Anderson Inlet Fish Habitats 2004

Geoff Nicholson and Leanne Gunthorpe (Editors)

February 2009

Fisheries Assessment Report Series No. 41

Anderson Inlet Fish Habitats 2004

If you would like to receive this Author Contact Details: Geoff Nicholson and Leanne Gunthorpe information/publication in an Fisheries Research Branch, Fisheries Victoria accessible format (such as large PO Box 114, Queenscliff Vic 3225 print or audio) please call the Authorised by the Victorian Government, Customer Service Centre on: 1 Spring Street, Melbourne 136 186, TTY: 1800 122 969, Published by the Department of Primary or email Industries. [email protected] Copies are available from the website: www.dpi.vic.gov.au/fishing © The State of Victoria, Department of Primary Industries, 2009. General disclaimer This publication may be of assistance to you but This publication is copyright. No part may be the State of Victoria and its employees do not reproduced by any process except in accordance guarantee that the publication is without flaw of with the provisions of the Copyright Act 1968. any kind or is wholly appropriate for your Preferred way to cite this publication: particular purposes and therefore disclaims all liability for any error, loss or other consequence Nicholson, G. and Gunthorpe, L. (Eds.) (2009) which may arise from you relying on any Anderson Inlet Fish Habitats 2004. Compiled by information in this publication. the Fish Habitat Assessment Group. Fisheries Victoria Assessment Report Series. Report No. 41. 20pp. (Department of Primary Industries, Queenscliff). ISSN 1329‐7287 ISBN 978‐1‐74217‐387‐0

Anderson Inlet Fish Habitats 2004 ii Table of Contents

Executive Summary...... 1

Introduction...... 3

Goals, Objectives and Strategies for Maintenance of Fish Habitats ...... 4 Strategic Directions ...... 4 Strategic goal ...... 4 Strategic objectives...... 4 Strategic activities ...... 4 Policy and Legislative Context ...... 4

2001 Assessment ...... 6

The 2004 Assessment ...... 7 Aims and Methods ...... 7 Aim, Objectives and Strategies of the Assessment...... 7 Boundaries of Anderson Inlet ...... 7 Definition of a Fish Habitat ...... 7 Methods...... 7 Assessment Methods...... 7

Key Fish Species and Their Habitat Requirements ...... 8 Fish Species in Anderson Inlet ...... 8 Key Fishery Species and Habitat Links...... 8 Estuary perch...... 8 King George whiting...... 9 Important Fisheries Habitat...... 9

2004 Assessment ...... 10 Status of Important Fish Habitat ...... 10 Threats ...... 10 Nutrients ...... 10 Sedimentation...... 11 Physical Disturbances ...... 11 Spartina ...... 11 Northern Pacific Seastar...... 11

Anderson Inlet Fish Habitats 2004 iii Management Implications...... 12

2004 Assessment—Summary...... 13 Status ...... 13 Research Priorities ...... 13

Acknowledgements ...... 14

References ...... 15

Glossary...... 16

Appendix 1—Fish Species ...... 18

List of Tables Table 1. Fish species targeted by recreational fishers within Anderson Inlet...... 8 Table 2. ‘Icon’ species for Anderson Inlet...... 8 Table 3. Habitats used by species in Anderson Inlet...... 9

Anderson Inlet Fish Habitats 2004 iv Executive Summary

The sustainable harvest of any fishery resource is • Phragmites dependent on maintaining the integrity of the • undercut banks/overhangs. habitats, environmental conditions and ecological processes that support the production To determine which of these habitats were of that resource. Fisheries Victoria has crucial to estuary perch in Anderson Inlet, the established a formal Fish Habitat Assessment 2004 HAG posed the following questions: process to provide scientific information on the • What are the factors that link estuary perch identity and status of marine fish habitats. This information is essential for facilitating protection to these habitats? of important fish habitats and thus continued • Which of these habitats drive the production production of fisheries resources. of estuary perch? Anderson Inlet is one of Victoria’s larger The 2004 assessment concluded that there was estuaries and supports a regionally significant insufficient information, either scientific or recreational fishery for both local and visiting anecdotal, to determine the extent to which anglers. estuary perch are dependent on any of the listed The second meeting of the Anderson Inlet Fish habitats for spawning or nursery activities. Similarly, the 2004 Assessment could not identify Habitat Assessment Group (HAG) occurred on 16 September 2004 at Inverloch. which habitats were primarily responsible for driving fish production in Anderson Inlet. Participants in the workshop updated the Sedimentation, altered water flows and the previous assessment. They began by reviewing the list of targeted species compiled in the 2001 spread of the invasive exotic spartina – all Assessment and added 5 species and one family interrelated processes – were identified as the major threats to Anderson Inlet fish habitats and of prey to those identified previously. to fish production more broadly. The 2004 HAG then identified a select group of targeted fish species, which best represented the In relation to these threats the 2004 HAG posed the following questions: recreational fishery in Anderson Inlet and which could be considered the ‘icon’ species for this • How do the threatening processes impact on water body. the factors that link fish to habitat? Two ’icon’ species were identified: • Which, if any, of these processes are • estuary perch significantly decreasing fisheries production in Anderson Inlet? • King George whiting. • Does spartina play a positive role in the The AI HAG then focused on estuary perch as production of estuary perch in Anderson this species is resident within the inlet and Inlet? depends throughout its life history on the quality The 2004 AI HAG concluded the threats may of the estuarine environment. Unlike the other targeted finfish species in Anderson Inlet, King cause: George whiting, estuary perch is more likely to • reductions in habitat for fish species reflect conditions within the estuary as an • ‘obligate’ estuarine resident. decreased availability of food • The known habitat requirements of each life reductions in fish production stage of estuary perch were then identified or • changes to fish communities, which may updated. Building on the broad habitats alter the quality of the recreational fishery in identified in the previous assessment, the 2004 Anderson Inlet. HAG identified a further 3 habitats used by estuary perch within the Inlet, namely: However, the 2004 AI HAG observed that over the past 30 years the habitats within Anderson • channels Inlet had changed markedly, co‐incident with the

