look at the current are affected by hydrological regime and and future potential impacts on marine catchment land-use, thus likely affecting food security by examining mapped global their suitability as a prey resource to catches associated with MPAs with varying terrestrial consumers. IUCN categories. Following this global analysis we examine in detail a range of MPA’s representing different sizes and conservation goals. This study explores whether the creation of MPA’s compromise or complement future food security.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 95 SPEAKER ABSTRACTS

Management Strategy Recovery Trajectories After Management & Evaluation of Alternative Mangrove Removal Using Implications of Fishing CPUE Based Harvest in Situ Mulching Down the Slopes & Control Rules for Abalone Seamounts within the Tonga EEZ

Malcolm Haddon, Sarah Hailes // NIWA Tuikolongahau Halafihi // Fay Helidoniotis // CSIRO University of Canterbury, Tonga Carolyn Lundquist // NIWA Fisheries Division A Management Strategy Evaluation (MSE) framework has been produced that can Mangrove removals (both legal and Dr Sharyn Goldstien, Dr Alex James // simulate an abalone fishery zone made up illegal) have occurred in northern New University of Canterbury of an array of statistical reporting blocks Zealand in recent decades, in response Dr Ashley Williams // Secretariat of the each containing an array of essentially to high rates of mangrove expansion in Pacific Community independent populations. This cannot tidal creeks and estuaries. However, there is limited information on the effects of be fitted to a natural fishery because, The Tonga deepwater drop-line fishery removal and the pathways and pace of given the spatial heterogeneity of abalone is important for the economy and food recovery. In Tauranga Harbour, large scale populations, the data requirements would security of the country, as happens in mechanical removal commenced in 2010 be prohibitive. Rather, the simulated zone other Pacific countries; however, the (total ~110 ha), providing an opportunity is conditioned to have properties similar to inconsistency in data collection, along to examine recovery trajectories a given area of coastline and to produce with lack of information available on concurrently at multiple sites subject to fisheries data that is similar to the real biology and ecology of deepwater fish in the same removal methodology. Here, thing. The assumption is made that the Tonga, has affected assessments of the we quantify the recovery trajectory of management of such a fishery involves fishery. The fishery started in the 1980s, benthic macrofaunal communities after a zone wide TAC and a zone wide legal at slopes and seamounts within the “mulching” (mechanical mangrove minimum length (LML). We have used this Tonga EEZ. The primary target species removal with in situ deposition). MSE simulation framework to compare are deepwater snapper (Etelis spp and We sampled benthic macrofaunal two alternative CPUE based harvest control Pristipomoides spp) which are widely communities at three sites in each of rules (HCRs), one of which has a small distributed across the Pacific Ocean. two estuaries (Waikaraka and Te Puna; variant. One of these compares the current A Maximum Sustainable Yield of 350 Tauranga Harbour) prior to mangrove catch rates against a predetermined target mt/year, from previous assessments, removal, and at 3, 6 and 12 months post- catch rate, modifying the present total has been used to manage the fishery removal. Waikaraka was also sampled at allowable catch (TAC) so as to manage since1992. Unfortunately, subsequent 24 months post-removal. Macrofaunal the fishery towards the target. The second landings never reached that point, cores were collected from mulched and alternative, and its variant, uses the and there is evidence of poor catch adjacent sandflat and mangrove areas. gradient of the proportional changes in rates and smaller fish sizes observed After 12–24 months post-mangrove CPUE over the last X number of years and in certain areas; highlighting the need mulching, some colonisation by for stratified data and an updated catch adjusts the TAC with respect to whether macrofauna had occurred in the removal limit. Here we characterized the Tonga the gradient is positive or negative. The zone; however, the resulting communities deepwater drop-line fishery, revealing variant is identical except that on the were dominated by opportunistic and that annual landings, catch rates and inception of the HCR the TAC is markedly disturbance-tolerant taxa including fishing efforts all increased considerably reduced, for example by 25%, and then Oligochaeta, Capitellidae polychaetes, within a few years of opening the the standard HCR is applied in future years. and Diptera (fly) larvae, and were not fishery, but have been in decline since There are many alternative states of initial representative of typical sandflat or 1988. Subsequently, catch rates and depletion, alternative LML, and alternative mangrove communities. While univariate the mean lengths for most species have initial catch levels (irrespective of state of measures such as species richness and fluctuated, but overall have declined in depletion), and natural variation is expected number of individuals did show increases recent years. To improve management in recruitment, and in the process of over time, multivariate comparisons of the Tonga deepwater drop-line fishery recruitment (such that not all populations suggest that the mangrove removal and seamount communities, we are are equally successful each year), there is zones did not show expected trends in collecting disaggregated data by location, variation in catch rates between statistical recovery. We hypothesise that the lack of and by depth. In addition, we aim to blocks, and variation in how the divers short-term recovery trends in macrofaunal better understand the biology and spatial distribute the TAC among the various communities was due to the lack of ecology of the deepwater fish species blocks. The analyses we present illustrate dispersal and the slow decomposition such as Etelis coruscans. Lesson learned the trade-offs that exist between the TAC rate of the mulchate and root material. from the Tonga drop-line fishery is and LML that can be applied to abalone applicable to drop-line fisheries in other populations but also how the outcomes Pacific countries. depend upon the initial state of depletion. While these analyses cannot be used to set policy they certainly illustrate the options available to the managers and the policy makers.

96 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Population Structure of Recruitment of Snapper in Exploring the Ecological & Freshwater Mussels in the Port Phillip Bay, Australia: Social Interface: Effective Raglan Catchment Patterns & Processes Engagement of the Native Fish Strategy

Mark Hamer // Waikato Regional Paul Hamer // Department of Fern Hames // Arthur Rylah Councill Environment and Primary Industries, Institute, Department of Environment Fisheries Victoria and Primary Industries Kevin Collier // Waikato Regional Council, The University of Waikato Kerry Black, Greg Jenkins, Hannah The Native Fish Strategy (NFS) aimed Jen Iles // Waikato Regional Council Murphy, Steve Swearer // University of to restore native fish populations in the Melbourne Murray-Darling Basin (MDB) back to Freshwater mussels are in decline 60% of their pre-European settlement throughout New Zealand. Factors causing Snapper, Pagrus auratus are the most levels. To achieve this, the NFS worked this decline include predation, water valued recreational and commercial with multiple stakeholders to transfer its quality changes, erosion, declines in inshore fish species of south-eastern research outcomes into local plans and dispersal vectors (e.g., changes to fish Australia. In Port Phillip Bay, they are of onground actions, and build long term passage) and potentially water takes. We iconic status. Each year, in late spring, advocacy to support native fish recovery designed a survey to estimate population spawning migrations enter the bay from across the Basin. A key distinguishing density and size structure of Echyridella coastal waters and so starts another feature of the Native Fish Strategy was menziesii and Cucumerunio websteri at frenzy of fishing activity. Historically catch genuine, targeted partnerships and 17 stream and river sites in the Raglan rates have varied considerably and our effective, planned engagement. State- catchment, northern New Zealand. We research has been aimed at predicting based Native Fish Strategy Coordinators undertook visual surveys consisting of and explaining this variation and the worked with a Community Stakeholder an initial 30 minute visual search of likely links between the environment and Taskforce to plan Murray-Darling habitats with underwater viewers to production of the fishery. Over the past Basin-wide programs, adapting and establish presence. If mussels were found decade, through the application of otolith implementing activities to their own a 50 m reach was intensively searched chemistry and sampling of the early life- local contexts. Building partnerships over all habitats present. Mussels were stages, we’ve come to fully appreciate the was a constant and active priority, with counted and the first 50 individuals of importance of the spawning aggregations multiple and diverse methods used each species were measured. When in the Bay for broad-scale fishery to engage stakeholders. Engagement mussels were seen a tactile search replenishment. This has underpinned the delivered key messages to a range of through the substrate was undertaken ongoing monitoring of 0-age recruitment targeted audiences, across a range of to find any buried individuals present in in the bay as a leading indicator of fishery scales, and in a range of contexts. This that area. We also recorded the presence replenishment. Over twenty years of approach was highly effective in building of dead mussels and bank middens pre-recruit survey data is now available, support, ownership, empowerment indicating predation by introduced along with age composition and catch and long term advocacy with the local mammals. If less than 50 mussels were rate data to clearly show the link between community and relevant stakeholders. found a further 30 minute search of likely spawning success in the bay and This approach also highlighted the need habitat was undertaken to try and locate variation in fishery production. Our focus for staff with a particular set of personal 50 individuals for size measurement. is now on understanding the processes attributes or values (such as trust, E. menziesii was found at 88% of sites that influence spawning success. We patience and persistence), as well as and C. websteri at 59%. Mussel density have demonstrated a close relationship professional skills and behaviours (such ranged from 0.005 per m2 to 2.5 per m2. between the abundance of larval and as reliability, consistency and credibility). Relative abundances of small mussels (E. 0-age life stages across 7 cohorts. For the future, we recommend increased menziesii <40 mm, C. websteri <50 mm) Understanding survival during the first effort in monitoring and evaluating the were highest in the Waingaro catchment few weeks of life in the bay is clearly social elements of riparian rehabilitation for both species. Population size the key to understanding interannual programs, and a more integrated structure followed a normal distribution recruitment variation. This presentation approach to exploring interconnected for E. menziesii but was skewed for C. summarises our previous research and socio-ecological systems. websteri suggesting an aging population. monitoring of snapper recruitment in Port The implications of these findings for Phillip Bay, more recent research on larval freshwater mussel conservation will be feeding ecology and progress towards discussed. modelling of larval food dynamics in the bay.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 97 SPEAKER ABSTRACTS

Limits to Relying on Effects of Climate Change Population Structure Phosphorus to Control on New Zealand Lakes & Connectivity in New Periphyton Growth: Stuff Zealand Coastal Marine Happens at the Interface Organisms: Contrasting with Algae Patterns in Two Surf-clam Species

Keith Hamill / River Lake Ltd David Hamilton // The University Danielle Hannan // Victoria of Waikato University of Wellington This paper looks at the ability to use nutrient limitation to control periphyton Chris McBride, Deniz Özkundakci, Chris Peter Ritchie, Jonathan Gardner, growth in the Manawatu River. It Hendy, Wei Ye // The University of James Bell // Victoria University of discusses why removing dissolved Waikato Wellington phosphorus from Palmerston North City Marc Schallenberg // University of Otago Waste Water (PNCC WWTP) has had Mary de Winton // NIWA Understanding how patterns of migration only limited successes in reducing the Dave Kelly // Cawthron Insititute connect populations of marine organisms rate of downstream periphyton growth. and ultimately determine their population Particulate phosphorus was found to structure is important for sustainable be readily available to periphyton under The potential impacts of climate change on NZ lakes are examined together with a fisheries management, establishment conditions of diurnally high pH in the of marine protected areas and for river water and within the periphyton consideration of how these effects may be mitigated. We briefly outline the origin and biosecurity purposes. Pipi (Paphies mat. Periphyton was found to trap river australis) and tuatua (P. subtriangulata) sediments within its mat and derive nature of NZ lakes, consider the historical climate, and examine the potential impact of are common and widespread bivalves phosphorus from these sediments by found in harbours and on beaches diurnal increases in pH (measured up to a future climate, up to 2100. In providing a context with which to evaluate the impacts around New Zealand. They form popular 9.6 at the periphyton surface). Increases recreational and customary catches, with in pH more readily released phosphorus of climate change in NZ lakes we draw comparisons with the massive landscape much potential for expanded commercial from sediment trapped by periphyton catches. Yet little is known about stock downstream of the Palmerston North changes that have occurred in the past 150 years as a result of human settlement and structure of these species or how wastewater treatment plant compared populations might be connected – my to upstream. The downstream sediment widespread conversion of forests, wetlands and lakes to agricultural land, or use of research addresses these questions quality was consistent with the settling using highly variable microsatellite DNA of alum flocculants. The Manawatu River freshwater for other economic benefits such as hydro power. There is little evidence markers. Pipi populations were found to upstream of PNCC WWTP discharge have high levels of differentiation and exhibits flow related dynamics in the of any long-term changes in lake water temperature but ENSO events can have gene flow was low among some parts nutrient concentrations and potential of the country. In contrast, most tuatua nutrient limitation of periphyton growth. major impacts on mixing regimes of deep lakes. The effect of climate change on NZ populations showed less differentiation During the early stages of a flow and gene flow was higher. These recession phosphorus is potentially lakes is likely to be a synergistic one, with major existing pressures from alien species, results highlight the different ways limiting periphyton growth but as flow that populations of marine species can further reduces nitrogen concentrations water extraction and eutrophication, acting in tandem with additional pressures be structured, even when comparing drop and become potentially limiting. closely related species. Furthermore, by After an extended period of low flow from forecasted increases in irrigation and water impoundment as well as new teasing apart the physical processes that dissolved phosphorus concentrations are responsible for producing observed in the river increased and periphyton alien species introductions, to negatively impact upon lake ecological integrity patterns of population structure, it is bioassays confirmed that nitrogen was easier to understand how the physical the primary limiting nutrient. The results and biodiversity. Actions to improve land management will be necessary to reduce complexity of the New Zealand coastal of this work has direct implications for marine environment might influence the choice of treatment process used to nutrient and sediment loads to lakes and provide greater resilience to storm events, population structure and dispersal remove phosphorus from wastewater pathways for marine species. effluent, and wider implications for river whilst also increasing surveillance, control managers wishing to control periphyton and eradication efforts for noxious alien growth by focusing on phosphorus freshwater invaders. limitation.

98 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Interactions Between The Development of a Reproductive Biology & Microphytobenthos & Maximum Count Aerial- Early Life History Traits Macrofauna Regulate access Survey Method to of the Eastern Blue Spot Intertidal Sediment Stability Estimate Harvests from Goby, Pseudogobius sp Large Scale Boat-based Fisheries

Rachel Harris // The University of Bruce Hartill // NIWA Kathryn Hassell // University of Waikato Melbourne Helena Armiger, Nicola Rush, Conrad Pilditch // The University of Richard Bian // NIWA Evan Hallein, Jessica French, Waikato Vincent Pettigrove, Stephen Swearer // Simon Thrush // NIWA, University of Marine recreational harvests from New University of Melbourne Auckland Zealand’s fish stocks are often taken Judi Hewitt, Andrew Lohrer, along coastlines in excess of 1000 km. The Eastern blue spot goby, Pseudogobius Samantha Parkes, Barry Greenfield, Observing and estimating levels of sp. is a small benthic species native to Michael Townsend // NIWA fishing effort and harvesting at this scale south-eastern Australia. Here we describe is therefore problematic, as catches differences in size and condition of are usually landed at a large number Biological activities within sediments juvenile and adult gobies collected from of access points over highly varying Victorian estuaries within Port Phillip affects its stability. But the interactions degrees of intensity. In these situations between sediment stabilising Bay, Westernport and the St George aerial survey methods are often used to river, Lorne. The selected estuaries microphytobenthos (MPB) and scale up interview data collected at a destabilising bioturbating macrofauna differ in levels of anthropogenic impact subsample of access points, to estimate and surrounding land use. Gobies has rarely been tested experimentally the harvest landed at all locations on in situ from multiple estuaries have been . In a large-scale field study we that day. Although the use of planes 2) plots on an acclimatised in the laboratory and manipulated 56 (1 m considerably increases the spatial scope exposed intertidal sandflat limiting suitable conditions to stimulate spawning of on-site survey techniques, the cost MPB activity using shade cloth and have been achieved. Blue spot gobies of operating these aircraft and the need creating a gradient (0-200 ind. m-2) are pair breeding, multiple spawners to cancel flights because of low cloud in the bioturbation/grazing pressure that produce large egg clutches (>200 on some days is problematic. We have exerted by the deposit-feeding bivalve eggs) at intervals of one to two weeks developed a novel form of maximum Macomona lilliana. Three months after under optimal conditions. Embryonic count aerial-access methods to minimise the manipulation, sediment stability development occurs over 5-7 days aircraft operating costs and ensure (erosion threshold and rate) in the plots (22–25oC) and larvae hatch at a body that estimates of total fishing effort was measured using a core-based device length of 2-3 mm. Upon hatching, blue are still available for those days when (EROMES) and the sediment properties spot goby larvae have well developed flights are cancelled. This approach and macrofaunal community composition eyes, some pigmentation, a single oil has been applied to survey several of ascertained. Although shading did not globule and a small yolk-sac that is New Zealand’s large scale recreational impact MPB biomass, differences in exhausted within 24-48 hr. By day 28 fisheries, most recently in 2011–12, macrofaunal abundance were detected post hatch, fin rays are well formed, between North Cape and the eastern Bay between shaded and non-shaded areas. metamorphosis is completed and body of Plenty. A comparison of the estimates Distance-based linear regression models length is 5-6 mm (average growth rate provided by this survey, with those indicated 23–35 % of the variation in ~0.1 mm/day). Gonad development has provided by two other independent and erosion data could be explained by a been observed as young as two months concurrent surveys suggests that these combination of sediment grain size old in lab-reared fish, and mature gonads estimates are reliably accurate and fit for (10–20%, p ≤ 0.03), MPB indicators have been observed in wild caught fish management purposes. (ratios of diatoms:cyanobacteria ≤ 8%, as small as 25 mm TL. The Eastern blue p = 0.05 and chlorophyll a:phaeophytin spot goby is widely distributed and ≤ 8%, p = 0.04) and macrofauna abundant throughout it’s range, and may (abundance 19%, p = 0.002 and richness represent a valuable model species for 11%, p = 0.02). As expected MPB biomonitoring studies and ecological indicators were positively correlated with research. sediment stability whereas a decrease in sediment stability was correlated with increased macrofaunal abundance. Our results demonstrate that even for sandy sediments exposed to frequent reworking by tidal currents and wind-generated waves, biological interactions significantly impact sediment stability.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 99 SPEAKER ABSTRACTS

Trout Bioenergetic Drift Food Preferences for newly Are Low Water Column Foraging Models for caught Common Clownfish Dissolved Reactive Interpreting Habitat (Amphiprion ocellaris) In Phosphorous Concentrations Suitability for Instream Captive Condition Essential for Benthic Flow needs Assessment Phormidium Blooms & Toxin Production?

John Hayes // Cawthron Institute Zulkifli Hamzah // University Mark Heath // Victoria University of Technology MARA, Perlis, Malaysia Wellington Nina von Westernhagen // Hawke’s Bay Regional Council Assoc. Prof Norsila Daim, Nawwar Zawani Susie Wood, Roger Young // Cawthron Kit Rutherford // NIWA Mamat, Assoc Prof Abol Munafi Ambok Institute Olivier Ausseil // Aquanet Consulting Ltd Bolong // University Technology MARA Ken Ryan // Victoia University (UiTM) Perlis, Malaysia Hydraulic-habitat based models (e.g. Benthic mat forming cyanobacteria of the RHYHABSIM) are the main means In ornamental fish trade industry genus Phormidium are abundant in many by which instream flow requirements around the world, most of the supply New Zealand rivers. When conditions for fish, and other aquatic life, are of ornamental fish was originated from are optimal Phormidium can proliferate, assessed in New Zealand and elsewhere. the wild. This may lead to depleted of forming extensive mats across large Predictions are most sensitive to the ornamental fish in the coral reef area. expanses of river substrate. Phormidium habitat suitability curves (HSC), the Many parties and fellow researcher can produce a range of neurotoxic biological component of the models. is developing method to cultivate compounds known as anatoxins. These HSC’s are usually empirically derived from ornamental fish in captive condition. To are of considerable concern when rivers frequency of occurrence, or density, data. start captivating ornamental fish, fellow are used as drinking water supplies or Because they are costly, river specific breeders need fresh ornamental fish for recreational activities. The relative empirical HSCs are rarely used when originated from the wild. Wild fish never contribution of nitrogen (N) and applying hydraulic-habitat models; instead ate pallet before and breeders must phosphorous (P) in regulating Phormidium existing empirical HSCs are transferred prepare feed, and this study objective is biomass and anatoxin production in lotic between rivers. A short coming is that to observe and identify their preferences systems are not well understood. In this some studies have found that habitat towards the feed. Four different of feed study the roles of N and P in growth and selection by fish can vary between rivers, were given for 20 days to 20 pairs of wild- anatoxin production were investigated season, and flow – putting into doubt caught common clownfish Amphiprion using batch cultures and in-situ nutrient the transferability of empirical HSCs and ocellaris. The feed were given and their substrate plate experiments. Five different predictions of hydraulic-habitat models. reaction and eating action were observed nutrient treatments were investigated A response to this problem is to develop and recorded. From initial observation, in the culture experiments. Phormidium general HSCs, from data sets gathered fish do have a different preference biomass was reduced significantly across of range of rivers, varying in size towards different feed. From data under low N treatments (p<0.001) and and form, hopefully without bias. I will collection, fish show different appetite to a lesser extent P (p<0.05). Anatoxin present generalised HSCs for adult drift towards different feed, the texture of concentrations were significantly higher feeding rainbow trout based on data from the feed might have affecting the fish in P limited treatments (p<0.05) and three New Zealand rivers. At the core of preferences. Preferred feed have higher peaked in the early growth phase in all the problem of transferability of HSCs amount of intake by the fish, and less treatment. Nutrient substrate plates were though is an inadequate understanding of preferred feed were often less eaten. At deployed in the Hutt River (Wellington). the functional basis for habitat selection. the end of the experiment, fish who eat The greatest biomass was observed Bioenegetics drift foraging models more appear healthy than the fish that on the N and P, and P treatments. provide such functional understanding ate less. Conclusion, the fish preference This result reflected the nutrient water and can be used to construct depth and towards different feed was important to testing, which suggested the system velocity HSCs. They allow HSC to be maintain good fish condition. This study is P-limited. Collectively these data predicted as a function of fish size, water will hopefully be able to help fellow suggests that Phormidium is adapted to temperature, food supply (drift density breeders to give proper type of feed thrive in low phosphorus environments and size) and water clarity. I will show towards newly caught fish. If ornamental where other algal species struggle how the habitat suitability predictions of a fish were successfully captivated, to compete. Reasons for this require rainbow trout drift foraging model can be hopefully in the near future, this will further investigations but could include: used to interpret empirical HSCs and to help reduce the environmental stress luxury uptake of P, access to alternative substitute for them. especially in the coral reef area. P sources or from bacterial processes in the mat that increase the biological availability of phosphorus.

100 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Designing a National Panel The National Panel Survey Management Strategy Survey – Avoiding Historic 2011–12 – it’s Mostly Evaluation of the Failures & Integrating Snapper Robustness of Alternative Technology Management Responses for Abalone

Andy Heinemann // National Andy Heinemann // National Fay Helidoniotis, Research Bureau Ltd Research Bureau Limited Malcolm Haddon // CSIRO

Jeremy Wynn-Jones // National Research Jeremy Wynn-Jones // National Research A Management Strategy Evaluation (MSE) Bureau Ltd Bureau Limited framework has been produced that can Alistair Gray // Statistical Research Alistair Gray // Statistical Research simulate an abalone fishery zone made up Associates Associates of an array of statistical reporting blocks each containing an array of essentially The national panel survey aimed The national panel survey has delivered independent populations. This cannot to measure the marine harvest by harvest estimates for a range of be fitted to a natural fishery because, recreational fishers over the period stocks across New Zealand. Note that given the spatial heterogeneity of abalone October 2011 to September 2012. The concurrent sampling of fish weights populations, the data requirements would methodology for achieving this entailed was required to convert the numbers be prohibitive. Rather, the simulated a two-phase population survey. The collected in this survey to weights. At zone is conditioned to have properties first phase drew a nationwide random a national scale just over half the total similar to a given area of coastline and probability sample of approximately number of fish harvested were snapper. to produce fisheries data that is similar 30,000 dwellings and physically visited The survey outputs include: estimates to the real thing. The assumption is each of these to screen the adult of harvest (numbers and weight) at a made that the management of such a residents for participation in marine QMA level for all stocks sampled, profiles fishery involves a zone wide TAC and a fishing. From this step, a reporting of participation in fishing by standard zone wide legal minimum length (LML). sample of fishers and non-fishers was demographic parameters, profiles of fish We have used this MSE simulation enrolled for the purpose of monitoring harvest by fishing method, estimates framework, with a harvest control rule their marine fishing over one year. The of proportions harvested by all fishing that attempts to achieve a target CPUE, monitoring system utilised systematic methods, fishing immigration and to compare how an abalone fishery might periodic texting and phone contact emigration between regions and various respond if managed with alternative over the year to determine whether the other profiles of fishing activity. A range strategies ranging from risk averse to sample marine fished or not, followed of outputs will be presented from fish risk prone. This has been implemented by a computer assisted phone interview stocks around the country. through simulating a fishery zone similar to those who marine fished, in order to Tasmania’s east coast abalone zone, to gather detail of their fishing activity first fishing it to different depletion levels for the period. The contact pattern was and then managing that simulated fishery designed to account for all 52 weeks with alternative combinations of total of the year for each monitored survey allowable catch (TAC) and legal minimum respondent. length (LML). Some of the questions addressed include whether apparently risky strategies, such as a relatively high TAC, could be mitigated by other management actions such as increasing the LML, or, visa-versa, can the apparent risks of a small LML be mitigated by a lower TAC? Using an MSE to test alternative strategies, which intuitively appear sensible, can help identify unintended consequences relating to other aspects of the fishery such as CPUE or the size distribution of the catch

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 101 SPEAKER ABSTRACTS

Warming Climate, Cooling Local Factors Drive Overview of Marine & Lake: the Changing Macrobenthic Species Estuarine Habitat Mapping Thermal Regime in Lake Richness in Intertidal Areas Approaches & Spatial Namunamu over 25 Years Across Scales Modelling

Ian Henderson // Massey Judi Hewitt // NIWA Judi Hewitt // NIWA University Silvia de Juan // NIWA Andrew Lohrer // NIWA Namunamu is a small deep lake in central North Island hill country that is currently We analysed diversity patterns at Mapping the biodiversity and ecology of exhibiting extreme behaviour in several six intertidal habitat types in eight benthic soft-sediments in shallow coastal respects. It remains thermally stratified locations in the New Zealand Auckland areas poses a number of challenges. for most of the year, mixing in winter region (North Island). Analysis aimed Large intertidal areas require use of for as little as two weeks. Anoxia below at investigating the relative effects of different sampling strategies to those of the thermocline is present whenever regional species pools, habitat types and deeper subtidal areas (>5 m at low tide), the lake is stratified and a dense layer local environmental factors on species but sampling both of these is easier than of anoxygenic photosynthetic bacteria richness. The potential for effects to sampling the intermediate depths. The develops annually. Recent measurements be scale dependent was explored by type of sampling utilised also depends indicate that densities of green-sulphur comparing the results for species richness on the study rationale, whether it be, bacteria are higher than any ever at α (local average species richness) (total for example, predicting distributions recorded in a non-saline holomictic lake. species richness within a location) and of particular species, baseline surveys The lake also recently experienced an (within-location heterogeneity) scales. of habitat type or mapping ecological event of total anoxia throughout the water Results showed that differences in the integrity. Here we discuss a number of column. Despite this, the surface waters effect of habitat types on, and diversities problems arising from trying to map/ usually support a diverse zooplankton were not consistent across locations, but model in such areas, the types of community and a stocked rainbow trout habitats with structuring fauna (cockles, strategies used and how to integrate fishery. Data collected from the lake in tubeworms and seagrass) were more results from different sampling strategies, the mid 1980’s shows that the severity likely to have higher average numbers especially when resolution differs. of stratification and anoxia has increased of species (α diversity) than mud and over this period but, surprisingly, the lake sand habitats. Cockle and tubeworm is now cooler overall. The potential roles mat habitats were also more likely to of climate warming and afforestation have higher total numbers of species of the once pastoral catchment in this (diversity). Increasing the spatial scale change will be explored. at which diversity was measured (α to γ) did not result in local factors becoming less important; patch size and habitat fragmentation were important at α and γ scales. Patch size generally had a positive effect on species richness, and number of patches and habitat fragmentation indices generally had negative effects. The decrease of species richness across scales linked with habitat fragmentation underline the importance of minimising habitat loss and fragmentation for the conservation of marine soft sediments.

102 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Defining the Risk of Degraded Inanga Spawning Temperature & Mass Cumulative Impacts to Habitat: Mending a Fishy Dependence of N & P Marine Biodiversity Achilles Heel Excretion by Common Carp: Implications for Lake Nutrient Regimes

Judi Hewitt // NIWA Mike Hickford // University of Brendan Hicks // The University of Canterbury Waikato Simon Thrush, Graeme Ingliss // NIWA Melissa Foley // Stanford University David Schiel // University of Canterbury Dai Morgan // The University of Waikato

Scientists, resource managers and Inanga, Galaxias maculatus, are the We used a metabolic theory of ecology planners are all aware of the potential basis of the modern whitebait fishery. (MTE) to explore scaling of metabolic for cumulative effects to occur as Throughout most of New Zealand, >95% rates by body size and temperature, evidenced by reference to them in of the whitebait caught are inanga. and to predict nutrient excretion by many important environmental policy Despite massive habitat loss through common carp (Cyprinus carpio). At high documents. However, to date cumulative coastal wetland drainage and intense biomasses, common carp have negative effects assessments have been based fishing pressure of recruits, the threat impacts on water quality, and one on simply adding up stressors with little classification of inanga is only ‘Declining’ mechanism is excretion of the nutrients consideration of differential responses, with “moderate to large populations” N and P. We measured whole-body and interactions or impacts on ecosystem having “low ongoing or predicted mass-specific excretion rates during dynamics. Here we utilise a novel Decline”. Inanga appear to be resilient to summer and winter for fish of different framework based around assessing these impacts because of large numbers sizes (wet mass range 28–1,196 g) to the potential for a threshold response of returning whitebait to most rivers, produce an allometric scaling model to occur. Stressors on the marine and their generalist feeding and habitat capable of predicting excretion at environment are broken down into preferences. However, we have shown different temperatures. We found positive 8 general categories of disturbances that a major threat to inanga populations relationships between both dissolved and and empirical results and theoretical occurs at the spawning stage where total nutrient concentrations and fish wet studies are utilised to generate a matrix often the obligate riparian habitat is mass in summer and winter, with greater of cumulative effects interactions greatly degraded. Inanga have adapted to excretion rates in summer (mean water between these disturbances (additive, using now ubiquitous exotic grasses for temperature 24.2ºC) than in winter (mean multiplicative, synergistic or antagonistic). spawning, but the limited spatial extent of water temperature 9.2ºC). Mass-specific Predicted responses of biodiversity at spawning sites makes populations within excretion rates decreased with increasing three different spatial scales (site, estuary, individual rivers vulnerable. Furthermore, fish size, consistent with the MTE, region) to individual categories are our data show that adults don’t move and the temperature-adjusted model determined using expert opinion analysed between rivers so if spawning habitat explained more variation for N excretion by Point of Truth calibration and generate in a river is absent, that river is a sink than for P. The proportion of dissolved the initial probabilities. These probabilities population. Here we present results of nutrients (NH4 and PO4) to total nutrients are then adjusted for the cumulative short- and long-term spawning habitat increased with increasing fish size. The stressors occurring within an area using rehabilitation experiments using fencing significance of these models is that they the cumulative effect matrix to give and artificial habitats. Each technique has can be used to predict population-based the probability of a threshold response produced increases in egg production, nutrient excretion by common carp when occurring at any particular spatial but severely degraded habitats have thermal history, fish density and size scale. This process although still ‘under considerable inertia when long-term distribution in a water body are known. construction’ has the potential to assist in rehabilitation tools are applied, and so marine spatial planning and making trade- require intervention over at least a few offs between different resource users. years. The good news is that rehabilitation of spawning habitat can transform sink rivers to source rivers and improve the long-term viability of inanga populations. Combined with preservation of pristine spawning habitats, this will provide an added ‘insurance policy’ to

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 103 SPEAKER ABSTRACTS

Te Awaroa – is There a Impact of Epibiota & Inanga Reproduction: Place for Waikato? Parasites on Life History Putting Fewer Eggs into Parameters of Cockles in a Multiple Baskets Recovering Estuary

Dan Hikuroa // Ngā Pae o te Thomas Hildebrand // University Jessica Hill // University of Māramatanga of Canterbury Canterbury

Dame Anne Salmond // The University of Mads Thomsen, David Schiel // University Michael Hickford, David Schiel // Auckland of Canterbury University of Canterbury

Te Awaroa is a movement, a project, a Austrovenus stutchburyi (the New Galaxias maculatus (inanga) occurs vision that by 2050 more than a thousand of Zealand cockle) is a shallow-burrowing, throughout the southern hemisphere Aotearoa’s rivers and their catchments will be healthy, supporting a full range of aquatic suspension-feeding bivalve that occurs in and is one of the most widely distributed and terrestrial indigenous biodiversity and sedimentary estuaries throughout New fishes in the world. Juvenile inanga meeting the cultural, social and economic Zealand. A. stutchburyi plays a crucial role (whitebait) are the basis of a culturally needs of all New Zealanders. The bold idea for benthic invertebrates by providing and recreationally important fishery. The was born following a presentation by Dame attachment space on its shell in habitats reproductive success of G. maculatus Anne at the Transit of Venus conference in that often lack other hard substrata. A. is closely linked to the availability and Gisborne in 2012 that linked ideas about the Age of Enlightenment and Maori philosophy stutchburyi also is a major ‘habitat’ for composition of dense riparian vegetation, and knowledge to our present ecological internal parasites, especially Curtuteria which comprises their obligate spawning crisis and ways to restore balance. Although australis. This trematode that can habitat. The quality of vegetation, fencing and planting riparian strips is not reduce the cockle’s ability to burrow by reproductive output and egg laying a new idea, the boldness of aiming for replacing foot tissue with metacercariae, interact to provide the swarms of larvae collaborative, concurrent, considered effort resulting in infected cockles spending associated with whitebait, but we defies the inherent simplicity of the idea. The evolving project plan has 5 key, more time on the sediment surface and know little about the specifics of these inter-related and integrated strands: exposing them to greater predation and critical interactions. It has previously I. Science-based: Restoration of riverside their shells to colonization by epibiota. been assumed that G. maculatus is an bush based on, and responsive to the The aim of my MSc study is to test annual species with most fish dying findings of conservation biology and facilitation mechanisms involving cockles, after spawning and that the timing of freshwater ecology. This would take epibiota and parasites. The ecological reproduction does not differ throughout research on a wide range of topics performance of the cockle (density, size, New Zealand. Here we present results into schools and communities, making scientific methods and insights widely and condition index) is likely to depend from adult fish collections over 14 months accessible. on external epibiota and internal parasite from multiple rivers of the south island. II. Environmentally clever production: loading. Sites are sampled throughout Histological analyses indicate a slight A step towards socially and the Avon-Heathcote, quantifying cockle offset in the timing of reproduction environmentally responsible production density, size structure of populations, between the east and west coasts, much in industry, forestry, agriculture, condition index and trematode and lower fecundity values than previously horticulture etc. by planting bush epibiota loadings. These relationships will reported and clear evidence of repeated buffers, fostering innovation in then be tested in the field. This will be spawning by individuals. It appears that strategies and ideas. Iwi innovation. discussed in the context of facilitation, significant numbers of inanga survive III. ‘Mucking In’: Bring people together – intermediate hosts and the ecology of post-spawning, but more work is needed town and country, different generations; scientists and the wider community the estuary, particularly with respect to to confirm the age structure of adult – to take care of our rivers. Reconnect ecologically important epibiota such as populations. This study highlights region- people with their rivers, learn to take nuisance macroalgae. specific differences in G. maculatus care of them populations which have implications for IV. Visionary: Use cutting edge effective management. communication techniques to transmit a kai-tiaki vision, ideas, findings, tool kits; to recruit support and investment of time and resources. V. Viral: An idea that spreads across New Zealand, engaging people in new and innovative ways of caring for native plants and animals, rivers and the ocean, based on cutting edge science and ideas of guardianship. The opportunity for the Waikato and its kaitiaki to lead the way forward for New Zealand by playing a role is ripe and for the taking, and the intention of this presentation is to catalyse discussion. Mauri ora!

104 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Revisited: Effects of Thin Amateur Harvest Estimates Broad-scale Stream Habitat Terrestrial Sediment for Scallop & Rock Lobster Mapping in a Best-practice Deposits on Recruitment in Bay of Plenty, New Dairy Catchment – a GIS Zealand 2010–11 & 2011–12 Based Approach

Aysha Hohaia // Auckland John Holdsworth // Blue Water Robin Holmes // Cawthron University of Technology Marine Research Ltd Institute

Kay Vopel // Auckland University of Bryan Manly // Western EcoSystems Eric Goodwin, John Hayes // Cawthron Technology Technology Inc Institute Conrad Pilditch // The University of Waikato Fishers using specialist methods such Practical catchment-scale survey methods as SCUBA or lobster pots usually form are needed to monitor the effects of best- Coastal urbanization, rising sea level a small proportion of all fishers in large practice farm management on stream and extreme rainfall events increase the scale harvest surveys. An on-site survey habitat. We trialled a broad-scale riparian supply of terrestrial sediments to coastal of recreational fishers using boats and and instream habitat mapping protocol habitats via waterways or from landslides. access points between Port Charles and (BHMP) on the Waikakahi Stream (a Eventually these fine clay sediments Maketu in the Western Bay of Plenty South Canterbury best-practice dairy are deposited on the seafloor. Previous estimated the boat based amateur harvest catchment). In total, 8.5 km of the riparian experiments with defaunated intertidal and fishing effort for scallops (Pecten zone and 2.7 km of in-stream habitat sediment suggested that the negative novaezelandiae) and red rock lobster were surveyed. Riparian survey results impacts of clay deposits on the burial (Jasus edwardsii) in the survey area. were interpreted using a GIS based rates of juvenile bivalves was due to a Interviewers stationed on 6 main ramps index of riparian habitat quality (RHQI). decrease on oxygen concentrations in and 4 marinas intercepted returning Instream survey results were interpreted the underlying sediments. We challenged vessels. Thirty six secondary ramps were separately with indices of fish habitat this link hypothesising that terrestrial clay covered in 6 areas (routes) using the bus quality. Index scores are displayed on deposits will negatively affect burial rates route method and roving interviewers. catchment maps using a georeferenced regardless of the oxygen concentration. Over the two years 83 % of boat trips traffic light system. High riparian habitat We observed the behaviour of juvenile involved some fishing activity. Harvest scores were positively correlated with Macomona liliana on four sediment estimates for boat based amateur fishers high trout and tuna (eel) habitat quality, surfaces in a laboratory flume: intact, during 2010–11 were 13.7 t of rock demonstrating that good on-farm riparian bioturbated intertidal sediment (C), lobster and 36 t of scallops. Poor weather management can maintain habitat to intertidal sediment depleted of organic over summer, biotoxin warnings and the support freshwater fishery species in matter by combustion (D), and clay Rena grounding with subsequent oil spill dairy streams. In addition, the RHQI deposits over C (CTS) and D (DTS). all had a negative effect on fishing effort highlighted areas where simple riparian Porewater analyses revealed that the in 2011–12, especially in the Tauranga mitigation/restoration measures could diffusive impedance of the clay deposit area. Harvest estimates were 7.8 t rock be targeted to further improve stream significantly decreased the oxygenation of lobster and 24 t of scallops in the survey habitat condition. Farmers and resource sediments in treatment CTS but not DTS, area for 2011–12. These results are managers have responded positively to due to high oxygen concentrations in D. compared to the national panel survey the survey method and simple scoring Behavioural observations revealed that for the same area in 2011–12 conducted system. We anticipate that with further (i) clay deposits significantly increased by NRB. development these tools could be applied the probability of burial, irrespectively of autonomously by stream stakeholders treatment, and (ii) juveniles were more to inform and monitor catchment-scale likely to burry into C than into D. We rehabilitation initiatives. reject our hypothesis and attribute our failure to document a negative effect of clay deposits on the recruits’ burial to the macrofaunal irrigation of the sediment (CTS) and the absence of organic matter (DTS). Our study emphasises the importance of identifying thresholds for the response of the benthic ecosystem to stress: what level of sedimentation will alter the macrofaunal activity sufficiently to affect recruitment?

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 105 SPEAKER ABSTRACTS

Kina, Ocean Acidification & Application of Light as a Fate & Effects of Estuarine Sensitive Males Bycatch Reduction Device Contaminants as Tracked (BRD) by Stable Isotopes in Tauranga Harbour, New Zealand

Michael Hudson // The University Darcie Hunt // Australian Maritime Julien Huteau // The University of of Auckland College Waikato

Daniel Baker, Mary Sewell // The Nick Rawlinson, Prof John Purser, Tauranga Harbour, covering an area University of Auckland Prof Giles Thomas // Australian Maritime of 210 km2 and protected along its College seaward border by Matakana Island is Marine environments are experiencing Dr Jenny Cobcroft // Institute for Marine one of New Zealand’s largest estuaries. large-scale change through increasing & Antarctic Studies Fast development of Tauranga city, particularly in the coastal areas has seen levels of atmospheric CO2 driving both Dr Troy Gaston // University of Newcastle increasing seawater temperatures and the resident population grow by 16.9% ocean acidification (OA). The resulting since the 1996 census. Unsustainable Bycatch is defined as the part of the changes to carbon chemistry and land management practices such as catch that is returned to the sea due seawater pH have direct implications for intensive agriculture and horticulture to regulations or lack of commercial marine life with varied and contrasting in the northern region (accounting for value. Benthic trawling is responsible outcomes. In general, species are 46% of the land catchment) is also for majority of the world’s bycatch and suggested to be optimally adapted increasing pressure on the health of represents a threat to the sustainability to the environmental conditions they the Harbour. In the last 20 years, the of global fisheries. Bycatch reduction are exposed to over evolutionary time, Tauranga Harbour has been associated devices (BRDs) are modifications to the and as a result have limited capacity to with extreme ecological changes; a loss prawn trawl system to reduce the capture tolerate change. As the early life stages of biodiversity as indicated by a decline of bycatch species. However, most BRD’s are reportedly the most sensitive to in seagrass (Zostera marina) and the mud are modifications to the posterior of the environmental perturbations, the critical snail (Amphibola crenata), in association trawl system, with little emphasis placed first step of fertilisation success (FS) of with an increasing abundance and fast on preventing the fish from entering the the broadcast spawning sea urchin, kina expansion of opportunist species such net and modifying the anterior of the (Evechinus chloroticus), was examined as sea lettuce (Ulva spp). In this paper, trawl system. This research presents a here across a CO gradient from present we examine, for the first time, the link 2 relatively novel concept of using light as day to IPCC predicted future levels (380 between trace element abundance a BRD to prevent fish entering the trawl to 1800 ppm). The results show kina to in surface sediments and estuarine net by increasing the visual warning. be resilient to near future OA (1,000 ppm) indicator species and the use of stable The BRD consists of LED lighting in a followed by a population level decline isotope labelling as a complementary housing that can withstand the rigours in FS towards 50% as atmospheric CO tool to track nutrient sources. Isotopic 2 of benthic trawling. Preliminary results increases to levels predicted for the year research was successfully used as a show that most species experience 23,00 (1,800 ppm). Closer investigation complementary method to understand a decrease in catch with the use of a shows that tolerances at the individual the origin (terrestrial vs more oceanic light BRD attached to the headline. To level (single male:female crosses) input) of metal concentration. Abundance understand the reasons for this result, the are highly variable, with evidence of of aluminium, arsenic and copper were visual acuity of several common species differential male/female sensitivities to closely related to freshwater input. Sites was determined. Furthermore, the environmental CO . At 1,800 ppm inter- depleted in 13C signature were closely 2 estimation of burst swimming speed can male variability and sperm performance located to freshwater input and displayed be used to depict a fish’s ability to avoid characteristics, not eggs, drive lower higher %TOC, also aluminium, arsenic the trawl system. Being able to predict FS levels. This research expands our and iron levels. Concentrations of these the biological factors behind a species’ limited understanding of the vulnerability latter elements decreased with the reaction to the BRD will be an important of New Zealand rocky reef species to distance from the outlet. Opposite trends tool for establishing the effectiveness OA by describing levels and sources were measured for potassium levels, of light as a BRD in other benthic trawl of sensitivity in kina; an ecologically, necessary macronutrients for plants and fisheries. recreationally and culturally important other species. species.

106 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Freshwater Fingerprints: Status of Australian Redmap: an Online Database Using Otolith Increment Snapper Stocks & & Mapping Resource for Biochronologies to Assess Associated Fisheries Observational Marine Broad Influences of River Species Data – Marine Inflows into Estuarine Monitoring, Community Habitats Engagement & Collaborative Research

Christopher Izzo // The University of Gary Jackson // WA Fisheries Gary Jackson // WA Fisheries Adelaide and Marine Research Laboratories, and Marine Research Laboratories, Department of Fisheries Department of Fisheries Greg Fergusonn // South Australian Research & Development Institute of Anthony Fowler // South Australian Gretta Pecl, Jemina Stuart-Smith, Aquatic Sciences Research & Development Institute Stewart Frusher // University of Tasmania Tom Barnes, Zoe Doubleday, Morgan Bonnie Holmes // Department of Dianne Bray // Museum Victoria, Melbourne Disspain, Bronwyn Gillanders // The Agriculture, Fisheries & Forestry, Natalie Moltschaniwskyj // University of University of Adelaide Queensland Newcastle Jodie Kemp, John Stewart // Department Melissa Nursey-Bray // University of The River Murray estuary is the largest of Primary Industries, New South Wales Adelaide estuarine system in temperate Australia Keith Rowling // PIRSA Fisheries & and supports a diverse fish assemblage, Snapper (Pagrus auratus) is an iconic, high Aquaculture represented by species with a suite of value species in all the mainland Australian Marcus Sheaves // James Cook biological and ecological niches. This states. The species has a long fishing University study aimed to assess the influence history in many locations and continues of long-term freshwater flows on the to support important commercial and Climate driven changes in the distribution growth of estuarine associated teleosts. recreational fisheries from the Gascoyne of marine species are being reported Using mulloway as a model species, region in Western Australia, around from around the globe. Redmap (Range this study contrasts otolith based the south of the continent, to northern Extension Database and Mapping multi-decadal biochronologies between Queensland. The 13 separate stocks that project, www.redmap.org.au) is an estuarine and non-estuarine populations are now recognized contribute to a national online database and mapping resource in South Australia. Biochronologies annual catch of around 3,500 tonnes that allows members of the public to were generated for additional species of per year. The biological sustainability of submit observational data (including photographs) of marine species occurring marine and freshwater teleosts, which these snapper stocks and the associated inhabit the River Murray estuary, to outside their known distribution (i.e. fisheries was recently assessed against species that may be undergoing range assess the broader effects of river inflows. a nationally agreed framework using shifts). Following a successful 3-year Biochronologies were based on otolith standardized terminology and reference pilot in Tasmania, the project has now increment width measurements and points and recently reported in the Status scaled-up to an Australian-wide long-term analysed using mixed effects models. of key Australian fish stocks reports. These biodiversity monitoring system designed Modern day biochronologies were also assessments and a follow-up national to be a low-cost, citizen science based broadly compared to biochronologies workshop held in Adelaide have identified approach to assess changing marine developed from indigenous midden a number of priority areas for snapper species distributions. Australia has over 3.5 million fishers and divers – many otoliths, to infer if patterns of growth and research and management including: river flows seen today are similar to those equipped with consumer electronics need for improved understanding of stock and the capacity to record verifiable in the past. Our results show variation in structure; need for fishery independent observations. However, one challenge growth between mulloway populations, methods of estimating snapper biomass; to the adoption of such datasets is the with flows influencing the growth of need for cross-jurisdictional stock perception of bias or low quality. In the estuarine associated population. assessments in some cases; need for addition to extracting geo-tag information More broadly, the effect of river inflows improved estimation of recreational catch; from photographs (validating location), appeared to be consistent among the improved understanding of effects of species identifications are verified by a teleost species examined. These findings climate change; increased formalization of large national panel of expert scientists using a semi-automated validation provide important insights into the harvest strategies for snapper fisheries. This relative effect of river inflows on estuarine workflow. This initiative has the potential paper is intended to complement a similar to generate large amounts of valuable associated fish populations, which has overview of snapper stocks and fisheries in quality data, engage communities in direct management implications. More New Zealand that will provide background climate science and raise awareness of generally, this study aids in identifying for a conference special session on ocean warming and its consequences. shifting baselines in life histories of fish snapper. Redmap is an early warning system and the environments in which fish live for changes occurring in the marine and breed. environment, and has the potential to play a key role in informing future management actions around Australia.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 107 SPEAKER ABSTRACTS

Marine Stewardship Conventional Research- Revitalising New Zealand’s Council Certification management of Western Most Urbanised River of Western Australia’s Australian Snapper Leading – Putting Theory into Fisheries to Successful Stock Practice Conservation & Fishery Outcomes

Gary Jackson // WA Fisheries Gary Jackson // WA Fisheries Alex James // EOS Ecology and Marine Research Laboratories, and Marine Research Laboratories, Department of Fisheries Department of Fisheries Shelley McMurtrie // EOS Ecology

Dan Gaughan // WA Fisheries & Marine Corey Wakefield, David Fairclough // The damage wrought by the 22 February Research Laboratories, Department of Western Australia Fisheries & Marine 2011 earthquake has provided an Fisheries Research Laboratories unprecedented opportunity to redesign Guy Leyland // Western Australian Fishing parts of Christchurch. Part of the earthquake recovery involves ten central Industry Council Snapper are commercially and rec- city anchor projects. The first of these reationally important in Western Australian to progress was the Avon River Precinct fisheries. A significant amount of biological The Western Australian Department of (ARP), which involves the redesign of research has been conducted on Snapper Fisheries has recently embarked on a a 30 m wide strip on either side of the in WA over a long period, along with program that will provide the opportunity Avon River for 3.2 km through the central for all of Western Australia’s commercial stock assessments, to drive conventional city, and aims to improve river health. fisheries to seek Marine Stewardship fisheries research-management Based on the priniciples we developed Council (MSC) certification. The MSC systems. In the Gascoyne Bioregion, the during the concept design phase (see is an international and independent commercial fishery targeting the oceanic Shelley McMurtrie’s presentation) the organisation that sets standards for well Snapper stock has been managed using ARP showcase “Watermark” construction managed and sustainable fisheries that a Total Allowable Commercial Catch/ project has recently been completed include detailed consideration of the effect Individual Transferable Quota system since in the most upstream part of the ARP. of fishing on both the targeted fish stocks 2001. Significant reductions in TACC have Here we have put our design theory and the broader ecosystem. The MSC’s assisted breeding stock recovery following into practice by undertaking substantial standards are widely recognised as the prolonged poor recruitment. The fishery instream enhancements along 200 m of most complete and comprehensive and has been twice assessed against the EPBC the Avon River. The condition of instream are entirely consistent with the Food and Act 1999, and is scheduled for Marine habitat has been improved by narrowing Agricultural Organization’s Code of Conduct Stewardship Council pre-assessment the base flow channel to increase water for Responsible Fishing, which requires this year. Recreational catches of three velocities and riffle habitat length; credible fishery certification schemes to separate inner Shark Bay stocks have cleaning riffle gravels of silt and sand; include: independent fishery assessment been significantly reduced since 1998, removing sediment from key depositional using scientific evidence; transparent to rebuild breeding stocks and maintain zones; adding boulder clusters to increase processes with built-in stakeholder recruitment via management measures habitat heterogeneity and fish cover; consultation and objection procedures; and including a TAC and seasonal and spatial reconnecting the river to its flood plain; assessment of the sustainability of target closures. Weight of evidence assessments and allowing the river to ‘self cleanse’. species, ecosystems and management (which determine risk to stocks using We anticipate trout spawning (which practices. An overview of the process by a combination of biological knowledge has not occurred here for over 20 years which the Department of Fisheries intends and fishing mortality assessments) in the due to siltation) will return this winter, to pursue independent assessment of the West Coast Bioregion in 2007 identified and the locally uncommon bluegill state’s 40+ commercial fisheries will be overfishing of key demersal indicator bully should colonise the reinvigorated provided. Initially, MSC pre-assessments species including Snapper. Significant riffle. Prior to the instream works we will be undertaken at a bioregional level; management measures were introduced undertook a comprehensive habitat, fish, within each of the state’s four marine to reduce catches by at least 50%. and invertebrate survey against which bioregions (North Coast, Gascoyne Management changes for the commercial to compare future monitoring that will Coast, West Coast and South Coast) the fishery included limited entry, Individual ultimately determine the outcomes of the fisheries will be considered as part of one Transferable Effort Units and a large spatial project. assessment process. This will consist of closure and for the recreational fishery, a evaluating (i) how well each of the main seasonal closure, a spawning closure in target species/stocks is being managed for Cockburn Sound and reduced bag limits. sustainability, (ii) ecosystem impacts across There are early signs of stock recovery. In all commercial fisheries in the bioregion and (iii) the effectiveness of the management addition, climate change has the potential systems being used. to impact the distribution and stock productivity of Snapper in WA. The current management framework has capacity to adapt as necessary.