Anderson Inlet Fish Habitats 2004 1 spread of spartina. The recreational fishery over • Determine which habitats are crucial for this period also had seen great changes, which sustaining the production of estuary perch in are thought to reflect spartina induced impacts on Anderson Inlet. the processes that govern fish production in this • Identify the factors that link estuary perch to inlet. the crucial habitats in Anderson Inlet. The 2004 HAG identified the following research priorities:

Anderson Inlet Fish Habitats 2004 2 Introduction

A fishery resource is dependent on maintaining • assess the current status of key fish habitats the integrity of the habitats, environmental • determine processes threatening these fish conditions and ecological processes that support habitats production of target fish populations. • make recommendations on fish habitat Management of fisheries includes identification research and monitoring needed to assist in and advocacy of management actions needed to the management of fish habitats. protect and where possible enhance ecosystems that support production of fishery resources. To Recreational fishing is an important activity do this it is necessary to know: undertaken by many people at Anderson Inlet, which is a popular tourist, holiday and • The type, location and extent of habitat and retirement destination. An assessment of the environmental conditions that are important key fish habitats within the inlet was for production and/or survival of key target undertaken to assist in defining research fish species within the system directions and management actions needed to • The links between particular provide sustainable utilisation of fish resources. habitat/environment conditions and This fish habitat assessment report is divided production/survival of stocks of key target into the following sections: species • A summary of the goals, objectives and • The current status and historical trends in strategies in place to maintain fish habitats the condition of key fish habitats; • A summary of the outcomes of the previous • The main threats (whether from fishing or assessment other non‐fishing human activities) to the integrity of each key fish habitat. • Details of the aims and objectives of the Anderson Inlet fish habitat assessment, and In 1995 Fisheries Victoria established a formal an explanation of the methods and processes Fish Habitat Assessment process to provide by which the assessment was conducted scientific information on the location and status of key marine and estuarine fish habitats, as an • Identification of the key fishery target species input to the development or review of fishery in the inlet management arrangements. This process • Update what is known of their habitat involves the participation of stakeholder representatives, scientists and fishery managers requirements in fish habitat assessment workshops, and the • The identification of habitats in the inlet that publication of workshop findings in the support the production of the ‘Icon’ species Fisheries Victoria Assessment Report Series. • Assessment of the likely main threats to the Information and advice provided by these fish well‐being of the identified key fish habitats habitat assessment groups (HAGs) complement • the matters and issues dealt with by formal The possible fisheries management stock assessment and fishery assessment implications of the identified threats to fish processes, and informs the development or habitat review of habitat protection objectives in Fishery • A summary of the assessment of fish habitats Management Plans for specified waters. in Anderson Inlet and the prioritising of The objectives of the Fish Habitat Assessment research/monitoring projects required to Process are to: improve future assessments of fish habitats in the inlet. • identify fish habitats in Victorian waters that are important in supporting production of key fishery target species

Anderson Inlet Fish Habitats 2004 3 Goals, Objectives and Strategies for Maintenance of Fish Habitats

Strategic Directions There is increasing evidence worldwide that the • Review legislative and policy frameworks to sustainable use of any fishery resource is support fish habitat protection. dependent not only on controlling the direct Fisheries Victoria is currently reviewing its impacts of fishing on fish stocks, but also on position in relation to the ʹhabitat advocacyʹ maintaining the integrity of the aquatic habitats, debate and fish habitat management. environmental conditions and ecological processes that are crucial for the production and/or survival of target fish species. This is Policy and Legislative Context particularly so in inshore marine, estuarine and The Victorian Government and the Department inland waters that are facing increasing pressures of Primary Industries are committed to applying from human population growth and associated the principles of Ecologically Sustainable agricultural, industrial, urban and tourism Development (ESD) to fisheries management. development. These principles are: Strategic directions on fish habitat assessment • To provide for equity within and between provided in the “Fisheries Strategy Towards generations in the use of natural resources 2000” (Fisheries Victoria 1997) are relevant to the • To enhance individual and community well‐ deliberations of Habitat Assessment Groups as being by following a path of economic follows: development that provides optimum current Strategic goal benefits while safeguarding the resource use • To secure the future of Victorian fisheries by options of future generations advocating the protection and maintenance of • To protect biological diversity and maintain essential fish habitats. ecological processes and systems Strategic objectives • To adopt a precautionary principle, so that • Identify critical fish habitats and threatening where there are threats of serious or processes in conjunction with stakeholders. irreversible adverse effects on resources or habitat, lack of full scientific certainty should • Lead and facilitate the development of not be used as a reason for postponing management arrangements that maintain or measures to prevent resource depletion or enhance the productive capacity of key fish environmental degradation. habitats. The Fisheries Act 1995 recognises these principles Strategic activities by including the following stated objectives: • Commission focused habitat assessment, monitoring and research programs. • To protect and conserve fisheries resources, habitats and ecosystems including the • Establish partnership arrangements to maintenance of quality ecological processes influence the management of non‐fishery and genetic diversity threats to key fish habitats. • To provide for the management, • Develop and implement fish habitat development, and use of Victoria’s fisheries, restoration programs in priority waters. aquaculture industries and associated • Establish a community based fish habitat biological resources in an efficient, effective protection focus across Victoria. and ecologically sustainable manner. • Identify funding opportunities for fish habitat The Fisheries Act 1995 also specifies that a Fishery improvement and cooperate with other Management Plan declared for a given fishery agencies in accessing these funds. must identify critical components of the ecosystem relevant to the fishery, current or

Anderson Inlet Fish Habitats 2004 4 potential threats to those components, and existing or proposed measures to protect or maintain key fish habitats.

Anderson Inlet Fish Habitats 2004 5 2001 Assessment

The 2001 Fish Habitat Assessment for Anderson Anderson Inlet. However, aside from the Inlet described its fisheries, management expansion of the invasive pest plant species agencies and key stakeholders (Nicholson & Spartina, these changes could not be Gunthorpe 2005). substantiated scientifically. Thirty‐three species or families of fish were The impact of the expansion of spartina in identified as components of the recreational Anderson Inlet on fish habitat and on the fisheries of Anderson Inlet. That assessment also production of key fisheries resources was not identified 11 species or families of fish, known, but it was likely to be negative. including major prey species that were targeted Spartina was considered to be a major threat, by recreational fishers. with the potential to physically exclude fish The habitat affinities of each life stage of each from a significant portion of the inlet, and to targeted species were identified from a change ecological processes that support combination of scientific knowledge and from production and/or survival of key fisheries the experience and knowledge of HAG species. participants. The HAG identified four research areas and one The 2001 AI HAG noted that: monitoring program, as high priorities. These were to: • The pelagic (water), seagrass, and unvegetated sediment habitats were used • Obtain an ecological ʹsnapshotʹ illustrating directly by most of the targeted species at the habitat associations of key target fish various stages in their life cycles species, ecological processes maintaining inlet health, and the biological processes that • Several species also used the snags and link fish to each habitat. riparian vegetation (such as mangroves) as foraging grounds and/or spawning sites • Undertake an integrated nutrient‐based study, which determines: • Low profile reef was also thought to be important to some species. 1. Nutrient levels within the water column of Anderson Inlet Likely major threats to the maintenance of these habitats were identified as: 2. Nutrient loads within the in‐flowing streams and drains • Increases in sediment deposition rates, particularly from catchment erosion 3. Nutrient re‐cycling within the sediments of Anderson Inlet during periods of high • Decreasing water quality associated with flow and low flow particularly in sediment and nutrient inputs relations to the . • Introduction and spread of pest species, • Quantify the rate of sedimentation occurring particularly the cord grass spartina in Anderson Inlet and identify major • Physical disturbances from recreational contributing sediment loads. boating and foreshore development • Undertake regular monitoring of seagrass • Unknown factors affecting seagrass coverage to determine natural dynamics and distribution and density. impacts on fish production. Anecdotal evidence suggested major degradation of fish habitats had occurred within