108 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Does Flow Variability Ocean Circulation Under The Role of Community in Mitigate the Effect of an the Ross Ice Shelf & its Whitebait – it’s a Two Way Invasive Alga (Didymo) on Impact on the McMurdo River Stream Fish Communities? Sound Region

Phillip Jellyman // NIWA Stefan Jendersie // University of Kim Jones // Whitebait Connection, Otago, NIWA Mountains to Sea Conservation Trust Jon Harding // University of Canterbury Pat Langhorne // University of Otago Vince Kerr // Whitebait Connection, Exotic species have irreversibly altered the Mike Williams // NIWA Mountains to Sea Conservation Trust New Zealand freshwater fauna and when Robin Robertson // University of New the invasive alga didymo was discovered South Wales For many Kiwis, the word ‘Whitebait’ is in 2004 there were suggestions that closely associated with ‘fritter’...but our it might completely alter freshwater The formation of sea ice in McMurdo educational programme, the Whitebait food webs. Surprisingly, the impact Sound is dominated by interaction with Connection, is changing that association of didymo on multiple trophic levels the ocean, with currents importing water for many New Zealanders, young and old. is largely unknown as studies to date masses that have been produced and We offer unique ways in which all New have only focussed on a single trophic modified beneath the Ross Ice Shelf (RIS) Zealanders can come to understand and level (e.g., invertebrates or fish). We and in the Ross Sea Polynya. A modified become involved in the life and future conducted a survey of 20 South Island version of the Regional Ocean Modeling health of our freshwater systems. Te aki waterways across a didymo biomass System (ROMS), a free surface, terrain- i te hunga tangata te tiaki inanga. The gradient to determine (1) the impact of following, primitive equation model, Whitebait Connection is an inquiry-led didymo on multiple trophic levels and (2) is used to numerically simulate the community-based action programme whether this impact was influenced by circulation of the Ross Sea including the that takes the lifecycle of the humble flow variability. Periphyton, invertebrate RIS cavity and, expanded to the north to whitebait as an analogy to communicate (Surber and drift) and fish data as well include parts of the Antarctic Circumpolar the need for a caring/holistic approach to as gut-content data were collected at Current. The strategy is to recursively our freshwater systems. It’s a fact – the each site. The frequency of flood events adjust lateral boundary conditions and way we use our land directly affects the and the time since the last major flood forcing at the surface in order to resemble health of our streams, rivers, estuaries were the most important variables in the large scale circulation of the Ross Sea and the sea. The story of the Whitebait determining didymo biomass across all aim at establishing behavior that agrees Connection brings home the reality sites. Didymo biomass strongly affected with observations. The objective is to of our freshwater sources. It provides invertebrate density and community move solution-constraining boundaries knowledge about freshwater ecology composition which was not surprising as far away as possible from the region and the effects of land management on given the findings of previous studies. of interest; i.e., the ocean underneath freshwater quality and quantity. We take Fish biomass decreased with increasing the RIS. The circulation within the the community out to experience their didymo biomass although didymo cavity is allowed to evolve without local freshwater environments first hand. biomass also had indirect effects on fish forced exchange at the ice shelf front This experience gets them connected communities. The relationship between which enables processes of ice-ocean and often inspires or empowers them didymo biomass and fish communities interaction at the base of the RIS and to take action. Action takes shape was complex and indicative results polynya evolution in the Ross Sea to in many different forms including; suggest that it is linked to prey availability provide boundary properties for a nested riparian planting, Inanga spawning site and fish feeding mode. Our results show high resolution ocean model of McMurdo restoration, ongoing monitoring projects, that didymo has a detectable effect at all Sound. The aim is to study the origin of fencing of waterways, stream cleanups trophic levels although the strength of oceanographic signals in the McMurdo and labelling of stormwater drains. The that effect is likely to be dependent on Sound region. programme engages the community didymo biomass and trophic level. through; school programmes, regional facilitated hui & national conferences, displays at regional field days, running community plant nurseries, and involvement in wide collaborative networks on community led restoration projects, hosting World Wetlands Day events, and involvement in international virtual field trips.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 109 SPEAKER ABSTRACTS

Do Life History Strategies Oil Dispersal Modelling: The Meeting of the Waters: Drive Trout Interactions in a Re-analysis of the Rena Tidal Dynamics & the Limit Species Complex of Non- Oil Spill & Open-source of Saltwater Influence in migratory Galaxiids? Modelling Tools the Waikato River

Peter Jones // University of Otago Hannah Jones // The University of Hannah Jones // The University of Waikato Waikato Gerry Closs // University of Otago Karin Bryan, Julia Mullarney, Kevin Collier, David Hamilton, Life history traits become specialised Willem de Lange // The University of Kohji Muraoka // The University of through natural selection to optimise Waikato Waikato reproductive success within environmental constraints. Fluvial Oil spill forecast modelling is typically The hydrodynamics of the Waikato systems represent a continuum from used immediately following a spill to low productivity headwater creeks to River estuary and delta area appear to allow effective mobilisation of response be relatively unknown compared to relatively productive lower catchment operations. Such models have two watercourses. Life history theory predicts many other North Island estuaries. Data components, a hydrodynamic driver and from a single survey in 1976 indicated that fish inhabiting such different a particle tracking model, but can provide environments will display divergent that the saltwater influence extended widely varying predictions depending just 6 km upstream of the mouth of reproductive strategies. This study on how wind and coastal currents are examined life history variation in a species the river, and the presence of a vertical incorporated. Accurate predictions front, rather than a salt wedge, at the complex of non-migratory galaxiids, require careful model calibration and distributed across a range of contrasting interface between marine and freshwater. verification against observations (of both Measuring spatial and temporal variability habitat types on the South Island of New currents, and oil dispersal and shoreline Zealand. Species occurring predominantly in ecologically relevant variables has accumulation). The aim of this work was previously been identified as crucial in high altitude, headwater creeks to undertake modelling of oil dispersal were characterised by a large egg, low when attempting to predict fish habitat. following the grounding of the container However, there appears to have been little fecundity and a late onset of maturity. ship “Rena” on Astrolabe reef (on the Species associated with lower catchment attempt since then to quantify spatial and approach to Tauranga Harbour) and temporal variability in fundamental (and systems displayed markedly smaller egg verify the results against information on size, higher fecundity and matured at relevant) variables such as temperature, oil accumulation collected by Maritime salinity and dissolved oxygen, despite smaller sizes. Post-hatch larval counts in New Zealand. We modelled tidally driven stream reaches suggest these differences the importance of this area as habitat currents on the shelf (using Delft3D) and and recreational fishery for many native in adult reproductive traits lead to in the harbour (using ELCOM) and used substantial differences in recruitment fish, such as whitebait species and eels. the modelled currents as forcing in the This survey was part of a wider study dynamics. Larvae were abundant in NOAA oil-spill model GNOME, along streams occupied by lower catchment that attempts to identify and manage with observed wind speed and direction whitebait spawning habitat in the delta species whereas recruitment was collected at Tauranga Airport. Model severely limited for headwater species. area of the Waikato River. We used a predictions were broadly consistent with combination of sensor technologies Preliminary findings also suggest larvae survey data provide by Maritime NZ, of lower catchment species disperse far (Biofish™ horizontal profile readings, with the exception of some hot spots of CTD casts, and deployment of high- more widely than those of headwater oil accumulation that occurred on open species. These profound differences in frequency temperature, salinity and coast beaches, likely due to surf-zone dissolved oxygen loggers) to capture reproductive strategies, recruitment and and rip-current circulation not being well larval dispersal appear to be important spatial and temporal variability in relevant represented in this implementation of the variables over a spring-neap tidal cycle. factors influencing species’ responses to model. Oil dispersal is highly dependent invasive salmonids. Interspecific variation Results from the survey suggest that the on prevailing wind patterns, and more saltwater influence can extend much in distributional overlap with salmonids accurate prediction would require better relate to observed differences in life further than previously described, i.e. observations of local wind patterns. 10–13 km upstream on the neap and history traits. These findings are highly Nevertheless, comparison of predictions relevant for conservation initiatives aiming spring tide, respectively. Furthermore, with observations indicated that the there is substantial lateral, longitudinal to mediate impacts of invasive fish on GNOME modelling approach was an native communities. and temporal variability in temperature, effective low-cost tool and both Delft3D dissolved oxygen and fluorescence, and GNOME are open source and freely reflecting the highly dynamic nature of available software packages, which could the interface between this large river and facilitate collaborative and progressive the saltwater/estuarine environment. coastal hazard management.

110 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Quantifying Benthic Duck Creek Realignment: Finding the Spawning Enrichment From Salmon Fish Rescue Sources of Victoria’s King Farms George Whiting

Nigel Keeley // Cawthron Institute Vaughan Keesing // Boffa Miskell Jodie Kemp // Department of Ltd Primary Industries, Fisheries Victoria Barrie Forrest // Cawthron Institute Catriona Macleod, Christine Crawford // Tanya Blakely, Stephen Fuller, Gregory Jenkins // The University of University of Tasmania Barbara Risi, Leigh Bull, Matiu Park Melbourne Paul Hamer // Department of Primary This talk outlines recent studies relating A residential developer sort and received Industries, Fisheries Victoria to understanding, evaluating and permission to divert Duck Creek, a Anthony Fowler // South Australian predicting benthic enrichment – using small coastal waterway in Whitby, Research & Development Institute salmon farm aquaculture as a case Wellington Region. An in-depth design study. A quantitative benthic enrichment and construction process was undertaken King George whiting is the most gradient was development using best to create the new channel, and enable valuable finfish species in Victoria, and professional judgement methods, which the diversion of Duck Creek. Duck Creek is the second most valuable in South unifies information from biological and supported a number of threatened and Australia; supporting major recreational physic-chemical variables. The resulting ecological significant native fish species, and commercial fisheries. Despite the seven stage bounded continuous including giant and banded kokopu, importance of this species, there are still variable was used to assign enrichment inanga, and longfin and shortfin eels. major gaps in our knowledge of the life- tolerance groups to benthic taxa using Prior to closure of the main channel and cycle of King George whiting, particularly quantile regression splines. A number of the subsequent livening of the diverted our understanding of movement and how key indicator taxa were discriminated, channel, we fished approximately one the stock is distributed across south- including several that were responsive kilometre of Duck Creek. We used a eastern Australia. The lack of knowledge ES to low-level changes in , but not range of fishing techniques, over four is a significant impediment to determining OM necessarily % , and 10 taxa for which days, to trap, record and transfer all whether single jurisdictional management ecological understanding was otherwise native fish from the affected reach. The is suitable for this species. The limited. The gradient was also used to ‘de-fishing effort’ caught nearly one recreational and commercial fisheries that evaluate the performance of five benthic fish per meter, however, there were no harvest King George whiting in Victorian and ten biotic indices for defining signs of a diminishing catch over time or waters are primarily based on sub-adult organic enrichment under different flow effort. The clearance of the substantial whiting (two to four years of age) found regimes. The most versatile indices were macrophyte beds along Duck Creek had a in bays and inlets. Despite significant BQI>M-AMBI>AMBI>log(N)>BENTIX. distinct effect on capture efficiency. While efforts, King George whiting in spawning M-AMBI best catered for different flow the variety of methods used produced condition have rarely been recorded environments, while the BQI was the differing results, and different methods in Victorian waters; the only known most effective under highly enriched favoured different fish taxa, the best taxa significant spawning areas for the species conditions. A subset of variables was richness and frequency of taxa caught are in South Australian waters. We use recommended comprising: two biotic came from EFM after macrophytes were otolith trace-element chemistry and daily indices (based on alternative taxa cleared from the stream channel. increment analysis of post-larval whiting classification schemes), total abundance, to assess whether sub-adult whiting in 2-). and a geochemical variable (redox or S Victoria are spawned in the area of the A subsequent, related study revealed South Australian adult fishery. Significant pronounced flow-related differences variation in Mg:Ca ratios and early larval in the magnitude and spatial extent of growth rates suggest the environmental benthic enrichment. Total macrofaunal conditions that Victorian whiting were abundances at high flow sites were nearly exposed to at spawning were different an order of magnitude greater than at to those experienced by the South comparable low flow sites, representing a Australian whiting. This variation could significant benthic biomass, and occurred be the product of either geographically in conjunction with moderate-to-high separate spawning locations or temporal species richness, and the absence of variation of spawning. We discuss these appreciable organic accumulation. The results further along with methods we atypical ecological conditions were are using to elucidate the cause of the attributed to i) minimal accumulation of observed variation. fine sediments, ii) maintenance of aerobic conditions in near-surface sediments, and iii) an abundant food supply.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 111 SPEAKER ABSTRACTS

Isolation & Invasion: Estuarine Environments of Are You What You Eat? Do Gudgeons & Gobies in the New Zealand: Forgotten Pleurobranchaea maculata Australian Arid-zone Ecosystems or Places of Obtain their Tetrodotoxin Future Opportunities for (TTX) Via a Dietary Source? Conservation?

Adam Kerezsy // Griffith University Helen Kettles // Department of Serena Khor // The University of Conservation Waikato Scattered populations of purple-spotted gudgeon and western carp gudgeon Philippe Gerbeaux // Department of Susie Wood, Paul McNabb, occur in isolated springs and river Conservation Dave Taylor // Cawthron Institute catchments of the endorheic Lake Eyre Lauren Salvitti, S. Craig Cary // The Basin in central Australia, suggesting Estuaries are nationally rare ecosystems, University of Waikato the family was more widespread – and they contain habitat for a wide range possibly represented by more species of indigenous fauna and flora including Pleurobranchaea maculata (grey side- – in wetter times. Similarly, gobies of numerous threatened species. They are gilled sea slugs) are opisthobrachs the genus Chlamydogobius occur in an essential link between catchments/ commonly found in shallow sub-tidal disjunct populations: the endangered rivers and the marine environments and areas around New Zealand. In 2009, a species Edgbaston goby, Elizabeth provide important ecosystem services, series of dog poisonings in Auckland Springs goby and Dalhousie goby are including mahinga kai. But estuaries are revealed the presence of the potent only found in the Great Artesian Basin under many direct and indirect pressures, neurotoxin tetrodotoxin (TTX) in this spring complexes alluded to in their from climate change, modification to species. In the North Island, high names, whereas the Finke goby occurs margins and from human activities in concentrations of TTX were detected only in the Finke River system in the the surrounding catchments. A focus on in P. maculata populations in Auckland, Northern Territory and the desert goby these ecosystems is therefore regarded Whangarei and Tauranga and low has a more widespread distribution as a high priority for conservation gains. concentrations in Wellington. By in the rivers and springs of arid South Very few estuarine and catchment contrast, South Island populations had Australia. All are closely related, and their areas are contained in conservation non-detectable concentrations. Within speciation is a result of their isolation: areas so to protect estuarine values toxic populations there was significant small populations of small fish marooned requires supporting and working with variability (up to 60-fold differences) in in small but permanent oases. The much Iwi, councils, communities, science TTX among individuals. The origin of TTX larger golden goby, Glossogobius aureus, providers and other interested parties. is highly debated with researchers citing is only found in the remote Georgina This presentation will outline Department either an endogenous or exogenous and Diamantina catchments in the arid of Conservation’s collaborative approach source with the host accumulating zone, despite a widespread distribution and some of the key directions TTX symbiotically or via food chain throughout the Indo-Pacific. It seems proposed to help address these issues transmission. The aim of this study entirely likely that populations of this including development of an online was to determine, using three different species crossed the Basin divide in the resource, compilation of spatial data and approaches, whether P. maculata obtain north and have adapted to desert living development of a spatial decision support TTX via dietary means. Firstly, a biopsy over time. In contrast, the most recent tool for catchment management, revision technique was developed to enable bottom-dweller to arrive in the arid zone of the national classification system, a non-lethal method for tracking TTX is a fast-adapting translocated species, supporting the consideration of estuaries concentrations during laboratory-based the sleepy cod, Oxyeleotris lineolata. as receiving environments for freshwater experiments. Secondly, non-toxic P. Most likely originating from escapees within the water reform work, an exercise maculata were maintained in aquariums from aquaculture, sleepy cod were of ranking sites and quantifying natural and fed spiked food in order to investigate first detected in the wild in the Cooper capital value, and exploring protection their ability to accumulate TTX and catchment in 2008 and since then have options. in which tissues it was sequestered. become more widespread. Priorities TTX was detected within 1 hr and was for management in the Australian arid rapidly transported to the mantle and zone include all endangered species of gonad. Average percentage uptake gudgeons and gobies in their respective decreased throughout the experiment. watery ‘islands’ and preventing the The final study involved a series of liberation of other potential pest species preference experiments to determine if P. such as sleepy cod. maculata, from both toxic and non-toxic populations, preferred TTX-containing food to non-TTX containing food with results indicating strong preferences for spiked samples. This study supports a dietary source of TTX in P. maculata.

112 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Southern Maori Perspective High-seas Demersal & Aquaculture Effects on the Management & Pelagic Monitoring, Co- Models to Inform Resource Knowledge Needs for operative Approach with Management in the Firth of Kanakana (Geotria australis) Industry, Technology & Thames Methods

Dr Jane Kitson // Te Ao Marama Rudy Kloser // CSIRO Ben Knight // Cawthron Institute Incorporated Graham Patchell // Sealord NZ Research Brett Beamsley // MetOcean Solutions Fish are of great cultural, social and Tim Ryan, Gordon Keith, Mark Lewis // Ltd economic significance to Ngāi Tahu CSIRO Hilke Giles, Vernon Pickett // Waikato Whānui (NZ’s Southern most Māori). Regional Council Mahinga kai, the use of foods and Management of high seas demersal resources, gathered from freshwater and pelagic fisheries requires an Development of aquaculture in an bodies is a cornerstone of Ngāi Tahu understanding of the targeted species economically and environmentally culture, identity and well-being. Mahinga and the structure and function of their sustainable manner requires a good kai is also viewed as a principle indicator ecosystem. Obtaining the necessary understanding of farm-scale effects of environmental health. Southland is spatial and temporal data to assess on the environment and the ability to a Ngāi Tahu stronghold for customary resource status and ecosystem forecast potential cumulative effects of harvesting of kanakana/lamprey. vulnerability is expensive and difficult increased development within a wider Kanakana are considered a threatened on the high seas. Harnessing the regional context. Cawthron Institute species and although there is little data gathering capability of the and MetOcean Solutions Ltd worked data, their decline has been noticed fishing industry through appropriate collaboratively with Waikato Regional by customary harvesters. From 2007 collaboration, management and policy Council (WRC) to construct an open- customary harvesters in Southland frameworks would be a cost effective source code 3D hydrodynamic model have been using traditional ecological solution. Development and application for use in a number of applications, knowledge to try and determine relative of technologies for industry can assist in including the planning and management abundance. In 2011 and 2012 adult the assessment of biomass of targeted of aquaculture in the Firth of Thames. runs of kanakana migrating back into species, habitats and the potential ability Application of transport information freshwater were affected by a ‘lamprey to avoid non target species and habitat from the hydrodynamic model provides reddening syndrome’ which resulted in at fine scales. Long term monitoring by predictions of mixing and transport significant mortalities of affected fish acoustic sensors can begin to document processes, which in turn were used to in Southland rivers. The cause of this variability and change in the functioning estimate cumulative effect gradients from condition, and the effects on kanakana of the broader pelagic ecosystem. This dissolved and solid wastes from finfish abundance (both in Southland and has recently been done by collecting and shellfish farms in the region. Benthic Nationally) remains unknown and is acoustic data from industry vessels at and water column results for possible frustrated by knowledge gaps of the ocean basin scales www.imos.org.au. finfish operations under varying tide fundamentals around this species’ At these scales it is possible to relate and wind conditions highlight potential life history and ecology. The recent patterns in acoustic scattering to the enrichment gradients at local to regional National Policy Statement on freshwater broader physical environment and surface scales. An important aspect of the project management requires increased Māori inferred primary production. Another has been ensuring accessibility to the involvement in decision-making. recent technological development has model and hindcast datasets by WRC Meaningful collaboration will necessitate been a net attached multi-frequency staff, which in turn can be used in the a synthesis of values-based knowledge acoustic optical system (AOS) that development of robust regional resource of taonga (treasured) species with has the capability to measure species management and monitoring frameworks contemporary environmental science. biomass and obtain optical measures and future modelling applications. This presentation suggests some of the of species and habitats. Using fishing likely information requirements, from a vessels we show how this technology Southern Māori perspective, to inform has been applied to pelagic high seas and limit setting on water quantity/quality deep-water demersal habitats including and freshwater management, including seamounts in Australia and New Zealand. Mātauranga Māori/traditional knowledge, Developing methods to collect high seas using kanakana as an example. information incorporating fishing vessels, acoustics, nets and net attached AOS technology is discussed.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 113 SPEAKER ABSTRACTS

Recovery of the Spawning Season Spatial Perspectives Endangered Trout Cod: Movements of a in Ecology What have We Achieved in Threatened Native Fish, More than 25 Years? Macquarie Perch, in the Yarra River, Australia

John Koehn // Arthur Rylah Wayne Koster // Arthur Rylah Casper Kraan // NIWA, University Institute for Environmental Research Institute for Environmental Research of Freiburg

Mark Lintermans // University of Canberra David Dawson // Arthur Rylah Institute for Andrew Finley // Michigan State Canberra Environmental Research University Jarod Lyon, Charles Todd // Arthur Rylah David Crook // Charles Darwin University Carsten Dormann // University of Freiburg Institute for Environmental Research John Morrongiello // CSIRO Simon Thrush // NIWA Brett Ingram, John Douglas // Fisheries Victoria Macquarie perch Macquaria australasica Following over-harvesting, pollution, and Dean Gilligan // Fisheries NSW is an endangered fish species that the direct and indirect impacts of climate inhabits rivers and impoundments in the change, many species distributions Recovery of threatened species is often southern Murray-Darling Basin, Australia. shift. Therefore, understanding current necessarily a long-term process. This An upstream spawning migration during and forecasting potential distributions paper details the progress towards the spring-summer has been documented of species is fundamentally critical for recovery of trout cod Maccullochella for populations that have become evaluating management options, and can macquariensis, an iconic, long-lived established in impoundments. Whether lead to a better integrated management fish species first listed as threatened riverine populations of Macquarie Perch of ecosystems. Hitherto, most broad- in the 1980s. The objectives, actions undertake a similar upstream migration scale research on mapping species and progress over three successive associated with spawning remains distributions ignores spatial patterns, national recovery plans (spanning 18 unknown. This study tests the hypothesis scale-dependent variability, and biotic years) are assessed and it documents that riverine populations of Macquarie interactions. Such omissions affect changes in population distribution and Perch exhibit synchronised migrations statistical analyses and the ecological abundance of and updates ecological during the spawning season. Thirty fish inferences drawn from them. Here we knowledge. Increased knowledge were radio-tagged in the Yarra River, review recent methodological advances (especially breeding biology and hatchery Victoria, and their movements tracked which encompass these shortcomings techniques, movements, habitats and over 10 months between May 2011 and and address their benefits. Abandoning genetics) has greatly influenced recovery February 2012. Radio-tagged fish typically the single-species vacuum, incorporate actions and the use of a population occupied small (e.g. < 500 m) reaches of environmental variation and cross- model was developed to assist with stream throughout the study. Movement scale processes, allows addressing management options and stocking behaviour of fish was complex, including questions whether relationships between regimes. Key recovery actions include: localized movements in both upstream abundance patterns and different biotic stocking of hatchery-produced fish to and downstream directions, but there and environmental processes change establish new populations; regulations on was no evidence of synchronised depending on spatial scales, as well as angling (including closures); education migratory behaviour. These results improve ecological interpretation. (particularly identification from the closely highlight the potential for variation in related Murray cod M. peelii); and habitat behaviour among lacustrine and riverine rehabilitation (especially re-instatement of populations of fishes which needs to structural woody habitats). In particular, be considered when planning for their the establishment of new populations conservation. using hatchery stocking has been a successful action. The importance of a coordinated long-term approach is emphasised and whilst there is uncertainty in ongoing resourcing of the recovery program, much has been achieved and there is cautious optimism for the future of this species.

114 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Haliotis iris Demography Fancy Meeting You in “Weed Cordons”, are they & Habitat Associations a Place like this – Fish an Effective Biosecurity within & Outside Five Communities in the Tool? New Zealand Marine Waikato Land Drainage Reserves Network

Alix Laferriere // Victoria Mike Lake // Waikato Regional Hamish Lass // Bay of Plenty University of Wellington Council Regional Council

Rob Davidson // Davidson Environmental The Waikato Regional Council is A two part trial was undertaken to test Ltd responsible for maintaining land drainage whether netted “Weed Cordons” are likely Jonathan Gardner // Victoria University of schemes throughout the region. The to reduce the risk of invasive aquatic plants Wellington River Catchment Services (RCS) group establishing in two of Rotorua’s cleanest has recently obtained a comprehensive lakes, Rotom and kataina. Marine Reserves in New Zealand are resource consents to carry out drain Invasive plants represent a significant defined as complete “no-take” and maintenance. As part of this process biosecurity threat to our pristine were established under the Marine RCS identified those drains that were environments. To reduce this threat “Weed Reserve Act, 1971. Marine reserves likely to contain high fisheries values. The Cordons” (a netting fence anchored to the are one management tool that allows large extent of the land drainage network lake bed) have been installed at boat ramps us to examine if and at what rate precluded the use of targeted surveys so in Lakes Rotomā and Ōkataina. These lakes populations recover after being depleted. values were determined based on historic currently contain very few invasive species This enforced cessation of extractive survey records as well as predictive but have a high risk of incursions from activities may allow the populations of models and prioritisation tools contained neighbouring “weedy” lakes such as Lake formerly exploited species to recover within the FENZ geodatabase. RCS now Rotoehu and Rotorua. to a more natural state. Haliotis iris, undertakes an ongoing programme of A trial was designed to test the commonly referred to as the black-foot fish surveys where planned maintenance effectiveness of the “Weed Cordons” via paua, inhabits shallow subtidal rocky works overlap with sites considered likely a simulated incursion from a boat and reefs and is the focus of important to contain high value fish communities. trailer or fishing equipment. The trial was customary, recreational and commercial The purpose of these surveys is to replicated in an un-netted area (non- fisheries. Paua are long lived species confirm whether “Threatened” or treatment) next to each “Weed Cordon” with limited larval dispersal and adult “At Risk” species are present so that referred to as the “Ghost cordon”. The movement patterns, which are life appropriate mitigation can be put in place. aim of the non-treatment was to test history characteristics that predict a The results of these surveys have helped what would happen if there was no Weed positive response to marine reserve better describe the fish communities Cordon present. The trial was undertaken implementation. It has been shown that supported by the land drainage network by releasing a total of 2880 weed fragments size composition of paua populations and the role that lakes play in structuring during a range of wind directions to gain can be highly variable on a small spatial these communities. The results have an accurate understanding what would scale, and habitat has been suggested also allowed us to reassess our ability to happen to the released fragments in a to influence the demography of the predict the presence of “Threatened” or variety of conditions. population. The small scale variation in “At Risk species in large modified stream The results revealed that overall the abundance patterns, calls for detailed networks. boat ramp “Weed Cordons” in the 3 investigations of habitat and abalone locations retained 84.9% of all fragments abundances within marine reserves and released in all wind conditions. In contrast their associated control areas. In the New where no “Weed Cordons “were present Zealand summer of 2013, we conducted 85.2% of all fragments released were either Haliotis iris and habitat surveys via not found or were found outside of the SCUBA within and outside Long Island- “Ghost Cordon” range. The effect that wind Kokomohau, Horoirangi, Tonga Island, direction had on fragment transportation Taputeranga and Kapiti Island Marine produced some surprising results which Reserves. We present here data about warrant further investigation to determine Haliotis iris density and size distributions whether future weed cordons can to be and their associations with physical and altered to maximise their effectiveness. biogenic habitat. Results from all five Overall it was concluded that the marine reserves will be synthesized to “Weed Cordons” in these lakes are working determine the local biological response effectively as a biosecurity tool but should of paua populations to marine reserve be complimented with other initiatives such implementation, in particular as this as portable wash down facilities, public relates to duration of protection. awareness, pest surveillance and lake weed spraying.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 115 SPEAKER ABSTRACTS

Detecting Recruitment Small-scale Variation in Triple Jeopardy in the Cross-subsidy: Snapper Bacterial Community Tropics: Assessing Dispersal from Leigh Structure & Function within Extinction Risk in Marine Reserve Freshwater Ponds Australia’s Freshwater Biodiversity Hotspot

Shane Lavery // The University of Gavin Lear // The University of Matthew Le Feuvre // University Auckland Auckland of Melbourne

Agnès Le Port // Leigh Marine Julia Bellamy, Brad Case, Hannah Buckley Freshwater ecosystems are under Laboratory // Lincoln University threat globally from habitat destruction, Adrian Croucher, John Montgomery // salinisation, pollution, invasive species The University of Auckland The extent to which bacterial communities and climate change. As a result many exhibit small-scale biogeographic patterns freshwater species are threatened with The benefits of marine reserves as in their distribution and function remains extinction. Predicting which species a conservation tool are now widely unclear. In this study, we investigate small- are most vulnerable is complex, recognised. However, whether they scale variability in bacterial community requiring knowledge of distribution, can substantially enhance surrounding structure and function within a patchwork population size, and niche and life- fished populations through increased of shallow alpine tarns. Using a grid-based history specialisation. Species with larval export and provide a buffer against sampling design, we collected 100+ small ranges, small population sizes and overexploitation remains a major research water samples located between 4 and narrow ecological niches are thought gap in marine reserve science. In New 60 m apart. For every sample, variability to be subject to a ‘triple jeopardy’ risk Zealand, snapper (Pagrus auratus) support in bacterial community structure was of extinction. Within Australia, almost important commercial and recreational monitored using a DNA-fingerprinting 20% of freshwater fishes are listed fisheries. A multi-disciplinary approach methodology (ARISA) whereas differences as threatened by the Commonwealth including 3D hydrodynamic modelling of in bacterial community function (i.e. government. The pristine Kimberley larval dispersal and parentage analysis is carbon substrate utilisation patterns) region is a hotspot of freshwater fish being undertaken to quantify the extent of were recorded from Biolog Ecoplates. biodiversity, with 50 species of freshwater connectivity, dispersal, self- recruitment The exact spatial location and dominant fish recorded and 17 endemic species. and local retention of snapper from a physico-chemical conditions (e.g., The endemics are highly range-restricted; well-established marine reserve (Cape pH, water temperature, depth) were eleven are known from single rivers, two Rodney to Okakari Point marine reserve). simultaneously recorded from every are found in single river reaches, and We will present an overview of our sample location. Results of multivariate all have little corresponding ecological research programme, and preliminary Mantel correlograms showed that, on data. Thus, the conservation status of results from hydrodynamic modelling and average, bacterial community structure Kimberley fishes is unknown and none DNA parentage analysis, to address the and function became significantly different are listed. By comparing range extents, importance of this reserve as a source of comparing samples located 20 m or population sizes and niche and life-history juveniles to fished populations. more apart. Variance partitioning revealed specialisations among range-restricted that purely spatial variation accounted endemics and widespread co-occurring for the more of the observed variability congeneric species, I aim to quantitatively in both bacterial community structure assess their extinction risk. Also, I plan to and function than the combination of determine the physiological capacities of purely environmental variation and these species to assess their persistence spatially structured environmental under predicted future climates. Using variation. Contour plots of bacterial collections from six months fieldwork community similarity revealed greater in the Kimberley during the wet and dry spatial structuring in bacterial community seasons, I will discuss the distributions structure than function suggesting and relative abundances in Kimberley that some of the changes in bacterial fish species and results for their degree community structure are functionally of specialisation. With the Kimberley ‘redundant’. Our investigation, which threatened by development, invasive is one of the smallest scale studies of species and future climate change, bacterial biogeography conducted within these endemic species may indeed be lentic freshwater, reveals the presence more vulnerable to extinction than their of distinct bacterial communities across widespread co-occurring congenerics. unexpectedly small spatial scales. We suggest that even within relatively mixed ponds, bacterial communities separated by distances of >20 m may be dispersal limited, differentiating at a rate which is faster than they are mixed together due to ecological drift.

116 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Mulloway Movement within A Review of On-ground Spatial Patterns in the Glenelg River Estuary Recovery Actions for Functional Redundancy within South-western Threatened Freshwater Fish & Ecological Resilience in Victoria & Beyond in Australia Wairoa Embayment, South Eastern Tamaki Strait

Jason Lieschke // Arthur Rylah Mark Lintermans // University of Drew Lohrer // NIWA Institute, Department of Environment Canberra and Primary Industries Sarah Hailes, Katie Cartner, Sanjay Freshwater fish are a highly threatened Wadhwa, Scott Edhouse, Judi Hewitt // Twenty-eight Mulloway (Argyrosomus group and recovery of these threatened NIWA japonicas) were tagged with internal species is an increasingly difficult acoustic transmitters within the Glenelg ecological and social challenge. There We undertook spatially intense sampling River estuary in South-west Victoria. are many different on-ground recovery of intertidal and subtidal soft-sediment The Mulloway were tracked via twenty actions available to managers, but no habitats in Wairoa Embayment (south receivers placed throughout the synthesis of what, how or why these eastern Tamaki Straight) with the estuary. This presentation will focus recovery actions have been deployed. objective of identifying ecological on: Mulloway movement within the Even though taxa may be nationally community types and their spatial estuary, entry and exit times between listed, implementation of recovery arrangements. Wairoa Embayment is the estuary and the southern ocean, the actions is usually the responsibility roughly 41% intertidal and 59% subtidal, influence of freshwater flows (salinity of individual states. A questionnaire with a total area of 21.2 km2. Water from levels) on Mulloway locations and larger was distributed to a variety of fisheries a relatively large and predominantly rural movements outside of the estuary to managers, researchers and private catchment flows down the Wairoa River the Murray Mouth (Coorong) in South individuals involved with threatened and directly into the Wairoa Embayment Australia. The presentation will also fishes. Details of on-ground recovery via a permanently opened channel. highlight the extreme angling pressure actions since 1990 were sought, along Suspended sediment concentrations on Mulloway within the Glenelg River with the reasons that initiated the in the Wairoa River appear to be high, estuary. action, and whether or not they had and the lower Wairoa River channel has an associated monitoring program. thick mangroves on both banks. There Recovery actions were grouped into are extensive sand and shell-dominated 12 categories with the most commonly intertidal flats in the embayment, utilised recovery categories being particularly north of the Wairoa River harvest control, translocation, habitat channel, with slightly elevated muddiness enhancement and stock enhancement. in the southeastern portion. No seagrass The number of recovery actions grew habitat is apparent in the embayment significantly in the decade beginning at present. It is important to recognize 2000 as the impacts of prolonged drought that ecological community types can in southeastern Australia intensified. vary substantially within single physical 58% of recovery actions occurred in classifications (e.g., intertidal sand, the Murray-Darling Basin, although this subtidal mud). Based on observed region only holds 27% of the 74 listed differences in the spatial distributions threatened freshwater fish in Australia. of abundant taxa within the Wairoa Few or no recovery actions were reported Embayment, we were able to identify for many species, and few actions 8 reasonably distinct community types occurred in northern or western parts of (4 intertidal and 4 subtidal). We also the country. More than 80% of recovery explored the data to examine the spatial actions reportedly had some form of distribution of functional redundancy monitoring. The diversity of management (which relates to ecosystem resilience) interventions is reviewed, and patterns and key ecosystem services such as and issues identified to guide future carbon sequestration by shell-forming recovery efforts. bivalves.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 117 SPEAKER ABSTRACTS

Juvenile Snapper & Their Managing Mangrove Impacts of Humans on Seagrass Nurseries – a Tail Expansion in Northern New Zealand Marine of Undersea Meadows & New Zealand Estuaries Ecosystems Since First Roving Small Fish Packs Settlement: Synthesis of Major Findings & Management Implications

Meredith Lowe // NIWA Carolyn Lundquist // NIWA, Alison MacDiarmid // NIWA University of Auckland Mark Morrison, Crispin Middleton, Dane New Zealand was the last major land Buckthought, Matthew Smith, Emma Mangroves in New Zealand are increasing mass to be settled by humans, occurring Jones // NIWA in distribution, and have responded sometime in the period 1230–1280 AD. Tegan Evans // The University of favourably to changing land-use and Consequently, New Zealand has a short Auckland, NIWA increased rates of sediment deposition and reasonably complete archaeological, Melanie Vaughan // Auckland Council, in estuaries. Many coastal communities historical and contemporary record of NIWA view native mangroves as pest species human exploitation of marine resources. that have decreased coastal access The collaborative, multi-disciplinary, and reduced amenity values, and there Taking Stock project exploited these Snapper (Pagrus auratus) are a key coastal is widespread support for estuarine natural advantages to examine the commercial and recreational fisheries restoration projects that result in removal effects of climate variation and human species in New Zealand. Recent work has of mangrove forests. Consent decisions impact on the structure and functioning shown that juveniles (c < 90 mm, <1 year for mangrove removal projects are of New Zealand shelf ecosystems over old) are often associated with biogenic often based on historical mangrove the timescale of human occupation. habitat types, including seagrass, horse abundance, prevention of coastal erosion, Two regions, the Hauraki Gulf and the mussels, and sponges, within estuarine flood protection and drainage, and the Otago-Catlins shelf, were chosen as case and sheltered water areas; all vulnerable to potential to restore human uses of the studies of the broader New Zealand wide degradation/loss through human activities, marine environment such as cultural changes as they were both settled by both land-based and marine. Sub-tidal or recreational access. However, the Māori at about the same time, but have seagrass meadows in particular support likelihood of successful restoration, and since experienced contrasting trajectories disproportionately high densities relative to the time required for habitat recovery to in human population size and marine other habitat types. We examined juvenile occur, are rarely considered in consent resource use. This paper synthesises snapper habitat usage for the three largest decisions. Key information needs to the major findings of the project and remaining seagrass meadow areas in assist decision-making for restoration provides some overall implications for northern New Zealand (southern Kaipara, activities that involve mangrove removal marine conservation and management Parengarenga, Rangaunu harbours). include: 1) what defines recovery, and gained from taking a long view of Seagrass areas were mapped (aerial should we expect sandflats to return human impacts on New Zealand shelf photography in Kaipara, satellite imagery in where historical impacts have changed ecosystems. East Northland), and these maps used to the underlying habitat; 2) what physical allocate fish sampling using beach seines attributes (exposure, tides, sediment (n = ~200 sites) across the harbours. High type, catchment, freshwater influx) juvenile snapper (11–80 mm) densities and biological attributes are associated were caught extensively in association with with limited (or fast) recovery; 3) what lush sub-tidal seagrass, and higher tidal methods (both machinery used, and velocities. In the Kaipara, catches ranged spatial and temporal scale of removals) from the multiple tens to low hundreds, are associated with speed of recovery; with apparent increasing juvenile size and 4) are long-term costs of maintaining with water depth (c 5 m range); in East a restoration site free from mangroves Northland catches ranged from several linked to physical and biological hundred up into the thousands. Baited/ attributes? Compiling scientific evidence un-baited cameras also revealed substantial on where mangrove removals have numbers of juvenile snapper. The remote (and have not) been successful can sensing data appeared to correlate well assist in estuarine restoration projects with differing juvenile snapper catch in identifying areas either too expensive rates. In East Northland, field observations to maintain, or unlikely to benefit from strongly suggested that sub-catchments restoration efforts. with less run-off/development/more native vegetation cover had better seagrass cover/ condition and higher juvenile snapper densities. These survey data are being used to assess how land-based impacts cascade into juvenile snapper production, and ultimately coastal fisheries productivity.

118 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Alexandriun catenella Marine Reserve Effect of Salinity on Blooms are a New Resilience in Response to Growth of Juvenile Yarra Problem for the Sedimentation Pygmy Perch (Nannoperca Aquaculture Industry in the obscura: Percichthyidae) Marlborough Sounds

Lincoln Mackenzie // Cawthron Diana Macpherson // The Hillary Mahon // Flinders University Institute University of Waikato James Harris // Flinders University Ben Knight // Cawthron Institute Prof Chris Battershill, Prof Cam Nelson // The University of Waikato The threatened Yarra pygmy perch In March 2011 saxitoxins were detected (Nannoperca obscura, Klunzinger 1872) in mussels from Tory Channel, Queen Te Angiangi Marine Reserve protects 446 is endemic to the south-eastern coast of Charlotte Sound (QCS). This signaled hectares of coastline in southern Hawke’s Australia, where its native river systems the beginning of a bloom of the toxic Bay. During a severe storm event in April have been heavily modified since dinoflagellate Alexandrium catenella, 2011, a significant area of the coast European settlement. The purpose of which over the next two months including the reserve, was subjected to this study was to explore the relationship progressed throughout the sound and a large-scale sedimentation event due between the growth rates of juvenile resulted in lengthy shellfish harvest to mass wasting of the adjacent coastal N. obscura and salinity. Growth trials closures. A. catenella had never hills. The hills are characterised by weak, were conducted using five salinity previously been identified in this region highly jointed mudstone that is rich in treatments (0.3–10.0 ppt) representing and the event appeared to be due to smectite clay minerals making them perceived and potential salinity values a recent incursion. It was feared that prone to erosion during rainfall, resulting within N. obscura’s environment. After A. catenella would spread to the major in extensive landslides. A large proportion eight weeks of exposure, growth was mussel growing areas within Pelorus of the landslide debris consists of the recorded as weight (g) and standard Sound, Port Underwood, Tasman and soft mudstone, which rapidly weathers length (mm). Growth was optimal when Golden Bays and become a serious and into fine sediment, therefore facilitating N. obscura was exposed to moderate chronic constraint on the productivity its easy dispersal and deposition offshore salinity concentrations (3.0–8.5 ppt), of the industry. Subsequent sediment at depths >30 m. Rapid weathering and therefore identifying the ideal salinity surveys have revealed that A catenella subsequent offshore transport of the range for N. obscura. During this study, benthic resting cysts are widespread fines suggests there was a relatively short juveniles from two brood-groups were within QCS, with particularly high period in which intertidal organisms were trialed simultaneously in an attempt numbers within the Onepua/Opua subjected to the effects of sedimentation. to quantify intraspecific variation in inlet extending off Tory Channel and Nevertheless an ecological intertidal phenotypic response to salinity, however this location is the origin of seasonally survey carried out after the sedimentation no significant differences in the genetic recurrent blooms. Analysis of sediment event on key species (paua (Haliotis spp), composition of the two groups was core strata from Opua Bay has shown kina (Evechinus chloroticus), and seagrass detected. This indicates a limited that A. catenella has been resident at (Zostera capricorni)) indicated an impact in genetic variance which may restrict the this location for at least several decades. both reserve and non-reserve populations. adaptability of N. obscura and impair Detailed observations on the progression A faster recovery pattern demonstrated its ability to survive continuing salinity of the annual A. catenella blooms in Opua by reserve populations was unexpected, modifications occurring in its native Bay have been made over the 2012 and given the small area of protection and habitat. 2013 summers and data collected on suggests some degree of resilience. physical, nutrient chemistry and biological Significant differences in paua and kina factors that influence the timing, demographics were observed between magnitude, duration and distribution of reserve and non-reserve populations, with the bloom from year to year. Research is larger numbers of juveniles recruiting ongoing to improve current monitoring within the reserve. The reserve continues technologies, understand the autecology to fare better. Importantly, the event of A. catenella in the sounds and develop permitted a comparison of responses to bloom prediction and tracking tools to severe sedimentation inside and outside enable management and mitigation of its of a marine reserve, where good ‘before effects in the future impact’ time series data afforded a unique opportunity to examine whether protection has increased ecological resilience to sedimentation.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 119 SPEAKER ABSTRACTS

Habitats at the Interface Some Issues Encountered Has Intertidal Mudflat of Estuaries & their with Catch Rate Biodiversity Changed as Catchments: how to Standardisation for Demersal a Result of Earthquake Consider Them in Coastal Scalefish Fisheries in Disturbance? Marine Spatial Planning for Western Australia the Kaipara Harbour

Leane Makey // Auckland Ross Marriott // Department of Islay Marsden // University of University of Technology Fisheries Western Australia Canterbury

Nina von Westernhagen // Auckland Commercial catch per unit of effort (cpue) Earthquakes are extreme natural events University of Technology information is often used to develop and with tsunamis can result in large Deborah Harding, Alyssce Te Huna // Te an index of historical fish abundance, scale changes in estuarine escosystems. Uri o Hau Settlement Trust typically when no other, more reliable In September 2010 and February 2011, data are available. Standardizing cpue Christchurch in the South Island of New Mangroves, seagrass, sandflats, mudflats, data for the influence of variables other Zealand was rocked by several large saltmarsh-­wetland complexes, tidal rivers, than the relative abundance of the earthquakes. Sand volcanoes, formed coastal forest, and coastal scrub are all fish population typically involves the from liquified sediment, appeared on the habitats at the interface of catchments application of Generalized Linear Models surface of the Avon-Heathcote Estuary/ and estuaries. These habitats are all (GLMs), of some form or another, to such Ihutai. Much of the city sewerage system currently represented in the Kaipara datasets. Fishery-dependent measures are infrastructure failed and large quantities Harbour and there were most likely often biased, however, and sometimes a of raw sewage were discharged into the other habitats present prior to land-use conventional GLM cpue standardization estuary. There were also coseismic shifts changes such as cockle, horse mussel will not be sufficient in correcting for in elevation with some areas lifted by up and scallop beds. Isolated remnants of these biases. Two such sources of bias to 0.5m and others subsided by 0.5 m. highly biodiverse areas still persist in the are: (i) cumulative fleet-wide increases This presentation describes the changes Kaipara Harbour. Coastal marine spatial in fishing efficiency over time and (ii) that occurred in intertidal mudflat benthos planning is a tool used to pro-­actively the influence of spatiotemporal fleet as a result of earthquake disturbance manage the use of resources, spatial dynamics on cpue. Both can result in and evaluates whether these resulted conflicts, population growth, protect violating direct proportionality between in changed functional relationships. or restore ecosystem services and cpue and relative fish abundance if not Communities have been followed over ensure benefits for future generations. properly accounted for, with potential time and the disturbance effects found My doctoral research investigated implications for advice arising from to be site and shore level specific. Some concepts where spatial planning for the stock assessments. I present some case habitat types recovered quickly while Kaipara Harbour considers habitats at studies for recent stock assessments of others are still showing the effects of the the interface of harbour and catchment demersal scalefish fisheries in Western disturbances. This presentation discusses to promote ecological and physical Australia to illustrate both scenarios, the resilience of estuarine communities to processes, address local socio-economic and some methods that have been earthquake disturbances and highlights needs and cross-system threats and implemented for addressing these issues. the need for remediation in some cases. stressors. Habitat data collected at I then outline a Masters (Research) study 400 sites in the Kaipara and other data that aims to address an issue that can sources, such as wading seabirds and compound difficulties in dealing with freshwater ecosystems of New Zealand, issue (ii): incomplete spatiotemporal data were considered to promote land-sea structures. planning. This will be presented and how they were incorporated into the coastal marine spatial planning software Marxan with Zones.

120 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Controlling Nuisance Algae Water Quality & the Lake Using a Microbial Water by Single Limiting Nutrient: Waikaremoana Trout Quality Stream/Sediment Where’s the Evidence? Fishery: Satellite Imagery Model to Explain Low-flow & High Frequency Water Microbial Persistence: Quality Monitoring those Bleeding Sediments

Kate McArthur // The Catalyst Chris McBride // The University of Graham McBride // NIWA Group Waikato Sandy Elliott // NIWA Control of nuisance growths of algae Mathew Allan, David Hamilton // The in rivers, lakes, estuaries and coastal University of Waikato Observations of faecal bacteria in streams waters is a significant resource Matthew Osborne, Rob Pitkethley // Fish most usually finds them at persistent low management concern internationally, & Game New Zealand concentrations during dry-weather low and in New Zealand. Increasingly, land flows, when deposition is most likely to use intensification, fertiliser application Lake Waikaremoana, a deep, monomictic be occurring. This can be a challenge, and animal stocking rates are causing and relatively pristine lake in the North for example detailed modelling of Campylobacter eutrophic effects in freshwater and Island of New Zealand, is an ecosystem in the Toenepi catchment marine ecosystems. Eutrophication not of cultural, economic, and conservation had difficulty in accounting for this only affects the structure and function significance. However, water quality in phenomenon. Since drainage inputs of aquatic ecosystems, sometimes with the lake has been infrequently monitored don’t seem to be the answer, we should pervasive effects on local biodiversity over recent decades. In late 2009, a consider whether microbial deposition and ecosystem health, but can also high-frequency monitoring buoy was and “sediment bleeding” be occurring degrade human aesthetic, recreational deployed, to improve understanding of simultaneously. It would seem from a et al. and cultural values for water. The water quality dynamics in the lake, with recent study (Yakarevich 2013, macronutrients nitrogen and phosphorus specific reference to the potential for lake Water Research 47: 2675) that this may are key contaminants of concern for light climate to impact the trout fishery. be possible. It would require that the managing aquatic systems at risk of or We used monitoring buoy data critical bed shear stress for entrainment suffering from eutrophication. Optimum to gain insight into the thermal and should be less that its counterpart for uptake of these nutrients for growth in mixing regime, hypolimnetic oxygen resuspension. Using realistic values of aquatic plants has been shown to occur demand, turbidity, light climate and key model parameters we explore the in a specific ratio (known as the Redfield linkages with water level, as well as algal conditions under which this can occur ratio). Theories for limiting algal growth production in Waikaremoana. Satellite and speculate on the need to modify through controlling the availability of images (MODIS, MERIS, LANDSAT7) “standard” models to account for this a single nutrient in an aquatic system were used to examine lake turbidity, phenomenon. (the nutrient in most limited supply) including ‘hindcasting’ turbidity in the have been adopted into management lake. High rainfall events transported strategies and policy in the past (e.g. large quantities of sediments and/ the Manawatu River Water Quality Plan or organic matter and nutrients to the and others). But there is little evidence lake. Historic satellite images showed to suggest that historical management that turbid inflows generally come from through control of a limiting nutrient has the north (Hopuruahine arm) and east been successful. Single nutrient control of the lake, and may result in spatial of algal growth is making a come-back heterogeneity of the light climate in in water resource management in New the lake. Monitoring buoy data suggest Zealand. We examine the international that turbid plumes may insert at density evidence around the use of nutrient dependent depth in the water column. limitation as a control tool and discuss These insertions can occur at depths the risks, advantages and disadvantages of the lake preferred by trout, and may of this approach for water management impact primary production by reducing in the context of freshwater and marine euphotic depth. Satellite images suggest systems. that surface turbidity following a flood in October 2005 was especially high. These events, along with the lake light climate dynamics shown by the monitoring buoy, are consistent with current thinking that severe flood events can impact the Waikaremoana fishery.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 121 SPEAKER ABSTRACTS

Assisting Water Resources Rock Snot on Solid Ground: South Island Rudd – just Management Using Long-term Stream Bed how Old are they, & when Quantitative Microbial Risk Stability & Didymo Blooms are they Spawning? Assessment

Graham McBride // NIWA Jonathan McCallum // University Helen McCaughan // Department of Otago of Conservation Dr Rebecca Stott, Dr Chris Palliser // NIWA Globally, the diatom Didymosphenia Léo Godard // Department of geminata (didymo) is recognised as Conservation Hearings of discharge consent a nuisance species in freshwaters applications commonly consider results as it forms mass growths on the Currently there is no published obtained from Quantitative Microbial Risk benthos. Research has shown that information on rudd (Scardinius Assessment (QMRA), directly considering didymo growth is controlled by the erythrophthalmus) populations in the pathogens as well as traditional faecal concentration of dissolved reactive South Island of New Zealand. From 2011 indicator bacteria. Examples are: phosphorus, assisted by a stable flow to 2013 the Department of Conservation Manukau, Hamilton, Picton, Timaru, regime. The purpose of this study was has been collecting otolith and gonad Napier, and the 2003 national freshwater to provide a greater understanding of data from selected Canterbury and West recreational guidelines (based on the relationship between long-term Coast rudd populations as part of its campylobacteriosis). In some cases stream bed stability and didymo growth. ongoing Pest Fish Programme. Otoliths the decisions of a Hearing may call I performed a stream survey at the were flat ground to enable annuli to be for subsequent confirmatory evidence reach scale (50 metres along the bank) counted, using reflected light and a black (Napier, New Plymouth). Yet in many across the South Island of New Zealand background. Gonads were weighed and ways QMRA falls into the category of comparing didymo standing crop and compared to body weights to assess their “young science”; there are therefore traps cover proportion to the Pfankuch index, ripeness peak/s. Preliminary data shows for the unwary. In this presentation we a qualitative bed stability assessment that the oldest rudd were six years and will first define the essential QMRA steps: tool. Pfankuch values, dissolved the West Coast fish grew faster than (i) Select the appropriate pathogen(s); reactive phosphorus concentration and the Canterbury fish. Gonad analysis so (2) Identify human exposures to those turbidity measurements were compared far showed two clear ripeness peaks pathogens; (3) Analyse dose response; as predictors of didymo standing for female fish, but only one for males. (4) Characterise risks. This sets the stage crop and cover using an information- Ongoing work is needed to collect more for clarifying at least some of the traps. theoretic approach. Models containing gonad data and to compare this with For example: (1) The most important Pfankuch bed stability to predict didymo age to show when they first spawn in pathogen(s) may not be identified standing crop and cover were the most the South Island. This information will if the QMRA team does not include parsimonious. These results suggest assist with better targeting of control and a microbiologist or a public health that long-term stream bed stability is eradication operations. specialist, and discussion with them an important environmental variable is needed to clarify whether to focus controlling the formation of didymo on infection or on illness as the end- blooms. point; (2) Recent exposure studies have refined (and in many cases reduced) the magnitude of exposures (e.g., how much water is ingested during a swimming event?); (3) Some literature on clinical trials and outbreak studies can be rather contradictory (e.g., for Campylobacter and Norovirus), and care is need to harmonise dose units; (4) Incorporation of various forms uncertainty is a challenging task. None-the-less, with careful application, QMRA can be very instructive in identifying risks to recreational water user and shellfish consumption, particularly for waters close to discharges.

122 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Microsatellite Analyses A West Coast Whitebaiter’s Responses of Three New Reveal Recruitment Perspective Zealand Native Fishes to Relationships in New Floods in a Small Stream Zealand’s Blackfoot Abalone (Paua), Haliotis iris

Tom McCowan // Paua Industry Des McEnaney // President of Amber McEwan // Riverscapes Council Ltd West Coast Whitebaiters Association Freshwater Ecology

Gerard Prendeville // PAUMAC7 This presentation gives a short history of Mike Joy // Riverscapes Freshwater Neil Gemmell // University of Otago the growth of a lifestyle and an industry Ecology on the South Island’s West Coast, Understanding recruitment patterns in including subsistence living of the early Floods are an integral part of flowing marine species is important for effective gold miners and the first commercial river systems yet our understanding of fisheries management strategies. New endeavours of the Chinese gold miners. freshwater fish behaviour during floods Zealand’s blackfoot paua (Haliotis iris) With the establishment of the industry is limited. In 2008, 67 redfin bullies is a species of customary, recreational came whitebait factories, which grew (Gobiomorphus huttoni), 22 shortjaw and commercial fishing importance. over time. Improvement of transport kōkōpu (Galaxias postvectis) and 29 Paua are broadcast spawners that options and rail links had an impact kōaro (Galaxias brevipinnis) were tagged have a planktonic larval phase, on the whitebaiters. The legendary with Passive Integrated Transponder meaning recruitment patterns are figures of the Haast opened a whitebait (PIT) tags and monitored in a 100 m largely determined by the extent of canning factory at Okuru, and set up study reach before, during or after three larval dispersal. The microscopic size New Zealand’s first commercial flying floods. Detection patterns of tagged fish and typically large quantities of larvae operation. Challenges were met in an indicated that they may be displaced or produced by broadcast spawning isolated and unforgiving land, including may move to areas with large substrates marine species means larval dispersal is issues with rail transport. The opening during floods. Two individuals returned to difficult to trace in situ. However, using of the Haast highway brought changes, the same locations during multiple floods, genetic tools, specifically parentage as did improvement in refrigeration. suggesting that previous experience analyses, it is possible to identify the With changes to the industry there was may influence refuge selection for parental origins of new recruits. These development of whitebaiting regulations. some individuals. While small changes relationships can be used to draw Issues facing both our lifestyle and in community composition occurred conclusions about the extent of larval the industry today include the rapid that could be attributed to concurrent dispersal and corresponding recruitment expansion of dairy farming and its impact, habitat changes, overall a remarkable patterns. We investigated recruitment with compliance rules evolving as we level of persistence of individual fish was patterns using genetic methodologies learn. Some of the steps being taken observed in the tagged community. based on ten microsatellite markers to address gravel extraction impacts, in paua populations in Tory Channel, consent shortcomings, and compliance Marlborough Sounds, New Zealand. issues include a restoration project at Parentage analyses between samples of Greymouth. I will consider a future review 200 adult and 200 juvenile paua returned and simplification of the whitebaiting up to seven positive parent-offspring regulations as a conservation measure. matches. These findings revealed events of ‘self-recruitment’ back to the same reef at scales of 10s of metres, and several events of longer-range dispersal up to 4 km. Information about the larval dispersal potential and recruitment in paua can be used in management strategies such as determining the scales and potential utility of protected areas.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 123 SPEAKER ABSTRACTS

Data Analysis & Modelling Bioeconomic Decision Forty Years of Monitoring to Assist Management Making for a Lobster the New Zealand Snapper Decision Making for South Fishery: Comparing Four Fisheries; What We Know Australian Snapper Fishery Management We Don’t Know Approaches

Richard McGarvey // South Richard McGarvey // South Jeremy McKenzie // NIWA Australian Research and Development Australian Research and Development Institute Institute With over 40 years of fisheries data collection, snapper (Pagrus auratus) is Paul Burch, John Feenstra, Anthony André Punt // CSIRO one of New Zealand’s most intensely Fowler // South Australian Research John Feenstra, Paul Burch, Janet monitored commercial fish species. and Development Institute Matthews, Adrian Linnane // South The wealth of snapper monitoring data, in addition to enabling fisheries Australian Research & Development scientists to better determine stock Institute Snapper catches and indices of status, also provides valuable insight abundance in South Australian waters Klaas Hartmann, Caleb Gardner // into snapper biology and ecology. show dramatic fluctuations in time and University of Tasmania Understanding the distribution and space. Not all of this variation appears abundance of a fish species in time to be recruitment driven, and snapper In Australasian fisheries, and worldwide, and space is a fundamental to both appear sensitive to levels of fishery tools of increasing sophistication are being fisheries management and the broader exploitation. The fishery in South Australia developed to account for the economic realm of coastal marine ecology. In this is managed by a flexible toolbox of effort impact of management decisions. Two presentation I investigate the snapper controls. Prior to 2012 these included effects of management decision making fisheries monitoring data for evidence temporal closures during the spawning can increase fishery profitability: catch, of spatial and temporal heterogeneity, season (no fishing in November), and thus revenues can rise, or effort, focussing primarily on growth, gear restrictions (no netting), size (38 and thus variable costs of fishing, can be movement, and recruitment. I also cm TL minimum size), and bag limits reduced. In the Australian southern rock discuss some possible future research for recreationalists. In this talk, we lobster fishery, landed price also varies directions for snapper, i.e. “what we summarise a suite of additional measures by month of the fishing season, and by know we don’t know”. that were evaluated to reduce overall lobster size. In these fisheries, an existing levels of human exploitation. A length- length-based stock assessment model, and age-based fishery model for the three whose parameters are estimated by fitting main gulf fisheries is described. This to multiple data sources using maximum was used to test additional management likelihood, has been developed for yearly measures: extensions of the November stock assessment. This model has now closure, commercial fishing trip limits, been extended to allow projections going reductions in the number of hooks forward in time, predicting catch rates, longline fishers can deploy, and quota. total catches, revenues, variable and fixed A new method to visually display the costs, and thus overall fishery profit, under relative performance of each strategy a wide range of possible management as a single point on a ‘management strategies. Four common fishery policies scatterplot’ to quantify the trade-off of have been examined with this decision increases in egg production with losses making tool: minimum size and maximum of catch will be described. Other more size limits, constant quotas, and quotas direct data analyses were undertaken which vary yearly to approximate a to compute the likely impact of various constant exploitation rate. The performance effort controls and their respective of these four policies are compared. levels, as percentage reductions in Maximum size yields the lowest future state-wide exploitation rate. In 2012, the average profit (as net present value, NPV), Minister and PIRSA Fisheries managers but raising minimum size improves NPV in implemented a comprehensive suite of the South Australian Southern Zone model. enhanced effort control measures to Constant quotas greatly improve on size reduce exploitation of snapper in South limits. The highest profits (as NPV) were Australian waters. predicted for the management approach which varies quota under a harvest control rule that mimics constant exploitation rate. Management scatterplots permit an easy visual way to see, at a glance, which strategies are the best performers.

124 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Planning for a Healthy Avon Sensitivity Analysis of a Of Fat & Fish: Do Limitations River – the Avon River Catchment Model (SWAT) in Membrane Remodelling Precinct Anchor Project to Simulate Flow & Loads of Capacity Contribute to Nutrients & Sediments in the Narrow Temperature Puarenga Stream, Rotorua Tolerances of Polar Fish?

Shelley McMurtrie // EOS Ecology Wang Me // Hohai University Victoria Metcalf // Lincoln University Alex James // EOS Ecology Jonathan Abell, David Hamilton // The University of Waikato Vanita Malekar // Lincoln University The destructive effect of the 22 February 2011 earthquake has resulted in a The Soil Water Assessment Tool (SWAT) Climate change models predict complete reimagining and rebuild of the is a process–based catchment model widespread loss of biodiversity and Christchurch CBD. First delineated in the designed to simulate water quantity and extreme change in polar regions. Whilst ‘blue print’ for the Christchurch Central quality in streams and rivers. The model we know that impacts are dictated Recovery Plan, the North/East Frames and provides a tool to evaluate the effects of by an organism’s ability to alter gene Avon River Precinct (ARP) (collectively different land management practices and expression in response to environmental called The Frame) are arguably the most subsequently inform the design of policy variation, we still lack understanding significant of the anchor projects to the to achieve water quality targets. Although of mechanisms by which organisms people of Christchurch. Extending for 3.2 SWAT has been used extensively adapt to thermal change. Antarctic km along the Avon River as well as a 12 overseas, it has yet to be widely trialled biota and in particular, notothenioid fish ha block of previously commercial land, in New Zealand. In this study, SWAT are an ideal system to explore thermal The Frame provides an unprecedented was configured for the Puarenga Stream adaptation, especially limitations in opportunity to match the community’s catchment (77 km2; Rotorua, Bay of gene expression capacity in organisms desire for a ‘green’ city and improve Plenty) which contains numerous point that exhibit narrow thermal tolerance the health of the Avon River – the and diffuse pollution sources. The model (stenotherms). I will provide an overview ‘jewel in the crown’ of Christchurch simulates stream flow and estimates of thermal adaptive theory and outline City. Given the current degraded state nutrient and sediment loads exported into key findings on the effects of AGW of the Avon River, improving its health Lake Rotorua downstream. Values for on Antarctic biota. Lastly I will outline required a design approach that was parameter values were either calculated my own research interests in this area. more than surface deep, with ecology using measured data or derived using Embedded within the accepted paradigm becoming a cornerstone of the concept both manual and automated calibration. of thermal limitation are changes in lipid design process. Through using the A Sequential Uncertainty Fitting (SUFI) saturation to maintain membrane fluidity past and present state of the river approach was then used to rank the and oxygen movement. Desaturases to inform restoration potential, and most sensitive model parameters. Based are key regulators of membrane lipid an understanding of urban ecology, on this sensitivity ranking, a manual composition and exhibit temperature landscape dynamics and waterway ‘one at a time’ routine was applied to regulation, suggesting they play central restoration design, we were able to investigate how parameter sensitivity roles in thermal adaptation. Delta-9 develop a set of key design criteria for varied for different components of the desaturase (SCD), our principal target, improving the health of the river. The stream hydrograph. Results showed that catalyses an initial, rate limiting step integration of these critical habitat and the sensitivity of some parameters greatly in unsaturated fatty acid formation. stormwater management features in the depended on the relative contribution of Notothenioid fish favour unsaturated concept design will mean we are well base flow and quick flow, whereas some fatty acids for metabolism and within placed to realise the overarching vision parameters were invariant to flow regime. membranes, invoking a key role for of a biodiverse and functioning river The results can help SWAT modellers to SCD. Our hypothesis is that membrane ecosystem that is balanced with multi- streamline model calibration and have remodelling, a universal temperature use, outdoor space essential to a modern important implications for quantifying response, occurs at reduced capacity city. The design approach and ecological uncertainty when modelling scenarios in stenotherms, contributing to narrow enhancements planned for The Frame is such as climate change which involve thermal tolerances, and limiting their an exemplar of what we can achieve in altered flow regimes. adaptive potential. We are determining our urban centres to improve the health SCD cDNA sequences in eurythermal and wellbeing of both environment and and stenothermal notothenioids, and people. SCD tissue distribution and expression level differences. Tissues from a thermal acclimation study on stenotherms are allowing us to test whether as temperatures increase, SCD mRNA levels are thermally unresponsive.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 125 SPEAKER ABSTRACTS

Sediment Impacts on Will I Get Sick if I Swim? Assessing the Potential Paua (Haliotis iris) & Kina Updating the National of Morphological & (Evechinus chloroticus): Microbiological Water Pigmentation Larval Building Indigenous Marine Quality Guidelines for Development Characters Science Capability Recreational Waters for Phylogenetic Analysis of Gobiidae

Sonja Miller // Victoria University Juliet Milne // Greater Wellington Tony Miskiewicz // Wollongong of Wellington Regional Councill City Council

Peter Edwards, Shane Parata, whina Brent King // Ministry for the Environment The Gobiidei are a very diverse group of VUCEL Incubator Team // Victoria fish comprising nine families with about University of Wellington Most regional and unitary councils 270 genera and 2,210 species. There throughout New Zealand undertake have been a variety of studies undertaken New Zealand comprises only 0.2% annual recreational water quality using morphological, osteological of the world’s land area, yet inputs of monitoring programmes in collaboration and molecular characters of adults to sediments to the coastal zone approach with Territorial Local Authorities and investigate phylogenetic relationships almost 1% of world sediment yields. the Public Health Units of District within the group. Larval developmental Sediments can negatively impact benthic Health Boards. Monitoring is carried series collected from southern Australian species such as pāua (Haliotis iris) and out over the summer months to assess waters of seven genera of Gobiidae kina (Evechinus chloroticus). Both species the microbiological water quality of (210 genera, 1,950 spp.) Arenigobius, comprise significant fisheries with over freshwater and nearshore coastal areas Afurcagobius, Favonigobius, Gobiopterus, 40% of commercial pāua quota in Māori commonly used for contact recreation. Paedogobius, Psuedogobius and ownership, while kina is an important The monitoring results are compared Redigobius and two genera of Eleotridae customary fishery. The Āwhina VUCEL to ‘trigger levels’ in the Ministry for (35 genera 155 spp.) Hypseleotris and Incubator, at Victoria University’s Coastal the Environment (MfE) and Ministry Philypnodon were assessed. For larval Ecology Laboratory (VUCEL), has been of Health (MoH) microbiological water development series of these nine genera, investigating the impact of suspended quality guidelines (2003). Monitoring ontogenetic changes in body shape and sediments on reproduction, growth, data collated over time are also used pigmentation patterns and the size at and oxygen consumption for pāua and to calculate a Suitability for Recreation development of fins, notochord flexion kina. However, we take an alternative Grade (SFRG) for each monitoring site. and transition to juveniles for each research approach. Our kaupapa Ten years on from their implementation, genus were documented. There was (goal) is to produce Māori and Pacific a comprehensive review and update considerable variation in these larval marine scientists who will contribute of the existing national guidelines is characters between the two families and to leadership and development in their now underway. The review is focussing between genera. The larval development communities. Our team comprises on a number of key areas, including characters were assessed to determine a Māori postdoctoral fellow, and site selection and sample number similarities and differences between undergraduate and postgraduate students requirements, the methodology for genera and then compared with the who are Māori or Pacific or non-Māori deriving SFRGs, the use of rainfall- proposed lineages for these genera based / Pacific but support our kaupapa. We related monitoring data, roles and on adult characters. all have backgrounds in the biological responsibilities, and reporting frameworks sciences and statistics, and belong to and communications. Complimentary Te Rōpū Āwhina (Āwhina) at Victoria guideline documents (eg, cyanobacteria University. The focus of Āwhina is to in fresh waters) will also be looked at produce Māori and Pacific scientists with consideration given to how these to contribute to Māori and Pacific guidelines can be used together to community development and leadership. provide a more comprehensive view of Our unique approach is important for water quality for recreational uses. This future Māori and Pacific development and presentation will touch briefly on these tino rangatiratanga (self-determination). areas and bring you the very latest update More importantly, our work is ground- on the process and progress underway to breaking as we are creating a model review the microbiological water quality for indigenous peoples and universities guidelines. to successfully work together to build indigenous science capability, while at the same time increasing knowledge around the impacts of sediment on important invertebrate fisheries. We discuss our research results in this context.

126 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Waikato Taniwharau: Grey Mullet Nurseries & Within & Among – Individual Competing Needs in Connectivity – Where did Variation Underpins the Management of the I Come From, Where will I Population-level Responses Waikato River Go? to Temperature in a Marine Fish

Dr Kepa Morgan // The University Mark Morrison // NIWA John Morrongiello // CSIRO of Auckland Bronwyn Gillanders // University of Ron Thresher // CSIRO Dr Linda Te Aho // The University of Adelaide Waikato Jeremy McKenzie, Crispin Middleton, In ecological studies the data we Marie Jordan, Dane Buckthought, Catriona collect is usually hierarchical. Repeated The Waikato River has significant Paterson, Emma Jones, Darren Parsons, measurements are taken from each of spiritual relevance for the Waikato- Keren Spong, Holly Ferguson, Meredith many individuals, which in turn span Tainui people and other river iwi, who Lowe, Matthew Smith, Andrew Miller // overlapping time periods, cohorts and regard it as an indicator of their mauri NIWA populations. Traditionally, we aggregate or well-being, and central to their Cameron Walsh // Stock Monitoring this data and explore biological responses to environmental variability at the within identity. The Waikato is also the focus Services Ltd of on-going tensions between Māori or among population level. Such an cultural and spiritual values and beliefs, approach, whilst valid, limits our ability and national engineering objectives. Grey mullet (Mugil cephalus) occur globally to explore the underlying mechanisms The river system is a strategic asset for from warm temperate to tropical waters driving population responses. The power generation and the flow has been in both hemispheres. In New Zealand expression of phenotypic traits, like extensively modified with the engineering its distribution is focussed around the growth, varies within an individual northern half of the North Island, where it is of dams, lakes, tunnels and canals used (adaptively, non-adaptively or neither) managed as one stock (GMU 1), with circa to generate one sixth of New Zealand’s depending on the environmental 900–1000 t extracted p.a. by commercial total electrical generating capacity. These conditions experienced. Investigating and recreational fishers. However, Catch power generation assets are now for phenotypic plasticity through individual Per Unit Effort (CPUE) analyses suggests sale. An analysis has been carried out reaction norms provide a means of that substantial smaller scale spatial using the Mauri Model Decision Making decomposing population level variation structure may exist, with possibly 5–6 Framework. The Mauri Model is unique into its within- and among-individual distinct sub-populations, some of which are in its approach to the management of components. This in turn aids ecological declining in abundance. Adult movement water resources as the framework offers and evolutionary interpretation of dynamics are complex, with ‘polymorphic’ a transparent and inclusive approach historical patterns, and facilitates behaviours including both estuarine more accurate prediction of biological to considering the environmental, residency and seasonal coastal migrations responses to future environmental economic, social and cultural aspects (partial migration) including along surf change. Here we apply novel statistical of decisions being contemplated. The beaches; and movement into freshwater techniques, that explicitly account for the Mauri Model is is capable of including systems including the Waikato River data’s underlying hierarchical structure, multiple-worldviews and adopts and associated lakes. However, juvenile to decompose population-level variation mauri (intrinsic value) in the place of grey mullet are estuarine-dependent, in tiger flathead growth (as inferred from money based assessments of pseudo making their nursery grounds relatively otolith analysis) into its within and among sustainability using Cost Benefit Analysis. well-defined. To assess potential spatial individual components. Our results An assessment is presented within population structure, in 2010 we sampled indicate that projected ocean temperature the context of new co-management 0+ fish (c 30–80 mm) from all putative aspirations that require decision nursery estuaries in northern New Zealand rises will result in spatially differentiated making to reflect the values of both the (n=80), with site (n=176) replication in changes in fishery productivity, but that Government and the Waikato-Tainui the larger systems. These fish are being the underlying causal mechanisms for peoples. How might the Mauri Model analysed using otolith chemistry to assess this temperature response are spatially contribute in the complex context of co- whether distinctive elemental ‘signatures’ variable. We show that what appear management of the Waikato River? Three exist for individual and/or groups of to be consistent among-population existing resource uses are assessed to estuaries. Field data on catch rates/rates of patterns in temperature-related growth illustrate the contribution that alternative detection are also being used to semi- are underpinned by varying levels of frameworks can make to an enhanced quantitatively assess which estuaries hold phenotypic plasticity and potentially understanding of the challenges that the most of the recruits. If the otolith approach micro-evolved directional change. new co-management regime will need to is successful, then the 2010 year class overcome. will be resampled in 2014/15 as adults; to quantify dispersal and spatial mixing of fish from different natal estuaries; assess possible source-sink dynamics between estuaries; and to better understand the different behavioural morphs contributing to the overall population/s.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 127 SPEAKER ABSTRACTS

A Fish in the Desert: Resolving Small-scale Effects of Short Term Ecology & Behaviour Flows & Turbulence: Exposure to Rena Heavy of the Desert Goby Novel Measurements Fuel Oil & the Dispersant Chlamydogobius eremius From Surface Fronts at Corexit 9500 on the Early Biologically Relevant Scales Life-stages of Seriola lalandi

Krystina Mossop // Monash Julia Mullarney // The University Simon Muncaster // Bay of University of Waikato Plenty Polytechnic

David Chapple, Bob Wong // Monash Stephen Henderson // Washington State Fenna Beets // The University of Waikato University University Early life stages of marine fish often exist A region of unique biogeographic Freshwater plumes play a critical role in in a temporary planktonic phase which history, the already extreme arid the nearshore transport and dispersal leaves them vulnerable to the effects of environment of the Lake Eyre Basin of of nutrients, pollutants and sediments. oil spills. Few studies in New Zealand central Australia is currently subject to However, in shallow environments such have investigated the toxic effects of oil change due to human activities, yet the as tidal flats, it can be difficult to resolve and dispersants on marine fish embryos implications for native aquatic species small-scale flow features, particularly and larvae. This study exposed the early are little known. Here, we focus on the on biologically-relevant spatial and life stages of kingfish, Seriola lalandi to a behaviour, ecology and distribution temporal scales. We present a novel dilution series of heavy fuel oil from the of the desert goby (Chlamydogobius design for a surface drifter, mounted Rena wreck as well as the commercial eremius), a small, bottom-dwelling fish with a pulse-coherent Acoustic Doppler dispersant Corexit 9500. There was no that inhabits fragmented habitat patches Profiler (ADP) for measuring near-surface trend evident between concentration of in the form of ephemeral rivers and (depths 0.18–1 m) flows. This new oil or dispersed oil and survival over 24 desert springs. Using a comparison of design allowed high-quality and high- hours. There was, however, macroscopic populations inhabiting different habitat resolution Lagrangian measurements of evidence of physical deformities in larvae types, I will present experimental data velocities and turbulence in depths as that had been exposed to the higher on i) morphology and ii) exploration shallow as 0.4 m. During repeated drifter concentrations of the water-soluble and dispersal behaviour within a deployments over the tidal flats of Skagit fraction of oil over a 48 hour period. phylogeographic framework. The results Bay, Washington, drifters were advected Sublethal damage of contaminant provide insights into the evolution and towards, and subsequently trapped on exposure on DNA strand length is under persistence of a desert-adapted fish, and a convergent surface front. The front investigation. Implications of this study implications for the management of two was clearly marked by a surface scum will be discussed along with possibilities closely related but endangered species, line and propagated across tidal flats at for further research. the Elizabeth Spring and Edgbaston the head of a freshwater plume. Depth- gobies. dependent velocities revealed regions of vertically sheared currents and wave motions not resolved by surface drifters alone. Near-surface turbulent kinetic energy dissipation rates were enhanced near the front at the plume’s leading edge, whereas dissipation measured in the stratified plume behind the front was suppressed. Moreover, high levels of backscatter, often accompanied by intensified turbulent dissipation were observed to briefly penetrate throughout the depth of the water column when the drifter propagated across small subtidal channels.

128 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Wind Force – Stratification Population Genetic Study of Shear Stress Interaction Time Lag Structure in Freshwater Effect in Maccullochella Depends on Lake Fish from Southwest peelii peelii Larvae Morphology Western Australia

Kohji Muraoka // The University of Jonathan Murphy // Murdoch Anna Navarro-Cuenca // Waikato University Charles Sturt University

David Hamilton // The University of Population connectivity that maintains Craig Boys, Wayne Robinson, Waikato morphological species similarity is Lee Baumgartner // Department of Piet Verburg // NIWA largely believed to be due to the historic Primary Industries, NSW coalescence of river basins in a period Max Finlayson // Charles Sturt University Density stratification in lakes influences continuous enough to counteract Daniel Deng // Pacific Northwest National an array of biogeochemical processes. genetic population divergence. Laboratory, USA Strong wind drags surface water and However, individual species biology and ecology suggests that not all species creates water column instability. This The construction of dams and weirs in are equally able to take advantage of effect of wind energy on overall lake the aquatic systems can have a negative these connections. Populations may be stratification usually involves a time effect on native fish requitement. Early differently isolated and thus represent lag. The mechanisms responsible for stages of Australian native fish may be different levels of evolutionary significant this concept are generally accepted, susceptible to injury or death as they pass units. Ecological indices may suggest but have not been well quantified. through turbines or weirs during their trends in population connectivity though This study examined wind shear stress downstream drift. it is only with the use of molecular with emphasis on determination of the The understanding of the influence markers that population structure can relationship between lake morphology of these mechanisms on the survival be accurately analysed. Two species of and the scale of wind driven energy of larvae fish is important to the freshwater fish endemic to the Southwest inputs. High frequency (< 1 hour interval) management of fish populations and of Western Australia (SWWA), Galaxias thermistor measurements from five lake infrastructure design. Murray cod occidentalis and Nannoperca vittata, were investigated; Lakes Feeagh (42 m (Maccullochella peelii peelii), has suffered 2 represent species that suggest population maximum depth, 3 km surface area, a decline in its population during the 2 structures defined by river basin the USA), Rotoehu (13.5 m, 7 km , NZ), last decade, which has resulted in an 2 coalescence. Both species are less than Rotorua (26 m, 80 km , NZ), Taupo (160 increased concern that this specie 2 200mm in length but they differ markedly m, 616 km , NZ). The Lake Analyzer could be vulnerable to turbines and in other biological traits. Preliminary software was applied to calculate the lake weirs passage during its downstream genetic results indicate vastly different physical stability metric Schmidt stability drift. Early stages of Murray cod were population genetic structures. Galaxias using temperature and hypsographic exposed to shear stress environments occidentalis, the more dispersedly data. Schmidt stability was used as the in the laboratory to establish injury and potent species due to greater swimming response variable of the wind stresses. mortality threshold based on estimates prowess and other behavioural attributes, Unique sensitivity analysis was carried out of shear stress rate. Larvae were possesses a population genetic structure for both the scale of wind speed and the exposed to a submerged jet with exit that is highly varied within individual scale of temporal representation of wind velocities from 0 to 10 m/s, providing populations, whilst possessing little speed. We found that the morphological shear stress of up to 1,296.87 cm/s/cm. differentiation between populations. features of the lakes were correlated with Major injuries and total mortality showed Nannoperca vittata, however, is a polar the time and energy required to weaken a significant increase related with the opposite. These species, that possess stratification, as described by Schmidt magnitude of shear stress, but negatively concurrent ranges, indicate that ecology stability decline. related with the age of the larvae. The and biology may have a larger impact on onset of injuries and mortality occurred their genetic population structure than at nozzle velocities of 3.13 m/s with geological opportunity would suggest. mortalities between 11.9% and 13.64%. Climate change projections for SWWA These results suggest that shear stress predict a reduction in available freshwater is an important mechanisms affecting habitats. As this increases, populations survival of larvae Murray cod when of species will disappear. Species such passing though weirs and hydropower as Nannoperca vittata will be at greatest facilities. risk of degradation due to a reduction in species genetic diversity.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 129 SPEAKER ABSTRACTS

Marine Protected Areas Characterisation of Subtidal Past & Present Location of – Where are We at? Rhodolith Beds in Northern the Subtropical Front South Progress in Implementing New Zealand & their of New Zealand the New Zealand MPA Associated Biodiversity Policy

Don Neale // Department of Wendy Nelson // NIWA Helen NEIL // NIWA Conservation K.Neill, N.Barr, R.D’Archino // NIWA Bruce Hayward, Ashwaq Sabaa // The New Zealand MPA Policy spells T.Farr // Royal Society of NZ Geomarine Research out ten tasks within a three stage S.Miller // ESR Mike Williams // NIWA implementation plan. Stage 1 is complete Rob Smith, Ross Vennell // Otago with a national classification based on Subtidal rhodolith beds were studied in University depth, substrate and energy categories northern New Zealand, examining their (Task 1), a protection standard that structure and physical characteristics The subtropical front (STF) is the northern defines which areas – including marine and documenting their associated extent of the Southern Ocean and is a reserves – qualify as MPAs (Task 2), and biodiversity. Field work was conducted major frontal zone that separates the mapping of existing management tools at two locations in the Bay of Islands, warm, low nutrient, salty subtropical within a GIS framework (Task 3). Stage Kahuwhera Bay and Te Miko Reef, in surface waters (STW) from the cold, high 2 has progressed with the development February and October. The rhodolith beds nutrient, fresh subantarctic surface waters of an MPA inventory (Task 4) and the were mapped using a combination of (SAW). As a result of the mixing between identification of network gaps (Task 5) techniques, and physical characteristics these two water masses, the STF is a that show there are many large gaps of the habitats were assessed. The region of high productivity. Over the last in the current MPA network in most rhodolith beds differed significantly few years several voyages on the RV biogeographic regions and for a range in terms of water motion, sediment Tangaroa have been dedicated to studying of habitat types. This second stage is characteristics and light levels. Two the oceanographic fronts and collecting nearing completion with the priorities for species of rhodolith forming coralline a transect of sediment cores from the establishing new MPAs (Task 6) presently algae were found, Sporolithon durum southern tip of New Zealand (46.5°S), being determined to identify future and Lithothamnion crispatum, and their down the Solander Trough to a latitude opportunities. Stage 3 will implement distribution and physical attributes were of 50°S, crossing the STF and sitting just MPA planning: in the nearshore measured. The associated diversity of north of the subantarctic front (SAF). environment using regional Marine the rhodolith beds was investigated, The hydrographic data has allowed us to Protection Planning Forums such as have sampling (1) invertebrates at three define the location of the STF, and show been most recently undertaken in the levels of association (epifauna, infauna, that it is bathymetrically constrained in Subantarctic and South Island West Coast cryptofauna), (2) macroalgae, and (3) this region by the Macquarie Ridge and biogeographic regions (Task 7); and in fishes, as well as recording the biogenic features on the Campbell Plateau. Data the offshore environment using an expert and non-biogenic substrates. A total from the sediment cores suggests that panel (Task 8). These tasks are combined of 1,088 lots of invertebrates (2,093 this has not always been the case, and with designating new MPAs in both the individuals) were collected and 82% the location of the STF has shifted over nearshore and the offshore environments of lots and 87% of individuals were glacial/interglacial cycles. Sea surface (Task 9). Monitoring and evaluation of identified to species level. Rhodolith beds temperature proxies suggest the STF did the MPA network (Task 10) will continue provide three-dimensional habitat for not pass south of New Zealand during the to evolve as technologies and scientific associated biota, and collections made last glacial maximum, 21,000 to 18,000 understanding of MPA design develops. during this study included new records of years ago, but moved in to the Solander Future progress in the remaining stages marine algae and invertebrates for New Trough very early in the deglaciation. The will need wide-ranging support from the Zealand and Northland, as well as new STF was at its most southerly position marine science community and others in discoveries of both genera and species. ~50°S during the early Holocene, 10,000 order to achieve the Biodiversity Strategy Significant differences were found in the years ago. The shifts in the position of objective to establish a representative species composition inside and outside the STF over the last 30,000 years had a network of MPAs throughout New the rhodolith beds at both Kahuwhera major impact on New Zealand’s climate. Zealand’s marine environment. Bay and Te Miko Reef.

130 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Undersea New Zealand The Marine Reservoir The Density Dependent Effect in the East Tasman Effects of Two Key Sea & Ocean-atmosphere Macrofauna Species on the Carbon Exchange Breakdown of Ulva

Helen Neil // NIWA Helen Neil // NIWA Clarisse Niemand // The University of Waikato New Zealand sits astride an active plate Rewi Newnham, Gavin Dunbar, Ashley margin, which results in a highly complex Pocock // Victoria University of Wellington Agnes Karlson // University of Otago, and diverse seascape from submarine Helen Bostock, Lisa Northcote // NIWA Stockholm University trenches to underwater volcanoes, to Quan Hua // Australian Nuclear Science & Candida Savage // University of Otago active submarine canyons and channels. Technology Organisation Conrad Pilditch // The University of Undersea New Zealand provides a unique Waikato insight into the deep-sea, and for the first Ocean waters have an apparent 14C age time since its original release in 1997, that ranges from several hundred to several Macroalgal blooms such as Ulva, are NIWA is publishing an updated product. thousand years older than coeval terrestrial a common disturbance to estuarine Using a Kongsberg EM-302 multi-beam 14C ages. This is the result of deep water benthic fauna worldwide. As large echo-sounder, and its predecessor upwelling and delay in exchange rates quantities of macroalgae break free (EM300), which have now been used for between atmospheric CO and ocean from the growing substrate, drifting mapping the New Zealand realm from 2 carbon. However, the amplitude of offset mats are formed that eventually deposit the Equator to the Antarctic for over has not remained constant over time, or in low energy environments including twelve years, an additional 500,000 km2 remained the same between different intertidal sandflats. Once these mats of the New Zealand seafloor has been ocean water depths. New Zealand lies start to decompose, the detritus is mapped in high resolution by NIWA. The at the critical junction between northern- incorporated into the benthic foodweb, inclusion of this data, and fifteen years of tropical climate influences and those of however, the ability to process detritus is additional survey data has resulted in a the Southern Ocean and its sedimentary likely to depend on the species present. new digital elevation model that reveals, archives may hold the key to understanding In this study, we examined the density for the first time, many features that have complex climate interactions back many dependent effects of two key intertidal remained hidden beneath the waves. thousands of years beyond historical bivalve species (the deposit-feeder This vast submerged continental region records. It has been suggested that the Macomona liliana and the suspension- comprises a variety of geomorphological Southern Ocean is the most likely area feeder Austrovenus stutchburyi) on the and geological structures. A combination of exchange between the oceanic and breakdown, loss and burial of Ulva. We of seabed maps, characterising the atmospheric reservoirs, with intermediate collected 72 cores from an intertidal shape and composition of the seafloor, water carrying the ‘old’ signature to sandflat that spanned natural gradients and deep-sea photography, allows us to lower latitudes. Evidence from the SW in bivalve densities and returned them illustrate and describe the morphological Pacific has shown a rapid increase in to a laboratory facility that mimicked features of the SW Pacific in New benthic foraminiferal 13C at the start of tidal inundation periods. Labelled (13C Zealand’s waters, providing a unique the deglaciation at intermediate depths, and 15N) Ulva detritus was added to the view of the topography of the seafloor, indicative of a ventilation event. However, surface of each core and 12 days later its ecological characteristics and other studies from the SE Pacific have the sediment was sampled to determine biodiversity hotspots. This mapping precluded the influence of an old carbon the depth distribution of Ulva and the product provides significant benefit for all source from the Southern Ocean and amount remaining (using chlorophyll a New Zealanders and for all users of the indicate that the deglacial 14C depletion (chl a) and isotopes signatures). Initial marine environment, revealing potential previously identified must have involved results showed strong vertical variations for fisheries, environmental management, other contributions, either an expanded in the chl a distribution with community conservation, hazard mitigation, and influence of a 14C-depleted North Pacific type and bivalve density. Chl a was energy and mineral opportunities, iwi and carbon reservoir or an alternatively sourced mixed deep into the sediments in cores recreational use, as well as providing key abyssal reservoir. A depth transect of dominated by high Austrovenus numbers baseline knowledge on which to build cores collected in the east Tasman Sea whereas in Macomona cores it remained well targeted future scientific research. off the west coast of New Zealand, sit at the surface. These differences in burial at the boundary of northern-sourced depths and mixing are likely to influence and southern-sourced waters. These detrital processing rates which will be stratigraphically constrained cores are examined using isotopic signatures. ideal for assessing deglacial 14C changes Knowledge of Ulva detritus processing in sub-Antarctic mode water, Antarctic as a function of community type will Intermediate Water, and upper and lower aid in our understanding of resilience to Circumpolar Deep Water. Here preliminary the disturbances caused by macroalgal results of reservoir age variations and ocean blooms. ventilation are presented showing variability with time and water mass.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 131 SPEAKER ABSTRACTS

Barra Gone Wild: Stuck in the Mud: Biogeo- Cage-scale Dissolved Investigating the Genetic chemical Processes in Oxygen Variability: Clay Consequences of a Subtidal Sediments in Point Observations Large-scale Escape of the Firth of Thames, New Farmed Barramundi Zealand (Lates calcarifer)

Tansyn Noble // James Cook Scott Nodder // NIWA Joanne O’Callaghan // NIWA University Craig Depree, John Zeldis // NIWA Craig Stevens // NIWA Carolyn Smith-Keune, Dean Jerry // James Cook University Previous NIWA modelling and field Dissolved oxygen (DO) is a relative investigations of the Firth of Thames, measure of how much oxygen is carried Expansion of sea-cage aquaculture New Zealand, shows that it exhibits a in a fluid. Low DO concentrations are has increased incidences of large-scale distinct shift from being predominantly an indicator of poor water quality with escapes of farmed fish. Aquaculture heterotrophic in the shallow parts of the major implications for a number of stocks commonly differ in genetic embayment that are affected by run-off ecosystem functions. In the context profile from wild populations due to from agricultural land, to autotrophic in of finfish aquaculture, sufficient DO few broodstock being used to produce the outer parts of the Firth, where more concentrations are necessary for fish progeny and artificial selection pressures nutrients are sourced from offshore. In respiration and their overall health. imposed by the culture environment. summer 2012, a research voyage onboard Using observations from an experiment When mixed with wild populations, RV Kaharoa was undertaken to gather at Clay Point, Marlborough Sounds in farmed fish can significantly affect the information along this heterotrophic- 2011, cage-scale variability of DO will genetic profile of the natural population. autotrophic gradient to obtain direct be discussed. Lower DO concentrations Escape events are well-characterised for estimates of sediment denitrification and were seen inside a stocked cage when temperate fishes but few studies have oxygen consumption rates in order to compared to vertical profiles adjacent to reported the occurrence and persistence corroborate the previous investigations. the cage, i.e. 75% saturation compared of tropical fish escapees in the wild. In Two shallow sites (7-8 m, FoT1 and 2) to 90%. Concurrent temperature, salinity 2011 a cyclone destroyed a barramundi were sampled in the inner part of the and flow observations will explore the sea-cage facility in the Hinchinbrook firth, where previous fieldwork has physical-biological coupling of cage-scale Island region, Queensland, releasing ~280 observed high air-sea pCO2 fluxes (i.e., dynamics. tonne of fish. One year after the escapee high community respiration), and two event genetic samples were collected sites sampled in the outer firth (~37 m, from 403 barramundi within Hinchinbrook FoT3 and 4) at the location of relatively Channel. Fish were assigned as farm low pCO2. Sediments in the inner firth escapees or wild by matching multi-locus varied markedly, with coarse shell hash microsatellite genotypes to those of the at FoT1 and well sorted olive-grey hatchery broodstock used to produce mud at FoT2. Sediments at FoT3 and progeny stocked into the sea cages. DNA 4 comprised fine muddy sand to silty parentage analyses confirmed escaped clay, with common bivalve fragments. barramundi had become established in Although the sediments were strongly the Hinchinbrook population, with 31% heterotrophic at all locations, sediment of fish sampled of farm origin. A single oxygen consumption in the inner firth male-female pairing accounted for 32% of was almost double the rates in the outer these escapees. Lower levels of genetic firth. Pore-water concentrations of NH4 variation, high relatedness, and deviations were high at the inner sites, although the from Hardy-Weinberg expectations were anaerobic flux of NH4 was low suggesting evident among escaped fish. If these that organic matter in the sediments fish reproduce then the genetic integrity is mineralised via oxic and suboxic and level of relatedness of the receiving (ie denitrification and Mn/Fe cycling) population may be affected over the processes. The results were consistent longer term. Results emphasise the need with predictions regarding the impacts of to monitor for genetic changes in this terrestrial runoff to this key New Zealand population into the future. coastal area.