Anderson Inlet Fish Habitats 2004 6 The 2004 Assessment

Aims and Methods Aim, Objectives and Strategies of the Smythe and Pt. Norman. For the purposes of this Assessment assessment the seaward extent of the Port Aim boundary was accepted as the seaward extent of To update data on the status of Anderson Inlet the Inlet. This area includes all waters of Anderson Inlet bounded by the high water mark. habitats upon which fisheries resources are dependent; identify management actions and The upstream boundaries of the assessment area recommend future directions for habitat are the limits of tidal salt‐water intrusion. research. Definition of a Fish Habitat Objectives A habitat is defined as the broad physical • Identify habitats important to estuary perch structures, zones and biological communities that in Anderson Inlet. support fish. The emphasis of this report is on those habitats which support fish targeted by • Provide up‐to‐date summaries of research recreational fishers and key prey species. and monitoring programs. Particular attention was given to estuary perch as • Assess the current state of fish habitats. the most estuarine‐dependent of the ‘icon’ • Identify processes, which pose major threats species. to estuary perch habitats. Methods • Provide a qualitative risk assessment of the Data main threats to estuary perch habitats. A literature search was undertaken to provide information on Anderson Inlet and the habitats • Identify management issues for critical contained therein published since the last estuary perch habitats. workshop was held in 2001. • Identify research and monitoring needs to Information was also obtained from published assist in the management of each habitat. papers and reports, and unpublished data and Strategies reports held by various State Government • Characterise the important habitats for each research agencies and Statutory authorities. of the fisheries resources of Anderson Inlet, beginning with estuary perch. Assessment Methods The workshop began by updating the previous • Establish archival databases of all relevant assessment, incorporating scientific data, research and monitoring material for each anecdotal information and management actions, important estuary perch habitat in Anderson which provided information on the current status Inlet. of fish habitats within the inlet. • Synthesise available data, identify the major An assessment of the status of each habitat was threats to each critical habitat and provide undertaken. The main threats to each habitat options to reduce these threats in Anderson were then identified and their implications for Inlet. fisheries management detailed. Finally the future research and monitoring needs for each Boundaries of Anderson Inlet habitat were identified. Anderson Inlet was declared a shipping port in 1913. The current seaward boundary of the Port of Anderson Inlet is a straight line between Pt.

Anderson Inlet Fish Habitats 2004 7 Key Fish Species and Their Habitat Requirements

Fish Species in Anderson Inlet The 2004 HAG reviewed the list of targeted These ‘icon’ species included both resident and species compiled by 2001 Assessment and added migrant species. Resident species such as estuary 5 species and one family of prey to those perch are reliant on fish habitats within the Inlet identified previously (Table 1). Sandworms were and its tributary rivers and creeks all of their life. identified as an important component of the Migrant species, exemplified by King George Anderson Inlet recreational fishery in the 2004 whiting, utilise both coastal and inlet habitats at Assessment (Appendix 1). different times in their life cycles.

Table 1. Fish species targeted by recreational Key Fishery Species and Habitat fishers within Anderson Inlet. Links Common Habitat The habitat requirements of each life stage of the Species Name 2001 Assessment ‘icon’ species were identified. Acanthopagrus butcherii black bream m, e This information: Platycephalus spp flathead spp m, e Aldrichetta fosteri yellow‐eye m, e (mig) • was based on the literature where it is mullet Sillaginodes punctata King George m, e (mig) referenced and for Anderson Inlet whiting specifically, when unreferenced, from the Pseudocaranx spp silver trevally m, e (mig) experience and knowledge of HAG Arripis trutta Australian m, e (mig) salmon participants, and, Ammotretis and/or flounder m, e • supplements that presented in the 2001 Rhombosolea spp. Mustelus antarcticus gummy shark m, e (mig) Assessment (Nicholson & Gunthorpe 2005). Macquaria colonorum estuary perch e, f Leptomithrax gaimardii (?) large orange m, e Estuary perch crab Research in noted that estuary FAMILY Bass yabbies m, e CALLIANASSIDAE perch were found along the mangrove fringes 2004 Assessment and were abundant over stone platforms Callorhynchus milii elephant fish m, e (mig) between mangrove clumps. Bank overhangs are Sphyraena novaehollandiae sea pike m, e (mig) also thought to be important habitat for larger Hyporhamphus regularis river garfish e Hyporhamphus melanochir sea garfish m, e estuary perch. Anguilla spp eel e, f, m FAMILY NEREIDAE sandworms m, e Snags have traditionally been thought to be an ‘m’ indicates marine, ‘e’ indicates estuarine, ‘f’ indicates important habitat for the production of estuary freshwater and ‘mig’ indicates migratory. ‘Bold ’indicates perch. However this association may not be as targeted species identified by the 2004 HAG. important as previously thought and may be a consequence of their preference for overhangs, The 2004 HAG then identified a select group of which are consistently being eroded. Mangroves targeted fish species, which best represented the or other woody shrubs growing on the edging recreational fishery in Anderson Inlet and could banks topple into the water as the supporting be considered the ‘icon’ species for this water ground is eroded away and form snags. body (Table 2). Estuary perch are found in all creeks entering Table 2. ‘Icon’ species for Anderson Inlet. Anderson Inlet and are probably more widely Species Common Name spread throughout the inlet and its tributaries Macquaria colonorum estuary perch than previously thought. Smaller ones can be Sillaginodes punctata King George whiting seen in the Tarwin River, extending from the mouth upstream for about 8 or 9 km to where Fish Creek enters the Tarwin. Estuary perch have