132 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Porirua Harbour – Part 1: Managing Water Quality Fine-tuning the Rotorua Desperately Seeking Clarity & Allocation in the Lakes Stocking Program Waianakarua River

Megan Oliver // Greater Wellington Dean Olsen // Otago Regional Matt Osborne // Fish & Game New Regional Councill Council Zealand

Juliet Milne // Greater Wellington The Waianakarua River is a medium-sized The Rotorua Lakes Selective Breeding Regional Councill river in North Otago that flows out of Program has been working for around Mal Green // NIWA a catchment that supports a diverse 35 years to produce and liberate quality Keith Calderl // Porirua City Council range of land uses including extensive stock to the Eastern Fish & Game Region. pastoral farming (35%), intensive farming Lack of sufficient spawning tributaries Porirua Harbour lies on the south-west (9%), and plantation forestry (9%). In dictates a requirement for stocking to coast of the North Island, and is regionally addition, there is substantial consumptive meet high angler demand. But can we significant comprising two largely subtidal abstraction of water for agriculture. work smarter to maximise returns for estuaries, the Pauatahanui and Onepoto Recent surveys indicate that the the angler’s dollar. Recently undertaken inlets. Despite high ecological, cultural Waianakarua catchment supports a very research suggests that spreading and recreational values, both estuaries diverse and abundant fish community liberations over a wider timeframe is have suffered from contamination and and good water quality, although the beneficial to survival and angler return habitat loss due to catchment run-off presence of benthic cyanobacteria mats rather than one off mass-release’s that and reclamation. Since 2011, Greater during summer has resulted in the have been the norm in the past. Utilizing Wellington Regional Council (GWRC) has warning signage. Otago Regional Council the ‘datawatch’ tagged fish monitoring convened annual Porirua Harbour and has implemented several planning program, 500 ‘T-bar’ tagged rainbow trout catchment science workshops to discuss instruments that will affect how the (Oncorhynchus mykiss) were liberated into environmental pressures and research Waianakarua catchment is managed in Lake Tarawera each month during 2010. and monitoring priorities to support the the future, including the establishment Subsequent angler and fish-trap tag- management of these estuaries. In 2012, of a minimum flow and allocation limit returns have illustrated the importance the Porirua Harbour and Catchment as well as water quality standards for the of timing trout liberations to avoid the Strategy and Action Plan was launched catchment, discharge limits and limits on incidence of early and/or late onset to address the three main environmental nitrogen leaching rates. winters that may affect yearling trout issues: sedimentation, pollution (toxicants survival. The results obtained to date will and nutrients) and habitat loss. This be discussed. strategy is a collaboration between Porirua City Council, Wellington City Council, GWRC and Ngati Toa and outlines a set of initiatives to address the issues. Following the first science workshop, sedimentation was identified as the biggest issue facing the harbour and the one, which if reduced through improved catchment management, would also lower pollution and enhance habitat restoration efforts. Subsequently, a target areal sedimentation rate of 1 mm/year has been agreed, which lies between the pre- human and present-day sedimentation rates. In this presentation, which is the first of two talks on managing sedimentation in Porirua Harbour, we discuss the sedimentation issue and how the target sedimentation rate has been arrived at.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 133 SPEAKER ABSTRACTS

Kakanui River, Otago Energy use in A Life History Review for Implications of Australian Fisheries: New Zealand Snapper Groundwater-Surface Economic Performance, Water Interaction Environmental Impact, & Implications for Management

Rachel Ozanne // Otago Regional Robert Parker // University of Darren Parsons // NIWA Council Tasmania Carina Sim-Smith // ClearSight The Kakanui River’s water resource is Anna Farmery, Klaas Hartmann, Bridget Consultants Ltd heavily used for irrigation purposes. The Green, Caleb Gardner // University of river has three minimum flow sites to Tasmania Tom Trnski // Auckland War Memorial manage water quantity, but concern has Museum been expressed about degradation of Energy inputs to fisheries production are Martin Cryer // Ministry for Primary Industries the water quality, particularly since the of increasing concern, as they represent Malcolm Francis, Bruce Hartill Emma introduction of irrigation water which has both a growing cost to fishermen and Jones, Agnès Le Port, Jeremy McKenzie, allowed for agricultural intensification. A a source of greenhouse gas emissions. Mark Morrison, Keren Spong, John Zeldis significant input of nitrogen (N) occurs Measuring and improving energy // NIWA between the upper and lower Kakanui performance of fisheries is critical to Larry Paul // NIWA (formerly) which changes the main-stem of the efforts to transition the industry into a Craig Radford // The University of Kakanui from N-limited to P-limited. world of increasing fuel prices, emissions- Auckland This change in chemistry is a result of based regulations, and consumer Phil Ross // The University of Waikato high N-groundwater input, sourced demands for low-carbon production. We Natalie Usmar // Saltwater Science mainly from animal waste. The drying assessed a range of Australian fisheries up of a tributary of the Kakanui during on the basis of fuel consumption as a Cameron Walsh // Stock Monitoring the summer months increases the driver of both environmental impact and Services proportion of nutrient-rich groundwater operational costs. We compared fisheries contribution to flow. As a result of the operating in different regions, targeting Snapper populations have contributed input of high N-groundwater, the lower different species and employing different to important fisheries in New Zealand Kakanui is unlikely to achieve low enough gears. This enabled us to identify those for hundreds of years and also form concentrations of N to prevent the recent fisheries which are most dependent on a crucial part of inshore ecosystems. proliferation of benthic algae biomass. the input of fossil fuels, and therefore As a result, more research has been may be most vulnerable to volatility in conducted on snapper than nearly fuel commodity prices. Many Australian any other New Zealand fish species. A fisheries, particularly crustacean fisheries, growing dimension to this research is the which have historically been more consideration of a broader ecosystem energy-intensive, have demonstrated context to all impacts on snapper the ability to adapt to increasing fuel populations (also known as an Ecosystem prices, with some decreasing their Approach to Fisheries). As such, it is consumption by more than 50% over the timely that ten years on from a previous past decade. Numerous factors influence workshop on snapper, the life history and the energy performance of fisheries, and environmental interactions of snapper in decisions made at the regulatory level New Zealand are being reviewed. Here may have significant impacts – both I present highlights from a workshop of positive and negative – which should New Zealand snapper researchers that be taken into consideration to ensure addressed the life history and threats to long-term economic and environmental snapper populations going forward. sustainability. We explore some of these management implications in relation to observed patterns and trends in fuel use by Australian fisheries.

134 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

The International A Big Body Essential to Global Expectations & Framework Governing the Inhabit Estuaries: a Study Requirements for science Role of Science in High on Mysids of Southern to Support High-seas Seas Fisheries New Zealand? Management

Rosemary Paterson // Ministry Sourav Paul // University of Otago Andrew Penney // Australian of Foreign Affairs and Trade, New Bureau of Agricultural and Resource Zealand Gerry Closs, Keith Probert, Jolyn Chia // Economics and Sciences University of Otago An outline of the development of the Mackenzie Gilliam // University of The adoption of UN General Assembly international framework governing the California Davis Resolution 61/105 on Sustainable role of science in fisheries management Fisheries in 2007 dramatically changed for high seas fisheries, as well as In temperate estuaries, mysid distribution international expectations regarding for fisheries within areas of national could be limited by an interaction protection of vulnerable marine jurisdiction. The fundamental obligations between physiological tolerance and ecosystems and low productivity in the 1982 United Nations Convention on life-history, specifically mediated by fish stocks in the high seas, and the the Law of the Sea (UNCLOS) have been body size. We tested such ideas by information required to do so. In parallel, elaborated through the Rio processes contrasting up-downstream distribution conferences of the Convention on (Agenda 21 and the Convention on of two common estuarine mysids Biodiversity have established increasing Biological Diversity). The UN Fish Stocks (Tenagomysis chiltoni: large bodied, requirements to assess and protect high- Agreement further advanced the role dominant in upstream, one cohort per seas biodiversity, resulting in an ongoing of science, and this has been reflected year and T.novaezealandiae: small bodied, process to identify Ecologically or in modern Fisheries Management dominant in downstream, multiple Biologically Significant Areas. While the Organisations such as the new South cohorts per year) species in southern New FAO and CBD have provided guidelines Pacific Regional Fisheries Management Zealand. Previous work has indicated on how these requirements might be Organisation. Rules and guidelines limited survival in fresh or sea water in met, many of the details of how this governing sustainable management cold conditions (< 5°C), particularly for should be done have intentionally been of fish stocks as well as to protect juveniles. In this study, we examined left vague. This has provided scientists vulnerable marine ecosystems have growth and fecundity in relation to participating in RFMOs or CBD processes been developed through the various UN distribution. Our field study indicated with substantial challenges on how to processes, via the Food and Agriculture that fecundity of gravid females was interpret these requirements, how to Organisation (FAO), the CBD and relevant positively related to body size, with larger clarify the aspects that have been left UN Resolutions. In particular, the annual bodied T. chiltoni being the most fecund. vague, what information is required to UN General Assembly Resolution on Environmental control of fecundity was provide the necessary advice and what Sustainable Fisheries and the 2008 also evident: Gravid T. novaezealandiae methods are appropriate for generating FAO International Guidelines for the were larger and more fecund in spring reliable analyses under circumstances Management of Deep-Sea Fisheries in the than autumn, and both species were of low information and high uncertainty. High Seas directly impact the application larger and more fecund in intermittent This presentation will briefly identify these of science in this area. estuaries which have agricultural and challenges; give a brief overview of what urban influence. In a subsequent growth science has so far been attempted; and experiment, salinity and food quality what gaps remain in providing the advice interact to influence growth of sub-adults. and evidence needed to support wise We are building different growth models management decisions for the high seas. to explore their maturity time under different habitat conditions. We suggest that cold freshwater in the upper reaches of estuaries may restrict T. chiltoni to spawning once per year, and to overcome such fecundity constraints they must grow larger than T. novaezealandiae which can take advantage of more saline and probably productive conditions downstream to grow faster and produce >1 cohort per year.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 135 SPEAKER ABSTRACTS

Flood Protection & Aquatic Integration of Biological Effects of the Antihistamine Ecology: Investigating the Traits into Regional Diphenhydramine on Algae Effects of Gravel Extraction Biomonitoring Programmes & Biofilm on the Hutt River

Alton Perrie // Greater Wellington Ngaire Phillips // Streamlined Chuyen Phung // Monash Regional Council Environmental University

Flood protection works involving channel Kevin Collier // Waikato Regional Council Michael Grace, Terence Chan // Monash realignment and gravel extraction are Martin Neale // Auckland Council University common activities in the beds of rivers Lawton Shaw // Athabasca University and streams across the Wellington region Regional councils generally employ (and elsewhere). However, the ecological metrics based on macroinvertebrate This study investigated the impacts effects of these works are largely taxonomic composition to describe of an antihistamine medication, unknown. To further our understanding, in the ecological health of the region’s diphenhydramine, on the algae 2012 Greater Wellington Regional Council aquatic resources. An alternative Scenedesmus sp. and on naturally commenced a series of investigations, approach is to use the biological traits occurring biofilm. Diphenhydramine, as one of which was to assess the effects of macroinvertebrates, as these reflect other pharmaceuticals and personal care of gravel extraction from the wetted changes in ecosystem function rather products, typically presents in surface channel on the aquatic ecology of the than just changes in macroinvertebrate waters at trace concentrations, and has Hutt River. Quantitative backpack electric composition. Trait-based biomonitoring also been identified in sediment and fish fishing, macroinvertebrate sampling and would fit readily into existing tissues. However, its ecological effects habitat assessments were undertaken biomonitoring frameworks employed are largely unknown, especially at the from riffle habitat at the ‘impact’ site by regional authorities, as the basic low level concentrations, which have prior to gravel extraction, immediately information (site-by-species composition been found in the natural environment. In after gravel extraction and approximately matrices) is already collected. For terms of the effects of diphenhydramine seven weeks later. Two ‘non-impact’ sites, traits (categories or modalities) to be on algae, experiments for determining located approximately 1 km upstream considered for integration into existing acute and chronic toxicity were and 1 km downstream of the gravel biological monitoring programmes, conducted at environmentally relevant extraction site, were assessed in the they would ideally need to satisfy the concentrations, for up to 11 days. same manner. Of data analysed so far, following criteria: (a) display low levels Growth rate, respiration rate and gross gravel extraction resulted in changes in of variation within categories of land- primary production of the Scenedesmus substrate size and a decline in abundance use intensity, and significant power to sp. were measured. The results show in the most commonly caught fish discriminate medium from low or high that chronic effects were more likely to prior to the extraction (bluegill bully). levels of development; (b) display greater appear than acute effects. There was no However, this decline in abundance was discriminatory power than that achieved detectable impact on the growth rate of mirrored at the site located upstream of by standard metrics; and (c) possess the algae, while there was evidence of the gravel extraction activity, whereas the ability to diagnose causal factors. suppressive effects on both respiration abundance of bluegill bullies increased In this presentation, we combine data rate and gross primary production downstream. Changes in the river flow from 2 regional councils to examine the of Scenedesmus sp. Pharmaceutical path as a result of the extraction activity potential application of traits to biological Diffusing Substrates (PHADS) were also resulted in the stranding of hundreds monitoring, using the land uses of native used to examine the impacts of chronic of fish, including a number of threatened vegetation and rural development. We exposure of diphenhydramine on species. The results of the investigation also present the outcomes of a more biofilms, a more ecologically complex and are discussed in the context of managing detailed analysis of a native vegetation- environmentally representative system of a river with significant ecological to-urban development gradient, using microorganisms. These substrates were values alongside the need for ongoing Auckland Council’s Freshwater Ecology deployed in Jock Marshall Reserve Lake engineering intervention to protect people Programme. We discuss the outcomes (Victoria, Australia) for three weeks to and property from flooding. of these analyses, identifying a core set allow biofilms to colonise and grow. After of traits that could be integrated into recovery, the biofilms were analysed in existing biomonitoring programmes run terms of chlorophyll a, respiration rate by regional authorities. and gross primary production. Changes in these variables help characterize biofilm’s responses to diphenhydramine. The most striking results were that diphenhydramine strongly suppressed biomass (chlorophyll a) and gross primary production, compared to the controls.

136 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Modelling –Developing High Intensity Survey & Foodweb Modelling of the a Strategic & Dynamic Multivariate Statistics Reveal Hauraki Gulf: Integrating Management Tool for the Zones Along the Longitudinal Archaeology, History, Marine Environment profile of the lower Waikato Fisheries Science & River: Implications for Food Ecology Webs

Vernon Pickett // Waikato Regional Michael Pingram // Department of Matt Pinkerton // NIWA Council Conservation, University of Waikato Alison MacDiarmid // NIWA Dougal Greer, Jose Borrero, Ed Atkin // Kevin Collier // Waikato Regional Council, eCoast University of Waikato Foodweb modelling was used to explore Cathy Liu // Waikato Regional Council, David Hamilton, Brendan Hicks // The how the structure and functioning of the University of Waikato University of Waikato Hauraki Gulf ecosystem has changed Hilke Giles // Waikato Regional Council Bruno David // Waikato Regional Council during human occupation. We developed 5 food-web models: (1) present day; (2) 1950 AD, just prior to onset of Having a good understanding of the The importance of environmental industrial-scale fishing; (3) 1790 AD, nearshore environment is of critical heterogeneity and discontinuities in before European whaling and sealing; (4) importance to achieving sound resource lotic ecosystems is well recognised 1500 AD, early Maori settlement phase; management practice. A truism, right? and continues to underpin studies (5) 1000 AD, before human settlement However in the rough and tumble of of hierarchical patch dynamics, in New Zealand. Each model quantifies policy making and implementation geomorphology and landscape ecology. the flow of organic matter through the pragmatism often rules, time frames for These patterns and features can be marine food-web over an annual period. decision-making are often short, and important drivers of river food webs and The model has groups representing existing information and resources are ecological function. The primary aim of biota from bacteria to whales. As often extremely limited. Consequently this study was to locate and characterise part of this project, 10 expert groups high reliance is placed on professional zones of potential ecological importance provided information to help estimate judgement and general theories (research along the lower Waikato River in North an initial set of over 700 parameters. based or otherwise), sometimes leading to Island, New Zealand, using a combination Biomass and catch parameters were high levels of uncertainty, that can lead to of high-frequency, along-river water quality derived from information including conservative and sometimes misdirected measurements collected in four seasons, historical reconstructions of catch decision-making. In order to address and river channel morphology data histories, fisheries stock modelling, these problems and improve the level of derived from aerial photos. Multivariate historical evidence, archaeological applied science surrounding Council’s analyses were implemented to classify information (middens), reconstructions functional activities, Waikato Regional river reaches in an a priori unstructured of past climate, or evidence gleaned Council has embarked on developing the manner along the 134-km surveyed from narratives. A semi-objective use of digital technologies to improve their distance and to then identify zones. The balancing method was used to adjust understanding of the marine environment. resulting clusters of physico-chemical simultaneously all parameters, minimizing One element of this work involves the use and morphological descriptors identified changes in parameters while taking into and development of numerical modelling zones that represent useful spatial units for account relative uncertainties. Trophic as a decision support tool to address management and to underpin ecological levels in the present day model agreed needs within the organisation and the studies such as the development of food well with stable isotope data taken in community. This paper will address our web models. These zones were shaped the study area. The historical ecosystem experiences to date in developing this by the physical complexity and channel models reveal substantial changes in technology using various estuarine and character of constituent river reaches, the pattern of ecological importance coastal model outputs as examples to and shifts, sometimes transitional, of during human occupation. In the models, illustrate its potential use in areas as diverse physico-chemical variables. Changes in marine mammals, sharks and crayfish as natural hazard management, sediment water clarity, chlorophyll fluorescence have declined in ecological importance, and contaminant transport, bio-security and specific conductance were driven while birds, smaller fish (large reef fish, assessments, and surf break protection. by tributary inflows and chlorophyll kahawai, snapper), and crabs have This presentation will also address the need fluorescence increased in the tidal increased in ecological importance. for improved data acquisition technologies, freshwater section of the lower Waikato such as monitoring buoys and remote River. The results highlight the dynamic sensing, as well as collaboration among spatial and temporal properties of these organisations and access to open data in zones which respond over different scales order to achieve larger scale integrated to climatic and hydrological changes, and marine management approaches. One which are likely to lead to differences in such approach is the Waikato Marine carbon flow and other aspects of food web Management Model, which will be briefly structure in the lower Waikato River. introduced here but presented in more detail in following presentations.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 137 SPEAKER ABSTRACTS

Enhancing Environmental Measuring & Modelling The Effects of Short- Biomonitoring Using Next- Water Column Nutrients term Increases in generation Sequencing & Sea Lettuce Blooms in Turbidity on Intertidal (NGS) Tools Tauranga Harbour Microphytobenthic Productivity & Nutrient Fluxes

Xavier Pochon // Cawthron Alex Port // The University of Daniel Pratt // The University of Institute Waikato Waikato

Kirsty Smith, Nigel Keeley, Susanna Wood Karin Bryan, Conrad Pilditch, Kai Bischof, Conrad Pilditch // The University of // Cawthron Institute David Hamilton // The University of Waikato Nathan Bott // South Australian Research Waikato Andrew Lohrer, Simon Thrush // NIWA Institute Jan Pawlowski // University of Geneva Nuisance blooms of sea lettuce (Ulva Turbidity is a major factor limiting benthic spp.) have been occurring in Tauranga primary production and nutrient uptake Recent technological advances in Harbour since at least the early 1990s, on estuarine intertidal sandflats during molecular methodologies provide but it is still unclear which environmental immersion periods. Estuaries can exhibit opportunities to develop innovative factors control or trigger these events. a wide range of suspended sediment diagnostic tools that can streamline and We examine over 20 years of available concentrations (SSC), however, few reduce costs associated with biological monitoring data of intertidal sea studies have quantified the effects of monitoring. Next-Generation Sequencing lettuce abundance, water column on benthic primary producers. Here, we (NGS) is a relatively new technique that nutrients and related parameters, as report on an in situ experiment examining can produce enormous volumes of DNA well as observations from a recent field the effects of short-term increases in or RNA sequence data cost effectively. campaign. The latter provides previously SSC on sandflat primary production This provides potential for sensitive and unavailable data on the spatial (distinctive and nutrient fluxes. Fine sediments rapid detection of all organisms present in subregions within the estuary) and (< 63 µm) were added to sunlit and any given environmental sample (water, temporal (consecutive tides to seasonal) darkened benthic chambers (0.25 m2) soil, sediment). The technique can be variability of water column nutrients as at concentrations ranging from 16–157 applied to a huge range of organisms well as on the drifting population of sea mg L-1 and kept in suspension for a 4–5 expanding the scope of monitoring lettuce (estimates of biomass standing h incubation period. In addition to solute programs into biota and/or habitat groups stock and flux from / to a subregion). fluxes we also measured macrofaunal that are currently not being surveyed due Preliminary results show differences in composition, sediment photopigment to technical limitations or poor taxonomic absolute concentrations of dissolved concentrations and physical properties. In knowledge. Two ongoing research water column nutrients between sunlit chambers, we observed a three- projects will be showcased to illustrate subregions (e.g., catchment-, intertidally- fold reduction in net primary production the pros and cons of using NGS for and subtidally-dominated). Net fluxes over (NPP) with increasing SSC (NPP, R2 = monitoring aquatic ecosystems in New consecutive tides also vary considerably 0.36, p = 0.05) and stronger reductions Zealand. The first project investigates the over a season and between sites, and when NPP was standardised by sediment detection limits of NGS (using the 454 fortnightly sampling at selected sites is chlorophyll-a content (i.e., photosynthetic 2 pyrosequencing platform) with direct ongoing to investigate the consequences efficiency, NPPchl-a, R = 0.62, p ≤ implications for the early detection of for time-averaged import/export balances. 0.01). Concurrent with reductions in a range of key-threats marine invasive Drifting sea lettuce biomass at times photosynthetic efficiency, there was a species. The second project explores reaches levels high enough to warrant four-fold increase in nutrient efflux from + the capacity of NGS (using Illumina and consideration as both a separate pool the sediment to the water column (NH4 , IonTorrent sequencers) for environmental and flux pathway of nutrients bound in R2 = 0.44, p < 0.01). SSC had no effect monitoring of bioindicator foraminiferal macroscopic tissue fragments, whose on solute fluxes in darkened chambers. + communities around fin-fish farms. hydrodynamic transport is most likely Changes in primary production and NH4 Once validated, NGS-based tools have quite different from dissolved and fine efflux were only correlated with SSC tremendous potential for improving New particulate water column nutrients. and light intensity. Our results imply that Zealand’s environmental management Using process-based / mechanistic increased exposure to sedimentation and of a variety of freshwater and marine mathematical models, we determine the frequency of storm events may severely ecosystems. likely interactions and relative importance impair benthic primary productivity and of these environmental factors in increase the flux of inorganic nutrients controlling sea lettuce blooms. from benthic to pelagic systems.

138 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

‘Toxic in Crowds’ – One Size Fits All? A Periphyton & Nutrient Mapping Cyanotoxin Regulatory Approach to Interactions Along the Production Across a Utilising Discharge Limits Tukituki River Under Eutrophic Lake to Achieve Improved Drought, Wet & Normal Environmental Outcomes Summers

Jonathan Puddick // Cawthron Justine Quinn // Auckland Council John Quinn // NIWA Institute Leon Blackburn // Auckland Council Kit Rutherford, Bob Wilcock // NIWA Susie Wood // Cawthron Institute Roger Young // Cawthron Institute Daniel Dietrich // University of Konstanz It is common knowledge that intervention Troy Baisden // GNS Science Shelly Rogers, Michèle Prinsep, is necessary to mitigate the ongoing Sherry Schiff // University of Waterloo Craig Cary, David Hamilton // The effects of urban contamination on Michael English // Wilfred Laurier University of Waikato our waterways. Intervention is usually University achieved via discharge consents, granted only if appropriate management practices Toxic cyanobacterial blooms are Nutrient-periphyton interactions were are implemented to avoid, remedy increasing in prevalence globally. Of investigated during summer under or mitigate effects on the receiving the known cyanobacterial toxins the normal (2011), wet (2012) and drought environment. However, insufficient data hepatotoxic microcystins are the most (2013) conditions along a 90 km long, exist to determine whether the proposed notorious. Laboratory studies have nutrient gradient in the mid-lower controls and limits are achieving shown correlations between the amount Tukituki River, that is driven by nutrient environmental outcomes. In particular, of microcystin produced per cell and a attenuation below upstream inputs not enough is known about specific multitude of physiochemical variables of enriched groundwater and treated receiving environments, which makes including nutrients, temperature and sewage. Steep gradients in dissolved setting discharge limits ‘guesswork’. pH. Whilst these laboratory based N and P concentrations occurred over Industrial and Trade Activities (ITA) within experiments allow environmental the top 30–40 km below nutrient inputs the Auckland region often rely on the conditions to be stringently controlled, under normal and drought conditions, perceived performance of ‘standard’ studying cyanobacteria in these ‘artificial’ whereas in wet 2012 the gentler gradient treatment devices rather than providing environments may alter or remove extended over 90 km. These patterns a full AEE which considers their specific variables that regulate microcystin were related to spatial and temporal receiving environment. Relying on the production. Over the past three years, our differences in flow, temperature, perceived performance of a device is group has been performing experimental periphyton biomass and ecosystem only a suitable approach if all receiving manipulations using mesocosms (55-L metabolism. In situ recirculating chamber environments are the same. The need to polythene chambers suspended in a studies showed contrasting patterns of review and set water quality limits at a lake) to study toxin production in a uptake/release of dissolved inorganic catchment level is gaining momentum more natural environment. During these and organic nutrients between light with the advent of the NPS: Freshwater studies we mimicked the formation and dark conditions that were reflected Management, the Auckland Council of a cyanobacterial bloom or scum in whole river observations at dawn vs Unitary Plan and the proposed ‘super by adding concentrated suspensions daytime. Periphyton abundance and catchment’ Network Discharge Consents. of cyanobacteria to the mesososms. community type (filamentous greens With this in mind, better information These experiments demonstrated a (FGA) vs cyanobacterial/diatom mats about the likely tolerances of specific strong correlation between microcystin (mats) were related to flow pattern, receiving environments is required to production and cell density in the local velocity, nutrients, substrate inform the consent process. Moving mesocosms. This year we profiled a size and invertebrates. Nutrient flux forward, environmental improvement small eutrophic lake (Lake Rotorua, influenced the dominant community cannot be achieved if councils and Kaikoura) to explore whether this same type along the gradient and reach scale businesses continue to operate in phenomenon occurred naturally with distribution among different habitats. an isolated manner. All parties need spatial variation in cell density around the Under moderate-high nutrient conditions to recognise the constraints and lake. Cyanobacterial density was assessed upstream, % cover by mats increased opportunities and work collaboratively to fluorometrically and spatial/depth with velocity, whereas FGA decreased. achieve the best environmental outcomes samples were collected to determine In contrast, at very low nutrient levels, possible. cell and microcystin concentrations, downstream under drought, mats were examine the expression of genes involved absent and FGA were strongly associated in toxin production and to ascertain with high velocity. Periphyton nutrient nutrient levels. This whole lake profile is content (N/C and P/C ratios) decreased being used to elucidate how interactions with distance downstream, a pattern between abiotic and biotic variables that was accentuated under drought influence microcystin synthesis and may conditions when nutrient depletion was ultimately help to predict parts of a lake or greatest. The findings have fed into the periods of greatest health risk. Tukituki River Integrated Management Model (TRIM).

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 139 SPEAKER ABSTRACTS

The Effect of Suspended Communicating Science Molecular Tools to Ensure Sediment on Oxygen Across the Marae Safe New Zealand Seafood Consumption in Haliotis iris – Harmful Algae Bloom Species

Taputukura Raea // Victoria Hannah Rainforth // Ngāti Rangi Lesley Rhodes // Cawthron University of Wellington Trust Institute

Dr Sonja Miller, Dr Joe Zuccarello // Kirsty Smith, Janet Adamson, Viliami Iwi and hapū experiences of western Victoria University of Wellington Langi, Mandy Edgar // Cawthron Institute science have not always been characterised by positive interactions. In New Zealand sedimentation is the There have been misunderstandings. Two decades have passed since a major most important land-based stressor on Knowledge systems have not always harmful algae bloom (HAB) in the Hauraki the coastal marine environment. The been respected, on both sides. Yet iwi Gulf led to a New Zealand-wide ban effects of suspended and deposited remain deeply interested in developments on shellfish harvesting until monitoring sediments on marine organisms include that assist in understanding and caring for programmes were instigated. Since that suffocation, reduced foraging efficiency their rohe and environment. When these time the identification and quantification and clogging of the gills of filter feeders. developments have arisen primarily out of HAB species has been carried out The blackfoot abalone, Haliotis iris (more of a western-science framework, there routinely by Cawthron Institute’s Micro- commonly known as paua) is endemic to is a need for western-based scientists to algae Laboratory. The analyses are labour New Zealand, comprising highly valued communicate the new knowledge across intensive and molecular tools are seen customary, recreational and commercial the marae. Similarly, western-based as the logical future of phytoplankton fisheries. Suspended sediment has been scientists need to know how to listen monitoring. shown to increase mortality in H. iris to the science held by iwi and hapū. In Fluorescent in situ hybridisation larvae, while juvenile H. iris are known a context where iwi and scientists are assays have been available commercially to avoid deposited sediment. However, seeking to work more closely together, for more than a decade to differentiate little else is known about the effects of communication needs to be a gateway, between neurotoxin producing and sedimentation on H. iris. It has been not be used as a gatekeeper. This non-toxic species of the diatom genus suggested that high concentrations of paper explores how to communicate Pseudo-nitzschia. Sandwich hybridisation suspended solids may block the gills science – both western and iwi-based – assays (SHA) are available commercially of H. iris incurring a metabolic cost between communities and practitioners. for the fish-killing raphidophytes and this due to increased mucous production Examples of how to translate between chemistry is used in the autonomous in to clear suspended solids from gills. I iwi and western science languages will situ Environmental Sampling Processor carried out preliminary work to examine be presented, along with an exploration (ESP), developed by the Monterey whether suspended sediment affects of the differences and similarities in Bay Aquarium Research Institute, oxygen consumption in H. iris. Oxygen the underlying frameworks and how to USA. Quantitative PCR (qPCR) assays consumption was significantly reduced find the common ground that will spark have been developed for neurotoxin when H. iris was exposed to elevated interest, trust, and respect. producing Karenia species and paralytic suspended sediment loads. I present shellfish poisoning Alexandrium further work in progress that looks at the species (including resting cysts). QPCR effect of suspended sediment on oxygen technology has also been adapted for consumption in H. iris and suggest use in the ESP, which was successfully possible implications for pāua fisheries in deployed in Tasman Bay, Nelson, in New Zealand. 2012. A SHA array for the simultaneous detection of multiple HAB species was included in that deployment. In the future it is expected that, with climate change and predicted HAB range expansion, monitoring programmes will need to include the identification of potentially toxic tropical and sub-tropical species. As these species are often benthic or epiphytic, internationally accredited sampling protocols are currently being developed. Future work will also focus on the use of Next Generation Sequencing technologies for the detection and enumeration of multiple species from complex environmental samples.

140 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Taking Strength from our Matauranga Maori, Science Gold Coast Seaway Partnerships & Health of the Toreparu SmartRelease: a Smarter Wetlands Way for Managing Releases from Wastewater Treatment Plants

Tom Roa // Waikato-Tainui Mahuru Robb // The University of Colin Roberts // DHI Waikato Opportunities to reinforce the principles Anna Symonds // DHI and visions of tuupuna (ancestors) and Ian Duggan // The University of Waikato past tribal leaders to restore the mana Shaun Awatere // Landcare Research – The Gold Coast water agency Allconnex (prestige) of te tupuna awa o Waikato (the Manaaki Whenua Water is responsible for the release of ancestral river of Waikato), have recently excess recycled water into the Gold become a reality with the introduction Wetlands provide critical habitat for native Coast Seaway. To meet future service into legislation of the Waikato River flora and fauna, along with a range of levels, Allconnex Water required a Settlement Deed. Opportunities include ecosystem services. With the loss of over solution capable of improving water korero (discussion) and mahitahi (working 75% of original wetland extent in the quality in the intra-coastal waterway together) with other iwi (tribes) on key Waikato, and continued degradation of while accommodating increasing loads matters of local, regional and national many that remain, these habitats urgently on treatment plants. A “SmartRelease” importance, and at the forefront of that require management plans that engage strategy was implemented to improve korero and mahitahi, is the whakatauki and communicate effectively with local the timing of each release to coincide (saying), ko au te awa, ko te awa ko au communities and encompass a variety with the non-symmetrical fluxes out of (I am the river and the river is me). The of values. Much of our understanding the Seaway. This is managed through positives that emerge for Waikato-Tainui of wetland function and “health” is an operational decision support system apart from the strengths of mahitahi is from studies based on western science ensuring a solution that is not only more the ultimate realisation that restoring the methods. However, there is a wealth cost-effective but gives the best possible mauri (life force) or health and well-being of knowledge to be gained from other outcome for the natural environment. of te tupuna awa (ancestral river), will methods of measuring health. Cultural The decision support system provides enable Waikato-Tainui and other river iwi knowledge and the development of a shell around a detailed computational to move forward as an iwi. cultural value-based indicators actively modelling suite that collects external engage indigenous communities and data, schedules the model simulations, provide effective tools to assist in wetland presents the results on an intranet page management. The Wetland Cultural and stores information in a database for Health Index (WCHI) was developed to further reference. The computational encompass these values when assessing modelling suite includes a high resolution wetlands. The Toreparu wetland covers 3D model representing the outfall plume 223 ha and is located between Raglan dynamics and a 2D model representation and Aotea Harbour, along the Waikato of hydrodynamic variations due to west coast. The Toreparu is classified as wind, wave and tidal forcing (produced a ‘swamp’ and is of high conservation from a Pacific Ocean spectral wave and value. It is very important to the people hydrodynamic models) for the Seaway of Mōtakotako marae, playing an integral area. The system is designed to optimise part in their cultural wellbeing; it has a the release taking into account the rich history and is home to many taonga operational requirements at the waste species. Working with tangata whenua water treatment plant, the water quality we are developing a site-specific WCHI, in the natural receiving waters and the and seek to understand how WCHI’s energy consumption while pumping out and western science methods can work the recycled water. The award winning together to assess the health of the Seaway SmartRelease system improves Toreparu wetland. We present preliminary water quality and defers the need for results of this work which illustrates that $60m in infrastructure to cope with western science based knowledge alone the increased load on the wastewater may be insufficient for the successful treatment plant from the growing management of culturally important sites population. such as the Toreparu wetland.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 141 SPEAKER ABSTRACTS

Engaging Ways to Behaviour of the Australian Restoration of Large-scale Present Information from Lungfish (Neoceratus Wetland Ecosystems: Computational Hydro- forsteri) During Flood Understanding the State, ecological Models Releases in a Large Functioning & Trajectory of Impoundment Habitat Whangamarino Eetland

Colin Roberts // DHI David Roberts // Seqwater Hugh Robertson // Department of Conservation Computational models describing the Hamish Campbell, Ross Dwyer // movement of water and behaviour of University of Queensland Paula Reeves // Wildland Consultants hydro-ecosystems are valuable tools in Kris Pitman // Pitman Consulting understanding, assessing and managing Wetlands associated with large riverine the effects of impacts on the systems. The Australian lungfish (Neoceratodus systems are subject to a range of More importantly, these tools have the forsteri) is a nationally listed vulnerable human-induced pressures. In New potential to provide an excellent way species. This listing reflects numerous Zealand the intensification of land use of presenting complex information on threats that occur within its restricted and river regulation has altered ecological hydro-ecosystems to the public. This natural range, including potential negative processes through modifications to paper will present an overview of some impacts from riverine impoundments. hydrological regimes and nutrient and of the different and more engaging Flood releases at impoundments can sediment inputs, changing the biological ways in which our data and information result in increased mortality risk due to composition, physico-chemical state can be communicated. As examples it physical damage of fish passing over and resilience of downstream wetlands. will include 3D visualisation of water spillways. For this reason information While improved wetland management movement, animated display of aquatic on how lungfish interact with spillway is increasingly advocated, science- species behaviour and the role of serious structures is needed to provide adaptive driven projects that restore large-scale gaming in communicating science. management responses to mitigate systems are relatively uncommon. The these risks. This study investigates Department of Conservation initiated the behavioural patterns of lungfish the Arawai Kākāriki wetland restoration associated with controlled releases programme in 2007 at three of New of flood water from a gated spillway. Zealand’s foremost freshwater sites, Horizontal and vertical movements of 14 including Whangamarino wetland. individual lungfish were compared before, Whangamarino forms part of the Lower during and after a series of flood events of Waikato River Flood Control Scheme variable magnitude and duration to assess (FCS) making it susceptible to periodic behavioural patterns. Lungfish were flooding. Our hypothesis was that tracked using acoustic transmitters and maximum water levels, and associated an overlapping array of omnidirectional pollutant loads, are above the limit acoustic receivers to provide accurate necessary to maintain ecological integrity. position estimates every three minutes. Ecological assembly rules were applied to These telemetry data were combined determine wetland vegetation response with spatially explicit environmental to alternative hydrological scenarios, information (i.e. bathymetry, distance integrating water balance models, habitat to dam wall, distance to lake margin) mapping and relationships between plant to assess changes in behaviour and composition and soil chemistry. Native habitat utilisation patterns associated plant dominance (mean % cover) was with flood events. In general, lungfish directly related to flood extent and soil preferred shallow water (<8 m) regions, phosphorus (TP mg/kg) under current rarely spending time in open water conditions (Bog: cover 100%, TP 309 mg/ areas. Activity levels increased during kg; Fen: 75%, 761 mg/kg; Swamp: 25%, flood events with some individuals 986 mg/kg). Assembly rules indicate ranging over large distances. Of the introduced taxa resilient to fluctuating fourteen individuals tagged, one fish conditions (facultative wetland plants, survived passage downstream over max. plant height > max. water depth, the dam spillway. This study provides annual life-history) will increase in greater understanding of lungfish dominance under existing FCS operation. behaviour within large impoundments, Mitigation options that consider trade- particularly dam spillways during flood offs between wetland conservation and events. Results will be used to inform river management are compounded management actions to mitigate by the large-scale and socio-economic impoundment-related risks on lungfish values associated with the Waikato River populations. floodplain.

142 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Setting Defensible Estuary Graphic Galaxiids: Mapping Effects of Warmer Oceans Monitoring & Management the Interface between & Reduced Light on Priorities Based on Coastal Science & Society Productivity of the Habitat- Risk forming Kelp Ecklonia radiata

Barry Robertson // Wriggle Dr Jenny Rock // University of Kirsten Rodgers // The University Coastal Management Otago of Auckland

Leigh Stevens // Wriggle Coastal Olga Khomenko // University of Otago Nick Shears, Alwyn Rees // The University Management of Auckland Visual representation is key to effective Understanding the distribution and risks science communication, particularly The ecological consequences of changing to coastal and estuarine habitats is critical when the subject matter is complex and climate are becoming increasingly evident to the effective management of ecological controversial. Mapping, in the broadest in terrestrial and marine ecosystems. resources as it underpins setting application of the method, allows us to Kelp forests are a highly productive defensible monitoring and management represent the interplay of participants habitat in temperate marine ecosystems. priorities. This talk describes the process (actors), scientific information, motives, Understanding how future environmental used to identify habitat vulnerability and geography, chronology, and a variety of conditions may affect kelp forests and coastal ecological monitoring priorities in social factors. Digital, web-based maps the ecosystem services they provide is the Tasman region based on an adapted in particular can be non-hierarchical and an important ecological question. The UNESCO methodology, and a transparent objective, allowing the user to negotiate effect of increasing water temperature risk-based matrix developed specifically their own way to an informed viewpoint. and reduced light on photosynthesis for broad scale assessments of New Here we describe a project in progress and productivity of the kelp Ecklonia Zealand beaches, dunes, rocky shores, that maps the issues surrounding galaxiid radiata was investigated in a laboratory and estuaries. It builds on previous risk fish in Otago. We explore some useful experiment. Kelp plants were held assessments undertaken in Hawke’s tools for representing the challenging in mesocosms at current maximum Bay, Wellington and Southland.The interrelationships between government summertime water temperatures (21°C), approach has three main components policy, conservation agendas, recreational and elevated temperatures (24°C), and that produce the following outputs: (1) and traditional fishers, and of course under ambient and reduced (by 80%) light ground-truthed coastal habitat maps in the fish (their biology). We conclude conditions. Reduced light had a greater GIS format, (2) vulnerability assessments with recommendations for the use of effect than increased temperature on based on the sensitivity of the receiving mapping approaches broadly in science kelp, with low light plants having reduced environment, human uses, and the communication. photosynthetic capabilities and greater upstream catchment specific risk factors tissue loss. However, after prolonged (stressors) associated with each section exposure to warm temperatures (7 of the coast, and (3) recommended weeks) and an extreme disturbance (17 coastal monitoring priorities. Stressors, days of darkness) the kelp in warmed and criteria for assessing their influence, water conditions exhibited much higher include: Fine Sediment (muds), Nutrients mortality. These results suggest that E. and Eutrophication, Disease Risk, radiata is relatively resilient to warming Toxicants, Climate Change, Drainage and ocean temperatures, but under warmer Reclamation, Freshwater Abstraction, conditions E. radiata is likely to be less Harvesting Living Resources, Invasive resilient to further disturbances. These are Species, Structures that disrupt sediment the first results to show how longer-term transport, Off-Road Vehicles, Toxic Algal exposure to potential future temperature Blooms, Dune Overstabilisation, Human/ and light conditions, in conjunction Animal Disturbance of Wildlife, Grazing in with additional disturbance, may affect High Value Habitat, and Natural Terrestrial productivity and survival of this important Margin Loss. The outputs are the basis Australasian kelp species. for a recommended management programme targeting key stressors. It includes 10 year management targets which, if achieved, will help restore the quality of the various coastal habitats, and indicators to allow easy tracking of management efforts and success in meeting targets.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 143 SPEAKER ABSTRACTS

Managing the The Astrolabe Aftermath: Green in the pristine: Unmanageable: Ecological Impacts of the Extensive subtidal Whitebait CV RENA on the Rock bloom of Microdictyon Where it all Went Down umbilicatum at Great Barrier Island, northern New Zealand

Hans Rook // Department of Phil Ross // The University of Sarah Sue Roth // The University of Conservation Waikato Auckland

Henk Stengs, Chris Annandale, Dave West Keith Gregor // Bay of Plenty Polytechnic Nick Shears // The University of Auckland // Department of Conservation Chris Battershill // The University of Jarrod Walker // Auckland Council Waikato People in New Zealand have fished A nuisance green algae Microdictyon for whitebait, inanga, inaka for over Following the October 2011 grounding umbilicatum has polluted the beaches of a hundred years. In many parts of and breakup of the CV RENA, access Tryphena Harbour, Great Barrier Island, the country even as late as the 1980s to Astrolabe Reef for research and with increasing frequency since 2008. whitebaiting was like the “Wild West”. monitoring purposes was restricted. This study aimed to identify the source Department of Conservation (DOC) With salvage activities taking priority population and to investigate the potential rangers required to enforce whitebaiting over environmental impact assessment it cause of these blooms. Diver surveys in regulations faced significant challenges appeared unlikely that researchers would October 2012 revealed extensive subtidal some of which are still violent. Decades have an opportunity to examine the reef beds of Microdictyon umbilicatum drifting later these rangers still ply the rivers of to determine the ecological impacts of unattached throughout the Harbour. New Zealand doing what they can to the grounding and oil spill. However, From diver observations and aerial achieve what is largely the unmanageable in August 2012, ten months after the imagery the extent of these drifts was task of looking after whitebait. We will grounding, University of Waikato and estimated at ~2 km2 covering most of the discuss the pragmatic, innovative and Bay of Plenty Polytechnic divers were sandy bottom throughout the Harbour collaborative ways DOC staff contribute able to visit Astrolabe Reef to examine from a depth of about 5 to 20 m. The to managing whitebait. These range the reef’s benthic communities and thickness of the drifts range from 5–35 from difficult and dangerous whitebait to collect specimens with which to cm, with an average biomass of 1.5kg “patrols”, to fencing and planting of assess chemical contamination. Here wet weight m-2. Total estimated biomass inanga spawning sites to presenting we present chemical analyses of fish in the harbour is between 1400 and 4600 evidence at Resource Management Act and invertebrate specimens collected tonnes. Preliminary analysis of sea water hearings. In this era of co-management from Astrolabe Reef and nearby offshore samples indicates relatively low nutrient we offer our views and efforts to the islands; chemical analyses of subtidal levels. Nonetheless, we hypothesise that discussion and work that needs to ensure sediments collected both on and adjacent only a small increase in available nutrients whitebait and whitebaiting remains a to Astrolabe Reef and Motiti Island; and is needed to promote extensive algal strong part of New Zealand’s culture and describe the benthic habitats of Astrolabe growth in this pristine environment. environment. Reef. As pre oil spill data for this reef Such drifts are novel worldwide, is largely non-existent, it is difficult to especially in relatively pristine definitively quantify the impacts of the waters which characterise the RENA grounding. However, comparisons coastal environment of Great Barrier with samples collected from nearby Island. Further research is underway control sites are indicative of a significant investigating seasonal patterns, potential but localised impact on and around nutrient sources and consequential Astrolabe Reef. This data also provides a effects on the local environment. clear indication of the work that will be Laboratory experiments also hope required to better quantify and monitor to reveal the role Nitrogen, depth, the ecological legacy of the CV RENA. temperature and turbulence play in growth rates of M. umbilicatum to increase our knowledge of this nuisance alga.

144 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Use of Web Cameras to The Effects of Nutrient First Report of Anterior Monitor Long Term Trends Losses on Stream Pallial Tentacles in Solen in Dynamic Recreational Periphyton – a Modelling dactylus from the Northern Fisheries Study in Hawke’s Bay Persian Gulf, Iran

Nicola Rush // NIWA Kit Rutherford // NIWA Hanieh Saeedi // The University of Auckland Bruce Hartill, George Payne, Andrew Miller John Quinn, Bob Wilcock // NIWA // NIWA Adam Uytendaal // Hawkes Bay Regional Mark J Costello // The University of Council Auckland There is an increasing recognition that Roger Young // Cawthron Institute Rudo von Cosel // Muséum national New Zealand’s marine recreational d’Histoire naturelle, Paris fisheries are growing, substantial and Like many gravel-bed rivers on the east dynamic. Although considerable progress coast of New Zealand, the Tukituki River Solenidae are deep burrowing bivalves has been made in developing reliable experiences prolonged summer low inhabiting intertidal and shallow sub-tidal methods of surveying recreational flows during which nuisance growths of soft bottom sediments mostly in tropical fisheries in recent years, these surveys are periphyton occur. A multi-agency study and sub-tropical areas. Solen dactylus usually conducted infrequently, because has made field measurements of nutrient has a restricted distribution within the of the cost involved. We describe a fluxes, biomass and productivity during Indian Ocean. Solen dactylus is frequently cost effective means of continuously two summer low flows (2011 and 2013). found on the sandy-muddy coast of the monitoring levels of recreational fishing A new, process-based computer model northern Persian Gulf, Iran. Specimens effort over the long term, based on web TRIM (Tukituki RIver Model) is being of S. dactylus were collected since 2006 camera technology. Web cameras have used to help understand the complexity from Bandar Abbas to study their biology been used to continuously monitor trends of nutrient transformations, uptake, and ecology. During these studies, in recreational effort on the northeast recycling and loss in the river, and its an unexpected pair of anterior pallial coast of the North Island since 2005, and effects on periphyton growth rate and tentacles at the dorsal end of the anterior the west coast since 2006. The indices biomass. Nutrient limitation switches pallial crest of the mantle was found. In of effort provided by these data have from phosphorus in the middle reaches the tentacles, two kinds of epithelial cells given us unprecedented insight into the to nitrogen in the lower reaches, because (pyramidal and vacuolated) and fibres temporal dynamics of New Zealand’s of denitrification. The model is used to (radial and longitudinal), and a branch of largest recreational fisheries. Although investigate the nitrogen mass balance and the pallial nerve located in the centre of a the resources required to operate these to explore whether nitrogen, phosphorus, haemocoel, were determined. A possible systems are relatively low, the effort both or neither should be managed to coherence of a furrow parallel to the required to interpret the imagery collected reduce nuisance periphyton blooms. DRP anterior shell margin with the presence can still be appreciable, and strategies concentrations did not drop below c. 4 of anterior pallial tentacles is discussed. have, and are, being developed to mg m-3 during summer low flows in 2011. All species with long anterior pallial substantially reduce costs and to extend It is not clear whether this is because tentacles have anterior shell furrows. the utility of the information provided. phosphorus was being released from Anterior pallial tentacles were found in bed sediments, recycled from detritus or numerous Solenidae from Asia to the was simply not being consumed because Middle East and Europe. However, more periphyton were nitrogen limited. The Solen species need to be examined for model helps address these questions. presence or absence of the anterior pallial tentacles and anterior shell furrows.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 145 SPEAKER ABSTRACTS

Variability in the Elucidating the Origin of The Importance of Importance of the Microbial Tetrodotoxin Austrovenus stutchburyi Food Web Across the for Biodiversity-Ecosystem Chatham Rise Functioning in an Intertidal Sandflat

Karl Safi // NIWA Lauren Salvitti // The University of Candida Savage // University of Waikato Otago Variability in the importance of the microbial food web and its role in carbon Paul McNabb, Dave Taylor, Susie Wood // Agnes Karlson // Stockholm University, transfer to higher trophic levels was Hawke’s Bay Regional Council Swedenl evaluated across the Chatham Rise, east Serena Khor, Craig Cary // The University Keith Probert // University of Otago of New Zealand, in early winter 2008. of Waikato Daniel Leduc // NIWA. Over this well-defined area of subtropical Conrad Pilditch // The University of convergence samples were taken in six Numerous cases of human illnesses Waikato regions (Boxes) at 23 core sites to assess and death have been attributed to the variability both across and along the consumption of tetrodotoxin-containing Chatham Rise. Clear gradients observed Biodiversity loss in coastal ecosystems organisms including pufferfish and in temperature, salinity and nutrients worldwide has prompted an urgent gastropods. Long believed to be could not alone explain the complex need to understand the importance of present only in pufferfish, TTX has changes observed in phytoplankton. Only key functional groups for ecosystem now been detected in a wide range of by identifying different areas as having functioning. We investigated the phylogenetically unrelated terrestrial communities at different successional effects of the loss of a key species, the and aquatic taxa including an increasing phases could we explain the observed cockle, Austrovenus stutchburyi, on number of organisms from temperate variations. Microzooplankton grazing on critical ecosystem processes, notably countries. It is uncertain whether this phytoplankton standing stocks reflected nutrient cycling and uptake of detritus in increase is due to improved testing this variability, ranging from only ~8% intertidal sandflats. Cockles are harvested capability and more intensive sampling, removal per day in the high phytoplankton commercially and recreationally, yet they or if there has been a global expansion biomass, >2 µm size class dominated are the main suspension-feeding bivalve of a microbial TTX producer. Despite South East Rise to ~127% removal in in New Zealand estuaries. Removal of this decades of research the exact origin the low phytoplankton biomass, <2 key species thus results in the loss of an and biosynthetic pathway of TTX remain µm dominated North West Rise. These entire functional group, which is likely to a mystery. Current literature supports results partly reflected microzooplankton have direct consequences for ecosystem three main hypotheses for the source of grazing efficiency which was highest functioning in marine sediments. Using TTX; endogenous, symbiotic bacteria or on the <2 µm phytoplankton fraction a block design, we manipulated cockle via bioaccumulation through a dietary -2 followed by the <20 µm fraction, while densities (no cockles; 300 m ) and source. In 2009, the opisthobranch 13 15 grazing was consistently unable to control added C and N-labelled macroalgae to Pleurobranchaea maculata (grey side- the >20 µm size fraction. Overall 3.2 select high and low density cockle plots gilled sea slug) was found to contain times the phytoplankton carbon biomass in Papanui Inlet, Otago. Nutrient and high concentrations of TTX in NZ; to our was grazed by microzooplankton in the oxygen fluxes across the sediment-water knowledge this is the most southern Northern Rise compared to Southern interface were measured and the uptake detection of TTX. Recently we identified Rise waters. This occurred even though of algal detritus by functionally different TTX in two further New Zealand marine the Southern stations had 1.6 times the benthic communities was determined organisms; a flatworm, Stylochoplana phytoplankton biomass of the North. This using isotope tracers. Oxygen uptake sp. and the bivalve Paphies australis. A investigation reveals that the subtropical rates were greater in high density cockle triangulated approach has been used convergence zone is more variable plots and increased with the addition to identify the origin of TTX in these than previously understood and shows of macroalgal detritus. There was high organisms. This has involved: extensive that complex and evolving food-web interspecific variation in uptake of the environmental surveys, an intensive structures occur across the Rise leading algal detritus, with highest uptake by a bacterial culturing effort (over 250 to variable transfer rates to higher trophic tanaidacean and a nereidid polychaete. strains), manipulative laboratory feeding levels. This multi-functional and mechanistic studies, localization of TTX within tissues approach enabled us to assess the using immunohistological methods, the relative performance of species within development of a new chemical method and among treatments and quantify to explore precursor or degradation the feeding niche of the different products and PCR based methods to communities. explore the diet of P. maculata. This talk will provide a summary of research findings to date and review strategies to be implemented in future studies.

146 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Science for Estuary Adventures in Paradise: Identifying Nutrient Load Management in NSW: Determining the Reference Targets for Waituna Lagoon: Combining Monitoring, (Pristine) Ecological Some Tips when Setting Research, Modelling & Condition of New Zealand’s Limits for Shallow Lake & Communication Lakes Estuary Systems

Peter Scanes // Office of Marc Schallenberg // University Marc schallenberg // University Environment and Heritage, NSW of Otago of Otago

Jocelyn dela Cruz, Angus Ferguson, There is a paradigm in lake conservation Keith Hamill // River Lake Ltd John Floyd, Jaimie Potts, Kirsty Brennan, and management that seeks to David Hamilton // The University of Waikato Aaron Wright, Brendan Haine // Office of compare the current condition of lakes Greg Larkin // Coastal Consultant Environment & Heritage, NSW to their reference condition, or pre- Jane Kitson, Dean Whaanga // Te Ao anthropogenic-impact condition. In this Marama Inc Effective management of estuaries relies way, the direction and magnitude of Barry Robertson // Wriggle Coastal on sound information about processes departure of the current state of lake from Management and status, good decision making and its reference state can be ascertained, Hugh Robertson // DOC potentially facilitating lake management effective communication to relevant Mike Scarsbrook // DairyNZ participants. In NSW (Australia) estuary and restoration. Scientifically determining Andy Hicks, Karen Wilson // Environment management is primarily the responsibility the reference condition of New Zealand of local government, with guidance lakes is the purpose of this study. Two Southland and financial support from the state approaches were used: 1. A present-day government. Scientific input comes from assessment using large datasets of Waituna Lagoon is a Department of a state-wide estuary health monitoring lakes which regresses key indicators of Conservation (DOC) scientific reserve program (including over 130 estuaries) and ecological integrity (EI includes indicators within a Ramsar listed wetland complex. from a series of specific research projects, of pristineness, nativeness, diversity Ongoing land-use intensification and generally funded by local government. and resilience) against catchment % hydrological modifications within the The data and process understanding from native vegetation cover and against catchment have been associated with a this research has been incorporated into an independent expert assessment of decline in water quality in both the lagoon ecological response models at three scales. present lake EI and 2. Inferences about and its major tributaries. Evidence of a At the State scale, a eutrophication risk historical lake conditions based on a decline in lagoon ecological values has assessment model which uses simple literature review of palaeolimnological also been observed, with a decrease in empirical relationships to assess risk from the abundance of keystone macrophyte land-use change has been developed studies on New Zealand lakes. Both species, Ruppia, and an increase in to enable land and estuary managers to approaches were applied to assess the abundance of macroalgae. These understand the risk to estuaries resulting reference conditions of shallow lakes, symptoms of eutrophication prompted from broad-scale landuse intensification deep lakes and brackish lakes, separately. (www.ozcoasts.gov.au/nrm_rpt/cerat/ A number of pristineness, diversity and an inter-agency response to prevent index.jsp ). More explicit models have resilience indicators converged at high the lagoon flipping from a clear-water, been created for different estuary types % catchment native vegetation cover macrophyte-dominated system to a turbid (e.g. barrier rivers, coastal lagoons). and at high EI scores, showing that the lagoon dominated by algae. The Lagoon These models link catchment landuse to indicators provide useful information Technical Group was formed, comprising ecological response via hydrodynamic for inferring lake reference conditions. lake experts from around New Zealand models. They require more data to run but Palaeolimnological studies provide to provide scientific advice to managers provide spatially explicit results for threats useful narratives of historical changes and stakeholders. Modelling and literature to seagrass beds and for eutrophication. in lake conditions which are different in review approaches produced similar loading targets, and the multiple lines of Nested within these models are sub- nature, but are complementary to the evidence provided the LTG with a more models that predict seagrass growth quantitative information obtained from robust manner of recommending load and biomass. The research that has the EI approach based on current lake supported the model development includes targets. Multiple lines of evidence were data. Together, these quantitative and stable isotope studies that have linked particularly valuable for Waituna Lagoon, qualitative scientific approaches help us changes in trophic status to changes in because complex interactions between to paint a robust, multivariate picture of the fundamental carbon source for fish sediment, macroalgae, macrophytes and what the reference ecological condition and invertebrates; seagrass metabolism phytoplankton generate considerable of New Zealand lakes was prior to human and growth; phytoplankton stimulation; uncertainty when predicting the influence. nutrient regeneration from sediments and ecosystem response. In view of the need meta analyses of nutrient status for NSW to urgently address nutrient loads that estuaries. Monitoring has been informed are well above levels required to support by analyses of the efficacy of existing healthy ecosystems and in response monitoring programs and by development to the NPS: Freshwater Management, and testing of new indicators of ecological Environment Southland is now in a processes (rather than standing stocks). position of being obliged to set load Council and community engagement targets for numerous shallow lake and has been supported through the use of estuary systems for which there is limited conceptual models and report cards to ecological data. Some ideas on how encourage understanding of ecological we will approach this, based on lessons processes and the need for local behaviour learnt during our Waituna response, will change. be discussed.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 147 SPEAKER ABSTRACTS

Responses of Estuarine Revisiting Diversity & CV Rena: Overview of an Seaweeds to Season, Resilience of Coastal Reefs: Approximate BACI Design Wastewater Discharges Why are so Many Species & Results of a Major & the Christchurch (Usually) Rare & What Marine Pollution Incident Earthquakes are the Implications for Sustainable Management?

Kristin Scheuer // University of David Schiel // University of David Schiel // University of Canterbury Canterbury Canterbury

Neill Barr, John Zeldis // NIWA Stacie Lilley, Paul South, Leigh Tait, Chris Battershill // The University of David Schiel // University of Canterbury Tommaso Alestra // University of Waikato Canterbury Blooms of the green algae Ulva sp. (sea The CV Rena grounded on Astrolabe lettuce) and the red algae Gracilaria The preservation of habitats and Reef, Bay of Plenty, New Zealand at sp. often indicate the effect of nutrient biodiversity are key planks both of “Life 2:20am on the 5th of October 2011. The enrichment in coastal ecosystems in a Changing Ocean” and in sustainable ship was carrying 1,368 containers, worldwide. A good example from New marine futures. We have previously including 32 classified as being Zealand is the Avon-Heathcote Estuary reported on long-term disturbance ‘dangerous goods’, and 1,733 tonnes in Christchurch where decades of experiments on algal-dominated reefs. of heavy fuel oil. Approximately 350 wastewater discharge have led to regular A central theme is the relative rareness tonnes of oil was lost between 5–11 blooms of these algae, most notably of most species in space and time. Yet October during a storm. Most of this Ulva. The diversion of the Christchurch we also have experimental evidence ended up on adjacent beaches and rocky City Wastewater outfall in March 2010 that these species can be ecologically reefs including a nearby offshore Island. occurred only months before the first of important. If we are managing for Successful salvage got most of the a series of major earthquakes affecting sustainable use of marine resources to remaining oil, but 256 containers were the region. After the most damaging meet what is now recognised as one of lost overboard and around 300 remain earthquakes in February and June 2011, the ten science challenges “for major and on the sunken ship. Two key questions overflows of raw sewage entered the enduring benefits for New Zealand”, then were immediately asked by the public: estuary via its two main rivers for several we had better work out the drivers of what is the environmental impact and weeks. Along with this there were also diversity, their natural cycles and how to how long to recovery? Here we discuss major changes that occurred in the deal with their long-term natural variation. the programme development, a quick topography of the estuary itself. We used We discuss these. survey as the oil was just landing, and an several biochemical indicators from Ulva outline of the impacts and lessons. These sp. and Gracilaria sp. (free amino acids, include ecological and chemical surveys, chlorophyll, tissue-nitrogen, growth cleanup lessons, environmental response and nitrogen stable isotope (δ15N)) to priorities, and the value of baseline monitor changes in the relative quantity monitoring (all in 15 minutes). and source of nutrient loading in this changing estuarine system. In addition to this monitoring work, the efficacy of these indicators were validated in a series of multi-factorial laboratory experiments. These demonstrated that interactions between light, temperature and nutrient concentration almost certainly regulate macroalgal growth in the Avon-Heathcote Estuary. However, we also observed that there is possibly an underlying intrinsic property of macroalgal growth during summer months suggesting that ‘seasonal’ change in the requirements for optimal growth may not be so straight forward.

148 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

A Changing Coastal Climate Restoring the River “Sky” Mechanisms Governing over the Past Several – Ngaa Karu o Matariki Degradation of Decades: the Biophysical Phytoplankton in Fjords Context for Ecological Changes & Marine Futures

David Schiel // University of Cheri van Schravendijk- Susanne Schüller // University of Canterbury Goodman // Waikato Raupatu Otago River Trust Stacie Lilley // University of Canterbury Candida Savage // University of Otago Richard Gorman, Craig Stevens // NIWA Rangi Mahuta, Julian Williams // Huakina Thomas Bianchi // Texas A&M Development Trust Philip Boyd // NIWA This project is mining existing Gannin Ormsby // Waikato Regional oceanographic and biological data to Council Doubtful Sound (DS) in Fiordland provide the biophysical context necessary Cindy Baker, Paul Franklin // NIWA represents a model estuarine system to for maintaining sustainability in the study mechanisms driving the fate of face of climate change. Experimental Tangata whenua have an intergenerational phytoplankton from the water column data on biotic thresholds and limits relationship with freshwater fisheries that to the sediment across strong estuarine related to oceanographic conditions is unique and integral to their identity. gradients. Large amounts of freshwater has demonstrated that changing Unfortunately, once policy is introduced enter DS creating a highly stratified oceanographic conditions have a to manage components of a natural (physical, chemical) upper water column significant effect on the resilience of resource, cultural lore and common in the inner fjord, and well-mixed water coastal ecosystems. These changes are law can clash, with potentially adverse column in the outer fjord. The light nested within large scale phenomena outcomes for both the resource and the environment in DS is dominated by such as El Niño and La Niña events. people. In 2007, representatives from steep fjord walls and freshwater rich New Zealand collects a wealth of Te Puuaha o Waikato (Port Waikato) in chromophoric dissolved organic relevant physical data (e.g., sea surface passed a resolution that they would matter, which influences phytoplankton temperature, wave forces, upwelling not participate in new Regional Council production and degradation. In this metrics, riverine output, sedimentation, policy around the notification of whitebait study, we use phytoplankton pigments currents and coastal topography), but stands. The foundation of this position to investigate how phytoplankton this is only partially analysed and barely was twofold: (1) protecting whaanau detritus is degraded, altered, and synthesised. Our coastline is ~11,000 rights and access to the fishery, and preserved within the water column and km long, so initially we focussed our (2) traditional agreements which were into the sediment record. Degradation analyses to coastal sectors, with the aim being impacted upon by a surge of new and preservation processes within of matching these to ecological data fishers as a result of the policy. Swirling the water column, sediment surface, over local, regional and national scales around these legislative and statutory and in long-term sediment records Here we discuss the changes to the impacts are the more, well researched, are evaluated using water samples, coastal climate, particularly with respect but just as complex biophysical issues grazing experiments, sediment traps, to SST and waves, and their ecological of spawning habitat decline, water early diagenesis experiments, and implications. quality degradation and other associated sediment cores. Irradiance, wind stress environmental impacts on traditional and water column stratification were whitebait fisheries. Recently the Waikato the most important factors influencing Raupatu River Trust has been working phytoplankton composition in the upper with the Waikato Regional Council and water column and explained 69.7% of the NIWA on two different, but very strongly variance in the pigment data. Copepod interconnected projects addressing grazing was a major driver of chlorophyll whitebait fishing structures and whitebait a destruction and conversion to steryl habitat restoration and reconnectivity. and chlorin carotenoid esters. Sediment This presentation will discuss the traps and early diagensis experiments ‘research whakapapa’ from the Waikato- revealed great spatio-temporal variability Tainui perspective for these two projects, of phytoplankton detritus and its and the need for greater integration drivers across the fjord, highlighting the of maatauranga, policy and science in importance of a spatially explicit sampling addressing the issues being faced by our scheme in fjords. Finally, long-term Tuupuna Awa. sediment cores indicate that DS is an ideal environment for phytoplankton pigment preservation and hence organic carbon burial.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 149 SPEAKER ABSTRACTS

Long-term Trends & Drivers Recent Update on Marine Habitat Suitability Curves of Variability in Coastal Protected Area Planning for Aquatic Invertebrates in Turbidity in the Hauraki & Design in the Ross Sea a Small New Zealand River Gulf Region (Antarctica) Under CCAMLR (the Commission for the Conservation of Antarctic Marine Living Resources)

Blake Seers // The University of Ben Sharp // Ministry for Primary Karen Shearer // Cawthron Auckland Industrys Institute

Nick Shears // The University of Auckland Since 2009 New Zealand has been John Hayes // Cawthron Institute working actively to design and propose Dean Olsen // Otago Regional Council Increased sedimentation in the coastal a large-scale Marine Protected Area in environment due to human activities can the Ross Sea region under the auspices Flow management decisions in New have negative impacts on biodiversity and of CCAMLR (the Commission for the Zealand are reliant on the reliability ecosystem processes. Deciphering the Conservation of Antarctic Marine Living of the habitat suitability curves (HSC) environmental drivers of sedimentation Resources). This process culminated most that are used in hydraulic habitat in the coastal environment is crucial to recently in consideration by CCAMLR of modelling (e.g. RHYHABSIM). Habitat understanding the influence humans a joint New Zealand – United States MPA suitability curves are used for generating have on sedimentation and how rates proposal at a special mid-year meeting predictions of how changes in flow will may be affected by climate change. The of the CCAMLR Scientific Committee, in affect lotic aquatic biota such as native Auckland Council have been collecting Bremerhaven (Germany) in July. fish, salmonids, and invertebrates. monthly water quality samples at various Dr Sharp in New Zealand’s Scientific To date, HSCs for invertebrates have locations in the Hauraki Gulf since 1991 Committee representative to CCAMLR been developed on moderate-large providing an opportunity to analyse long- and has led New Zealand’s scientific rivers. However, a concern is that these term trends in turbidity, an indicator of engagement with CCAMLR to design may overestimate depth and velocity sedimentation in the coastal environment, and propose a Ross Sea region MPA. In requirements in a small river. To help as well as the primary drivers of variation this talk he will describe the systematic address this information gap we have in turbidity. Trend analysis revealed conservation planning approach utilised developed HSCs for nine aquatic no increasing or decreasing trends in by New Zealand and the underlying invertebrate taxa from the Rainy River, a turbidity over the last 20 years, but rather scientific rationale of the joint NZ-US tributary of the Motueka River, Nelson. indicating cyclical patterns potentially proposal, which seeks to optimise Higher suitability occurred at shallower related to larger scale climatic processes. achievement of multiple ecosystem depths and slower velocities in the Canonical correlation analyses showed protection and fisheries management Rainy than in larger rivers studied. This that turbidity at wave-exposed open objectives while also considering work expands (with two new species) coast sites was most strongly associated the needs of the existing CCAMLR the current library of invertebrate HSCs with wave action and showed relatively science programme that underpins the used in hydraulic modelling of physical insignificant associations with the management of the Ross Sea region habitat. Our curves will increase the other climatic variables. In contrast at toothfish fishery, and providing for reliability of habitat modelling analysis Waitemata Harbour sites turbidity was ongoing sustainable harvest consistent for smaller rivers, and can be accessed most strongly and positively correlated with the CCAMLR Convention. He through RHYHABSIM (http://www. with rainfall therefore showing much will also discuss the recent response jowettconsulting.co.nz/). more intra-annual variability. These results of the CCAMLR Scientific Committee clearly indicate that the drivers of turbidity to the Ross Sea region proposal and differed among sites and suggest summarize scientific advice emerging that the effects of climate change on from the recent special meeting, to guide sedimentation in the coastal environment designation of a Ross Sea region MPA, will not be homogenous throughout the an outcome that will require consensus region. agreement from all CCAMLR Members.

150 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

The Kimberley Ark: The Secret life of Zombies: The Early Life History of Assessing & Conserving Consequences of Snapper in the Kaipara Freshwater Fish Co-habitation & Dispersal Harbour – a Special Biodiversity in Australia’s with the Living Dead Nursery Area for Snapper Last Pristine River Systems

James Shelley // University of Jeffrey Shima // Victoria University Carina Sim-Smith // The University Melbourne of Wellington of Auckland

Freshwater ecosystems worldwide are Stephen Swearer // University of Andrew Jeffs, Craig Radford // The experiencing a period of unprecedented Melbourne University of Auckland biodiversity loss. Effective biodiversity Erik Noonburg // Florida Atlantic conservation requires accurate estimates University Little is known about the early life history of biodiversity and knowledge of species’ of snapper, particularly on the west coast threat of extinction. The Kimberley region Many fishes produce excess offspring, of New Zealand. We investigated aspects in remote north-west Australia, which and most individuals will die before of the early life history of snapper in now faces imminent expansion of mining they can reproduce. These “living-dead” the Kaipara Harbour, which is the most and agricultural operations, is both a may persist in populations for extended important nursery area for snapper on biodiversity hotspot and a black hole in periods, to shape evolution and exact the west coast of New Zealand. Gonad scientific knowledge. At least 18 (~40%) unknown costs on survivors that analyses showed that recruitment of the region’s diverse freshwater fish successfully breed. The importance of to the harbour must originate from species are found nowhere else and “survival of the fittest” is well recognised spawning activity outside the harbour. many of these endemics are extremely across biological disciplines, but what Larvae spent 18–28 days in the plankton range-restricted. However, a lack of are the consequences of the surviving before settling in shallow waters of the surveys, and ecological and genetic weak? Demographic “zombies” can harbour. The successful spawning period studies means that current biodiversity compete for resources, attract predators, that produced settled juveniles was estimates are not robust and the risk of and alter the fates of the fittest, though only 29–63 days, despite a spawning extinction these species face is unknown. they are rarely the focus if investigation. season of ≤4 months, indicating that This project will help to establish the true Since Darwin’s seminal work, existing recruitment to the harbour may be biodiversity of the Kimberley freshwater paradigms have been preoccupied with limited by environmental conditions fishes and assess their extinction risk winners. Our previous research on a that affect larval survival or transport using a combination of molecular small marine fish, the common triplefin to settlement habitats. Daily settlement techniques and ecological analyses. (Forsterygion lapillum), indicates that was significantly positively correlated to Hypotheses on the causes of diversity zombies may be created when young tidal range and on-shore winds (of the in fish communities will be tested by individuals experience unfavourable previous day) in 2010 and to temperature constructing phylogenies for three of conditions during larval development. in 2011, suggesting that these variables the regions major families (Terapontidae, We use LA-ICPMS and image analysis to may assist the on-shore transport and Eleotridae, Plotosidae). Furthermore, unlock the “environmental fingerprints” survival of larvae. Recruitment may also microsatellite data will be used to assess and demographic records preserved be affected by growth rate and resource- gene flow, population connectivity, and within fish otoliths, to infer that: (i) larval allocation strategies. Growth of fish from population genetic structure within fish developing in offshore waters acquire the Kaipara Harbour was faster than species to evaluate their extinction risk distinct traits that transform them into growth at other sites. Resource-allocation in the face of future impacts. Finally, demographic zombies; (ii) zombies in post-settlers was found to change reproductive and early life-history ecology regularly recruit to reefs alongside from maximising growth in summer will be investigated to assess their individuals that are predestined to survive; to maximising lipid accumulation in contribution to the range-restriction and and (iii) zombies may be more readily mid-autumn. Lipid concentrations in fish evolution of the Kimberley’s endemic shuffled between distant populations. We during summer and early autumn were species. I will present my project ideas present results from empirical studies and very low, making them very vulnerable to and design, evidence of morphologically mathematical modeling, which together, starvation mortality. Overall, these results distinct fish groups that I have found reveal how the presence of demographic provide us with a better understanding during my surveys, and the preliminary zombies can affect local population on the ecological processes that affect results of my phylogenetic analysis. structure and alter the stability of a reef the recruitment of snapper, which can fish metapopulation. be used to more effectively manage populations of this important species.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 151 SPEAKER ABSTRACTS

Response of an Estuarine Matauranga, Science & Development of an Community & Food Management – a Practical Acoustic Method to Web to Eutrophication Example on the Te Arawa Distinguish Elasmobranchs & Earthquake-driven Lakes from Teleosts in the field Disturbance

Jennifer Skilton // University of Hera Smith // Te Arawa Lakes Trust Ross Smith // Hydrobiology Canterbury The Te Arawa Lakes are taonga to Te Clément Bonini, Sean Gallanagh, Dylan John Zeldisn // NIWA Arawa and the continued, uninterrupted Sortino, Dustin Hobbs // Hydrobiology David Schiel // University of Canterbury traditional, spiritual, cultural relationships with the lakes is paramount. Te Arawa In response to a desire to develop Benthic invertebrate communites are Lakes Trust is representative of 62 hapu a method to monitor endangered critical in estuaries, affecting sediment and iwi of Te Arawa and responsible for elasmobranchs near a proposed structure and function and occupying managing the funds and assets under bauxite mine south of Weipa, north key food web positions. Eutrophication the Te Arawa Lakes Settlement Act 2006 Queensland, Australia, Hydrobiology, and disturbances can severely impact which saw the return of 14 lakes to Te with support from Rio Tinto Alcan, the diversity and abundance of primary Arawa. Implicit in that management is the examined the potential for dual- producers and consumers and, in turn, health and wellbeing of the lakes, formal frequency hydroacoustics to distinguish alter trophic interactions and change relationship protocols, decision making elasmobranchs from teleosts in the the structure of entire food webs. in including freshwater fisheries. The field. Trial data collection using captive Christchurch’s Avon-Heatchcote estuary settlement recognises and acknowledges sharks, rays, banjofishes, guitarfishes has been subjected to two types of the mana of Te Arawa and their holistic and sawfishes in the presence of a range disturbances over recent years: 1) the relationship with the lakes and provides a of teleosts in the aquaria of SeaWorld diversion of wastewater from the Avon- vehicle for Te Arawa to be involved in the and Underwater World in southern Heathcote estuary to an ocean outfall in decision making now and in the future as Queensland provided training and testing March 2010 that immediately reduced kaitiaki and landowner of the Te Arawa datasets. These were used to develop nitrogen loading to the estuary by >90% Lakes. Investing in collaboration and and test an algorithm to distinguish the and; 2) four cataclysmic earthquakes partnerships has unlocked opportunities two groups. Subsequent field trials in the between September 2010 and December and recognises that the integration of project area alongside other sampling 2011 that caused liquefaction (new scientific knowledge and matauranga demonstrated that the hydroacoustic sediments) to cover 30–65% of the connects, restores and contributes to algorithm identified elasmobranchs in estuary surface and resulted in huge improving, protecting and restoring areas where they were observed by volumes of raw sewage entering the freshwater environment and indigenous other means and at average sizes that estuarine environment. Field surveys on biodiversity. The acceptance and use of were realistic. The technique was prone multiple occasions before the diversion, matauranga in collaborative projects on to erroneous classification of other post-diversion/pre-earthquake and post- the lakes has been recognised in future objects, such as mangrove prop-roots, as earthquake showed that the earthquakes research strategies and enabled kaitiaki elasmobranchs, but transect design and had a significant impact on infaunal and key stakeholders to protect, sustain post-hoc editing could reduce that error. and epifaunal communities, reducing and restore the biodiversity, health and taxa richness and abundance. Although wellbeing of the lakes. effects were site-specific, communities in most areas recovered to pre-earthquake status within two years. The earthquakes did not appear to affect the estuarine food web structure, but stable isotope analysis showed that δ13C and δ15N values of food sources and consumers varied spatially, temporally and in relation to the diversion of wastewater. In particular, food sources and consumers from the most eutrophic site showed marked increases in isotopic values during the three year period following the diversion. There was a clear separation of sites but their isotopic signatures are beginning to converge.

152 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

An Investigation into Developing a Bryozoans of the Fisheries Interaction Effects Complementary Seed Krusenstern Expedition using Atlantis Supply for Year Round Greenshell™ Production

Michael Smith // University of Rebecca Smith // The University of Abigail Smith // University of Otago Melbourne Auckland Mary Spencer Jones // Natural History Elizabeth Fulton // CSIRO Greenshell™ mussel production in Museum, London Robert Day // University of Melbourne New Zealand is constrained by two main factors. The first being the highly At the beginning of the 19th century, Fisheries management is commonly seasonal nature of Greenshell™ mussel Tsar Alexander I and Baron Nikolai P. based on the outputs of single-species production as mussel spawning occurs Rezanov commissioned an Estonian stock assessment models. While such from July to November and during this Captain called Krusenstern to explore models are appropriate for tactical issues period mussels cannot be harvested the northern Pacific, establish trade with such as quota setting, they typically omit due to their poor condition. Anecdotal China and Japan, enhance links in South explicit trophic interactions between evidence suggests that Hauraki mussels America, and consider the possibility of different parts of the ecosystem. To may develop at a different time of the using California as a Russian colony. No successfully manage multiple fisheries year to Kaitaia mussels. The second is Russian ship had yet crossed the equator; in the same ecosystem, we need to the industry’s heavy reliance on spat it was an expensive and ambitious understand the knock-on effects of fishing supply from Kaitaia, as approximately expedition. The Nadezhda under the one species. We used a simulation model 80% of the spat used in the New Zealand command of Captain Krusenstern and of the southern Benguela ecosystem, Greenshell™ mussel industry is collected the Neva (under Captain-Lieutenant built in the Atlantis framework, to explore from 90 Mile Beach in Kaitaia. This study Lisyansky) set sail from Kronstadt (St. fisheries interaction. We measured implements a series of experiments to Petersburg, Russia) on 7 August 1803. the impact of fishing different stocks determine whether mussels obtained They travelled across the Baltic and individually at FMSY, the hypothetical from Kaitaia and the Hauraki Gulf have Atlantic Oceans, past the Canary Islands level of fishing effort which produces different condition cycles, and growth and Brazil, round Cape Horn, on to the maximum sustainable yield in a single- rates when grown in Hauraki Gulf and if Hawaiian Islands, Kamchatka and Japan. species model. We then applied FMSY to it is commercially feasible to collect spat Krusenstern and the Nadezhda arrived all stocks simultaneously and compared in the Hauraki Gulf. Spat-catching ropes back at Kronstadt on 19 August 1806, just the simultaneous yield to the sum of are set at two sites and two depths in the over three years after they had left, with yields from the individual applications Hauraki Gulf and changed every three all hands safe on board. Upon his return, of FMSY. Contrary to expectations, weeks. To evaluate spat settlement the Krusenstern wrote a detailed report the total catch was higher under the spat ropes are carefully rinsed and the published between 1809 and 1812 in St simultaneous scenario. We explored our subsequent material washed through Petersburg. One of the scientific results results using qualitative models and by a series of successively finer mesh of the Krusenstern expedition was the studying the trophic interaction between sieves. The spat are divided into three discovery, collection, and naming of many species at different levels of the foodweb, size classes and then counted under a new invertebrates, among them various and found that our overall result was microscope. Mussel spat sourced from bryozoans. The bryozoan genera Pherusa, driven by two key factors: volumetric both the Hauraki Gulf and Kaitaia have Krusensterna, Tilesia are all products dominance of small pelagic fish in the been seeded onto neighbouring lines in of the expedition. In New Zealand only total catch, and asymmetric influences the Hauraki Gulf and are sampled every the genus Hornera, a widespread and of competition and predation between three weeks to measure growth and speciose genus of cyclostome bryozoans, piscivorous and planktivorous species. condition. commemorates the Krusenstern The simultaneous increase in fishing expedition so far away and long ago. pressure across multiple species in the model led to increased effective carrying capacity for small pelagic species (due to reduced competition), but reduced carrying capacity for piscivorous species (due to reduced small pelagic prey). This has important implications for the design of tactical multi-species models for use in ecosystem-based fisheries management.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 153 SPEAKER ABSTRACTS

Do Aquatic Insects lay 20 Years of Stability: An Integrated Systems Their Eggs on One Rock Genetic Stock Structure Approach to Estimating the Basket? of the Iconic Australian Harvest of Marine Amateur Barramundi (Lates Fisheries calcarifer)

Brian Smith // NIWA Carolyn Smith-Keune // James Neville Smith // Ministry for Primary Cook University Industries Richard Storey // NIWA David Reid // New York Shannon Loughnan // Flinders University Martin Cryer, Eugene Rees // Ministry for Dean Jerry // James Cook University Primary Industries Successful reproduction and oviposition of adult aquatic insects may ultimately With increasing pressures on wild Reliable estimates of the catch of marine regulate benthic juvenile biomass, fisheries, including predictions of additive amateur fishers in New Zealand have abundance and distribution within a impacts of climate change, it is vital we proved elusive. Telephone-diary surveys stream. Therefore, the availability of understand the current stock structure of were implemented between 1993 suitable oviposition habitats may be exploited fish species to better monitor and 2001 and seemed cost-effective. a potential bottleneck to successful and predict future change. The iconic However, surveys with apparently small recolonisation of restored habitats by Australian barramundi is an important design differences generated radically aquatic insects. Adult females returning commercial, recreational and aquaculture different catch estimates, often with to oviposit may respond to a suite of target species with a history of restocking wide confidence limits. Subsequently, cues when selecting an oviposition and evidence of genetic stock structure. direct observational methods have been site. If so, the egg mass distribution of Diverse genetic methods and incomplete applied to some key stocks and areas different insect species are expected spatial sampling of past studies makes a and are considered reliable, but such to vary both within and among stream more complete and current day picture of surveys can be expensive and cannot reaches depending on hydrology and genetic stock structure highly desirable be applied nationwide. Following a land use. What are these cues, and can for future monitoring. We have examined detailed and comprehensive review over we quantify them by characterising egg the genetic stock structure of Lates the past 4 years of our bitter historical mass distributions? We recorded egg calcarifer from the southern limits of experience with telephone-diary surveys, mass distributions at 5 random transects the species distribution in Queensland we have implemented an integrated within 50 m reaches at 6 streams (3 across the tropical north of Australia and catch (harvest) estimation system. In native forest, 3 pasture) in spring and down the Western Australian coast to this paper we outline what we consider summer. At each transect (regardless of the Pilbara region. We utilised sixteen to be an integrated catch estimation whether eggs were present) we recorded microsatellite markers and examined system and show some results from a range of physical stream and channel 1297 individuals from 45 locations across the comprehensive nationwide survey characteristics from overhead riparian the species range. Nineteen genetically implemented for the 2011/12 fishing year. cover to substrate embeddedness. Where distinct stocks have been identified eggs were present, we also recorded and the pattern of stock structure is egg dimensions and position on the remarkably similar to that revealed by rock, took photographs, and retained allozyme electrophoresis in the 1990’s. the egg masses for identification via Temporally replicated samples obtained genetic analysis. Initial results indicate from 6 locations indicate stability of that emergent rocks appear more allele frequencies for the past 18–20 desirable for oviposition than submerged years, however, a temporary shift in allele rocks. Desirable rocks were covered by frequencies in one Queensland river multiple eggs masses belonging to many system coincided with the release of a species, and were predominately laid on large number of stocked barramundi. As the underside of these rocks. Emergent stocking activities are likely to continue rocks may increase the intensity of the for this species we are continuing horizontally polarised light reflected from to evaluate the environmental and the water surface which may be one of geographic drivers of observed genetic the important visual cues aquatic insects structure. Furthermore, we are turning use to find desirable oviposition sites. to powerful next generation DNA sequencing technologies to explore the adaptive potential of discrete barramundi stocks.

154 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Nutrient Enrichment Effects Ecological Effects of The Role of Food on Photosynthesis in the Undaria pinnatifida: What Availability & Predator Wetland Plants Typha Does Our Not-so-recent Pressure on Sea Urchins orientalis & Phormium tenax Arrival Do? Sheltering Behaviour

Brian Sorrell // Aarhus University Paul South // University of Arie Spyksma // The University of Canterbury Auckland Hans Brix // Aarhus University Chris Tanner // NIWA Stacie Lilley, David Schiel // University of Richard Taylor, Nicholas Shears // The Bev Clarkson // Landcare Research Canterbury University of Auckland

Anthropogenic nutrient enrichment can Since its discovery in Wellington Harbour The sea urchin Evechinus chloroticus allow fast-growing species with high in 1987, Undaria pinnatifida has spread is one of the most dominant grazers photosynthetic capacity to out-compete around New Zealand’s coast and it is now in subtidal reef ecosystems around less vigorous species in freshwater a permanent, and often highly abundant, New Zealand. Aggregations of these wetlands. We compared the effect of component of low intertidal and shallow echinoderms have the ability to nutrient enrichment on photosynthetic subtidal systems. While its geographic completely strip away dense kelp forest gas exchange in two tall canopy spread and the underlying mechanisms of leaving behind urchin barrens devoid dominants, the inherently fast-growing invasion have been well-documented, few of standing algae. This deforestation species raupo (Typha orientalis) and studies have examined the effects of this only occurs when urchins are out in the slower-growing flax (Phormium tenax). species on coastal ecosystems. Undaria is open (exposed), actively feeding on live Photosynthesis was compared between a highly unusual species in New Zealand kelp. This research investigates how 9 field locations differing in nutrient as there is no analogous native kelp with food availability and predator pressure availability where the two species respect to its annual life history and fast (not direct predation) affect an urchins co-existed, and in an outdoor growth canopy formation. Thus, experiments sheltering behaviour. Determining experiment. Raupo accumulated higher are needed to determine its effects and, what causes an urchin to come out concentrations of nitrogen (N) and more generally, to incorporate it into our from shelter into the open will help us especially chlorophyll in its leaf tissue understanding of coastal community understand how urchin barrens form and than flax. Photosynthetic rates were structure and processes. Here, we why some areas and not others have significantly higher in raupo than flax in broadly assign ecological effects into constant barrens or constant kelp forests both field and experimental situations, two categories; (1) ‘interactive effects’, even if they are geographically similar. except at very low nutrient availability, whereby we test the role of Undaria Two separate experiments conducted in where they were similar. Photosynthesis in community structure and patterns outdoor mesocosms tanks were used in raupo increased strongly with N of diversity, and (2) ‘subsidy effects’, to test how subsidies of drift algae (high availability, whereas there was only whereby we assess its contribution to food availability) and injured conspecifics a weak relationship between N and coastal primary production and potential (predator pressure) influenced urchin photosynthesis in flax in experimental nutrient input into coastal systems. We sheltering behaviour. Results from the cultures, and no effect at all of N on flax present data from 2-year press removals food availability experiment showed no photosynthesis in the field. Both species of Undaria, in situ measures of primary significant differences between overall had significantly higher photosynthesis production in the resulting communities behaviour in urchins in the control and rates in experimental cultures than in with and without Undaria, and estimates treatment tanks with both having high the field; for raupo this was due to N of shore-wide production. exposure rates throughout the day. limitation in the field, whereas for flax it In contrast, urchins subjected to the was due to lower stomatal conductance scent of an injured conspecific showed in field plants than experimental plants. significantly high levels of cryptic The differences in photosynthetic behaviour compared to control tanks physiology between these two species where urchins remained highly exposed. suggest a clear mechanism for the These results suggest that urchins will dominance of raupo over morphologically respond strongly to injured conspecifics similar species in wetlands subject to and will remain highly cryptic to avoid nutrient enrichment. The maximum predation. This suggests that the photosynthetic rates achieved by raupo in presence of predators in marine reserve -2 -1 this study (up to 60 µmolCO2 m s ) are sites may facilitate trophic cascade effects amongst the highest ever recorded for C3 by altering sea urchin behaviour rather plants. than through direct predation alone.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 155 SPEAKER ABSTRACTS

Ecological Effects of Mass-marking Purple- Considerations in using a Water take on the spotted Gudgeon the Daily Egg Production Kaipatangata Stream, Mogurnda adspersa Larvae Method (DEPM) to Provide Wairarapa for Ecological Study a Fishery-independent Estimate of Biomass for South Australia’s changing Snapper Fishery

Brett Stansfield // Environmental Danswell Starrs // The Australian Mike Steer // South Australian Impact Assessments Limited National University Research and Development Institute

This presentation investigates the Brendan Ebner // CSIRO Tony Fowler, Rick McGarvey, Tim Ward, ecological effects of a water take during Stephen Eggins, Christopher Fulton // The Nathan Bott // South Australian Research low flows on a small stream using benthic Australian National University & Development Institute biological monitoring, fish monitoring, diurnal temperature and dissolved Studying the early life history phases There has been a dramatic switch in the oxygen monitoring and WAIORA (water of fishes is problematic in part due to spatial structure of South Australia’s allocation impacts on river attributes) limited techniques for tracking individuals snapper fishery over the past five years. modeling. A 100 l/s low flow limit has through space and time. Gudgeons Spencer Gulf (SG) has traditionally yielded been recommended to safeguard the exhibit a wide range of early life history the State’s highest snapper catches, ecology of this stream. Further concurrent dispersal strategies, yet unravelling however, in recent years it has been gaugings are recommended down the the complexity and consequences of superseded by Gulf St. Vincent (GSV) catchment to have a better understanding larval behaviour is hampered by limited and the South East (SE), two regions that of effects below the Wairarapa Fault marking techniques. We examined if had previously attracted little attention where significant water loss occurs. TRAnsgenerational Isotope Labelling from fishers. Commercial fishers rapidly Some cross validation of the WAIORA (TRAIL) could be employed to mass-mark responded to this increase by adjusting model with real time monitoring is also the larvae of female Purple-spotted their fishing behaviour, shifting from presented. gudgeon (Mogurnda adspersa), a using conventional hand-line gear to common freshwater Australian eleotrid. adopting improved long-line technology We injected mature female M. adspersa to maximise their fishing efficiency. Catch with enriched 137Ba, 87Sr and a cocktail rates in this sector subsequently appeared of both to produce multiple unique to “boom” in NGSV raising concerns markers for larvae. We examined if the about the long-term sustainability of the marking procedure impacted upon larvae resource at the current levels of fishing morphology, growth and survival in a intensity. Management responded by series of controlled experiments. We imposing daily trip limits to control catch found that TRAIL was a valid means and plan to implement spatial closures to of mass-marking larvae, in addition to protect snapper spawning aggregations minimal impacts on larvae morphology, from the summer of 2013/14 onwards. survival and growth. Application of TRAIL The recent change in fishing efficiency has the potential to quantify the extent combined with the aggregative nature and consequences of early life history of snapper and new management dispersal, and to inform biogeography regulations have compromised South and conservation of species of Mogurnda. Australia’s ability to use ‘catch per unit of fishing effort’ (CPUE) as a reliable estimate of stock biomass. There is consequently an urgent need to develop a fishery-independent estimate of biomass that feeds into the existing stock assessment model and ensures future harvest strategies are developed from unbiased information. The DEPM has been suggested as a feasible technique to fulfil this requirement. This presentation will discuss the considerations underpinning the use of this method, how it will be integrated into the stock assessment process and its additional benefits.

156 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Fishery. What’s going on The Rapid Expansion of Transport Non-linearities in with South Australia’s Gross Eutrophic Zones Coastal Seas: Determining Iconic Cuttlefish Spawning in New River Estuary, Source & Fate of Flow Aggregation? Southland (2001–2012) Fhrough Aquaculture Installations

Mike Steer // South Australian Leigh Stevens // Wriggle Coastal Craig Stevens // NIWA Research and Development Institute Management David Plew, Joanne O’Callaghan, Mark Sam Gaylard // Environmental Protection Barry Robertson // Wriggle Coastal Hadfield, Jens Petersen // NIWA Authority Management Olivier Ausseil // Danish Shellfish Center Nick Ward // Environment Southland Each winter tens of thousands of giant An expanded aquaculture industry Australian cuttlefish (Sepia apama) New River Estuary (NRE) is a large (4,600 is seen by many as a key economic aggregate on a discrete area of rocky reef ha) “tidal lagoon” estuary situated near focus for New Zealand. Unlike many in northern Spencer Gulf to spawn. This Invercargill at the confluence of the uses of coastal waters, these activities is the only known dense aggregation of Oreti and Waihopai Rivers. It drains a have a quasi-permanent physical spawning cuttlefish in the world and it primarily agricultural catchment and has presence that continuously disturbs has declined from a peak in abundance had eutrophication and sedimentation the flow – and in turn the operation of ~183,000 animals in 1999 to 18,530 in identified as problems since at least 1973. of the installation is influenced by the 2012, representing a 90% reduction over Broad scale assessments of sediment, background transport. There is a natural 13 years. The nature and extent of this eutrophication, and habitat modification tendency to simplify representations decline has become a concern for many issues have been undertaken in 2001, of coastal transport processes when South Australians and given the iconic 2007 and 2012 using the National Estuary seeking to quantify impacts on the status of the species, it has also attracted Monitoring Protocol and subsequent environment. This is possible but needs considerable media attention. The obvious extensions. Results show large sections to be supported by an understanding questions that have been frequently of the estuary remain in good condition, of which processes, and when, to asked by the community is “what has but document a significant decline ignore. Here I will synthesize our work caused this decline over the years?” in estuary quality. In particular, gross over the past decade on flow-structure and “will the local cuttlefish population eutrophic conditions (excessive mud, interactions in coastal environments. recover?”. These are very challenging high nuisance macroalgal growths, poorly Our approach is to first consider the questions to definitively answer as there oxygenated sediments, toxic sulphides) basic scaling for any situation to identify most likely a suite of inter-connected have expanded from 23 ha in 2001, 49 likely dominant processes and then factors driving the declines in cuttlefish ha in 2007, to 240 ha in 2012. This has record targeted field observations, often abundance and biomass. This complexity caused a significant (44%) loss of dense with novel techniques. We then seek is apparent when considering the range intertidal seagrass beds (which now to model the important facets of the of factors that have been suggested by comprise <2% of the estuary). The macro- observations and then iterate to improve the general public, government agencies invertebrate community in these gross overall understanding. Questions we and non-government organisations, as eutrophic areas is also severely degraded consider here are (i) flow distortion of the potential contributors to the decline. with little animal life able to establish structure away from the coast; (ii) flow Such speculation has included: natural in the anoxic sediments, and the few complexity due to variability in the coastal variation; industrial pollution; fishing surface feeding species limited to those environment and (iii) the effect of the flow pressure; environmental irregularities; tolerant of poor conditions. The changes on the installation itself. These themes increased predation pressure; disease; clearly show the capacity to assimilate contribute to concepts like “deposition seismic activity; tourism; and local catchment nutrient and sediment loads is footprint” and “water column depletion”. aquaculture ventures. A recent study currently exceeded in the upper estuary The work not only provides guidance for considered all possibilities and provided a settling basins, and serve a clear warning operation but is also crucial for identifying preliminary evaluation upon which further that problems are likely to continue to impacted ecological processes and so is investigation can be based. The results of worsen if management action is not relevant to regional planning strategies as this study will be presented. The flow-on taken. To that end, work is currently well as industry-focused issues. ramifications of these findings and the underway to set catchment nutrient current research direction will also be and sediment guideline thresholds that, discussed. if achieved, will protect against further degradation and ideally help return the estuary to a healthier condition.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 157 SPEAKER ABSTRACTS

Speculation on the Science on Tap: Using Dispersal of the Invasive Existence of a Victoria Bayesian Networks to Oriental Weatherloach Land (Antarctica) Coastal Inform Collaborative Water (Misgurnus anguillicaudatus) Current Planning in Hawke’s Bay in the Lower Murray River Post 2011 Flooding

Craig Stevens // NIWA, University Richard Storey // NIWA Lara Suitor // Department of of Auckland Environment, Water and Natural Jim Sinner // Cawthron Institute Resources Mike Williams, Natalie Robinson // NIWA Tim Sharp // Hawke’s Bay Regional Pat Langhorne // University of Otago Council Irene Wegener, Kate Mason // Stefan Jendersie // University of Otago, Suzie Greenhalgh // Landcare Research Department of Environment, Water & NIWA John Quinn // NIWA Natural Resources

The ocean beneath the Ross Ice Shelf Freshwater management decisions in Before regulation, flow in the Murray is one of the least known volumes of New Zealand increasingly are made by River was highly variable, a trait of water on the planet. We do know that: collaborative stakeholder groups (CSGs) lowland rivers in arid regions. In the (i) pressure effects cause some of the comprising major water users and Lower Murray, this regulation has water in the cavity to be very cold, to communities of interest. In the Greater effectively isolated the river channel from the extent that it is colder than its in Heretaunga and Ahuriri area (Hawke’s many wetlands and floodplain habitats, situ freezing point and (ii) the earth’s Bay), increasing water quality issues and and an extreme lack of out-of-channel rotation will cause any outflow to be demands for water abstraction led to a flows in the past decade resulted in many preferentially steered to the west – i.e., review of the regional water plan. A CSG floodplain areas not receiving adequate the Victoria Land coast. Consequently it was convened by the regional council to flooding water for over 15 years. This has would seem likely that there is some form balance competing human and ecological resulted in various forms of ecological of coastal current along this coast. Here demands for water and propose an degradation occurring within this region. we synthesize various data to examine agreed set of management decisions. A number of high-flow events occurred this hypothesis. This topic is especially Stakeholders came with different values, along the Lower Murray River between important because any outflow from the perspectives and levels of knowledge summer 2011 and autumn 2012. During Ross Ice Shelf Cavity is likely predisposed about freshwater in the catchments. this time, fish sampling was undertaken to forming sea ice rapidly. This has Their task required a good understanding to elucidate the temporal and spatial implications for feedback that can of the ecological, economic, social and variability in fishes using inundated influence ice shelf basal melt rates. cultural aspects of the river systems. floodplain and wetland habitats. In our The CSG began by describing how they sampling, the Oriental Weatherloach understood these aspects of the river (Misgurnus anguillicaudatus), an invasive systems by developing an “influence species previously not documented in the diagram” (conceptual model) for each Lower Murray River in South Australia, aspect. The influence diagrams were was captured at a number of wetlands refined by a science team and presented and floodplain sites. This presentation back to the CSG. Then they were discusses the occurrence and persistence combined into a Bayesian Network (BN). of Oriental Weatherloach across sites BNs quantify cause-effect relationships within the Lower Murray River after between variables using probabilities to detection and dispersal in 2011. Although reflect the certainty with which those the data presented is observational, it relationships are known. Scientific theory, demonstrates that between 2011 and empirical studies and expert opinion are 2013 a range of size classes of the all used to describe these relationships. species have been captured across a The Bayesian Network was designed to variety of habitat areas between the help the CSG understand the effects of South Australian and Victorian Border to different management decisions on key the Lower Lakes. values and choose options with high likelihood of achieving objectives.

158 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

BoP Rotorua Lakes Algal Predicting Inanga Do Mangroves Play a Major Monitoring Programme: Spawning Sites using a GIS Role in the Geomorphic linking Science to Policy & Model Evolution of New Zealand Plans Estuaries?