Anderson Inlet Fish Habitats 2004 8 been sighted up to 12 km upstream from the depends throughout it’s life history on the Inlet. quality of the estuarine environment. Unlike the other targeted finfish species in Anderson Inlet, Most recreational fishing effort occurs only up to King George whiting, estuary perch is more the Fish Creek drain as the Tarwin River likely to reflect conditions within the estuary as becomes difficult to navigate further upstream. an ‘obligate’ estuarine resident. Larger fish can also be seen in this region, although not as many are seen during February Building on the broad habitats identified in the to April as other times of the year. Smaller fish previous assessment, the 2004 HAG identified a can be seen all year. A lot of estuary perch can be further 3 habitats used by estuary perch within seen in the river during winter as they hunt the Inlet (Table 3). elvers migrating upstream. To determine which of the habitats listed in Table Estuary perch can be found at the edges of 3 are crucial to estuary perch in Anderson Inlet, subtidal seagrass meadows but have not been the 2004 HAG posed the following questions: observed on intertidal sandbanks. It is thought • What are the factors that link estuary perch that they avoid being among or near spartina, to these habitats? e.g. are all mangroves though it is unclear whether the perch are equally important? avoiding intertidal banks or the spartina. • Which of these habitats drive the production Smaller estuary perch juveniles (up to 5 cm) stay of estuary perch? around the phragmites reeds and rock‐stabilising walls bordering the lower Tarwin River. Larger Food chains fuelled by detrital matter generated juveniles may be found among the fringing by the breakdown of seagrass have been found to mangroves of the inlet. be fundamental to fish production in Western Port (Longmore et al. 2002) and in the King George whiting Lakes (Longmore et al. 2005 unpublished data). King George whiting can be found throughout the inlet, although preferred regions appear to be Given the limited extent of seagrass within from Mahers Landing to the mouth of the Anderson Inlet – only 2% of the total inlet area – Tarwin, and around the entrance of the inlet. it was thought unlikely that seagrass habitat drives fish production. Seagrass is probably the more important habitat for the younger stages. Historically, it is likely It is not known which habitats are primarily that there was substantially more seagrass responsible for sustaining fish production in habitat within Anderson Inlet than is present Anderson Inlet. now. It is uncertain what other habitats are The 2004 assessment also concluded that there important to King George whiting within the was insufficient information, either scientific or Inlet. It is thought probable that King George anecdotal, to determine the extent to which whiting are not as prevalent today as they were estuary perch are dependent on any of the listed the past. habitats for spawning or nursery activities. Important Fisheries Habitat The AI HAG then focused on estuary perch as this species is resident within the inlet and Table 3. Habitats used by species in Anderson Inlet. 2001 Assessment 2004 Assessment pelagic (water) channels seagrass Phragmites unvegetated soft bottom Undercut banks/overhangs snags (generally eroded tea‐trees in deep holes) rocky reefs mangroves.

Anderson Inlet Fish Habitats 2004 9 2004 Assessment

Status of Important Fish Habitat Since 2001, to the knowledge of the AI HAG • Decreasing water quality associated with participants, no scientific studies have been sediment and nutrient inputs undertaken in Anderson Inlet to determine the • Introduction and spread of pest species, current status of its fish habitats. particularly the cord grass spartina Threats • Physical disturbances from recreational In 2004 the consultative process for the boating and foreshore development establishment of the Anderson Inlet Fishery • Unknown factors affecting seagrass Reserve Fisheries Management Plan identified distribution and density. the following habitat issues within Anderson Inlet (DPI 2006). The 2004 AI HAG updated the current status of the threats identified by the 2001 assessment. • Catchment land use and activities, including This information: regional river health strategies and their relevance to Anderson Inlet, consequences • is based on the literature where it is of removing or extending levee banks referenced and for Anderson Inlet around Anderson Inlet, riverine specifically, when unreferenced, from the contaminant and sediment loads into the experience and knowledge of HAG inlet, rural sewering and silting of channels participants, and, around Mangrove Island near the top of the • augments that presented in the 2001 inlet. Assessment (Nicholson & Gunthorpe, 2005). • Potential impacts of recreational fishing on Nutrients the habitat were propeller and hull scouring Long‐term nutrient trends are not available for of seagrass beds and mud flats, and the Inlet but Waterwatch data is available from disturbance from high powered fishing fixed sites along the length of the Tarwin River. boats in shallow waters which may scare The fixed sites have been established since fish away. around 1992. The closest Waterwatch fixed site • The wake from water‐ski boats is causing to the estuary is at Tarwin Lower. bank erosion in the Tarwin River. It is likely that tidal flushing assists with • There is a claim that jet skis around nutrient dispersal within the Inlet, but not in the mangrove areas and the mouths of creeks tributary creeks and rivers. While fish deaths perturb ‘fish breeding’ areas. through environmental stress have not been observed within Anderson Inlet, they have been • Re‐snagging activities in the Tarwin River seen in the Tarwin River. and Screw Creek were suggested as a means to improve estuary perch and black bream Both Screw Creek and Pound Creek have habitats. excessive growths of algae. These algal communities are believed to be sustained by • Fishing access at the banks of the Tarwin enhanced levels of dissolved nutrients River is causing bank erosion. originating from overland runoff. • It is claimed that Pt. Smythe is eroding, The 2004 Assessment reiterated the belief that resulting in increased sand movement into the Tarwin River catchment is the predominant the inlet and likely smothering of seagrass. source of terrestrial water and nutrient loads These are broadly consistent with the likely entering the Inlet. major threats identified in the 2001 Assessment The relevant agencies (Gippsland Coastal Board (Nicholson & Gunthorpe 2005) listed below: and West Gippsland Catchment Management • Increases in sediment deposition rates, Authority) acknowledge the issues that arise particularly from catchment erosion from nutrient stress and have tried to address

Anderson Inlet Fish Habitats 2004 10 them through actions such as the development • Boat screw scour among seagrass and of Regional Catchment Strategies. benthic vegetation. Sedimentation The number of boats accessing the upper end of One of the greatest threats to Anderson Inlet’s the Inlet has increased due to enhanced buoy fish habitats is considered to be the sediment marking of the channels. loads entering from the tributary rivers and Applications may be made to relevant streams and particularly the Tarwin River. The authorities to limit activities that can affect bank participants at the 2004 HAG considered the erosion. Tarwin to be more turbid (i.e having greater sediment loads) over the preceeding 10 months Spartina than they had observed previously. Around 300 ha of Inlet edge banks are infested with spartina and it is reported that the Spartina Sediment inputs to the Tarwin and to the Inlet coverage is increasing. arise from: Within the Inlet, spartina extends from Screw • Historical activities – through river Creek (westernmost position on the northern straightening works shore of the Inlet) through to and up the Tarwin • Continuous erosion events resulting from River. Spartina occurs along the southern shore catchment activities, such as cattle crossing of the Inlet from the Tarwin to around the Tarwin and riverbank access Townsend Bluff (westernmost position on the southern shore). Spartina appears to have • Flood events. recolonised areas that had previously been Catchment land‐use activities, including pea cleared by the application of herbicides. farming, potato farming, dairy farming and Spartina also appears to have isolated patches of forestry, are thought to encourage overland mangrove from fish, although it also appears to flow/transport of topsoil into creeks and encourage the growth of very young streams. The top end of the Inlet around the mangroves. Mangroves may in some instances Tarwin River mouth is heavily silted. The replace it once the sediment has consolidated. presence of spartina further traps silt and enhances silt build‐up, exacerbating the problem A lot of what were historically clean sand banks of channels narrowing and shallowing. This have been invaded by spartina, which has appears to be particularly bad around the top of subsequently trapped fine sediment. the Inlet. It is thought likely that some hybridisation of Overland sediment runoff into streams and spartina is occurring within the Inlet. rivers is being addressed through Regional Catchment and River Health Strategies under Northern Pacific Seastar the guidance of the West Gippsland Catchment During late 2003, Northern Pacific seastars were Management Authority. The Regional found on rock exposed at low tide just outside Catchment and River Health strategies have the entrance to Anderson Inlet. targets and objectives of reducing sediment and Later seastars were found within the Inlet, nutrient loads. The strategies are limited in that between Ayre Creek and Smythe. Volunteer they address diffuse source issues and are divers, organised by the Department of unable to address flood event sedimentation Sustainability and Environment, removed some issues. 300 seastars. Physical Disturbances Exploratory diving was also done further up the A number of physical disturbances were Inlet and outside the Inlet in the marine park, suggested to have detrimental effects on fish but no seastars were found in these regions. habitats within the inlet. These were: • Bank erosion from wakes generated by speedboats and ski‐boats and the practice of wake‐boarding, particularly around the lower Tarwin • Bank erosion from shore based fishing around the lower Tarwin and Point Smythe