Alastair Suren // Bay of Plenty Graham Surrey // Auckland Andrew Swales // NIWA Regional Council Council Catherine Lovelock // University of Paul Scholes // Bay of Plenty Regional Julian Sykes // NIWA Queensland Council Malcolm Green // NIWA Kit Rutherford // NIWA Inanga (Galaxias maculatus) are a Vernon Pickett // Waikato Regional Olivier Ausseil // Aquanet Consulting Ltd diadromous freshwater fish that comprise Council the majority of New Zealand’s highly Paul Denys // University of Otago Increasing algal blooms in the Rotorua valued whitebait fishery. This species is Lakes since the 90’s lead to Te Arawa known to spawn in streams and rivers The role of mangrove forests in the Maori Trust Board, RDC and BoPRC amongst riparian vegetation inundated geomorphic evolution of estuaries develop a Rotorua Lakes Strategy. by high spring tides, at the interface of and coasts has historically been of Its overall vision is to preserve and fresh and salt water. These locations considerable scientific interest. Moreover, protect the lakes for present and future are increasingly under pressure from the role of biology in landscape evolution generations. TLI targets were set for disturbances such as stock grazing, land is an emerging theme in geomorphology. each lake and schemes implemented development and erosion, which can In autochthonous systems remote from to achieve these including: sewerage severely affect the breeding success terrigenous sediment inputs, mangroves reticulation, riparian fencing, land use of inanga. A key factor in being able to have a fundamental influence on coastal geomorphology through peat change. Water quality has improved protect these vulnerable spawning areas deposition. By contrast, the mangrove in Rotorua, Rotoiti and Rotoehu and is to identify where they are located, a forests of continental margins and appears stable in other lakes. BoPRC task that can be both time-consuming and labour intensive. This paper high islands, such as New Zealand, are undertakes monthly TLI monitoring, supplied with terrigenous sediments. quarterly phytoplankton monitoring, presents a first-cut GIS model that has been developed to predict where likely In these mud-dominated systems and weekly cyanobacterial surveillance there are conflicting views about the inanga spawning areas may be located, in summer. These programmes were geomorphic role of mangroves. Is based upon modelled tidal values and a designed to investigate and report the mangrove ecology largely driven by LiDAR-derived Digital Elevation Model. region’s natural resources, provide a physical processes (e.g., sedimentation), snapshot of current condition and detect This technique shows promise in enabling with mangroves colonising intertidal overall trends. Another requirement more targeted surveys to locate areas flats after they become ecologically was to determine whether objectives of that inanga currently use to spawn, or suitable? Alternatively do biophysical regional plans are being achieved. Clear that could benefit from environmental feedbacks enhance sedimentation so feedback loops are needed between enhancement to increase their utility as that mangroves accumulate mud more monitoring and planning/policy. The spawning sites. rapidly than would otherwise occur on TLI has clearly defined metrics and unvegetated intertidal flats? This question measureable targets, and monitoring and also has implications for environmental feedback are being done. However, for managers. Accelerated sedimentation phytoplankton monitoring, no metrics in North-Island estuaries following catchment deforestation has created exist, and no measureable targets set. For opportunities for mangrove-habitat cyanobacterial monitoring, specific alert expansion. Concerns regarding the level trigger values exist (MfE guidelines) resulting loss of ecological and amenity but no targets have been set. It is thus values has led to mangrove removal unclear how algal monitoring connects in some estuaries. Public debate has to Lake Action Plans via feedback loops. sometimes been ill-informed, including Does this represent a failure of monitoring the role that mangroves play in estuary to provide timely data to characterise sedimentation. Observations from the current lake conditions, or a failing of Firth of Thames made over a range policy and plans to set better objectives? of time-scales relevant to estuary- The obvious disconnects between sediment dynamics, geomorphology current lake algal monitoring programs and mangrove-forest development are and policies and plans will be discussed, used to address this question. These which need to be rectified to maximise data include high-resolution radioisotope the benefits of monitoring. geochronology from sediment cores (years–decades), sedimentation and surface-elevation dynamics (seasonal) and continuous observations of meteorological, hydrological and estuarine processes driving sediment supply and delivery to the mangrove forest (i.e, river discharges, mudflat resuspension, hydroperiod).

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 159 SPEAKER ABSTRACTS

Impacts of Climate Evaluating Ontogeny & Toxic Scavengers, Change on Macroalgal Population Connectivity Zombies & Alien Invasions: Assemblages: Interactions of Antarctic Toothfish Facilitation from Native between ocean (Dissostichus mawsoni) & Invasive Bivalves for Acidification & Rising within the Ross Sea Using Pleurobranchaea maculata Temperatures in Complex Otolith Chemistry Communities

Leigh Tait // University of Raymond Tana // The University of David Taylor // Cawthron Institute Canterbury Waikato Susie Wood, Shaun Ogilvie, Paul McNabb David Schiel // University of Canterbury Brendan Hicks, Conrad Pilditch, Stuart, // Cawthron Institute Hanchet // The University of Waikato David Hamon, Alice Anderson, Larn Anthropogenic influences on climate and Wilkinson // Hauraki Maori Trust Board biogeochemistry have the potential to Knowledge on the early life history Jarrod Walker // Auckland Council cause drastic changes to the functioning and population structure of Antarctic Craig Cary // The University of Waikato of marine communities. Although there toothfish (Dissostichus mawsoni), a is a growing body of evidence on the relatively long-lived (max. 50 years) Bivalves are ecosystem engineers that responses of species to various forms of bentho-pelagic species found in waters can facilitate other species through climate change, the combined impacts around Antarctica south of about 60°S, increased habitat complexity and of multiple stressors on more complex has been particularly elusive. However, provision of alternative food sources. assemblages are poorly understood. several life history hypotheses have been These processes were highlighted after Through a series of lab and field proposed for this species based on ocean a series of dog deaths on New Zealand experiments in New Zealand and Oregon circulation models, population genetics beaches, where the deadly neurotoxin, we show that macroalgal assemblages and data collected by scientific observers tetrodotoxin (TTX), was identified as may be more severely affected by ocean from the Ross Sea Antarctic toothfish the causative agent. Populations of acidification and rising temperatures than fishery. Here we review these hypotheses sea-slugs, Pleurobranchaea maculata, components of these assemblages alone. and outline how we can test them using were found to contain high levels of TTX Here we show through a series of tests trace element markers in fish otoliths. in the range of 5-2450 mg kg-1, with that respiration of naturally structured Specifically, we used scientific observers the toxin found in all life-stages. Diver algal assemblages greatly increases with on board New Zealand longline vessels surveys, at beaches where dog deaths rising temperature, causing a decline in to collect otoliths and water samples had occurred found P. maculata reached NPP. The respiration Q of assemblages 10 across four regions within the Ross abundances of 0.9 per m2 on beds of (the difference in metabolic rates over Sea during the 2011–12 fishing season. Musculista senhousia, the invasive Asian 10ºC) averaged 2.9 compared to a Q 10 Based on the ratios of five elements Date mussel. Large non-toxic populations of 2 often seen in other autotrophs. (Li:Ca, Sr:Ca, Al:Ca, Zn:Ca, and Mn:Ca) of P. maculata have subsequently However, the GPP Q averaged 2, 10 in the otolith edge, preliminary jacknife been found on offshore mussel farms indicating that respiration was more classification results indicate that habitat (growing native Greenshell™ mussels, severely affected by rising temperature. signatures associated with the Ross Sea Perna canaliculus) in another part of the Furthermore, the combined effects of shelf, continental slope, northern and country. Results of field experiments and low pH and temperature indicated an north eastern regions showed only weak Q-PCR assays suggest that both invasive enhanced effect of decreasing pH at separation. Possible reasons for this are and indigenous mussel beds facilitate higher temperatures in coralline algae, discussed. Analyses are on-going and population explosions of P. maculata by showing that multiple stressors have the will include assessments of otolith natal providing novel egg-laying habitat, ideal potential to combine synergistically at signatures across different size classes settlement and recruitment substrata further detriment to NPP. In particular, and habitats to determine evidence of and an on-going food source for this increased respiration rates and rising population structuring and ontogeny scavenging species. compensation points have the potential within the Ross Sea. The results of which to greatly affect the carbon balance of will have particular relevance towards macroalgal assemblages through declines future management of this fishery. in subcanopy NPP, the impacts of which may be exacerbated with combining stressors, such as temperature and pH change.

160 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Lake Kimihia Restoration Facilitation Cascades Can a Species’ Response to Project Increase Biodiversity in a Climate Change be Inferred New Zealand Estuary from Analysis of Otolith- based Growth Rates?

John Te Maru // Waahi Whaanui Mads Thomsen // University of Ronald Thresher // CSIRO Trust Canterbury John Morrongiello // CSIRO Paul South, David Schiel // University of Canterbury Lake Kimihia is one of the lower Waikato A responses of species, populations, River lakes, and located in Huntly. It is and individuals to climate change can culturally significant to Maori. The once Evidence is emerging that chains of range from physiological and evolutionary mighty lake was a food basket for local positive species interactions are common compensation in sedentary species Maori community providing eels, birds and ecologically important. For example, to migrations by more mobile ones and other resources. primary habitat-formers can facilitate that follow changes in environmental The lake is now less than a third secondary habitat-formers to directly and conditions. Determining which strategies of its original size as a result of mining indirectly facilitate habitat-associated are used by a species and the mix within activities in the 1950s. The modified plants and animals. Such ‘facilitation and among its populations is difficult lake is set to bemodified further as the cascades’ are particular important in without extensive field studies. We test proposed Huntly section of the Waikato ecosystems where epiphytic and epizoic whether ontogenetic trends in growth Expressway will be constructed very life-styles are common (e.g., in tropical rates (reaction norms) for individual fish, close to its southern shore. forests and estuarine seagrass beds). when compared with predictions based Despite all this, the tributaries Here we document that facilitation on temperature change, can be used running into the lake are still important cascades in the Avon Heathcote to infer the mix of strategies used by a habitat for whitebait species, particularly Estuary (AHE) increase biodiversity species. We test this idea by analyzing banded kokopu and in 2011, Waahi and control community structures of and comparing long-term growth rates Whaanui Trust, Solid Energy and NZTA Macroinvertebrates. More specifically, across the species’ ranges for two coastal began discussing how Lake Waahi we quantify spatio-temporal variability in temperate Australian species: banded and its tributaries can be restored. This the effects of three co-existing habitat- morwong, which are strongly site- presentation outlines the work to date. formers (seaweeds, seagrass, cockles) attached as juveniles and adults, and tiger in controlling invertebrate community flathead, which may not be. Both species structures We then compare our results have been subject to rapid warming over to facilitation cascades from similar the last half century, providing a robust ecosystems with different biogeographies environmental signal against which the (estuaries from different continents) and species’ responses can be assessed. to different ecosystems inhabited by fundamentally different co-existing habitat formers (e.g., trees-epiphytes and marsh- mussels). Our results show high variability of indirect facilitation in the AHE, comparable to highest and lowest levels of indirect of facilitation recorded from similar habitats on different continents as well as across different ecosystems. Our results also suggest that multiple habitat-formers should be managed and conserved within a system to maximize the system’s biodiversity.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 161 SPEAKER ABSTRACTS

Environmental Futures Space Matters when ‘Old man Schnapper’: in New Zealand’s Marine Counting on Biodiversity to Reconstructing 140 Years Ecosystems: a Dynamic Overcome the Cumulative of the Queensland Pink Approach Towards Effects of Disturbance in Snapper (Pagrus auratus) Managing for Resilience Seafloor Habitats Fishery

Simon Thrush // NIWA Simon Thrush // NIWA Ruth Thurstan // University of Queensland Judi Hewitt, Ian Tuck, Graeme Inglis // Judi Hewitt, Drew Lohrer, Carolyn NIWA Lundquist // NIWA Sarah Buckley, John Pandolfi // University Richard LeHeron, Karen Fisher, Nick Lewis of Queensland // The University of Auckland Interaction between the diversity of Dave Schiel // University of Canterbury. local communities and the degree of Pink snapper (Pagrus auratus) is an iconic Jo Ellis // Cawthron Institute connectivity between them has the species in southeast Queensland, but in potential to influence local recovery rates recent years concerns have been raised Project Introduction: As we look to the and thus profoundly affect community regarding the long-term sustainability future of our marine ecosystems we can dynamics in the face of the cumulative of the fishery. A 2009 stock assessment foreshadow many changes associated impacts that occur across regions. While found that pink snapper was likely with a wide range of resource uses such complex interactions have been overfished, using the year 1945 – the year and climate. But we would hope to see modeled, field experiments in natural that statewide landings data first became more benefits also, through integrative ecosystems to investigate the importance available – as a historical reference point. management, a better recognition of interactions between local and However, although landings records are of multiple uses and values, and an regional processes are rare, especially not available prior to 1945, recreational understanding of cumulative impacts. so in coastal marine seafloor habitats fishing parties have targeted aggregations New Zealand can gain a strong advantage subjected to many types of disturbance. of snapper in open ocean waters since if we can define the acceptable limits Defaunation experiments can be used the 19th century. Furthermore, catch of ecological sustainability and develop to test the relative importance of local rate data only began to be gathered from new management models, underpinned habitat features and colonist supply in commercial and charter fishers in 1988, by robust science. Marine Futures is influencing macrobenthic community hence large gaps in knowledge exist investigating how we can get better recovery rate. Our results emphasize that prior to this date and still exist for the at: developing more future focused the connectivity to the regional species recreational fishery. Using catch rate data decision-making processes; using pool influences recovery rate and, while collated from early newspaper reports, science to break-down our often siloed local habitat effects were important, the scientific surveys and interviews with approach to use and the stewardship; strength of these effects was affected contemporary fishers, we reconstruct the and incorporating the views, aspirations by broader-scale site characteristics and history of the Queensland pink snapper and values of all stakeholders. A key connectivity. Empirical evidence that fishery from the 1870s to the present element of this project is the recognition cross-scale interactions are important day. Our findings indicate that significant that understanding social-ecological in disturbance-recovery dynamics quantities of snapper were caught prior to systems dynamics are important not emphasizes the complex dynamics the commencement of landings statistics, only in considering marine futures but underlying seafloor community responses and that throughout the 20th century also in learning how to better engage to cumulative disturbance. snapper populations have undergone society in decision making. Our approach localised depletion, with declines masked to engaging people’s creativity and by technological advancements. These opening up a conversation on the future data extend the state of knowledge of the of marine ecosystems involves the use fishery by an additional seven decades of environmental future scenarios. By and provide a picture of the changing helping make visible constraints, options, conditions of the snapper fishery over and risks to different sectors of resource a 140-year period. By collating and users, we hope to engender end-users analysing these multiple sources of data, to take responsibility for action. In this we aim to provide essential data for future ‘marine futures’ session you will hear stock assessment models and develop a some of the science behind the project, broader understanding of how historical but this project is about participation and data can be successfully integrated into we want to hear from you about what you contemporary fisheries management. would wish the future to be for marine ecosystems.

162 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

The Impacts of Flow & From Rivers to Reservoirs: Mapping Ecosystem Temperature on Macquarie Post-impoundment Growth Services in the Marine perch (Macquarie australasica) & Recruitment of an Environment: Dealing with Population Dynamics: Endangered Fish Issues of Scale, Uncertainty Implications for Water & a Lack of Data Delivery & Threatened Species Management

Charles Todd // Department of Zeb Tonkin // Department of Michael Townsend // NIWA Environment and Primary Industries Environment and Primary Industries Simon Thrush, Andrew Lohrer, Judi Zeb Tonkin // Department of Environment Jarod Lyon, Graham Hackett, Justin Hewitt, Carolyn Lundquist // NIWA & Primary Industries O’Mahony, Glen Johnson // Department Megan Carbines // Auckland Council of Environment & Primary Industries Malene Felsing // Waikato Regional Macquarie perch (Macquaria australasic) Council is an endangered freshwater species The construction of major dams has in south-eastern Australia. The species been a major cause in the collapse of The ‘ecosystem services’ (ES) were translocated to the Yarra River as riverine fish populations throughout the approach has become a powerful tool early 1912, resulting in an abundant and world. There are however instances, in environmental management and a where the resulting impoundments self-sustaining population which still way of accounting the many different have created or even enhanced local exists today. Melbourne Water has an benefits derived from natural systems. fish populations, including threatened environmental legislative responsibility However, use of ES in marine realms to manage the Yarra Rivers Macquarie species. More often than not, any such benefits to local fish populations within is fraught with difficulties: In many perch population. With concerns over or upstream of these newly formed areas we lack adequate knowledge of low recruitment success in recent years, habitats are short-lived, owing to the the distributions of habitats and their Melbourne Water has invested in a initial trophic upsurge, followed by a associated ecosystem functions that, in population modelling approach to predict subsequent population crash. Macquarie turn, limits our ability to map and quantify future trends and the effectiveness of perch (Macquaria australasica) in south services. Furthermore, the vast areas over environmental flow management for the eastern Australia, are one such species, which management is needed means species. This work builds on the Macquarie with an initial boom in populations within that acquisition of detailed information at perch recruitment model by King et al. several impoundments, following by these scales is untenable. Management is (2011) which combines a number of a general trend of population decline needed today and therefore approaches environmental variables, including flows to very low levels or extinction. The must be able to use the best available and temperature. Utilising this model, we newest of these impoundments, Lake information in conjunction with used an approach similar to that of Todd Dartmouth, appeared to be yet another techniques that facilitate the filling of example, with research indicating a sharp et al. (2005; Murray cod) to develop a knowledge gaps. Here we present a decline in population size since its initial stochastic population model for Macquarie synopsis of our work and a demonstration perch including the impacts of flow and boom throughout the 1980’s. Given the importance of the population to the of our ‘Ecosystem Principles Approach’ in temperature and other environmental cues overall status of the species, a monitoring the mapping of three ecosystem services as well as accounting for the impacts of program was established in 2008. In (biogenic habitat formation, nutrient additional threatening processes such addition to this general monitoring recycling & ecosystem productivity) at the as fishing to examine if any of these objective, the research coincided with scale of the Hauraki Gulf. We also present processes are driving recruitment failure. the end of the prolonged south-eastern the use of rapid assessment techniques Using 37 years of flow and predicted Australian drought, and subsequent to characterise habitats with implicit links temperature data, the population dynamics refilling of the Lake. This prompted the to a variety of services in estuarine and of Macquarie perch were assessed based hypothesis that the refilling phase of Lake harbour systems. We demonstrate the upon flow, temperature, and pre-spawning Dartmouth would result in another trophic benefits of even basic information in the flow requirements. Recruitment failure upsurge, and ultimately, an increase absence of detailed data and how this was observed when accounting for a large in the size of the Macquarie perch can be appropriately used in goods and increase in flow (greater than twice the population. We present the results of a services assessments. previous days flow) during the post- study which used growth chronologies, spawning period. The model successfully to reconstruct Macquarie perch growth predicts the observed low recruitment rates throughout the three major filling in recent drought years indicating that phases of the impoundment. Recent annual netting surveys, coupled with a sharp increase in flows in the post- aging data were then used to assess spawning period may be the driver for any associated changes in recruitment low recruitment. Future use for the model strength and population size. The results will be to include predicted in-flows to of the study are discussed in relation to the Yarra River to model potential impacts Lake productivity, recruitment dynamics from climate change. and how dam management and climate change may facilitate the preservation of this endangered species.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 163 SPEAKER ABSTRACTS

Murray-Darling Basin Lake Taupo & its Temperature Trends in Fishes: Phylogenetic Catchment: Are We Rivers & Lakes Relationships & Meeting the Limits? Distributional Patterns

Peter Unmack // University of Bill Vant // Waikato Regional Piet Verburg // NIWA Canberra Council While air temperatures in New Zealand Carlos Gonzalez-Orozco, Bernd Gruber, Jon Palmer // Waikato Regional Council are known to have increased by about Arthur Georges // University of Canberra 1ºC over the past century, little is known Michael Hammer // Northern Territory More than 10 years ago, the Waikato about how the changing climate has Museum Regional Council became concerned affected the aquatic environment. As Mark Adams // South Australian Museum about the effects of increasing catchment a part of the Climate Change Impacts loads of nitrogen on the water quality of and Implications Project time series of water temperatures in rivers and lakes As the second largest river basin in Lake Taupo. Calculations showed that were analysed, using data of monitoring Australia, Murray-Darling Basin has most (>90%) of the manageable nitrogen programs carried out by NIWA and suffered major impacts from human entering the lake came from areas of by regional councils, respectively, and development to the detriment of its pasture in the catchment. A variation to compared with trends in air temperature. fishes and other aquatic inhabitants. the Regional Plan was developed, and Monthly measured water temperature The combined effects of flow regulation, was finally confirmed by the Environment increased during 1989–2012 in 89% of 77 riparian vegetation removal, soil erosion Court in 2011. The Plan aims to maintain sites in 34 rivers in the North and South and introduced species like redfin, trout the lake’s current water well into the Island. The average change in water and gambusia have decimated the fauna future (“by 2080”), by managing loads temperature was +0.20ºC per decade, to where the majority of native fishes are of nitrogen in the catchment. It aims to while air temperatures of the Virtual now either extirpated, endangered or do this by (1) capping all manageable Climate Network (VCN) at the same with significantly reduced ranges. Here sources at their 2001 levels, and (2) locations (at <3 km distance) increased we seek to improve our understanding of reducing some of the manageable by 0.07ºC per decade over the same the evolutionary relationships of fishes, sources to offset much of the load that period. Trends were mainly driven by low both in terms of their relationships to is still in transit to the lake. Over the past values in the 1990’s (but temperatures surrounding drainages and also the 10 years there has been a moderate- in 1989 and 1990 were high), peak relationships within Murray-Darling sized increase in the concentration of values in 1998 and 1999 and fairly stable Basin. Murray-Darling Basin is nitrogen in the lake; but concentrations temperatures since then. Annual mean surrounded by more river basins than of phosphorus and chlorophyll a have stream temperature anomalies correlated any other in Australia and thus has decreased. Over the same period there strongly with air temperature anomalies diverse relationships, primarily to the has been a moderate increase in the load (R2 = 0.81). The trends in water northeastern coastal drainages (primarily of nitrogen entering the lake from the temperatures appeared not correlated Burnett River), southern coastal drainages catchment, and a moderate decrease with (small) shifts in time of day of in western Victoria and northwest with in the load of phosphorus. Increases in measurements, or trends in stream flow. the Lake Eyre Basin. Within the basin the loads of nitrogen were anticipated The trends in stream temperatures were most species have low levels of genetic in the Plan, and are consistent with the also not correlated with altitude. For only divergence and diversity which could multi-decadal storage of nitrogen in the a few lakes, data sets of temperature exist be due to recent origins, bottlenecks catchment’s groundwater. However, of similar length. In most of these lakes, and high dispersal abilities. We explore some of the increases have occurred no significant trends existed in surface these patterns and highlight the need to in streams draining areas of native and temperatures, with some exceptions. understand biogeographic relationships pine forest, suggesting that the load of in order to better manage and conserve nitrogen that was leached from historic remaining fish populations. land use practices and has been stored underground is likely to be larger than previously-predicted.

164 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Brine Communities in In Search of Ecological Hapū & Whānau Antarctic Sea Ice was Thresholds – What can Partnerships in Tuna Found to have Silica & We Learn from Stressor- Research in the Wairua Phosphorus Limitations response Relationships & Mangakāhia River to Inform Limit Setting in Catchments Streams?

Francisca Vermeulen // Victoria Annika Wagenhoff // Cawthron Nicki Wakefield // Ngā Kaitiaki o University of Wellington Institute Ngā Wai Māori and NIWA

Dr Ken Ryan // Victoria University of Roger Young, Joanne Clapcott, Eric Allan Haliday, George Tuhiwai, Hona Wellington Goodwin // Cawthron Institute Edwards, Erica Williams, Jacques Boubée Cathy Kilroy // NIWA // Ngā Kaitiaki o Ngā Wai Māori, NIWA Nutrient status of algae is important Ada Pastor Oliveras // University of in assessing the physiological limits to Barcelona In January 2012 Ngā Kaitiaki o Ngā Wai primary production. Field samples from Kelvin Lau, Gillian Lewis // The University Māori (representing Te Parawhau, Te 3 different Antarctic habitats (seawater, of Auckland Kahu o Torongare, Te Uri-ro-roi, Ngāti sea ice and brine) were analysed for Hau and Te Ore Wai hapū ) launched a nutrient limitation by the nutrient induced five year strategic plan with the vision of Agricultural land use puts pressure on fluorescence transient (NIFTs) method. “Te huarahi hei whakahokia mai te mauri freshwater ecosystems worldwide, mainly This approach is highly appropriate for o nga awa” taking in the waterways through non-point source pollution. the study of nutrient limitation in sea from the headwaters to the confluence Setting effects-based limits on discharge ice as it generates a near instantaneous of the Wairua and Mangakāhia Rivers. of the major stressors at the catchment nutrient limitation assessment. A positive The aspirations of Ngā Kaitiaki o Ngā Wai level is a promising policy instrument to NIFTs response was observed in brine Māori are categorised under a number prevent or reduce ecological degradation. communities indicating a silicate and of themes, including Kaitiakitanga, Limit setting requires knowledge of the phosphate limitation. In contrast, no Environment, Cultural, Social and assimilative capacity of an ecosystem with immediate responses were observed after Economic. Ngā Kaitiaki o Ngā Wai Māori regard to those stressors, or in other words, the addition of PO -3 or NO - to seawater actively maintains a variety of internal 4 3 the ecological threshold beyond which and sea ice samples, but a delayed and external collaborative partnerships to ecosystems should not be allowed to move. response occurred for silicate, and this implement research and environmental Scientists have tried to detect ecological was likely due to the high demand for restoration projects needed to inform thresholds through investigation of silicate by diatoms. Brine communities the group in freshwater management stressor-response relationships anticipating from the mid-section of the sea ice decision-making processes. For an initial period of resistance followed by consisted of diatoms and dinoflagellates, example, tuna [freshwater eels] are an an abrupt change in an ecological variable while diatoms dominated seawater and important taonga [treasured] species along the stressor gradient. However, such sea ice communities. These 2 different in the Mangakāhia and Wairua River response shapes were rarely observed. phylogenetic groups have different catchments. Many whānau, marae and Consequently, alternative approaches for nutrient requirements and therefore a hapū harvest tuna from the catchment threshold definition need to be adopted to dual nutrient limitation of Si and P was as part of their regular dietary intake, inform limit setting. Furthermore, in order to evident in the brine but not in the bottom as well as for hui and tangi. In addition set limits protective of ecological integrity, ice community nor in the seawater. The to concerns regarding local land use relationships between stressors and a range brine community was collected early practices and the associated effects of biological indicators including multiple December and these results suggest that on water quality and fisheries habitat, trophic levels and structural as well as it was already nutrient limited. Generally, tangata whenua are also concerned about functional attributes should be considered. sea ice primary production can continue the reduced availability of tuna. Given Hence, we conducted an extensive field until January when the ice breaks up, that the group is continuing to build the survey collecting benthic samples of and it is therefore likely that the nutrient capabilities and capacities required to macroinvertebrates, algae and bacteria, limitation in the brine severely limits realise the aspirations contained in the as well as measuring stream metabolism primary production in this part of the sea strategic plan, in this presentation we and cellulose decomposition potential ice. will use tuna as an example of the types at 58 stream and river sites spanning of outcomes we have already achieved a wide gradient in catchment land-use over a relatively short time period in intensities. Exploratory analyses showed a partnership with NIWA, as well as outline range of response shapes to gradients of our priorities for future research and nutrient concentrations. We will present environmental improvement. the statistical approaches, compare the thresholds defined for different biological indicators, and discuss the implications for the definition of an ecological threshold that is likely to protect stream ecosystem integrity and can inform limit setting in streams.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 165 SPEAKER ABSTRACTS

Swimming in Auckland’s What’s been Happening to Engineering Estuaries to Harbour Waters; Can the Lampreys Down South? Maximise Biodiversity, We Predict the Risk to Species Protection & Swimmers Resilience in the Great Barrier Reef Lagoon

Jarrod Walker // Auckland Council Kathy Walls // Ministry for Primary Nathan Waltham // James Cook Industries University, Australia Auckland City is hosting national and international water related sporting Anjali Pande, Jaap Knegtmans, Wendy Marcus Sheaves // James Cook events which utilise Auckland ‘s McDonald // Ministry for Primary University, Australia waterfront harbour. Currently there is little Industries consideration for public health related Desire for coastal living and urbanisation issues. The majority of these events are In September 2011, the Ministry for has replaced natural, soft, shoreline supported by very little bacteriological Primary Industries (MPI) was notified habitats with built infrastructure in information to inform the event organisers of a mass mortality of lamprey, Geotria many places. Among the anthropogenic and the participants of the relative risks australis, in the Mataura River, Southland. perturbations affecting coastal processes of swimming in the harbour. In this talk I Upon further investigation it became and resilience (e.g. overfishing, freshwater will present enterococci concentrations evident that lamprey populations in other diversion, sedimentation and dredging) related to rainfall from sampling Southland rivers were also affected. the most tangible is coastal foreshore done in the Waterfront. Highlight the Lamprey (kanakana) are a taonga species engineering in response to urban and shortcomings of the current recreational and the mortalities were cause for industrial development. These engineered water quality monitoring program and considerable concern by tangata whenua shorelines can offer extension to existing present Auckland Councils bathing beach in Southland. MPI was also concerned estuaries, though biodiversity is generally forecasting model developed by DHI. that other freshwater fish species may lower compared to the natural habitat be potentially impacted, such as trout, replaced. Exactly how well these newly salmon and native fishes. Affected created habitats mimic natural habitat lamprey were tested for a range of is unknown, and although structures pathogens but no conclusive evidence for comply with engineering standards, a primary pathogen was identified as the there are few attempts by managers to cause of the mortalities and it was unclear incorporate biota-friendly features, which whether other contributing factors were results in a complex mosaic of hard, responsible. Laboratory testing ceased engineered surfaces and habitat (e.g. at the end of 2011 because the seasonal pontoons, jetties, rock/concrete walls). kanakana migration upriver had finished Understanding the ecology of coastal and no further specimens could be development and consequences for obtained. In August 2012, MPI was again biodiversity cannot advance by simply alerted to dying kanakana in Southland documenting change, rather robust rivers. A surveillance programme was experimental programs are needed that implemented which involved: collection yield novel engineering solutions to of specimens for laboratory testing, a maximise biodiversity. In tropical systems targeted catch and release data collection sea level rise is the greatest climate programme, gathering observational data change risk factor, and consequently from stakeholders; and, receiving public expansion of coastal armouring and reports via the MPI Pest and Disease development is set to increase rapidly. We 0800 Hotline. By the end of the kanakana explored the habitat function of a variety migration in 2012, an exotic or emerging of engineering structures in an urbanised pathogen had still not been found in estuary connected to the Great Barrier the affected specimens. The results of Reef lagoon. The results show the need the investigations into the two mortality for practicable and affordable ecological events and the findings of a technical engineering designs, to achieve advisory group, convened to address conservation planning and policy change. options for managing future mortality Collaborative, cross continent, research is events in Southland, will be discussed. supported to assess whether the results here are more general.

166 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Anti-cancer Potentials Sustainable Management & Abiotic limits on Larval of Fucoxanthin Contents Economic Optimization in Transport Shape a Species Extracted From New Australian Commonwealth Distribution Zealand Undaria pinnatifida Fisheries

Kelvin Sheng WANG // Auckland Na Wang // University of Manna Warburton // University University of Technology Queensland of Otago

Dr Jun Lu, Dr Yan Li, Dr Lindsey White // You-Gan Wang // University of Worldwide, the distribution of Auckland University of Technology Queensland amphidromous fishes is associated with high relief landscapes. Recent The brown seaweed Undaria pinnatifida The appealing concept of maximum work has highlighted the association of amphidromous fish distributions with (U. pinnatifida) (Harvey) is important as economic yield (MEY) has been widely these landscapes on a continental scale. dietary foodstuff, and used for medical adopted to obtain new management The forces driving these distributions treatment supplement in East Asian strategies. However, the traditional on a continental scale are likely taking countries. The major component of U. MEY (MEY ) maximizes the net profit of f place on smaller scales as well within pinnatifida, fucoxanthin has recently been harvesting fish stock and stops the “rent the distributions of single species. found to induce apoptosis in various cancer drain” to the society. It may be more We explored the occurrence of the cell lines. This study investigated whether appropriate to use a broad MEY (MEYSRM) amphidromous New Zealand torrentfish other potential anti-cancer compounds which is based on the value chain of the across its distribution, examining could be found in fucoxanthin content overall fishing sector, to reflect better landscape features and correlating extracted from New Zealand (NZ) U. society’s interests. We evaluate the them with the presence of the species pinnatifida. Several types of human cancer implications of managing fisheries to based on the New Zealand Freshwater cell lines were used in this study including achieve MEYSRM using a number of the Fish Database. We found a correlation lung carcinoma A549, NCI-H522, colon Australian Commonwealth fisheries, and between specific river features (average adenocarcinoma WiDr, Lovo, hepatocellular illustrate how this framework incorporates downstream slope in lower reaches) and carcinoma Hep G2, breast adenocarcinoma fish chain sectors, employment and other the presence of torrentfish. Torrentfish MCF-7, malignant melanoma Malme-3M, positive externalities. The results show may be excluded from rivers that possess cervix squamous carcinoma SiHa, and that benefit of extending harvest to a appropriate adult habitat, but also possess neuroblastoma SK-N-SH. Anti-proliferative higher level, which still compromises slow moving lower reaches. We propose effects were determined by 24hr-72hr. sustainability objectives, overweighs the that abiotic features constraining larval transport in these rivers are excluding Pure fucoxanthin showed anti-proliferative economic rent loss in the fishery industry. torrentfish from occupying or recruiting effects in all cancer cell lines in dose- and out of them even though they posses time- dependent manners. The ranking of appropriate adult habitat. We further anti-proliferative sensitivity to fucoxanthin postulate that abiotic larval transport was in the order of Malme-3M > SiHa limits may help explain distributions of > Lovo, MCF-7, NCI-H522 and A549 > amphidromous fishes worldwide. Hep G2 and WiDr > SK-N-SH. Similarly, Whe management of diffuse anti-proliferative effects of fucoxanthin pollution is at the heart of a debate extracted from New Zealand seaweeds facing the Hawke’s Bay Region – how were found in all types of cancer cell lines should pressure to intensify agricultural in dose- and time- dependent manners. production and the potential effects on These three fucoxanthin extracts (purity of the water quality of the Tukituki River be fucoxanthin: 0.2%, 43.5% and 60.8%) were balanced? The National Policy Statement achieved through a series of fucoxanthin for Freshwater Management 2011 requires isolation and purification procedures. Regional Councils to set objectives and Compared with anti-proliferative IC50 of limits for both water quality and water pure fucoxanthin standards, the significant quantity. Based on a values assessment anti-proliferative effects of fucoxanthin of the Tukituki catchment, nutrient limits extracts were found in some cancer cell have been set to meet key management objectives. These limits have been lines including WiDr, Lovo, and NCI-H522. incorporated into a Plan Change for the In conclusion, fucoxanthin as a type of Tukituki River. HBRC will manage The marine carotenoid possessed effectively management of diffuse pollution is at the anti-proliferative effects to multiple types heart of a debate facing the Hawke’s Bay of cancer cell lines. Thus, fucoxanthin Region – how should pressure to intensify can be the important phytochemical with agricultural production and the potential chemopreventive effects. Furthermore, effects on the water quality of the Tukituki some of novel compounds with potential River be balanced? The National Policy anti-cancer effects might be contained in Statement for Freshwater Management New Zealand U. pinnatifida. This suggested 2011 requires Regional Councils to set U. pinnatifida as part of a human diet objectives and limits for both water quality could possibly decrease the risk of cancer and water quantity. Based on a values especially for human colon, and lung assessment of the Tukituki catchment, cancer. nutrient limits have been set to meet key management object.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 167 SPEAKER ABSTRACTS

Great Australian Bight Evidence for Localized Lake Waahi Restoration Collaborative Research Depletion in Fisheries for Project Science Program: a New Small Pelagic Species; Partnership for a New Potential Management Whole of Ecosystem Responses

Tim Ward // South Australian T.M. Ward, A. Ivey, P.J. ROGERS & Erina Watene-Rawiri // Waikato- Research and Development Institute J. EARL // South Australian Research Tainui College for Research and and Development Institute Development David Smith // CSIRO Rod Lukatelich // BP Developments Localized depletion of target species Lake Waahi is very important to the Australia has recently been highlighted as an local Maori community and has been for issue of public concern regarding the generations. The puhi eel (shortfinned A new four-year, $20M collaborative management of fisheries for small pelagic male migrant) is a particular delicacy for research partnership has commenced species. This presentation summarizes the local Maori community. in the Great Australian Bight (GAB). The published evidence of 1) localized Waahi Whaanui Trust, Genesis science programme will be one of only depletion of small pelagic fishes through Energy and Waikato Raupatu River Trust a small number of whole of system the spatial/temporal concentration of are working together to restore Lake studies undertaken in Australia, and the fishing activity and 2) related impacts Waahi. The project is co funded by the first for the GAB, of which little is known on populations of predatory species. Waikato River Authority. Currently the of this unique ecosystem. The science Evidence of localized depletion is Lake is highly turbid, nutrient enriched, programme aims to obtain information examined for the South Australian sardine and full of pest fish including Koi Carp, about the marine environment and fishery (SASF). The SASF is identified as Perch and Catfish. potential marine resources within a suitable case study for investigating the This presentation outlines the work the Ceduna sub-basin. It includes potential for localized depletion of a small completed to date and proposed for research themes on oceanography, pelagic species because: 1) fishing effort future years. There is a special focus on pelagic and benthic ecology, iconic is concentrated in a small proportion Koi removal, wetland creation and the and apex predators, geopetroleum and of the total area over which the stock establishment of a nursery. geochemistry, and socio-economic is distributed; and 2) information, both analysis of potentially affected extensive fishery-dependent (e.g. spatially communities. The data and information explicit catch, effort and age/size data) obtained will provide qualitative and and fishery-independent (egg, larval quantitative models of the structure and and juvenile surveys, adult age and dynamics of the GAB ecosystem, and reproductive data, foraging patterns and will inform decision makers to support reproductive success of key predators), sustainable development in the region has been collected to support the and monitor possible future impacts of management of the fishery. Findings are oil and gas exploration. The programme used to identify and assess options for will involve the collection of the deepest addressing the potential for localized set of samples ever taken from the depletion in harvest strategies for small GAB and will provide an insight into the pelagic fisheries. Relevant components of distribution, diversity, and ecology of the the new harvest strategy for the SASF are deepwater species of animals, plants and described. microbes which reside in the central and eastern GAB. This science programme is a collaborative research initiative involving BP Developments Australia, CSIRO and Marine Innovation Southern Australia (South Australian Research & Development Institute, University of Adelaide, Flinders University).

168 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Fisheries Ecology, Tag-Recapture Models & Reconnecting Whitebait to Economics & Culture: Site-fidelity: What Happens the Places they Need to Be getting the mix right for the When a Fish goes on its Sepik-Ramu, PNG OE?

Alan WEBB // Hydrobiology Qld Pty Darcy Webber // Victoria University Dave West // Department of Ltd of Wellington Conservation

Richard Arnold, Shirley Pledger // Victoria Bruno David // Waikato Regional Council Between 1991 and 1997, the Sepik- University of Wellington Hannah Jones // The University of Ramu, was stocked with eight non-native fish species under two joint FAO and Alistair Dunn // NIWA Waikato PNG government projects, the rationale Cheri van Schravendiik-Goodman // being that the existing fishery would The assessment models of some fish Waikato Raupatu River Trust not meet the protein needs of a future stocks are informed by tag-recapture Paul Franklin, Cindy Baker // NIWA regional population, the introduced data. Good tag-recapture data is species would occupy “vacant niches”, generally considered a valuable type As with most of New Zealand’s native exploit under-utilised resources and of data due to its ability to inform freshwater fish the main whitebait species not impact upon the native aquatic estimates of population size, growth and inanga (Galaxias maculates) needs access community. European best practice migration rates. However, tag-recapture to and from the sea and lowland rivers, protocols were used for species selection experiments are expensive and several streams, lakes and wetlands at various and quarantine processes and advice assumptions must be made to analyse stages of its lifecycle. Those lowland provided by a panel of international the data. This talk focuses on one of regions of New Zealand are also sought experts. Fish surveys were undertaken to these assumptions, that tagged fish after by humans to live in or farm. Living ascertain the existing fish stocks. Village mix homogenously, and investigates in and farming these areas requires surveys were undertaken to assess the why this assumption may not always extensive modifications of the wetlands types of fish exploited and their local hold. The root of the problem lies and rivers by humans. The end result is economic value. A 2002 preliminary in the way that fish and the fishers inanga do not have free access to large survey found that all introduced species arrange themselves, which is usually parts of their previous habitat or it no had established populations and some far from spatially homogeneous. For longer exists. Using the lower Waikato species were contributing to food and instance, fish move, sometimes a lot. River as an example we will show the income generation. Fish surveys in They also tend to assort into groups extent of the loss and ways of identifying 2008-2009, however, revealed ecological of fish of similar size and aggregate priority areas for action to reconnect shortcomings of the project with in clumps where food or habitat is inanga with the places they need to introduced fish species dominating, some available. Some species simultaneously get to. Specific areas to be identified species dispersing beyond expected undertake mass migrations to spawning will be spawning sites and prime limits and drastic reductions in several grounds before returning to where they lowland inanga habitat. Tools we will native species including locally preferred came from, a phenomenon known demonstrate the use of include: historical food fish. A loss of aquatic vegetation as site-fidelity. Similarly, gradients of and recent records of inanga spawning caused by introduced herbivorous fishing mortality occur across stock sites, historical and current wetland, species is now a potential threat to assessment boundaries, or fishing records of inanga occurrence, river and culturally and economically important mortality can be much higher in spatially floodplain bathymetry, research on what crocodile populations due to a loss of aggregated clumps as fishermen exploit makes good spawning or adult habitat, nesting material. Widespread community the behaviours of the fish they target. spatial maps of barriers and streams and dissatisfaction also revealed a lack of We have developed a novel model to predictive models of fish presence etc. adequate consultation by proponents simulate some of these characteristics When combined with local and traditional regarding species selection and their in a fishery and have focused on a fish knowledge these methods will highlight limited appreciation of traditional population that displays site-fidelity. This priority habitats and actions to restore economic, fishing and fish preservation model attempts to develop data with a inanga habitat and populations. practices. While well meaning, the realistic injection of variation and spatial stocking projects revealed the importance complexity in the fish themselves and the at the outset of getting the scientific, way fishers exploit them. The final goal is economic and cultural mix right to avoid to develop assessment models capable or minimise adverse outcomes. of eliminating the homogenous mixing assumption in assessments informed by tag-recapture data.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 169 SPEAKER ABSTRACTS

The Sulfide Footprint of Monitoring Cyanobacteria The Effects of Common Marine Farms in Recreational Waters Carp (Cyprinus carpio) on – How Effective are the Zooplankton Diversity & Current Guidelines? Abundance: a Large-scale Field Experiment

Peter Wilson // Auckland Susie Wood // Cawthron Steve Woods // The University of University of Technology Waikato Juliet Milne // Greater Wellington Kay Vopel // Auckland University of Regional Council Ian Hogg, Ian Duggan, Conrad Pilditch Technology Wendy Paul // Wendy Paul Consulting Jonathan Banks // The University of Wendy Williamson // ESR Waikato Routine environmental monitoring is a Karl Safi // NIWA Adam Daniel // The University of Waikato, requirement for the operation of mussel David Hamilton // The University of Fish & Game New Zealand and fish farms in coastal waters of New Waikato Zealand. One important process that We are undertaking a large-scale field affects the environmental performance In 2009, interim guidelines for managing experiment using paired lakes at the of such farms is the enrichment of cyanobacterial risk in fresh waters used Hamilton Zoo to determine the effects the seafloor with organic matter. for recreational purposes were released of pest fish on lake ecosystems. The available tools and techniques in New Zealand. The aim was to help Following a pre-manipulation period to directly or indirectly assess this agencies responsible for managing as part of a “before and after, control enrichment, however, are laborious and cyanobacteria proliferations develop and impact” (BACI) study design, we time-consuming. We have developed monitoring protocols appropriate for will introduce common carp (Cyprinus a method to derive the concentration local conditions, and to encourage carpio) to determine the effects on the of sedimentary sulfides, a product of the adoption of a nationally unified zooplankton population and community the microbial degradation of organic approach. The guidelines set out a dynamics. Pre-manipulation monitoring matter, from a sediment profile image. monitoring framework for establishing commenced in August 2012 and finishes Our analyses of sediment underneath the public health risk from cyanobacteria in June 2013 with a complete draining and around one mussel farm off the in lakes (mainly planktonic) and rivers of both lakes to ensure non-native fish eastern coast of Waiheke Island revealed (mainly benthic). A three-tiered alert are absent. In July and August 2013, 2 = 0.95) between a strong correlation (R level framework that incorporates a common carp will be added at a density the concentration of acid volatile sulfides monitoring and management action of 400 kg/ha to the ‘impact’ lake. The and the colour intensity of the sediment. sequence is used. Regulators can use lakes will then be monitored for a further We propose to use this correlation to this framework for a graduated response 12 months to determine the effects describe spatial and temporal changes in to the progression of cyanobacterial of the manipulation. We will test the the organic matter content of sediment blooms. The guidelines include several hypotheses that the addition of carp will: underneath marine farms with in situ major changes from the previous current (1) increase the concentration of nutrients sediment profile imaging. We will present standard practices; the use of biovolume in the water column; and (2) increase results from the first trial of our approach estimates for planktonic cyanobacteria the concentration and particle size of and discuss how changes in the depth instead of cell concentrations, and the suspended sediments. As a consequence and size of the farm sulfide footprint can incorporation of benthic cyanobacteria of nutrient changes we predict that the be used to assess farm environmental thresholds based on abundance and the phytoplankton community will shift performance. occurrence of detaching mats. Most from one dominated by cryptomonad Regional Councils and District Health and green algae to one dominated Boards around New Zealand are now by cyanobacteria. As a consequence using the guidelines, although some of increased suspended sediments, challenges have been encountered. we predict that large filter feeding Case-studies will be used to illustrate cladocerans such as Daphnia will decline their effectiveness and suggestions and that the zooplankton community will for possible areas for refinement. The be dominated by rotifers. potential to integrate the cyanobacterial guidelines into general recreational water quality guidelines for New Zealand will be discussed.

170 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Can Downstream Riparian Cultivation of the Giant Fish Assemblages in the Buffer Zones Enhance Kokopu (Galaxias argenteus) Coorong (2006–2013): Pasture Stream Restoration the Need for Freshwater within an Agricultural Flows Landscape?

Aslan Wright-Stow // NIWA Matthew Wylie // University of Qifeng Ye // South Australian Otago Research and Development Institute Steph Parkyn, David Reid // Independent Brian Smith, Kerry Costley // NIWA Gerard Closs, Mark Lokman // University Juan Livore, Luciana Bucater, David of Otago Short // South Australian Research & In New Zealand the wide spread Development Institute conversion of forest to agricultural land Whitebait has both notable cultural has caused significant degradation to significance as a recreational fishery The Coorong is the unique estuary of stream and riparian ecosystems. Re- pastime and considerable aquaculture the Murray-Darling Basin, located at the planting riparian buffers is often one of potential due to the value of its terminus of the Murray-Darling River. the first steps taken in an effort to restore translucent larvae. In New Zealand, Freshwater flows play a pivotal role stream function and species composition this fishery comprises five species that in maintaining estuarine habitat and but the factors influencing the magnitude belong to the genus Galaxias. Galaxias functionality and affecting aquatic biota. and timeline of success are not well maculatus (inanga or common jollytail) is The present study investigated spatio- understood. In 2000 we assessed nine the most frequently encountered species temporal variation in fish assemblage Waikato riparian buffer zone planting contributing up to 99% of the catch. The structure and distribution, abundance schemes at sites with wetted widths remaining four species contributing to and recruitment of key species along the between 1.3 m and 7.7 m (at that time the fishery are G. brevipinnis (koaro), G. Murray estuary, North and South lagoons plantings had been established 2–24 fasciatus (banded kokopu), G. postvectis of the Coorong in the recent drought, years, buffer lengths ranging from (shortjaw kokopu) and G. argenteus flood and high flow years (2006–2013). 196–4200 m, buffer widths 7.2–75 m) (giant kokopu). Attempts at artificially During drought and low flow conditions and compared them with unbuffered rearing whitebait have met with limited (2006–2008), fish assemblages were control reaches upstream or nearby. success both here in New Zealand dominated by marine species in the At most sites no significant changes and in Chile using G. maculatus. We Murray estuary, and the South Lagoon in macroinvertebrate communities hypothesised that using the largest became unsuitable fish habitat due to towards “clean water” or native forest species in the genus (giant kokopu) its extreme hypersalinity (four times communities was observed. In 2011 as an alternative for the production of that of seawater). Following substantial we reassessed the same sites. Between whitebait could help overcome some of freshwater inflows and reconnection of 2000 and 2011 invertebrate community the current barriers limiting large-scale freshwater and estuarine environments, metrics (# taxa, #EPT taxa, %EPT taxa, production. In addition, understanding salinities decreased significantly along MCI, QMCI) either increased (P<0.05, the environmental conditions required for the Coorong (2010–2013). Consequently, ANOVA) or remained unchanged at all spawning and embryonic development fish assemblage composition changed; sites. At five sites invertebrate metrics of giant kokopu enable the augmentation species richness, diversity and abundance at riparian reaches increased relative to of dwindling populations or the increased. The freshening of the those observed at the control sites. These reestablishment of extinct populations, Coorong also resulted in a southward were generally, although not always, sites thus aiding conservation efforts. We range expansion and enhanced with larger buffer areas (width x length). investigated the effects of salinity and recruitment of several estuarine and Improvements at three control reaches temperature on fertilisation and hatching catadromous species including congolli were likely to reflect improved landuse in wild and captivity-acclimated giant (Pseudaphritis urvilli), greenback flounder management within the catchment. kokopu. Fertilisation rate decreased (Rhombosolea tapirina) and sandy sprat Results suggest that downstream riparian as water salinity increased and (Hyperlophus vittatus). Smallmouth buffer zones can enhance pasture results suggest that cooler incubation hardyhead (Atherinosoma microstoma) stream restoration within an agricultural temperatures appear to be important to recolonised the South Lagoon with a landscape but that expectations of yield high hatch rates. We also described dramatic increase in abundance following riparian restoration efforts should be the sequential changes during embryonic increased flow and salinity reductions tempered by time scales – good things development and produced juvenile fish to <100‰. This study highlights the take time! in order to establish a captive breeding importance of freshwater inflows in colony. maintaining and restoring estuarine habitat, facilitating fish recruitment and promoting abundance and diversity in estuarine fish assemblages.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 171 SPEAKER ABSTRACTS

Functional Responses of Climate Change & Water Feeding, Metabolism, Stream Ecosystems to Resources: a Scenario- Nutrient Assimilation Riparian Rehabilitation based Modelling Study in a & Growth of Juvenile Dairy Catchment Sea Cucumbers (Australostichopus mollis) at Different Temperatures

Roger Young // Cawthron Institute Christian Zammit // NIWA Leonardo Zamora // The University of Auckland Kati Doehring, Joanne Clapcott // Ms Srinivasan, Robert Wilcock, Einar Cawthron Institute Hrenisson // NIWA Andrew Jeffs // The University of John Quinn // NIWA Auckland The potential impacts of climate change Changes in land use can have dramatic (CC) on water quantity and quality in a In the present study the importance effects on stream ecosystem structure dairy-dominated catchment, Waiokura, of seawater temperature for the food and function. Concerns about land use of North Island, New Zealand, was intake, food utilization and growth of change and the degradation of stream investigated. In this scenario-based aquacultured juveniles of the Australasian ecosystems has led to increasing modelling study, a hydrology/water sea cucumber, Australostichopus mollis, efforts to rehabilitate these systems. quality model was calibrated and were examined. The juveniles (16.5±0.5 g, Riparian buffers are a key tool for stream validated using observed data from wet weight) were experimentally exposed rehabilitation and aim to increase shade 2001–2010. The calibrated model was to four seawater temperatures (15, 18, and natural organic matter inputs and then used to simulate the impacts of 21, and 24 °C) for 105 days, during restrict inputs of sediment, nutrients CC over two 20-year periods, 2030–49 which they were fed mussel waste, a and other contaminants. However, (“2040”) and 2080-99 (“2090”). Modelled highly effective natural food source, the effectiveness of rehabilitation data from these two future periods were that is utilised by sea cucumbers under programmes is rarely monitored and compared against modelled simulations co-culture conditions beneath mussel there is almost no data on changes from the 1980 to 99 (“Current”) period. farms. At each temperature treatment to ecosystem function resulting from Under CC scenarios, average annual the feeding, nutrient assimilation, rehabilitation efforts. To address this rainfall was predicted to be similar to that metabolism, growth and survival of the knowledge gap we measured stream of Current, though the intensities might juveniles were evaluated. Overall, the sea ecosystem metabolism, organic matter be higher and frequencies rarer than cucumbers responded negatively to an decomposition, organic matter retention Current. On average, air temperatures are increase of temperature from 15 to 21ºC and stable isotope composition of primary predicted to increase from 2 to 4ºC over with decreased food intake, and growth consumers at 11 sites where riparian Current, and a combination of warmer rates, and elevated metabolism. The buffers have been established and at 11 conditions and infrequent storms under survival of juveniles was compromised neighbouring control sites which are not CC conditions may result in dry periods when held at 24 °C. Most importantly, buffered from the surrounding pastoral longer than those under Current. Also, the energy available for growth and the land use. The riparian buffers range more intense storms can potentially food conversion efficiency of juveniles in age from 5 to 34 years, with buffer increase the occurrence of infiltration- at 15ºC were greater than for those length ranging from 196–4200 m and excess overland flow from grazed growing at 21ºC which was reflected in buffer width from 7.2–75 m. Preliminary paddocks compacted by animal traffic. In the growth rates (i.e., 0.71±0.05% d−1 results suggest that despite substantial direct consequence, the stormflows are versus 0.28±0.05% d−1). The results of increases in shading of the study reaches, predicted to be flashier but the average this study suggest that consideration there were minimal changes in any of and median streamflows are predicted to of ambient temperature regimes will the measures of ecosystem function. be less than those under Current owing be a critical factor for the selection of This lack of response to rehabilitation to less frequent storms. Larger flood suitable aquaculture locations for A. mirrors earlier results for invertebrate events might result in greater transport mollis due to the risk of mortality at higher communities at a subset of the same sites of nutrients and sediments from land to temperatures (≥24 °C) and markedly and indicates that there is considerable water and within streams. Simulation improved growth and food utilization at hysteresis in response to riparian of nutrient (nitrogen and phosphorus) lower temperatures around 15 °C. rehabilitation. Many indicators of stream transport indicate that a larger infiltration- health are likely to require rehabilitation excess overland flow may result in larger of substantial lengths of riparian zone available transport from land to water rather than just efforts at the reach scale, than those available under Current. and improvements in stream ecosystem structure and function will take time.

172 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

Influence of Climate on Linking Nitrogen & Carbon What is the Future for Pelorus Sound Mussel Cycling in the Coastal Fisheries? Aquaculture Yields: Ocean – Implications for

Predictive Models & CO2 Emissions, Ocean Underlying Mechanisms Acidification & Land Use

John Zeldis // NIWA John Zeldis // NIWA Shijie Zhou // CSIRO

Mark Hadfield, Doug Booker // NIWA Kim Currie, Mark Gall // NIWA Tony Smith // CSIRO

Multiple regression models were used The propensity of a coastal water body Oceans are under pressure: the scientific to predict aquaculture production in to emit or consume CO2 is related to literature describes overfishing, bycatch Pelorus Sound, which supports 68% of its ‘net ecosystem metabolism’ (NEM). and discards, loss of biodiversity, New Zealand’s NZ$204 million per annum NEM is positive, or ‘autotrophic’, ecosystem deterioration, ocean mussel (Perna canaliculus) aquaculture where gross primary production acidification, etc. Commercial fisheries industry. Mussel meat yield was modelled (GPP) exceeds community respiration are also under pressure: more stringent using biological data, including seston (CR), and dissolved inorganic carbon regulations (on gear, season, space, (indexed by particulate nitrogen, PN), (DIC) is consumed, and negative or quota, bycatch, etc.), expansion of phytoplankton and nutrients collected ‘heterotrophic’ where CR exceeds marine protected areas, increases in over 9 yr (July 1997 to November 2005) GPP and DIC is generated. In turn, DIC fishing costs, social license to operate. by the mussel industry, and physical, generation is strongly related to CO2 What is the future for fisheries? There climatic data, including Southern efflux at the sea-air boundary (measurable are many questions at both strategic and

Oscillation Index (SOI), along-shelf as partial pressure of CO2 or pCO2). operational levels. How can we conserve winds, sea surface temperature (SST) Coastal NEM is controlled by the supply marine ecosystems on which fisheries and Pelorus River flow, held in New of organic matter to the system, either rely? What does biodiversity really mean Zealand national databases. Yield was as direct loading of fixed material or from in relation to fisheries? Why do we want best predicted using biological data excessive inorganic nitrogen loading to reduce bycatch? Is indiscriminate collected locally at the farms inside the which fuels fixation and respiration in bycatch reduction consistent with the sound, but it was also predictable using subsurface water. A potentially serious principles of responsible fisheries? only physical data collected distant from consequence of the evolution of DIC is What species should be harvested at the farming region. Seston (mussel food) lowered pH (acidification). Thus, there an ecosystem level? How should we was also predictable using the physical are important links between carbon and harvest the age and size structure of a data. Optimal predictor sets for yield nitrogen cycles in coastal systems and population? Can we increase fisheries and seston differed between summer inputs from land, which affect NEM, CO2 production while reducing negative and winter half-years. In summer, deep balance, and acidification. In this talk we impacts on the environment? How can water at the sound entrance (which describe NIWA coastal nutrient budgets we determine ideal fishing pattern and enters the sound through the estuarine for the Hauraki Gulf and Firth of Thames, intensity to maximize food production - circulation) was nitrate (NO3 )-rich during the latter of which receives high runoff while minimizing environmental impacts? upwelling conditions (negative SOI, from Waikato region farming and is highly Can a target species be sustainably NNW wind-stress and cool SST). The net-heterotrophic. We describe our recent harvested while catch of other species - increased NO3 levels, in turn, triggered ship surveys of the carbonate system of are minimized? Can we simultaneously increased PN within the sound. In the the Hauraki Gulf/Firth region which show optimize conservation, food production, winter, PN was unrelated to upwelling high pCO2 and significant acidification in and social and economic benefits? How - and NO3 effects at the entrance and was the Firth. We describe regional (Firth-Gulf- can society accept and utilize currently instead related to river flow. Remotely- continental shelf) and seasonal variation low-valued components and non-target sensed SST data showed that in summer in these properties, and how we are components? Can industries add value upwelling affected the entrance waters combining nutrient budget and carbonate to currently low-valued components? of the sound under negative SOI and system surveys with sampling of bio- Can cultural exchange and development upwelling-favourable wind-stress, optical properties, firstly, to understand of seafood processing techniques patterns which dissipated in winter. These the drivers of NEM and secondly, to influence people’s dining habits? How results show that time-series of physical determine if we can assess them using can eNGOs, food industry professionals, drivers can be useful for explaining remote sensing. media, educators, and retailers play a role production variation of farmed bivalves in implementing balanced harvest and and indicate the prospects for using data supporting sustainable fishing? We will routinely collected in national databases discuss some of these questions that are for predicting mussel yield. shaping the future of fisheries.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 173 SPEAKER ABSTRACTS

A Cross-sampling Method for Estimating Abundance & Detectability for Aggregated Populations with Varying Local Abundance

Shijie Zhou // CSIRO

Neil Klaer, Ross Daley, Mike Fuller, Anthony Smith // CSIRO Zhengyuan Zhu // Iowa State University

Fish and wildlife often exhibit an aggregated distribution pattern while local abundance changes constantly due to movement. Estimating population size and survey detectability (i.e., gear efficiency) for such elusive species is technically challenging. We developed a statistical method to deal with this difficult situation, particularly for fish populations where gear efficiency is almost never perfect. The method involves a mixture of two statistical models: a negative binomial function for modelling animal distribution between- and within-grid cells, and a binomial function for modelling detection (catching) of animals. The innovative approach is to use more than one fishing gear to simultaneously catch the same population in each grid cell at the same time. We carried out computer simulations on a range of scenarios and estimated the relevant parameters using a Bayesian technique. We then applied the method to two fish species, Tiger Flathead and Draughtboard Shark, to demonstrate its utility. Simulation results indicated that the models can accurately estimate both abundance and detectability. For the four gear types that caught Tiger Flathead and Draughtboard Shark – longline, Danish seine, gillnet, and trawls, gear efficiency varies between species and gear types, ranging from 0.08 to 0.77. This cross-sampling method can evaluate gear efficiency cost effectively using existing fishery catch data or survey data, reducing reliance on costly field experiments. More importantly, it provides a means for estimating gear efficiency for gear types that are extremely difficult to study by field experiments.

174 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 SPEAKER ABSTRACTS

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 175 POSTER ABSTRACTS

176 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 POSTER ABSTRACTS

Monday 19 August, 4:15–5:30pm Venue: The Academy

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 177 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

BANDA Fiona Auckland University of Preliminary Characterization of the Population Dynamics of 30 Technology Redfin Perch (Perca fluviatilis) from Lake Wainamu, New Zealand BARR Neill NIWA The combined effects of low pH & elevated temperature on 22 the growth of three frondose, & two calcareous rhodolith seaweeds from New Zealand BEET Clare University of Waikato Ancient or recent: when did freshwater rotifers invade marine 8 habitats? BENNETT Kristi University of Waikato Mitochondrial DNA variability among closely-related species 39 pairs of New Zealand caddisflies (Trichoptera) BLAIR Jennifer Kessels Ecology Can biological & cultural indicators be used to assess impacts 4 of dairy farming in agriculturally influenced catchments? BLAKELY Tanya Boffa Miskell Ltd Future proofing Duck Creek 31 BURTON Tracey NIWA LakeSPI reports now available online 42 CANNING Adam Massey University Are stream food webs more stable in forest or pasture? 36 CARTER Kelly NIWA Macroalgal blooms associated with mangrove removals 11 CARTNER Katie NIWA Centimeter scale variation in microphytobenthos on tidal flats 17 COLLINS Gemma University of Waikato DNA Barcoding of the New Zealand Freshwater Rotifers 9 CUSENS Jarrod AUT Temperate mangroves as a model ecosystem to study plant 14 carbon & water relations DE GROOT Neeltje University of Waikato Extent of burial of the Rena oil spills within Bay of Plenty 54 coastal sediments DELORME Natali The University of Auckland Effect of temperature & salinity on early development, & adult 23 righting time of Evechinus chloroticus DRUMMOND Jennifer NIWA, Northwestern Dynamics of Microbial Transport in Streams – 41 University a Multiple Tracer Stream Injection Experiment DUGGAN Ian The University of Waikato Craspedacusta sowerbii polyps in New Zealand: medusae are 38 inadequate for determining distributions & introduction timing EDHOUSE Scott NIWA Developing a drop camera methodology to monitor the spatial 57 extent of subtidal benthic habitat patches. EIVERS Rebecca University of Waikato A decision making toolbox for constructed wetland design 43 within intensive agricultural land-use FENTON Tony Alchemists Ltd A Web Based Directory of Decision Support Systems to Improve 60 Their Understanding & Use GIBBS Max NIWA Sediment dispersion in estuaries from river inflows determined 16 using compound specific stable isotopes GREENFIELD Barry Waikato University Spatial variation in functional group diversity in a sandflat 21 benthic community: Implications for system resilience GRITCAN Iana Auckland University of Effect of nutrients on growth & potential spread of temperate 13 Technology mangroves in New Zealand HILL Jessica University of Canterbury Tagging Experiments on Adult Inanga: Growth & Migration 34 HOHAIA Aysha Auckland University of Terrestrial sediment deposits acidify the pore water of intertidal 2 Technology sandflats HOPKINS aareka Ngaa Muka Development A Wai Quality Assessment Model for North Waikato Streams & 44 Trust Lakes HUGHES Andrew Before & after integrated catchment management in headwater 46 stream: changes in water quality HULBERT Colleen The University of Auckland Modern estuarine habitats & organism-sediment interactions at 20 Mangawhai Estuary, North Island, New Zealand JACKSON Susan The University of Auckland Prioritisation of Biodiversity Datasets in the Hauraki Gulf Marine 58 Park JONES Matthew AUT Role of scavenging in basketwork eel on northeastern Chatham 26 Rise, New Zealand JONES Andrew University of Queensland Improved Confidence Intervals for Genetic Estimates of Effective 34 Population Size KIM Yong-Hae Gyeongsang National Effects on the escapement of juvenile halibut from shacking 24 University codend generating by cap-like canvas MACKENZIE Lincoln Cawthron Institute Benthic dinoflagellate toxins in flora & fauna of Rangaunu & 50 Parengarenga Harbours MADARASZ- Anna Hawke’s Bay Regional It’s a buoy!! 55 SMITH Council

178 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

MALEKAR Vanita Lincoln University Genetic studies on thermal adaptation & membrane saturation 25 in Antarctic fish MAMAT Nawwar Centre for Ocean Research, The Potential Use of Sugarcane Bagasse in Pelleted Fish Feed 49 Zawani Conservation and Advances MORGAN Kepa The University of Auckland Catchment-scale Riperian Zone Optimisation using the Mauri 45 Model MUELLER Hannah The University of Waikato A pressure-response framework for evaluating economic 62 & environmental drivers in the management of freshwater resources in New Zealand: a case study of the Rotorua Lakes NEWCOMBE Emma Cawthron Institute POI: Open science for a healthy Pacific Ocean 59 PARKES Samantha NIWA Pheromones as a biosecurity tool: does a common attractant 7 exist between portunid crabs? PATTERSON Michael Horizons Regional Council Fishing the hills – Results of an extensive fish survey in the 32 Ruahine & Tararua Ranges RAYES Courtney The University of Waikato Boring through Marine History: Shipworms, Pillbugs & Gribbles, 6 & their current New Zealand Status ROGERS Shelley The University of Waikato Effects of sample processing on the concentration of 51 microcystins detected in Cyanobacteria ROWLING Kevin Retrenched (NSW Fisheries) Fisheries Research in Eastern Australia – at the Interface...or 28 About to Go Under SAVAGE Candida University of Otago Marine Metre Squared – a citizen science project for long term 65 monitoring of the New Zealand seashore Lena Hydrosphere Research Ltd How much nitrogen is too flipping much? Predicting the N 3 loading threshold for seagrass collapse SCHNABEL Kareen NIWA Marine invertebrates of New Zealand: diversity, tools & 5 opportunities SHARMA Ashish Auckland University of To study the Immunostimulant activity of watse paua blood & 48 Technology guts SHEARS Amy Horizons Regional Council Integrated geophysical study of depth-to-basement & sediment 15 thickness in Otago Harbour, New Zealand SHEARS Amy Horizons Regional Council Managing the effects of gravel extraction in the Manawatu- 61 Whanganui Region SINGLETON Nathan Waikato Regional Council Regional Estuary Monitoring Programme: a decade of trends 18 SINGLETON Nathan Waikato Regional Council Tairua Harbour – environmental monitoring in paradise 19 SMITH Josh NIWA Observations of giant kokopu spawning habitat in an urban 33 Hamilton stream STOREY Richard NIWA Predicting climate change effects on life at the land- 37 freshwater interface THURSTAN Ruth University of Queensland Can fisher knowledge provide accurate estimates of the past? 35 TRAN Phan Auckland University of Allometry, biomass & litter decomposition of the New Zealand 12 Technology mangrove Avicennia marina subp. australasica VALLER Tammy The University of Waiakto Catchment-derived contaminants in Hamilton City urban & 52 peri-urban streams VAUGHAN Melanie Auckland Council Auckland marine habitat mapping 56 WADE Oliver Consultant Testing the effects of technological modifications to an inshore 27 trawl in Hawke’s Bay, New Zealand WANG You-Gan The University of Implications of Gain Functions in Fisheries Management 29 Queensland, Australia WATSON Nathan The University of Waikato Assessing Next Generation Sequencing of rotifer communities 40 to measure lake water quality WEBBY Ashley The University of Waikato Acute toxicity of MV Rena pollutants 53 WONG Ka Lai Auckland University of Nutrition & Reproduction of New Zealand Scallops 47 Clara Technology WOODS Steve The University of Waikato Rapid assessment of zooplankton diversity using next 10 generation sequencing

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 179 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Preliminary Characterization The Combined Effects Ancient Or Recent: When of the Population Dynamics of Low pH & Elevated Did Freshwater Rotifers of Redfin Perch (Perca Temperature on the Growth Invade Marine Habitats? fluviatilis) from Lake of Three Frondose, & Two Wainamu, New Zealand Calcareous Rhodolith Seaweeds from New Zealand

Fiona Banda // Auckland University Neill Barr // NIWA Clare Beet // The University of of Technology Waikato Kate Neill, Sheryl Miller, Wendy Nelson, Armagan Sabetian Graeme Moss // NIWA Ian Duggan, Ian Hogg, Gemma Collins // Kristin Scheuer // University of Canterbury The University of Waikato A baseline study was conducted in 2012 and 2013 at Lake Wainamu We examined the effect of changes in We compared the species and genetic (West Auckland) as an initial step in pH and temperature predicted to occur diversity of rotifers between marine characterizing the population dynamics around New Zealand coasts by 2100, on and freshwater habitats. Rotifers are of redfin perch in New Zealand. A total five seaweeds. Over the 12 day duration widespread and commonly found in of 124 fish samples in 2012 and 151 of the experiment Ulva showed increased marine, freshwater and terrestrial (soil) fish samples in 2013 were histologically growth rate in response to low (7.65) pH ecosystems. However, in marine habitats, analyzed and sagittal otoliths examined seawater, relative to ambient (8.05) pH, at rotifers are relatively species poor and to obtain estimates of reproductive, all temperatures examined. The optimum are largely unstudied. We focused on age and growth parameters. Results temperature for growth in Ulva at ambient the two main rotifer genera found in indicated a population age range of pH was between 15 and 18 °C, however marine environments: Trichocerca and (0–6) years with an average of 86.15% at low pH the optimum temperature for Synchaeta. There are over 20 Synchaeta of population between (0–2) years. The growth was lower at 13 °C. Gracilaria species in marine environments, which L∞ was 180.23 mm standard length and had the highest growth rate at 22ºC at are thus seemingly more diverse than 248.22 mm standard length for 2012 ambient pH but had significantly lower their freshwater counterparts with and 2013 respectively. 23.5% of females growth in low pH seawater at this same around 12 species recognized globally. were reproductively inactive at time temperature. At lower temperatures In contrast, there is only one marine of sampling, 60.5% females showed there was little evidence of a growth Trichocerca species (T. marina), with oocyte development and 2.7% were response in Gracilaria to pH level. Undaria considerably higher diversity found in mature spawning. Males were either had the highest growth rate at 11ºC at freshwater habitats (>70 species). Here, inactive or had active spermatides with both ambient and low pH seawater, and we examined the genetic relationships none showing mature spawning. The similarly to Gracilaria, growth showed among freshwater and marine Trichocerca results suggest that redfin perch in Lake little response to pH level. Compared with and Synchaeta species using DNA Wainamu spawn at different time of the the growth patterns observed in these sequencing of the mitochondrial COI year than previously documented in New three frondose seaweeds, we found that region. Using divergence values within Zealand. This finding has a significant two rhodolith species (Sporolithon durum and among habitats, we test the implication to the effectiveness of redfin and Lithothamnion crispatum), under hypothesis that marine taxa represent perch eradication programme in New similar experimental conditions, clearly ancient invasions from freshwater Zealand. demonstrated that the combined effects habitats. Our preliminary data suggest of elevated temperature and decreased that marine Synchaeta species are closely pH, predicted for our future coasts, had a related to their freshwater counterparts, significant negative impact on growth. indicating a recent invasion of the marine environment followed by rapid diversification. In contrast, individuals of Trichocerca marina were deeply divergent relative to the freshwater taxa, indicating a potentially more ancient association with the marine environment.

180 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Mitochondrial DNA Can Biological & Cultural Future Proofing Variability Among Closely- Indicators be Used to Duck Creek related Species Pairs of Assess Impacts of Dairy New Zealand Caddisflies Farming in Agriculturally (Trichoptera) Influenced Catchments?

Kristi Bennett // The University of Jennifer Blair // Kessels Ecology Tanya Blakely // Auckland Council Waikato Gerry Kessels // Kessels Ecology Vaughan Keesing, Stephen Fuller, Barbara Ian Hogg // The University of Waikato Mahuru Robb // Kessels & Associates, Risi, Leigh Bull, Matiu Park Brian Smith // NIWA University of Waikato Jonathan Banks // Cawthron Institute Sam Karaka // Ngati Tahinga Duck Creek is a small lowland waterway Paul Hebert // University of Guelph in Whitby, Wellington Region, which The effects of dairy farming on stream flows into the nationally significant We used mitochondrial DNA (COI) water quality and nutrient loads have Pauatahanui Inlet. The creek had sequence variability to examine levels been well studied in New Zealand, but historically been constrained in an of genetic divergence among closely- the effects on stream fauna such as incised channel through a golf course. related species pairs of New Zealand macroinvertebrates and fish are less Despite this modification the creek still caddisflies (Insecta: Trichoptera). Based well known. Assessing the effects on retained very high ecological values with on an analysis of 509 individuals covering stream fauna is important for determining a diverse macroinvertebrate and native a putative 130 species, seven closely ecosystem function, and many aquatic fish fauna, including giant and banded related species pairs were identified, species are also culturally important for kokopu, inanga, lamprey, and longfin consisting of morphologically distinct Maori communities. Cultural indicators and shortfin eels. As part of a consented species, each restricted to either the have recently been developed for development, 1.2 km of the creek were to North Island or South Island. Another assessing ecosystem health of New be realigned to allow for the existing golf five species showed similar or greater Zealand freshwaters, but have not yet course to be developed into a residential levels of “intraspecific” divergence, with been widely implemented for assessing subdivision. Boffa Miskell played an genetically distinct populations on each the effects of dairy farming. We measured integral part in designing the new reach, island. Sequence divergences between water quality, biodiversity and cultural including a meandering channel with these twelve “species pairs” ranged from indicators before dairy farm conversion, diverse in-stream habitats and extensive 0.41% between Confluens olingoides/ and will measure the effects of dairy riparian plantings. Ultimately, the aim was Confluens hamiltoni, to 9.92% between farm conversion on these parameters to create a fully functional waterway, to the North and South Island populations of over the next 3 years. In doing so, we flow through the residential development Pycnocentria evecta. Based on molecular aim to provide a case study for both within a Council Reserve. The design clock estimates, divergences for these scientific and farming communities also aimed to provide equivalent or twelve species pairs has occurred within detailing the effects of dairy farm better freshwater habitat than the original the last 5 million years, with most dating conversion on key aquatic biodiversity channel, supporting the same diversity to the beginning of the Pleistocene (2 and cultural indicators, as well as and abundance of freshwater species. mya). We conclude that: 1) population evaluating the efficacy of the initial farm/ fragmentation during the Pleistocene stock management regimes and stream glaciations and the subsequent closing of retirement and planting programmes the Cook Strait land bridge have played for enhancing stream biodiversity. This important roles in the isolation and study involves a partnership between speciation of New Zealand caddisflies; farm managers, local Iwi and scientific and 2) the diversity of New Zealand advisors; this collaborative approach will caddisflies, and other aquatic taxa, is provide a framework that others can use underestimated and requires re-evaluation in similar situations. using a combined morphological and molecular approach.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 181 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

LakeSPI Reports Now Are Stream Food Webs Macroalgal Blooms Available Online More Stable in Forest or Associated with Mangrove Pasture? Removals

Tracey BURTON // NIWA Adam Canning // Massey Kelly Carter // NIWA University Mary de Winton, John Clayton // NIWA Carolyn Lundquist // NIWA Russell Death // Massey University Steven Pratt // The University of Waikato Users of LakeSPI (Lake Submerged Plant Indicators) can now access information • Aim: To determine if riparian cover In recent years, mangrove removals online, via NIWA’s web-reporting portal (forest or pasture) influences the have occurred in many estuaries in lakespi.niwa.co.nz. Results for more stability of six Taranaki streams northern New Zealand as a response to than 200 lakes are now available in a crossing the boundary of the Egmont rapid expansion of mangrove habitat. standardised format that can be used National Park. Removal methods have varied in the for regional and national reporting. • Both the un-weighted and amount of biomass removed; most The LakeSPI monitoring method uses invertebrate-weighted food webs leave below-ground biomass (roots and submerged aquatic plants as indicators were made for twelve sites on six pneumatophores) intact, while some of lake ecological condition. It is based Taranaki streams (one upstream also left above-ground biomass (stumps on the principle that New Zealand lakes forest, the other downstream in and branches) in situ, either intact or can be characterised by the composition pasture) using abundance data as mulchate. Observations between of native and invasive plants growing in collected between 1997 and 2003, 2010–2012 documented macroalgal it, and the depths at which they grow. and diet data from 31 published blooms in four estuaries in Tauranga Submerged aquatic plants make good sources. Harbour (Waikaraka, Te Puna, Waikareao, indicators of lake condition as they are Omokoroa) where mangrove removal • Microsoft Network 3D, NEXCADE, easy to observe, reflect environmental had occurred, and mangrove mulchate and R with packages Foodweb and conditions over an extended period and was left in situ. Percent cover and IGRAPH were used to calculate the bring a focus to the shoreline margins, species composition of macroalgae was network parameters for each food where greatest public interaction occurs. determined using a 0.25 m2 quadrat web and analyse their stability LakeSPI complements other physico- at 5 m intervals on transects through by calculating the robustness, chemical methods of lake monitoring. mangrove removal zones. Macroalgal conducting Sequential Perturbation NIWA’s web-reporting portal allows blooms were observed on all mulch sites, Analysis, and an Algae removal lakes with LakeSPI data to be searched and on some occasions, 100% cover ewvent. by name, their size, depth, type and in large (>1 ha) patches was observed. condition, or through the use of advanced Seasonal and between-site variability in No significant difference was found in geospatial mapping software. Users can macroalgal abundance was apparent. robustness between closed and open choose to view LakeSPI reports for single However, most macroalgal bloom canopy sites in both the un-weighted lakes or as groups of selected lakes, and species were Ulvaceae, an algal family (closed canopy average: 37.26%, open previous LakeSPI data is available for known to respond to increased nutrient canopy average: 37.77%, p=0.592) and indicating change in lake condition over concentrations with increasing growth weighted webs (closed canopy average: time. Lake managers now have greater rates. Macroalgal blooms consisted of 42.29%, open canopy average: 40.65%, access to reliable and standardised Ulva sp. (tubular form) and filamentous p=0.141). The SPA results indicate that information on the condition of the lakes species such as Rhizoclonium spp. on average open canopy sites collapsed they monitor. and Percursaria percursa which were to extinction with fewer sequential clearly attached to pneumatophores or perturbations than closed canopy sites remaining mulch material (and growing (closed canopy: 49.6% of all species, directly on site), as well as Ulva sp. (sheet open canopy: 36.3% of all species, form: sea lettuce) which was observed p=0.0297). After removing Algae from the at the edge of many patches, and could webs, there was no significant difference potentially have washed in from outside in mean percentage node loss (closed the mulch zone. It is also of interest canopy: 13.83%, open canopy: 17.84%, that P. percursa had previously not been p=0.339), however weighted webs documented on New Zealand’s North showed more nodes were lost in open Island. canopy webs than closed canopy (closed canopy: 9.46%, open canopy: 25.27%, p=0.047).

182 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Centimetre-scale Variation DNA Barcoding of the Temperate Mangroves as a in Microphytobenthos on New Zealand Freshwater Model Ecosystem to Study Tidal Flats Rotifers Plant Carbon & Water Relations

Katie Cartner // NIWA Gemma Collins // The University Jarrod Cusens // Auckland of Waikato University of Technology Drew Lohrer // NIWA Ian Duggan, Ian Hogg, Clare Beet // The Sebastian Leuzinger, Andrea Alfaro // A study on the centimetre-scale variation University of Waikato Auckland University of Technology in microphytobenthos of intertidal sediments was carried out at Whitford Rotifers (Rotifera) are an integral Water and carbon relations of plants are embayment to test how well data from component of freshwater ecosystems tightly coupled via leaf pores (stomata) a new in situ benthic fluorometer, the and often provide a key indicator of lake because they control both CO2 uptake Benthotorch®, compared to data collected trophic status. We are currently assessing and water loss. Understanding water and using the more standard extractive the molecular diversity of New Zealand carbon relations of trees is particularly technique for measuring sediment rotifers using a sequence fragment of important due to their key role in the pigment content (a proxy for microphyte the mitochondrial cytochrome c oxidase global carbon and water cycle. For abundance). An area of 12 m2 was subunit I (COI) gene. Rotifers were example, current global change induced sampled with 48 sediment cores and 600 collected from a variety of freshwater broad-scale shifts in climate regimes will benthotorch measurements in a regularly habitats throughout New Zealand, have a strong impact on water availability spaced sampling grid, allowing us to and morphologically identified prior to trees, with important implications map sediment chlorophyll a content and to DNA sequencing of the COI gene. on the amount of carbon stored per examine spatially paired data collected All collection and sequencing data, as unit forest area. Mangroves are an by each method. Sediment in the cores well as individual photographs have ideal model ecosystem because they was freeze dried and homogenised, and been entered onto the Barcode of Life represent a mature, yet highly accessible, chlorophyll a was extracted from a 5 Datasystems (BOLD) database and monospecific forest stand undergoing g sub-sample by boiling the sediment are now part of the publically available periodic, predictable salt stress via tidal in ethanol. Sediment chlorophyll a molecular identification platform (www. inundation. We will use state-of-the-art content (µg g-1) was analysed by boldsystems.org). To date, we have sensors to monitor continuous stem spectrophotometry using acidification assessed roughly 300 specimens radius changes, leaf water potential and to separate out degratory products covering >45 species, 20 genera, and sap flow rates, combined with an eddy (e.g., phaeophytin). The Benthotorch®, 5 orders. Analysis of within-species covariance flux tower. This, together in contrast, is a non-destructive method variability has also revealed high levels with the assessment of daily and that requires no sample preparation of “intraspecific” genetic divergence for seasonal non-structural carbohydrate and takes less than 20 s to complete. It some taxa. For example, cryptic species concentrations in various plant tissues utilises the fluorometric characteristics have been confirmed for Lecane bulla and will allow us to answer the following of the different algal pigments present in are in agreement with other international questions: (1) what factors limit mangrove surficial sediments, providing readings studies. Our developing sequence library growth at what times? Can these patterns in µg cm-2 of chlorophytes, cyanophytes, will be used for the rapid, accurate, and be generalised to other forest stands? and diatoms. Although the Benthotorch® routine identification of rotifer taxa as (2) How do mangroves transpire water is rapid and possesses many advantages well as for the testing of phylogenetic against the strongly negative water over the traditional method, questions hypotheses. We are currently using the potential of salt water? Are they taking remain about how well it quantifies library to develop and test a molecular up fresh water through stomates? These microphytobenthos abundance. In fact, version of the rotifer trophic lake index. fundamental ecophysiological questions both methods showed high variability at will be complemented by providing an relatively small spatial scales, suggesting accurate quantification of the carbon that perhaps only relatively large pools and fluxes of this ecosystem. differences in chlorophyll a content (i.e., ± 2 µg g-1) may be ecologically meaningful.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 183 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Extent of Burial of the Rena Effect of Temperature Dynamics of Microbial Oil Spills Within Bay of & Salinity on Early Transport in Streams – Plenty Coastal Sediments Development, & Adult a Multiple Tracer Stream Righting Time of Evechinus Injection Experiment chloroticus

Neeltje de Groot // The University Natalí Delorme // The University of Jennifer Drummond // of Waikato Auckland Northwestern University, NIWA

Willem de Lange // The University of Mary Sewel // The University of Auckland Rob Davies-Colley, Rebecca Stott, James Waikato Sukias, John Nagels // NIWA Temperature and salinity are important Alice Sharp // NIWA, University of Sediment cores were obtained from 12 environmental factors affecting the Waikato coastal sites within the Bay of Plenty to normal functioning of marine animals, Aaron Packman // Northwestern determine the extent and characteristics particularly those living in shallow waters University of buried oil following the Rena oil spills and tide pools, like the New Zealand sea urchin Evechinus chloroticus. The aim of between October 2011 and January Water-borne diseases are a significant this study was to evaluate the effect of 2012. Sites were selected based on local concern and a prevalent health issue. different combinations of temperature community preceptions of continuing Currently we have limited ability to and salinity levels on early embryos oil presence. Cores were taken to a predict the downstream transport (fertilization and normal development depth of ~1 m, which was sufficient to of contaminant microbes in waters, within 24 hours post fertilization) and reach titanomagnetite placer deposits especially from diffuse sources of faecal adult animals (through righting time) of produced by coastal erosion in the pollution such as livestock manure in E. chloroticus. Embryos were exposed 1970s and hence represent a maximum rural areas and sewage leaks in urban to five salinity levels (29, 31, 34, 35 possible burial depth. Subsamples were land. Micro-organisms can be viewed as and 37 ppt) and two temperatures (18 elutriated with dichloromethane solvent fine organic particles (biocolloids) that and 21ºC); whereas adult animals were to extract any organic material, and then migrate downstream through a series exposed to five salinity levels (24, 29, 34, analysed by gas chromotography mass of deposition and resuspension events, 39 and 44 ppt) and three temperatures spectrophotometry (GCMS) to identify which results in a wide range of microbial (17, 20 and 23ºC). Fertilization was the compounds present. The results were residence times. In-stream stores of high in all treatments, with the lowest compared to a fingerprint library of Rena microorganisms are mobilized during fertilization (86%) at a salinity of 29 ppt oil and known degradation products flood events, and contaminated storm and temperatures of 18 and 21ºC. Normal prepared using the same instrument. waters are a major hazard to downstream development was also reduced at 29 ppt No traces of Rena oil were identified, water users such as water supplies, and temperatures of 18 and 21ºC, with indicating that the beach clean-up bathers and shellfish consumers. We are 40–50% of normal embryos at 24 hours procedures and natural degradation were conducting studies to gain insights into post fertilization. In the case of adult effective at removing the oil spills. contaminant micro-organism dynamics in animals, the righting time was higher at streams with a campaign of experiments 24 ppt (>15 min) at 17 and 23ºC. Overall, and modeling. These results can also be this study showed that embryos were used to improve understanding of nutrient more sensitive to lower salinities than (C, N, P) spiraling and fine sediment adult animals. Therefore, adult animals movement in river systems. We present may potentially be able to cope better findings from a field injection study of than early embryos with short-term multiple tracers into an agricultural stream natural variations in salinity at naturally that compared the transport and retention occurring temperatures. of E. coli and synthetic fluorescent fine particles that can be reliably measured to low concentrations. We found that the fluorescent particles and E. coli behaved similarly and contrasted with a solute tracer (rhodamine WT). Our results show the importance of the underlying sediment and in-stream vegetation as a reservoir for micro-organisms in streams.

184 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Craspedacusta sowerbii Developing a Drop Camera A Decision Making Toolbox Polyps in New Zealand: Methodology to Monitor for Constructed Wetland Medusae are Inadequate the Spatial Extent of Design within Areas of for Determining Subtidal Benthic Habitat Intensive Agricultural Distributions & Introduction Patches Land-use Timing

Ian Duggan // The University of Scott Edhouse // NIWA Rebecca Eivers // The University of Waikato Waikato Fraser Aidney, Judi Hewitt, Drew Lohrer, Kevin Eastwood // The University of Simon Thrush // NIWA David Hamilton // The University of Waikato Waikato The monitoring of subtidal benthic John Quinn // NIWA The freshwater cnidarian Craspedacusta habitats using transects is suitable for sowerbii, native to the Yangtze valley, determining species identities, densities Elevated nutrient and sediment levels has invaded lakes and ponds throughout and other information on habitat types. have been associated with agricultural the world, including New Zealand. Most However, the use of transects provides expansion and intensification. Many distribution records globally have to little information on changes in the peat lakes in the Waikato are within date been based on observations of the sizes, shapes and characteristics of catchments used for dairy production jellyfish stage only, including numerous habitat patches over time. To monitor and are particularly susceptible to recent publications. We aimed to long term changes in the spatial extent eutrophication. Restorative management determine whether polyps are widespread of benthic habitats, as well as gather of selected lakes is being implemented in New Zealand lakes, and geographical data on density, size and composition, through the construction of wetlands areas, outside of where medusae have we trialled new methodologies using and sedimentation ponds to intercept been observed, and whether constructed a drop camera system. We sought to runoff from dairy farms, however waters are more easily invaded than accurately delineate the spatial extent design guidelines are lacking. This study natural waters. Our results indicate that of a specific benthic habitat type (in this aimed to fill this knowledge gap using C. sowerbii is common and widespread case, patches of the structure-forming literature and a field study examining in New Zealand, and far more so than is pinnid bivalve Atrina zealandica). We efficiencies of existing treatment systems. apparent from observations of medusae. tested the repeatability of the method (as Inflows and outflows of up to twenty- We argue that observed occurrences this is critical for temporal monitoring) six treatment systems were sampled of the jellyfish provide little useful and the cost-to-benefit ratio of post- over five seasons from 2010 to 2011. information regarding the distribution of processing of video data in the laboratory Seasonality and different catchment soil this species, and that published records versus cheaper on-board processing types significantly influenced suspended of new jellyfish occurrences provide only. Independent video data was also solids and nutrient loads primarily driven unreliable estimates of the timing of collected by divers to ground truth the by variation in pH, flow rates and water introduction or spread of C. sowerbii in drop-cam footage and assess its relative temperature. Nutrient concentrations new regions. We found no evidence that utility. The drop-cam patch survey method were significantly correlated with pH constructed waters were more readily may be useful for monitoring patches of (ammonium r = -0.47; nitrate r = 0.45; invaded than natural waters. Overall, large conspicuous animals such as Atrina, organic nitrogen r = -0.42; and phosphate accurate determination of Craspedacusta but less so for other key species such as r = -0.50) suggesting different soil occurrence and distribution requires infaunal bioturbators. Accurate definition types within peat environments may systematic surveys of the polyp stages. of patch boundaries and quantification strongly influence nutrient cycling and of Atrina densities (individuals per m2) attenuation. Hydraulic residence time is really only possible with laboratory was a useful predictor of the extent of post-processing of the video footage. nutrient reduction of some treatment The method is not well suited for finding systems, while depth and the presence patches, but with modification it may be of macrophytes were more appropriate suitable for monitoring existing patches predictors for others. A framework that have been identified. has been developed for key design considerations (including physico- chemistry, morphology and hydrology) for wetland treatment systems; key elements are sufficient residence time to allow for biochemical processing and retention of suspended solids and particulate nutrients is presented.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 185 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

A Web Based Directory Sediment Dispersion Spatial Variation in of Decision Support in Estuaries from River Functional Group Diversity Systems to Improve Their Inflows Determined Using in a Sandflat Benthic Understanding & Use Compound Specific Stable Community: Implications Isotopes for System Resilience

Tony Fenton // Alchemists Ltd Max GIBBS // NIWA Barry Greenfield // The University of Waikato Marjan van den Belt // Massey University Sediment is a major contaminant of Steve Markham // Tasman District Council water, carrying nutrients and pathogens Conrad Pilditch // The University of Beat Huser // Waikato Regional Council from land, smothering benthic habitat Waikato and affecting biodiversity in estuaries and Casper Kraan, Simon Thrush, Judi Hewitt A web based directory of decision support coastal waters. Information on the source // NIWA systems (DSS’s) has been created through of the sediment is a key requirement for targeting sediment control measures. an Envirolink tools grant. The directory Community resilience to environmental However, before you can manage provides relevant information on a wide stressors depends upon the vulnerability, something, you have to know what range of DSS’s for use in environmental adaptability and connectivity of living to manage. A forensic stable isotope management and other local government organisms. Recent studies suggest that technique (Gibbs, 2008) was developed decision-making. The range of DSS’s the function(s) a species performs may to track sediment sources from land within the directory includes computer be more influential in driving community by land use and identifying land-use models and assessment methods and response than the more traditional practice that exacerbate erosion. This frameworks. Provision and collation of measures of abundance and occurrence. enables mitigation of erosion by changing this information in one directory aims Where a number of species are performing land-use practices at a landscape scale. to improve the understanding and similar functions, this gives rise to This technique has been used to identify capability of potential users to get the redundancy within the community, an sources of sediment impacting on 19 most out of the tools that are currently important resilience attribute. To assess estuaries in New Zealand and is being available. The Directory contains two resilience, we focus on the functional tested overseas in 15 countries around types of information: (1) Basic information diversity of a benthic community from a the world. It has also been used to track (metadata) on each of the included large intertidal area in the Kaipara Harbour, the movement of sediment through DSS’s, such as; purpose, scope, state of New Zealand. Based on intensive sampling wetlands and harbours, such as the development, input/output data required, of 400 macrofaunal and 360 sediment Kaipara Harbour (Gibbs et al., 2012). key references and links to further cores with an area of 300,000 m2 we information; (2) Case studies on some identified 115 taxa and 23,682 individuals. of the included DSS’s. These provide Linking species attributes (including, body practical examples of the application of type, body size, feeding mode, living a DSS. The case studies aim to provide depth etc.) we identified 26 functional an additional understanding of how groups that characterise important suitable a DSS might be for supporting a functional attributes of the macrobenthic particular decision process by illustrating community. Analyses were conducted how the DSS has been already applied to assess group redundancy considering to a situation. The examples have been both occurrence and abundance, as well chosen for their applicability to Regional as spatial patterns in their distributions, Council management needs. Although which in turn represent key characteristics primarily established for Regional of community resilience. Findings indicate Council and Unitary Authority users the various levels of redundancy for different Directory is open to the public and is also functional attributes (ranging from 1 to likely to be useful to other government 13 species per group). Moran’s I spatial agencies, researchers and consultants. correlograms revealed distribution patterns The Directory has been designed to make ranging from small-scale homogeneity the information held in its database highly to large-scale heterogeneity with spatial accessible. A range of search options are arrangements including gradients and available from the Home Page. Further distinct patches. Abundance maps showed development of the directory is planned that some groups, such as tube worms to increase the number of DSS’s and case and large free-moving suspension-feeding studies. See the Directory at: www.tools. bivalves, show strong and opposing envirolink.govt.nz. spatial distributions with clear boundaries separating them. These findings emphasise a joint role for spatial variation in functional diversity and species redundancy in structuring community resilience.

186 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Effect of Nutrients on Tagging Experiments on Terrestrial Sediment Growth & Potential Spread Adult Inanga: Growth & Deposits Acidify the of Temperate Mangroves in Migration Pore Water of Intertidal New Zealand Sandflats

Iana Gritcan // Auckland University Jessica Hill // University of Aysha Hohaia // Auckland of Technology Canterbury University of Technology

Andrea Alfaro, Mark Duxbury, Sebastian Mike Hickford, David Schiel // University Kay Vopel // Auckland University of Leuzinger // Auckland University of of Canterbury Technology Technology Conrad Pilditch // The University of The diadromous fish Galaxias maculatus Waikato Mangroves are salt-tolerant plants that (inanga) is one of the most widely occupy intertidal areas of coastlines and distributed freshwater fishes in the Coastal urbanization, rising sea level estuaries throughout the tropics and in world, occurring throughout the and extreme rainfall events increase the some temperate areas. In the tropics, southern hemisphere. The post-larval supply of terrestrial sediments to coastal mangroves have a great ecological juveniles of this species form the basis habitats via waterways or from landslides. value, including supporting high species of New Zealand’s whitebait fishery Eventually these fine sediments are diversity, providing breeding and nursery as they migrate back into freshwater. deposited on the seafloor where they habitats and a variety of human services This essentially annual species spawns can alter the functioning of soft sediment (e.g., fire wood, food, shelter). In exclusively in tidally inundated riparian ecosystems. Cummings et al. (2009) temperate New Zealand, our one species vegetation in upper estuaries. The showed that terrestrial clays deposited (Avicennia marina subsp. australasica) is success of spawning is closely linked on defaunated intertidal sediments at the southernmost limit of the global to the availability and composition of affect the microbial decomposition of mangrove distribution. Recent studies suitable riparian vegetation. It has been organic matter by increasing the diffusive on New Zealand mangrove ecosystems widely assumed that after entering a distance between the source and sink of have highlighted important differences river as whitebait, mature fish do not reactive solutes. This increase changed from their tropical counterparts, such migrate to other waterways before the sediment–seawater flux and the as much lower faunal biodiversity. One spawning. Therefore, whitebait that enter pore water distribution of hydrogen ions of the still under-investigated research a waterway are committed to finding and dissolved oxygen. However, the areas is the role of nutrients on mangrove critical spawning habitat in that river if importance of such changes remained growth and productivity. In general, they are to spawn successfully when they questionable, because mixing and mangroves are highly productive in mature. If spawning habitat is absent irrigation of the sediment by macrofauna low-nutrient environments because they or degraded, their ability to contribute was experimentally excluded. In have strategies that allow them to use to future generations is compromised. a laboratory flume experiment we stored nutrients during periods of low Consequently, degradation or reduction confirmed the results of Cummings et nutrient availability. Previous studies of spawning habitat in individual estuaries al. for bioturbated intertidal sediment have shown contrasting results from can lead to the formation of ‘sink’ (mainly tube-building polychaetes and positive to negative effects of nutrient populations. Here we present the results juvenile bivalves): thin deposits (1.4 mm) enrichment (e.g., due to human activity) of a tagging study to track adult fish of terrestrial clay acidify the pore water on mangrove growth. Thus, more detailed across waterways during the spawning of the underlying intertidal sediment studies on nutrient cycles are needed season. This study will provide a measure decreasing pH by ~0.1 units after 18 h. to clearly identify the role of nutrients of stream fidelity in adult fish along with Such decrease may negatively affect on growth, productivity, and potential basic population characteristics and benthic community recruitment because spread of mangroves in New Zealand. dynamics. This knowledge will allow it can lead to dissolution mortality of In this study, the uptake, storage and whitebait conservation and habitat “just-set” juvenile bivalves. Next, we will release of nutrients through these rehabilitation to be targeted at productive repeat our measurements under in situ plants are quantified, and results will be waterways and estuaries. conditions of a sheltered mid-intertidal used to model nutrient dynamics in the sandflat. Mangawhai Harbour Estuary. The outcome will be crucial to future management and conservation efforts of mangroves in this country. In addition, the results of this project will be integrated within a larger mangrove program led by the Mangrove Research Group (AUT and UoA).