Anderson Inlet Fish Habitats 2004 11 The 2004 AI HAG was therefore only able to re‐ Management Implications iterate the basic concepts identified by the 2001 In relation to the threats described above and in Assessment. the 2001 Assessment, the 2004 HAG posed the The threats may cause: following questions: • Reductions in habitat for fish species • How do the threatening processes impact on the factors that link fish to habitat? • Decreased availability of food • Which, if any, of these processes are • Reductions in fish production significantly decreasing fisheries production • Changes to fish communities, which may in Anderson Inlet? alter the quality of the recreational fishery in • Does spartina play a positive role in the Anderson Inlet. production of the ‘icon’ fish in Anderson The management implication is that these Inlet? threats have the potential to decrease the In the absence of any new information on productivity and quality of Anderson Inlet’s changes to the aquatic habitats and environment recreational fishery. in Anderson Inlet, it was not possible for the 2004 AI HAG to assess the extent to which the threatening processes are affecting the production of the ‘icon’ fish species.

Anderson Inlet Fish Habitats 2004 12 2004 Assessment—Summary

Status The observations of the 2004 AI HAG were in • Which, if any, of these processes are part based on known catchment activities and significantly decreasing the production of assumptions made generically about the type of estuary perch in Anderson Inlet impacts these activities are known to have in • Does spartina play a positive role in the other locations supported by the observations of production of estuary perch in Anderson habitat condition made by the participating Inlet? members of the HAG. The threats may cause: The 2004 AI HAG broadly confirmed the 2001 assessment findings. • Reductions in habitat for fish species Building upon the 2001 assessment, the 2004 AI • Decreased availability of food HAG focused on identifying the factors • responsible for driving fish production in Reductions in fish production Anderson Inlet, particularly in relation to • Changes to fish communities, which may estuary perch. alter the quality of the recreational fishery in To do this the 2004 HAG posed the following Anderson Inlet. questions: The 2004 AI HAG observed that over the past 30 • What are the factors that link estuary perch years the habitats within Anderson Inlet have to these habitats? changed markedly, co‐incident with the spread of spartina. The recreational fishery over this • Which of these habitats drive the production period also has seen great changes, which are of estuary perch? thought to reflect spartina induced impacts on the processes that govern fish production in this The 2004 AI HAG was unable to answer these inlet. questions. The 2004 AI HAG identified spartina, Research Priorities sedimentation and altered water flows—all The 2004 AI HAG identified the following interrelated processes—as the major threats to research priorities: Anderson Inlet fish habitats and to fish production more broadly. • Determine which habitats are crucial for sustaining the production of estuary perch The 2004 AI HAG tried to assess the degree to in Anderson Inlet. which these processes would impact fish production in Anderson Inlet by posing the • Identify the factors that link estuary perch to following questions: the crucial habitats in Anderson Inlet. • How do the threatening processes impact on the factors that link estuary perch to habitats

Anderson Inlet Fish Habitats 2004 13 Acknowledgements

This report was prepared by the Fish Habitat Brett Millington (CEO Gippsland Coastal Board) Assessment Group from discussions and a Mal Gibson (West Gippsland Catchment compilation of contributions by members of the Management Authority) group. Participants at the Anderson Inlet fish habitat assessment workshop held on 16 Brian Martin (Parks Victoria) September 2004 at Inverloch are listed as follows: Ron Elton (Eel Fisher) Dick Brumley (Fisheries Victoria) Sharon Elton (Eel Fisher) Jeremy Hindell (Primary Industries Research Victoria, PIRVic) Noel Maud (Gippsland Coastal Board) Geoff Nicholson (Primary Industries Research James Andrews (Fisheries Victoria) Victoria, PIRVic) Lance Lloyd (Fisheries Co‐management Council) Murray MacDonald (Fisheries Victoria) Jodie Smith (Fisheries Victoria) Corrie Banks (Fisheries Co‐management Council)

Anderson Inlet 14 References

Department of Primary Industries (2006) Longmore A.R. and Nicholson, G.J. (2005) Anderson Inlet Fisheries Reserve Relative importance of different Management Plan – 2006. Fisheries habitats as food sources for commercial Victoria Management Report Series No. fish in the Gippsland Lakes 28 Unpublished. Longmore A.R., Nicholson, G.J. and Abbott, B. Nicholson, G. and Gunthorpe, L. (2005) (2002) Identifying habitats important to Anderson Inlet Fish Habitats 2001. the food supply of commercial fish in Compiled by the Fish Habitat Western Port. Marine and Freshwater Assessment Group. Fisheries Victoria Resources Institute Internal Report No. Assessment Report No. 42. (Fisheries 36. Queenscliff Victoria Victoria: East Melbourne).