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 187 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

A Wai Quality Assessment Before & After Integrated Modern Estuarine Habitats Model for North Waikato Catchment Management & Organism-Sediment Streams & Lakes in Headwater Stream: Interactions at Mangawhai Changes in Water Quality Estuary, North Island, New Zealand

Aareka Hopkins // Ngaa Muka Andrew Hughes, John Quinn // Colleen Hulbert // The University Development Trust NIWA of Auckland

Whanau (families) and hapuu (tribes) Improvements in land management Kathy Campbell, Paul Augustinus, Lorna affiliated to Ngaa Muka Development practices, such as the establishment Strachan // The University of Auckland Trust (NMDT) are experiencing renewed of riparian buffers and afforestation of Andrea Alfaro // Auckland University of optimism and enthusiasm for restoring degraded areas, are often implemented Technology the mauri (life force) of awa (rivers and in an attempt to improve stream water streams), shallow lakes and flood plains in quality. Despite the popularity of such The Mangawhai Estuary, North Island, their tribal rohe (area). That optimism and approaches, there are few long-term New Zealand, provides a unique look at enthusiasm is driven by the realisation studies that quantify their impact. This organism-sediment interactions within that their kaitiakitanga (guardianship) study analyses the water quality effects a changing sediment environment. obligations and responsibilities will be of the implementation of an integrated The estuary can be divided into three re-asserted. As kaitiaki (guardian) they catchment management (ICM) plan, in general divisions; the lower, middle, will be able to restore elements in the 2001, within a sheep and beef grazed and upper estuary. The lower estuary is landscape that are important to them, an headwater catchment. Regular monthly located closest to the estuary inlet and opportunity afforded them by the Waikato water quality samples were obtained is composed primarily of rippled sands. River Authority Clean-up fund in North between 1995 and 2010. The middle to upper portions of the Waikato and elsewhere. Constructing a Results show that since the ICM estuary mark a gradual shift to a muddier wai (water) quality assessment model is plan implementation, optical water environment along with an increase the focus of this project. A wai quality quality (TSS, water clarity) has improved in mangrove (Avicennia marina var. assessment model based on whakapapa by 30–40%. The nutrient response to australasica) populations. The identification (genealogy) to Papatuaanuku (earth the land use changes has been more of numerous different habitats throughout mother) and Rangi-nui-aatea atua (sky complex with no significant changes the divisions of the estuary show shifting father) was constructed to provide an in concentrations of DRP, TP and ichnology and neoichnology across alternative model to western science NH4-N. The median concentration of different sedimentological environments. models that is simpler, cheaper and total organic nitrogen has decreased These habitats are differentiated based only uses western science to detect by ~40%. In contrast, nitrate and TN on grain size, physical and chemical faecal coliforms in open wai bodies, a concentrations have both steadily parameters, vegetation, and ecology. The contaminant tapu (sacred) to whanau increased at 5%/y and 3%/y, respectively. different habitats have been depicted and hapuu across all of Aotearoa (NZ). Water clarity and sediment and using ArcGIS computer based mapping Uptake of the wai model requires kaitiaki nutrient concentrations at two control software and show the zonation and to gain an understanding of ecosystems catchments have remained largely static. boundaries of the individual habitats. as their tuupuna (ancestors) had. Google Rapid improvements in the water Sediment infill history of the estuary Earth technology provides kaitiaki with clarity, TSS and TON are most likely a is examined through the process of capability to do that by creating profiles of result of the removal of stock access to vibracoring. Vibracoring has allowed the catchment, awa, ngaahere (forests), streams and riparian areas. Increases in for the extraction of 2 to 6 meter long tipu (plants), repo (wetlands), dwellings nitrate (and TN) concentrations may be cores from various locations throughout and dairy platforms. These profiles were related to a number of factors: the estuary. The stratigraphy within the required to create the model framework. • Lag in catchment response due to vibracores represents a general shift to We provide classifications to complement residence time of groundwater. muddier sediments with the influence other classifications in the literature • Decreased instream nutrient uptake of mangrove populations. Mangrove to enable both static and dynamic wai due to shade-induced reductions of expansion is promoting sedimetological quality assessments for streams and lakes instream biomass. and ecological shifts within the estuary. in North Waikato to be made by kaitiaki. Results from this study show multiple • Nitrate leaching from gorse which differences to those of similar scientific became widespread in the pine areas. studies concerning mangrove populations within tropical environments. Mangroves within New Zealand’s temperate climate support a different type of ecosystem then their tropical counterparts. Both advantages and disadvantages of mangrove populations are observed within this study.

188 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Prioritisation of Biodiversity Role of Scavenging Improved Confidence Datasets in the Hauraki in Basketwork Eel on Intervals for Genetic Gulf Marine Park Northeastern Chatham Estimates of Effective Rise, New Zealand Population Size

Susan Jackson // The University of Matthew Jones, Barbara Breen // Andrew Thomas Jones // Auckland The University of Auckland University of Queensland

Carolyn Lundquist // NIWA Basketwork eels (Diastobranchus capensis Estimates of effective population size Mark Costello // The University of Barnard, 1923) are common bycatch in are important tool in conservation Auckland deep-water fisheries of orange roughy genetics and have future potential as (Hoplostethus atlanticus Collett 1889) in a means of monitoring commercially The Hauraki Gulf Marine Park, established New Zealand waters. However, little is important fisheries species. The linkage in 2000, is recognised for its outstanding known about their ecology and feeding. disequilibrium method is current by biological diversity, including marine This poster describes the food and far the most commonly method for mammals, seabirds, shorebirds, fish, feeding of 135 basketwork eels from estimating effective population size. invertebrates and plants. Currently, northeastern Chatham Rise, New Zealand, Whether making point estimates of 5.4% of the Hauraki Gulf Marine Park is from water depths of 1062–1196 metres. the current effective population size, or protected under existing Marine Reserves Basketwork eels from northeastern trying to detect on-going trends in the or Cable Protection Zones. Information Chatham Rise were primarily piscivorous, size of a population, producing accurate about hotspots of biological and habitat with the diet supplemented by squid, confidence intervals is important so as diversity can be used to determine high natant decapod and mysid prawns. to properly quantify the uncertainty of priority locations for further protection The weight of food increased with the the results. Depending on the size of or restoration of biodiversity, and inform size of the eel, but the numbers of food the population, the data used, and a placement of a network of representative items did not, nor was there any major number of other potentially confounding marine protected areas. Here, we compile ontogenetic shift in the composition of factors, the techniques currently used existing scientific datasets, including the diet. The presence of fragmentary to generate confidence intervals for information to describe habitats such food items (fish heads and tails, beaks, estimates of effective population size as depth, exposure, and substrate, and and tentacle crowns of warty squid Onkia using the linkage disequilibrium method identify gaps in protection of particular ingens (Smith, 1881), and seaweed), do not always have accurate coverage habitats. We also identify existing suggests that scavenging was important probabilities. For example, this means biological datasets (e.g. demersal to basketwork eels. Scavenged material that at a 0.05 significance level, the fish; rocky reef fish) that exist for the made up approximately 40% (by weight) confidence intervals do not contain the full Hauraki Gulf Marine Park. We use of their diet, suggesting they perform an true value being estimated 95% of the Zonation software to identify priority important role in the recycling of carrion time. We examined a number of ways areas for protection in terms of both at mid-slope depths on northeastern to improve the confidence intervals for habitat and biological information, and Chatham Rise. These eels could benefit linkage disequilibrium method based compare priority areas based on each from influxes of fisheries discards, which genetic estimates of effective population type of information. Future research in turn, may alter the composition of size. We present some numerical results will identify compatibilities between deep-sea ecosystems. based on a simulation study comparing biodiversity protection and recreational the current most commonly used method opportunities. to generate confidence intervals with the new ones. These results show that these new methods have better coverage performance than those currently in use. We also discuss some of the general issues surrounding the accuracy of genetic estimates of effective population size.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 189 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Effects on the Escapement Benthic Dinoflagellate It’s a Buoy!!! of Juvenile Halibut Toxins in Flora & Fauna of from Shacking Codend Rangaunu & Parengarenga Generating by Cap-like Harbours Canvas

Yonghae Kim // Gyeongsang Lincoln Mackenzie // Cawthron Anna Madarasz-Smith // National University Institute Hawke’s Bay Regional Council

New method of increasing juvenile fish Andrew Selwood, Paul McNabb, Lesley Oliver Wade // Hawke’s Bay Regional escapement from trawl codends is to Rhodes // Cawthron Institute Council encourage fish to approach the netting Paul Barter // Cawthron Institute by generating an active shaking motion A variety of environmental samples in the codend. The effects of actively were analysed and passive solid phase New Zealand nearshore coastal waters stimulating devices (ASD) in the shaking adsorption toxin tracking (SPATT) are the receiving environment for the codend on juvenile flatfish were studied devices were installed in Rangaunu and freshwater drainage system and receive to increase escape rates from the cod. Parengarenga Harbours. These revealed the impacts of land-based activities. Three kinds of model codend were used: the pervasive influence of a variety of Despite this, coastal waters have received a traditional codend, a fluttering flag-like bioactive polyether compounds secreted less monitoring attention relative to their net panel, and a double conical rope array by benthic dinoflagellates within the freshwater and terrestrial counterparts. as ASDs. Escape responses of juvenile mangrove and sea-grass habitats of At present, nearshore coastal water bastard halibut (Paralichthys olivaceus), these estuaries. Pinnatoxins (PnTxs) and quality sampling in New Zealand is body length BL = 8.2 ± 0.7 cm) were okadaic acid (OA) and its esters were the generally restricted in terms of spatial observed in a circulating water channel. most abundant, although traces of other and temporal resolution, giving rise to Three model codends (length 130 cm polyether compounds (dinophysis toxins, ‘point in time’ data sets. If ‘point in time’ and diameter 40 cm) were made with 43 pectenotoxins, spirolides) were also data are collected over a sufficiently mm mesh generating shaking motion detected. The deposit feeding sea-hare long time period, it may be possible to by unbiased cap-like canvas at the end Bursatella leachii contained relatively high determine water quality trends, however of the codends. The shaking distance as levels of pinnatoxins and lesser amounts these intermittent samples are generally an amplitude was 60% of the codend of OA esters in its tissues. Although there inadequate to detect the subtle changes diameter and its period was 5 s around. was abundant OA in these environments in water quality that indicate the status The escape rate was significantly greater cultured oysters did not incorporate this of coastal waters. Recent developments in the shaking model codends ranged toxin, presumably because they were not in measurement technology have made 85–88% than in non-shaking state of exposed to Prorocentrum lima cells in the real-time and continuous measurement the codends 55–63% respectively. The water column or were unable to digest practical and cost-effective. As a moving velocities of the fish for 2 s these cells. The low levels of pinnatoxins consequence, resource managers are escaping were faster in the shaking cases sequestered by oysters in these now able to provide context to the 2 BL/s than in non-shaking cases 1 BL/s estuaries, despite persistent and very ‘point in time’ data derived from routine for three model codends respectively. abundant populations of the causative monitoring programmes using real-time There was no difference in escape rate dinoflagellate, is probably also due to the data collected at high frequency. In 2012 between three model codends either in general inaccessibility of these cells to the Hawke’s Bay Regional Council (HBRC), shaking or non-shaking cases. Therefore, shellfish and therefore there appears to with the assistance of the Cawthron the shaking codend as sieving effect be a low risk to human consumers. Institute, deployed HAWQi (HAwke’s Bay operated actively driving fish to the net Water Quality information) water quality panel and weakening optomotor response buoy, to collect continuous water quality of fish by variation of net position possibly information from three depths in the to panic and then to try more escape coastal water column (surface, 5 m and resulted in reduction of juvenile by-catch. 14 m depth). Electrical conductivity, water temperature, turbidity and chlorophyll a, and meteorological parameters collected 1 m above sea level are transmitted from HAWQi to the HBRC’s HydroTel telemetry system using inductive modem telemetry. HBRC plans to deploy an Acoustic Doppler Current Profiler (ADCP) during 2013.

190 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Genetic Studies on Thermal The Potential Use of Catchment-scale Riparian Adaptation & Membrane Sugarcane Bagasse in Zone Optimisation Using Saturation in Antarctic Fish Pelleted Fish Feed the Mauri Model

Vanita Malekar // Lincoln Nawwar Zawani Mamat // Dr Kepa Morgan // The University University Universiti Teknologi MARA, Malaysia of Auckland

Dr Victoria Metcalf // Lincoln University Fatimah Tahira, M. Nasir // Universiti Dr Dan Hikuroa // Nga Pae O Te Teknologi MARA, Malaysia Maramatanga The impacts of climate change are Brian Peacock // Lafayette College, USA dictated by an organism’s ability to An assessment of the potential use alter its gene expression in response of sugarcane bagasse for wheat flour Riparian zone restoration is one of the to environmental variation. However, substitution in pelleted fish feed was most ecologically sound solutions to understanding how organisms adapt carried out. Diets were formulated to water quality and runoff management to thermal change is lacking. Polar include five inclusion levels of wheat issues. When planning a catchment organisms like Antarctic fish may be flour being substituted by sugarcane scale restoration project, the choice of especially affected their supposed narrow bagasse (Control-0%, D1-25%, D2-50%, sites must be optimized to minimize thermal tolerance may have limited D3-75% and D4-100%). Results showed financial, social, and cultural impacts adaptive potential to rising temperatures. that protein content increased with the whilst maximizing environmental Antarctic fish, such as the notothenioids, substitution levels of sugarcane bagasse benefits such as nutrient removal. The also favour unsaturated fatty acids for between 50 and 100% (29.8%–31.3% integration of the Mauri Model decision metabolism and within membranes, protein). The differences in protein level making framework with established invoking a key role for the desaturase of each treatment were relatively small, approaches in pollution control and enzyme steraoyl-CoA-desaturase (SCD). thus not giving any significant difference cost benefit analysis has developed Polyunsaturated fatty acid (PUFA) (P>0.05). The lipid content in pellets an approach for prioritizing riparian synthesis is catalyzed by SCD, allowing a showed a fluctuating trend where it zone restoration. Assessment uses a mechanism for membrane properties to increased between 8.8 and 10.2% in combination of two quantitative metrics: be altered depending on environmental control, D1 and D2 treatments. However, terrain-landuse analysis to identify areas temperature. This research aims to lipid levels decreased to 9.9% in D3 and of high areal pollutant flux and the Mauri better understand linkages between lipid it increased again to 10.4% in the D4 Model decision-making framework to saturation and thermal adaptation. SCD treatment. No significant differences effectively integrate the social, cultural, will be cloned and characterized from two were found in lipid levels of all formulated environmental and economic factors. key Antarctic notothenioids and two non- pellets. The highest carbohydrate content The result is a simple, flexible restoration Antarctic notothenioid relatives. Fatty acid was observed in D1 (47.1%) and the site optimization tool that utilizes readily composition and gene expression level lowest was exhibited by the D4 treatment available GIS data and can easily be changes of SCD and other gene targets (41.6%). No significant differences were implemented by planners in a variety of in response to thermal acclimation will be observed in carbohydrate levels in all catchments. The approach was applied as examined. This project will contribute to treatments (P>0.05). The results of ash a case study to the Tarawera Catchment understanding of thermal adaptive theory content for each inclusion level ranged in the Bay of Plenty, New Zealand with and climate change prognoses for biota, from 9.5 to 10.5%. Moisture content in the objective of decreasing nutrient enhancing New Zealand’s contribution pellets showed no significant differences pollution in the watershed. The metrics to integrative research on life in extreme among all treatments. It is suggested that used in this tool proved effective in environments. the optimal level for replacing wheat flour anticipating hydrological, environmental with sugarcane bagasse in fish feeds is and anthropologic constraints that were 50% since it exhibits the considerable used to pick sites for restoration. The final amounts of protein which is 29.8%, result was an ordinally ranked map of 10.2% lipid, 9.9% moisture, 6.6% ash and potential restoration sites. It is anticipated 43.3% carbohydrate. that this technique will prove useful in a variety of catchments despite variation in management goals and geographic location.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 191 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

A Pressure-Response POI: Open Science for a Pheromones as a Framework for Evaluating Healthy Pacific Ocean Biosecurity Tool: Does a Economic & Environmental Common Attractant Exist Drivers in the Management Between Portunid Crabs? of FreshwaterResources

Hannah Mueller // The University Emma Newcombe // Cawthron Samantha Parkes // NIWA of Waikato Institute Cindy Baker, Kristel van Houte-Howes, David Hamilton // The University of Chris Cornelisen, Rowan Strickland // Wayne Smith // NIWA Waikato Cawthron Institute Graeme Dooler // The University of Portunid crab species have established Waikato, University of Western Australia Pacific Ocean research and knowledge themselves as marine pest species in transfer is currently dispersed and is many parts of the world (e.g. Carcinus maenas and Charybdis helleri in the USA; Patterns of economic and environmental generally not adequately addressing Carcinus mediterraneus in Japan, and pressures, and policy responses to critical ocean health issues. The Pacific Carcinus maenas in Australia). In New mitigate problems that arise can be Ocean Initiative (POI) is an exciting Zealand the Asian paddle crab Charybdis discerned in the management of new way for science and communities japonica has established populations in freshwater resources. Many factors, to improve ocean health through a the Whangarei and Waitemata harbours, including environmental degradation culture of collaboration and sharing of and in the wider Hauraki Gulf. At present and economic restraints, influence the knowledge. POI provides a pathway for the impact on native species is still way resources are managed. Extensive project development and communication unclear, although there are concerns resource degradation, however, is often between ocean users, knowledge that the presence of this large predator only recognised in policy responses providers and funders, and builds on may influence populations of the native when ecosystem health has been the willingness of scientists to work paddle crab Ovalipes catharus. In light of severely affected, and a large part of together on projects that benefit ocean these concerns, the development of new the population is affected by ensuing health. The concept of POI was first methods for surveying and / or controlling problems. Using New Zealand and the introduced at the 2012 NZMSS/AMSA C. japonica numbers could be hugely iconic Rotorua lakes as a case study, this conference and has continued to gain beneficial to biosecurity managers in New research draws on international examples momentum, with progress in key areas, Zealand. Recently, uridine diphosphate to trace developments in freshwater including; a commitment to supporting (UDP), a nucleotide released during chitin management over several decades. Based further development for two years by biosynthesis, has been identified as a on a pressure-response framework, this the Cawthron Institute, establishment sex pheromone in C. maenas. Pre-moult research puts freshwater management of POI as an independent charitable female crabs release UDP, which attracts regulations and developments both trust, and the development of an on-line males for guarding and mating during the in New Zealand and overseas into a collaborative tool for project development. moult cycle. As UDP is a physiological by- comparative perspective. It illustrates There are a number of exemplar projects product and released by many crustacean the interplay of pressure-response that currently in development, which in turn species, it could potentially function as led to outcomes of management of will provide a foundation from which to a sex pheromone in multiple species. water quality in the Rotorua lakes. Due build further interest and participation of As such, we investigated whether UDP to dynamic responses of ecosystems, knowledge providers and end users. POI operates as an attractant in the invasive degradation often proceeds too far offers an environment that encourages C. japonica, which poses a biosecurity before new regulations take effect, collaboration and open science by risk, and the native portunid crab, making restoration more challenging. facilitating diversification and expansion Ovalipes catharus, where an attractant In freshwater ecosystems and lakes in of funding opportunities for end-user- has potential applicability to New particular, ecological and social lag times focussed ocean health solutions. Get Zealand’s commercial crab fishery. This play an important role. The identification involved, submit project proposals and poster presents the study results which of common patterns of pressure and contribute to project development by found interspecific activity of UDP within response can therefore help identify visiting POI at www.pacificoceaninitiative. portunid crabs. points for improvement of future org. regulations aimed at lake restoration.

192 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Fishing the Hills – Results Boring Through Marine Effects of Sample of an Extensive Fish Survey History: Shipworms, Processing on the in the Ruahine & Tararua Pillbugs & Gribbles, & Concentration of Ranges Their Current New Zealand Microcystins Detected in Status Cyanobacteria

Michael Patterson // Horizons Courtney Rayes // The University of Shelley Rogers // University of Regional Council Waikato Waikato

Logan Brown // Horizons Regional Ian Duggan, James Beattie, Ian Hogg // Michèle Prinsep, David Hamilton // The Council The University of Waikato University of Waikato Susie Wood, Jonathan Puddick // Cawthron Institute In early 2011, Horizons Regional Council, Marine wood borers have been, and in conjunction with the Department of continue to be, a major concern for Daniel Dietrich // University of Konstanz Conservation, conducted a fish survey wooden ships and marine infrastructure of 61 sites in the southern Ruahine and worldwide. Three families of marine Cyanobacteria are capable of producing northern Tararua Ranges. The purpose of wood borer from two phyla occur in toxic compounds of which microcystins this was to locate new fish populations New Zealand; Teredinidae (Mollusca), are the most notorious. Microcystins and to establish baseline data. Of the and Sphaeromatidae and Limnoriidae pose serious health risks to animals and 61 sites surveyed 25 had either never (Arthropoda), otherwise known as humans by irreversibly inhibiting protein previously been monitored, or had one shipworms, pillbugs and gribbles, phosphatase enzymes, causing liver failure or more species found which had not respectively. Of the known species in and neurological impairment. Several previously been recorded at that site. The New Zealand, most are considered decades of research have been dedicated survey found 14 fish species including non-indigenous or are of uncertain to determining the environmental factors a single lamprey, the first dwarf galaxias origin. Although assumed to have regulating microcystin production and populations found in the Manawatu invaded New Zealand via wooden ships, its ecophysiological role. Culture-based River catchment on the north-western introductions are historic, and it is studies that manipulate environmental side of the Ruahine Ranges (Pohangina possible that some were present in New factors typically associated with a bloom catchment), and several large populations Zealand prior to human colonization. have shown contradictory results and of the at risk shortjaw kokopu. Two key components contribute to this only yielded small changes in microcystin Comparison of these results against the research. Firstly, a historical review quotas (microcystins per cell). These Leathwick Freshwater Fish Predictive seeks to address our understanding of findings might be due to the use of model (2005) showed the model the historic impacts and responses to different methods for preserving, extracting underestimated the presence of several borers. Secondly, field sampling for wood and quantifying microcystins. A recent in large galaxiid species, relative to what we borers is being undertaken at historically situ study showed that an increase in cell observed. As the model was based on important ports for analysis of the COI density resulted in eighteen-fold increases data from the New Zealand Freshwater gene locus to examine genetic diversity in microcystin quotas. This highlighted the Fish database, this discrepancy may be and geographical structuring of wood need to further investigate the methods a result of a deficiency in freshwater fish borer taxa. Historical results illustrate used and the length of time between the monitoring and reporting in similar hill the profound impacts of marine wood concentration and preservation steps when country habitat in our region. borers globally, particularly in the period assessing microcystin concentration. The after 1800, coinciding with significant microcystin concentration of two different growths in shipping, migration and Microcystis strains (CYN06 and CYN11) global interaction. New Zealand reports and one Planktothrix strain (CYN60) of wood borer damage and management were quantified using high performance attempts began in the mid nineteenth liquid chromatography coupled to mass century. Timber coatings and chemical spectrometry after processing via; (1) impregnation were first utilized, but from direct freezing (no prior cell concentration) 1860 their management shifted to the and extraction by freeze-thaw cycles, use of imported and native tree timbers, (2) cell concentration by centrifugation thought naturally resistant, and by the and extraction in methanol and (3) twentieth century chromium copper cell concentration by filtration and arsenic preservation was introduced. extraction in methanol. Results show Despite relentless efforts worldwide, comparable microcystin concentrations no infallible method for marine borer for all the methods and suggest that cell resistance exists. concentration prior to preservation does not affect microcystin concentration. The results from this study have recently been applied to an in-lake mesocosm experiment performed at Lake Rotorua, Kaikoura.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 193 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Fisheries Research in The Importance of How Much Nitrogen is too Eastern Australia – at the Austrovenus stutchburyi Flipping Much? Predicting Interface...or About to Go for Biodiversity-Ecosystem the N Loading Threshold Under? Functioning in an Intertidal for Seagrass Collapse Sandflat

Kevin Rowling // Retrenched Candida Savage // University of Lena Schallenberg // (NSW Fisheries) Otago Hydrosphere Research Ltd

In recent years all eastern Australian Agnes Karlson // Stockholm University, Marc Schallenberg states have seen a significant reduction Sweden in the funding and resources available Keith Probert // University of Otago Seagrasses play an important role in lakes for assessing the status of exploited Daniel Leduc // NIWA and lagoons by stabilising sediment and fish stocks. In New South Wales, March Conrad Pilditch // The University of competing with nuisance macroalgae 2013 saw the closure by the NSW Waikato and phytoplankton for nutrients. Government of the iconic Cronulla Eutrophication can cause a sudden Fisheries Research Centre, which for disappearance of seagrasses resulting in Biodiversity loss in coastal ecosystems more than 100 years has been one of shifts to macroalgal and/or phytoplankton worldwide has prompted an urgent the pre-eminent marine research sites dominant systems. This regime shifting need to understand the importance of in the southern hemisphere. Its closure or ‘flipping’ is one of the most important key functional groups for ecosystem led to the retrenchment of about half ecosystem dynamics to predict in aquatic functioning. We investigated the of the fishery assessment scientists systems, given the complete reversal effects of the loss of a key species, the based at Cronulla, and the transfer of of species dominance and modified cockle, Austrovenus stutchburyi, on the remainder to disparate, inappropriate nutrient cycling that can result. Such critical ecosystem processes, notably locations. An inquiry by a NSW a shift occurred in Lake Ellesmere/Te nutrient cycling and uptake of detritus in Parliamentary Select Committee found Waihora (Canterbury) and it is feared intertidal sandflats. Cockles are harvested there was no reasonable justification that intensification of dairying will also commercially and recreationally, yet they for the closure – the decision lacked drive Waituna Lagoon (Southland) to a are the main suspension-feeding bivalve an appropriate business case or any similar regime shift. This study sought in New Zealand estuaries. Removal of this cost/benefit analysis. This ‘expedient’ information on nitrogen (N) loading rates key species thus results in the loss of an approach has typified the restructuring which have caused collapses of seagrass entire functional group, which is likely to of fisheries agencies in the other communities in coastal lakes/lagoons/ have direct consequences for ecosystem eastern Australian states, where embayments around the world. Based functioning in marine sediments. Using reductions in research staff numbers on an extensive literature review, we a block design, we manipulated cockle may have serious implications for the found that N loading thresholds causing densities (no cockles; 300 m-2) and future sustainability of commercial and seagrass community collapse occurred added 13C and 15N-labelled macroalgae to recreational fisheries, as well as reducing between 20 and 100 kg N per year per select high and low density cockle plots the employment prospects for fisheries hectare of water body area. The current in Papanui Inlet, Otago. Nutrient and scientists in Australia. One significant best estimate of the N loading rate for oxygen fluxes across the sediment-water factor contributing to this situation Waituna Lagoon is 180 kg N/ha/y, which interface were measured and the uptake appears to have been the placement of is above the maximum threshold for of algal detritus by functionally different Fisheries (which has a natural resource seagrass collapse based on overseas benthic communities was determined management function) under agriculture- studies. Thus, our study indicates that using isotope tracers. Oxygen uptake dominated Department of Primary to safeguard the seagrass community in rates were greater in high density cockle Industries portfolios. Waituna Lagoon, the rate of N loading plots and increased with the addition from the catchment should be reduced by of macroalgal detritus. There was high at least 44%. Our finding is supported by interspecific variation in uptake of the an ecological model of Waituna Lagoon algal detritus, with highest uptake by a and by a nitrogen loading threshold for tanaidacean and a nereidid polychaete. the lagoon independently determined by This multi-functional and mechanistic an expert in the health of coastal lakes/ approach enabled us to assess the lagoons. relative performance of species within and among treatments and quantify the feeding niche of the different communities.

194 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Marine Invertebrates of To Study the Immuno- Integrated Geophysical New Zealand: Diversity, stimulant Activity of Watse Study of Depth-to-basement Tools & Opportunities Paua Blood & Guts & Sediment Thickness in Otago Harbour, New Zealand

Kareen Schnabel // NIWA Ashish Sharma // Auckland Amy Shears // Horizons Regional University of Technology Council Sadie Mills, Anne-Nina Loerz, David Bowden, Dennis Gordon, Daniel Leduc // Noemi Gutierrez-Maddox, Andrea Alfaro, Abigail Smith, Andrew Gorman NIWA Jun Lu, Yan Li // Auckland University of // University of Otago Technology A recent inventory of the New Zealand Understanding how a harbour has filled Animalia (including vertebrates) by D.P. The black-footed abalone Haliotis iris (or emptied) in the past is critical to Gordon listed a total of ~35,000 terrestrial is the main commercial species of understanding the current sedimentary and aquatic species. Notably, only about abalone in New Zealand, and is known processes. Integrated geophysical a third of these (just over 13,000) are as “paua”. It is grown for its flesh and research can be used to uncover such marine, despite the fact that the New for its shells, which are polished and information on the past environment Zealand marine realm is 15 times larger used as ornaments. OceaNZ Blue Ltd. and changes over time. The aim of this than its land mass. This difference Situated in Ruakaka mostly conducts research was to determine the depth- becomes even more striking when one cultivation of abalone in New Zealand, to-basement, sediment thickness and considers the deep-sea environment: not where they produce cocktail-size abalone ancient sedimentation in Otago Harbour even 800 invertebrate species are known for local and international markets. One using lithological records alongside two from depths >1500m, meanwhile, these of the big threats for this industry is the complementary methods: land-based deep waters cover more than 65% of the risk of diseases and mortality. In order to gravity anomaly profiling and marine New Zealand Exclusive Economic Zone. address the health of the stock, a good single-channel seismic reflection. The first deep-sea samples in this region understanding is needed on the immune The gravity surveys around Otago were taken by the HMS Challenger in system of this under-studied species. Harbour modelled a maximum depth- 1874 with intermittent extensive regional Hemocyanin (Hc) is a high molecular to-basement at ~100 m deep near the sampling since then. More recently, new weight respiratory protein, which carries current entrance and >70 m at the South technologies including camera systems oxygen using two copper ions found in Dunedin paleo-entrance. The seismic is adding exciting new resources and the hemolymph of most crustaceans and reflection survey observed the greatest opening up new opportunities. We will molluscs. Oxygen binds with the copper basement depth (~76 m) just 1km from summarise the ongoing research efforts ions that impart a blue colour to Hc when the current entrance. Appearing like two in the New Zealand deep sea (beyond the it is oxidized. Due to their large size, elongated valleys, the basement surface continental shelf), highlighting some of Hc exerts an immunostimulant activity was shallowest at Goat and Quarantine the technological advancements that are in mollusks, but the mechanism of the Islands and the rocky harbour margins adding a wealth of information and data stimulant effects on paua is unknown. and deepest towards the paleo-river that in turn allow insights into deep-sea A detailed study of H. iris blood and gut mouths. The “V”-shaped bedrock valley biodiversity and ecosystem functioning. fluids will provide valuable information and thick sediment fill at the current While it is not surprising that the regarding the mechanisms that control its entrance was indicative of a steep river- recognition of new taxa happens at a rate immune system and may provide a tool incised and/or fault-incised valley. The much faster than they can be described, for early disease assessment. total sediment volume in Otago Harbour some encouraging progress has been was estimated at 1.62 billion m3. This made over the last years. Nevertheless, sediment package accumulated at a varied the possibilities for discovery remain rate, predominantly depositing sediment endless. during the last post-glacial sea-level transgression. The volume equates to an ancient sedimentation rate of ~90,000 m3/y since the last glacial maximum (~2 mm/y). Investigating the sub-surface of Otago Harbour has provided information on basement geometry, pre-human sedimentation and geomorphological evolution, thus providing further knowledge to inform management of Otago Harbour. The same combination of methods could be useful for other shallow coastal sub-surface surveys.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 195 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Managing the Effects of Regional Estuary Tairua Harbour – Gravel Extraction in the Monitoring Programme: Environmental Monitoring Manawatu-Whanganui a Decade of Trends in Paradise Region

Amy Shears // Horizons Regional Nathan Singleton // Waikato Nathan Singleton // Waikato Council Regional Council Regional Council

Harold Barnett, Jon Bell, Peter Blackwood Hazel Needham, Hilke Giles // Waikato Wilma Blom // Auckland War Memorial // Horizons Regional Council Regional Council Museum Sediment dwelling organisms The removal of gravel from river (macrofauna) perform many important Waikato Regional Council (WRC) channels and banks has a long history ecological processes that regulate conducts the long-term Regional Estuary in the Manawatu-Whanganui Region. ecosystem function. Estuarine habitats Monitoring Programme (REMP) in the The demand for gravel use and flood and their associated biological southern Firth of Thames and Whaingaroa control works to protect various land communities have been identified as (Raglan) Harbour. REMP focuses on uses has led to significant modification being highly vulnerable to the pressures intertidal benthic macrofauna and of physical characteristics, ecology and disturbances associated with sediment characteristics as “indicators” and natural character in some rivers. increasing human activities, highlighting of the health of the region’s estuaries. Horizons Regional Council is responsible the need for regular monitoring of these WRC wants to expand its REMP into for managing these effects whilst unique habitats. =In April 2001 Waikato Tairua Harbour, Coromandel Peninsula, simultaneously providing for flood Regional Council initiated the Regional and in November 2012 a pilot survey protection and allowing the extraction of Estuary Monitoring Programme (REMP) was undertaken. The Coromandel east gravel which benefits the local economy. at five permanent monitoring sites in coast is a popular holiday and retirement Horizons has a number of tools to two key estuaries; the southern Firth destination, but it is also seeing increased manage this balance, such as, a code of Thames and Whaingaroa (Raglan) intensities in farming, forestry and of practice for river works, policies on Harbour. The objective of this long-term horticulture. Despite this, little is known total allocation limits and protection monitoring program is to assess both the about it the coastal ecology in this area. of significant habitats and a long-term current status and temporal changes in The aims of the Tairua REMP are to monitoring programme of the gravel intertidal sediment characteristics and collect baseline and longitudinal data resource through cross-sectional river associated macrofaunal communities. to help WRC assess the state of the surveys. We will use a number of case Macrofauna have been widely used estuary, detect environmental change, studies to illustrate how these policy, as indicators of estuary health in determine the effectiveness of current science and monitoring tools feed back environmental monitoring programmes as well as plan future work programmes. to inform policy reviews and consenting globally, as certain species respond Initial results of the pilot survey show of gravel extractions. As a result of these predictably to many kinds of natural and the macrobenthic community in Tairua management tools, the consenting man-made stressors.Sites are monitored Harbour may be quite different from that process is better informed to avoid either quarterly or twice a year. On found in the southern Firth of Thames adverse effects of gravel extraction. each sampling occasion 12 replicate and Whaingaroa (Raglan) Harbour. An macrofaunal cores are collected in each amphipod found in the upper reaches monitoring plot. Sediment samples are of the estuary may be a new species collected for analysis of physical and more characteristic of phreatic systems. chemical characteristics. Continual We also found an isopod which, though monitoring over many years enables probably not a new species, belongs the natural variability and cycles in to a genus which does not fit into any organism abundances to be differentiated known isopod family. Based on records from those attributed to changes to in the literature it has been previously environmental conditions. The Firth recorded only from Stewart Island and of Thames and Whaingaroa (Raglan) the Chathams. Harbour maintained distinct macrofaunal This poster describes the findings communities over the 10 year period. of the pilot survey and outlines the aims Sediment and community structure have and design of the Tairua REMP, which not changed dramatically at an estuary commences in July 2013. wide scale. However within each estuary site specific changes concurrent with environmental change were observed. These trends in organism abundance and sediment properties will be presented.

www.waikatoregion.govt.nz/Environment / Natural-resources/coast/Regional-Estuary -Monitoring-Programme/

196 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Observations of Giant Predicting Climate Change Can Fisher Knowledge Kokopu Spawning Habitat Effects on Life at the Land– Provide Accurate Estimates in an Urban Hamilton Freshwater Interface of the Past? Stream

Josh SMITH // NIWA Richard Storey // NIWA Ruth Thurstan // University of Queensland Paul Franklin, Cindy Baker, Paul Lambert // Richard Storey Brenda Bartels // NIWA Adam Uytendaal // Hawke’s Bay Regional Sarah Buckley, John Pandolfi // University Council of Queensland Little is known of the spawning habits of giant kokopu (Galaxias argenteus). Located at the interface of land and Fisher knowledge is increasingly It is generally thought that the adults water, intermittent streams are extremely accepted as a valuable tool to help derive migrate to a common spawning site, sensitive to changes in annual rainfall and past trends in species abundance or but spawning has never been observed temperature with respect to the length of environmental conditions. Yet inferring or any eggs discovered until now. Giant their dry period. Climate models predict trends from fisher knowledge is fraught kokopu nests have been discovered in longer and more frequent droughts in with uncertainty, and little is known an urban park in the middle of Hamilton. eastern parts of New Zealand where about the accuracy of such data in Adult giant kokopu (43) ranging in size intermittent streams are common. comparison to records of catch and from132–303 mm were PIT tagged using What will be the impact of such climate effort. We interviewed Queensland 12 mm tags in a 500 m long section of a change on aquatic communities of fishers from the trawl, line and net small Hamilton urban stream that flows intermittent streams in these areas? Will industries about their memories of past into the Waikato River. Fish movements the impacts be greater in streams that catches, catch rates, seasonal trends were monitored regularly by spotlighting lack protective riparian forest? Several and general perceptions of change and the use of a handheld PIT detector. intermittent streams in central Hawke’s over time for their target species. Each A fixed PIT aerial was positioned in the Bay were monitored for five years to fisher’s response was compared to their lower section of the stream to detect fish determine the effects of dry vs. wet years individual records of catch and effort, leaving the stream. Ripe fish, both male on aquatic invertebrate communities. either sourced from personal logbooks and female, were found in early June. During the driest years, intermittent or from records collected by Queensland Shortly after this three separate giant streams ceased flow for up to 6 months, Fisheries, for which individual catch and kokopu nests were found. It appears whereas during the wettest year, streams effort has been recorded since 1988. that the majority fish in this particular did not dry at all. Intermittent streams in We report upon the accuracy of fishers’ stream spawn in-situ and don’t undertake native forest showed a slight decline in recollections compared to their individual significant migrations for spawning. total invertebrate richness, and a clear catch rate data and discuss the value Spawning occurred during high flow decline in EPT richness, EPT abundance – and the limitations – of such data for events on at least two occasions, as and %EPT abundance with increase in management. development was less advanced in dry season length. In nearby perennial one nest compared to the other two. streams, EPT richness and abundance Eggs were laid in dense wandering jew showed a much smaller decline with (Tradescantia fluminensis) at two sites dry period length. Correlations between and dense yorkshire fog (Holcus lanatus) invertebrate metrics and dry period at the other. This new knowledge will length were not stronger in pasture support conservation and restoration of than forested intermittent streams. this iconic New Zealand species. These results indicate that invertebrate communities respond to short-term (year- to-year) variability in dry period; they may show stronger responses to long-term increases in dry period length associated with climate change.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 197 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Allometry, Biomass & Litter Catchment-derived Auckland Marine Habitat Decomposition of the Contaminants in Hamilton Mapping New Zealand Mangrove City Urban & Peri-urban Avicennia marina Subp. Streams Australasica

Phan Tran // Auckland University of Tammy Valler // The University of Melanie Vaughan // Auckland Technology Waikato Council

Sebastian Leuzinger, Andrea Alfaro // Susan Clearwater // NIWA Jarrod Walker, Marcus Cameron, Megan Auckland University of Technology Nicholas Ling, Dudley Bell // The Carbines // Auckland Council University of Waikato Boyd Taylor // EcoGIS Kevin Collier // The University of Waikato, Mangrove ecosystems are considered to be of high ecological and economic Waikato Regional Council Accurate mapping of the marine importance throughout the tropics and environment is a challenging and subtropics. Globally, these ecosystems Awareness of the consistently degraded expensive task. Auckland Council are under threat due to land use state of urban streams with lower has used satellite and aerial imagery, conversion as a result from high biodiversity has heightened worldwide, data points and expert knowledge population pressure in coastal areas. increasing restoration initiatives to to map intertidal habitats across the Conversely, temperate mangroves in ameliorate adverse effects. This study Auckland Region. We use worldview New Zealand are expanding, but their examined anthropogenically-derived two multispectral satellite imagery biodiversity and ecological role differs contaminants (metals, metalloids, which was designed for greater water from their tropical counterparts. There PAHs) in water and sediments, and penetration and has a 1.8m resolution. is limited available information and bioaccumulation in shortfin eels (Anguilla The analysis identified spectral signatures diverging views of how mangrove australis) in Hamilton City urban and for marine habitats at a 5–8 m resolution expansion may affect the various peri-urban streams to identify areas where for 2,000 km² of Auckland’s east coast, stakeholders’ interests, which have led to biota may be affected and therefore, including the majority of offshore conflicted management initiatives. Recent restoration initiatives constrained. islands. The analysis involved splitting studies on New Zealand mangroves Smaller streams with fully urbanised the bands and running classifications have mainly focused on faunal aspects catchments and greater imperviousness over single habitats. Each classification and are generally lacking basic ecology had generally higher concentrations of was then compiled to generate final and biology of our local mangroves. This Zn, Cu and Pb in the dissolved phase and/ habitat assignments and boundaries. study investigates the allometry, biomass, or sediments. Dissolved Zn and Cu were There is a vast expanse of data collected and litter production and decomposition of concern in a number of stream sites through Council monitoring and research of the New Zealand mangrove, Avicennia with concentrations exceeding water programmes. These datasets have been marina subsp. australasica, conducted at quality guidelines during rain events. collated to present amalgamated data Mangawhai Harbour Estuary. Quantitative Seasonal mean concentrations of Zn layers detailing sediment and intertidal analyses of tree biomass, soil samples, and Pb exceeded sediment guidelines vegetation types in Auckland. These litter production and decomposition in some streams with fully urbanised maps will be useful in the marine spatial are used to estimate carbon pools and catchments, while arsenic concentrations planning process. The identification of fluxes. Preliminary results indicate that in sediments of Hamilton Lake and some marine habitats will allow for calculations root biomass is relatively similar among tributaries of the Kirikiriroa catchment of habitat area, coverage, rarity, biomass replicate cores, and that fine roots are were of concern to aquatic life. Hamilton and productivity on a regional scale, more densely concentrated in the top Lake sediment caused significant which will be a first for some marine 20–40 cm. These data are fundamental mortality to burrowing amphipods habitats in Auckland. for a better understanding and (Paracorophium lucasi) in 10-day toxicity quantification of temperate productivity tests. Peri-urban stream sediments and carbon storage in mangrove- showed elevated concentrations of Zn and dominated estuaries. In addition, they Cd due to agricultural use. Sediment Hg provide basic information for research on concentrations exceeded guidelines in a nutrient, water, and carbon cycling that number of urban and peri-urban streams. are underway as part of the Mangrove Non-physiologically regulated metals Research Group (AUT and UoA). and metalloids in livers of eels reflected sediment concentrations, with elevated Pb, Hg and As in eels from urban sites and elevated Cd in those from peri-urban sites. Although sediment PAH concentrations did not exceed ANZECC guidelines, the PAH metabolite pyrene-1-glucuronide was significantly elevated in the bile of urban eels compared with rural controls.

198 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 MONDAY 19 August, 4:15–5:30pm, The Academy // POSTER ABSTRACTS

Testing the Effects Implications of Gain Assessing Next Generation of Technological Functions in Fisheries Sequencing of Rotifer Modifications to an Inshore Management Communities to Measure Trawl in Hawke’s Bay, New Lake Water Quality Zealand

Oliver Wade You-Gan Wang // University of Nathan Watson // The University Queensland of Waikato Rick Burch Laws Lawson // Te Ohu Kaimoana Na Wang // University of Queensland Jonathan Banks // Cawthron Institute Adele Whyte // Ngati Kahungunu Clare Beet, Gemma Collins, Ian Duggan, Incorporated The fundamental aim in fisheries Steve Woods, Ian Hogg // The University management is to determine an optimal of Waikato Over the past three years we have fishing effort for sustainably harvesting tested three modifications to an inshore from a replenishable resource. The Lake water quality is typically assessed demersal trawl using a catch comparison Northern Prawn Fishery (NPF), one of from physical and chemical variables method. The focus of these trials Australia’s most valuable fisheries in (e.g., dissolved nutrients, water clarity). has been testing the efficacy of the terms of gross production value, has been However these variables can fluctuate modifications in releasing unwanted by- managed under the MEY objective since markedly over short periods and thus catch and discards. These modifications 2006. The recent average catches of tiger accurate measurements of the water utilise varying sizes and orientations of prawn species are about 1,250 tonnes quality require frequent monitoring mesh in different locations within the only while the maximum sustainable which can be problematic if access trawl. All fish caught were identified and catch stated from different studies are to the lake is difficult and/or funding measured and an existing glmmPQL around 3,000–4,700 tonnes. How to make limited. Bioindicator organisms integrate model was used to analyse the catch more efficient use of a fishery for society biological, chemical and physical factors data. Findings indicate that all three rather than fishing operators depends over time producing a measure of water modifications had some impact on the critically on the MEY functions applied. It quality from less frequent monitoring. catch composition. The test shows a may be more appropriate to use a MEY Rotifers are commonly used in the reduction in numbers of fish caught that which is based on the value chain of the rotifer trophic level index (rotifer TLI) depends primarily on the morphology overall fishing sector, to benefit more to assess lake water quality as they of the species. The fish species that was groups rather than the fishing fleet only. are numerous and species rich, and encountered in highest numbers during We illustrate cases where broad MEY is community composition integrates the trials was Gurnard (Chelidonichthys larger than traditional MEY at different environmental conditions over time. kumu), with 42 species encountered all values of price elasticity of demand Identification of rotifers requires specialist together. Gurnard was also the species and multiplier effect. We also evaluated taxonomic knowledge and is time- that saw the largest and most consistent the net profit assuming there were no consuming. Next generation sequencing reductions in numbers of smaller fish buyback scheme (which was undertaken (NGS) enables the characterisation of using the trawl modifications. to achieve traditional MEY) in 2005 and communities from their DNA and we the fishing fleet was kept at 89 vessels are testing the feasibility of using NGS since 2005, and concluded that 40% to characterise rotifer communities. more catch on average (2006–2009) and Before an NGS-based rotifer TLI can be an additional total profit of A$17 million widely implemented, the performance (excluding crew cost) could have been of the NGS platforms under different gained in addition to the many million community structure has to be evaluated. dollars of savings in the buyback scheme. Here, we will present preliminary data on These findings have great implications artificial rotifer communities that range for future management in Australia and from homogenous species abundances elsewhere as there is a grave concern of to communities that are dominated by a overfishing worldwide. single species with low abundances of other species. We will also compare an NGS based rotifer TLI to the traditional morphology based TLI.

AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013 // 19–23 August 2013 // Hamilton 199 POSTER ABSTRACTS // MONDAY 19 August, 4:15–5:30pm, The Academy

Acute Toxicity of MV Rena Nutrition & Reproduction Rapid Assessment of Pollutants of New Zealand Scallops Zooplankton Diversity Using Next Generation Sequencing

Ashley Webby // The University of Ka Lai Clara Wong // Auckland Steve Woods // The University of Waikato University of Technology Waikato

Christopher Battershill, Nicholas Ling // Andrea Alfaro, Barbara Breen // Auckland Jonathan Banks // The University of The University of Waikato University of Technology Waikato, Cawthron Institute Ian Hogg, Ian Duggan, Gemma Collins, The wreck of the container ship MV Rena The New Zealand native scallop, Pecten Clare Beet // The University of Waikato on Astrolabe Reef in the Bay of Plenty novaezelandiae, has undergone extensive in October 2011 discharged 350 tonnes harvesting pressure by commercial and Traditional methods of determining of heavy fuel oil (HFO), large quantities recreational fishing, and has experienced zooplankton community composition of general cargo, and other goods significant population declines. for ecological studies or environmental classified as environmentally hazardous, Scallop growth and recruitment are assessments require time to process in particular sodium hexafluoroaluminate highly variable in time and space. This samples, a high level of expertise in or cryolite. Given the almost total absence variability leads to an unpredictable and identification and may miss rare and/ of toxicity data on New Zealand marine unsustainable fishery. In order to maintain or cryptic species. We are developing species, this project sought to assess the and maximise the potential of the scallop a molecular genetic technique to acute sublethal toxicity of cryolite, HFO, fisheries in New Zealand, culturing speed up and standardize the routine and oil dispersant to a range of culturally scallops under controlled optimal monitoring of zooplankton communities. and commercially important species. conditions may prove to be a successful We are currently testing different gene Exposure to 1:10000 cryolite or 1:10000 practice for re-seeding wild populations. regions (e.g. COI, 28S, 12s) to find a HFO for up to 96 h caused no lethality In addition to which are likely to alleviate suitably short and universal fragment or measurable acute sublethal effects alleviating the current fishing pressures that could identify species using current to sub-adult snapper (Pagrus auratus), on this species, cultivation of this species next generation sequencing platforms. spotted wrasse (Notolabrus celidotus) may result in new aquaculture markets Individual species will be sequenced and or rock lobster (Jasus edwardsii), for New Zealand. Scallops have gained added to the Barcode of Life Datasystems although bile polyaromatic hydrocarbons much attention worldwide because of (BOLD) database for reference. Following (PAH) reached levels several orders their high economic value. However, preliminary evaluation, next-generation of magnitude higher than controls. nutritional requirements vary among sequencing approaches (e.g. Ion Torrent, The dispersant Corexit 9500 did not species, depending on growth rates, 454, Illumina) will be used with DNA apparently increase PAH body burden longevity and maximum size of each extracted directly from environmental when combined with oil. Continuing species. In general, temperature and samples. The focus thus far has been studies will evaluate further conditions nutrition (food quality and quantity) on rotifer taxa. However, this will be of exposure and longer term measures have been found to be important factors extended to cover the cladocerans and of sublethal effects following acute that affect scallop production. The key copepods as well. This approach will exposures, and evaluate effects in other to success in scallop aquaculture will be used to rapidly assess zooplankton fish and shellfish species from rocky and rely on the understanding of feeding, diversity in lakes, as well as to monitor soft shore habitats. growth, development and behaviour in its zooplankton community changes in the natural environment to recreate optimal ecosystem (e.g. Rotifer Trophic Lake growth conditions in land-based culturing Index). operations. Hence, the investigation of environmental and biological parameters that affect scallop nutrition and reproductive condition form an integral part of the rationale for this research. Information gathered from this research can be applied to culturing techniques in laboratory and commercial settings.

200 19–23 August 2013 // Hamilton // AQUATIC SCIENCE AT THE INTERFACE CONFERENCE 2013