Anderson Inlet 15 Glossary

Algae: A large group of non vascular plants, Ecologically sustainable development: The many are microscopic, and live in water. management of resources to meet the needs of the present generation without Anoxic: Devoid of oxygen. compromising the ability of future Anthropogenic: Changes resulting from human generations to meet their own needs. activities. Ecosystem: The physical, chemical and biological Aquaculture: Farming of plants or animals in environment of a community of organisms, water. and all the interactions among those organisms and between organisms and their Benthic: Belonging to the sea floor. environment. Benthos: Organisms living on or in association Effluent: An outflow usually wastewater (eg with the sea floor. sewage). Bioaccumulation: The concentration of Epiphyte: A plant growing on top of another substances (especially toxicants) in the surface (eg crab shell, pier pylon, seagrass). tissues of plants and animals. Estuary: That area within the mouth of a river Biota: All living organisms in a region. which is influenced by the sea. Bivalve: a type of mollusc possessing two shell Eutrophication: An increase in the nutrient valves joined by a hinge (eg scallops and status of a water body, and consequently the mussels). rapid growth of plants, both natural and as a Bloom: Microalgae occurring in dense numbers result of human activity. Excessive plant in a water body. production may deplete oxygen and suffocate animals. Catchment: The area of land from which run‐off from rain enters a waterway. Exotic species: Any species that is not of natural origin to a location. Chronic: Over a long period of time. Opposite of acute. Fauna: All kinds of animals. Community: In the biological sense, a Filter feeder: An animal that obtains food by community is a group of plants and animals filtering particles from water. that live together in a particular habitat. Fish: (a) live, fresh, imported or processed Often they are critically dependent on each aquatic invertebrates with gills including other, with a loss of one species leading to crustaceans, molluscs and all other forms of an impact on others. aquatic life other than reptiles, amphibians Contaminant: A substance out of place (also and mammals. pollutants). (b) Fish products or any part of the fish. Crustacean: Animals living in water which have Fishery: The taking of fish described by reference a hard outer surface and jointed limbs and to the species taken, the gear used and the belong to the class crusteacea. purpose of the Fishery. Demersal: Used for fish that live on or near the Fishery resources: The stock or stocks which sea floor. support the fishery. Detritus: Non‐living organic matter (eg dead Flora: All kinds of plants. seagrass). Food chain: The sequence of consumption of Ecology: The study of living of organisms and plants by animals and those animals by their relationships to one another and the other animals. environment. Food web: A complex of food chains.

Anderson Inlet 16 Groundwater: The part of rainfall which seeps Salinity: The salt content of the seawater. into the ground and moves slowly in a Seafood: The edible marine organisms. horizontal direction. Seagrass: A group of flowering vascular plants Habitat: The place where a plant or animal lives. which live in seawater. They take root in the Heavy metals: A general term for cadmium, sea floor. copper, iron, mercury, nickel, manganese, Sediment: The solid material that sinks to the lead, zinc, arsenic and selenium. substrate. Hydrocarbons: Compounds of hydrogen and Sewage: Loosely applied to any waste sent to a carbon such as petroleum. treatment plant. Ichthyoplankton: Fish eggs and larvae which Stakeholder: An individual or organisation float in water. interested in and able to influence the Infauna: Animals living within the sediment on management of (in this instance) Western the sea bed. Port and its fisheries. Inputs: Substances entering a water body. Stormwater: Run‐off during storms. Invertebrate: Animals without a backbone. Substrate: A surface on which organisms live or into which they burrow. Larvae/Larval Fish: Early stage(s) of the life‐cycle of fish. Often fish drift in the upper layers of Sustainability: A characteristic of a process or a the water column with varying degrees of state that can be maintained indefinitely. swimming ability. Sustainable development: Improving the Macrophyte: A seaweed. capacity to convert a constant level of physical resource use to the increased Microalgae: Single celled plants. satisfaction of human needs. Mollusc: An invertebrate animal with a shell (eg Sustainable growth: A term applied only to mussel) and belonging to the phylum renewable resources. It means using them Mollusca. at rates within their capacity for renewal. Nutrients: Substances required for plant growth Suspended matter: Particles suspended in water. (eg fertilisers). Toxic: Poisonous. Organism: A living entity. Toxicant: A poison. Organochlorines: Complex organic molecules with chlorine atoms attached (eg pesticides). Trophic: Related to food chains and food webs. Pelagic: The water column. Turbidity: Cloudiness caused by sediments suspended in water. Phytoplankton: Microalgae that live in the water column. Wastewater: Water that has been used and discarded. Plankton: Aquatic, free‐drifting suspended organisms, generally but not always Zooplankton: Small animals which live in the microscopic. water column. Pollutant: A substance in excess or not belonging. Glossary compiled from definitions Producer: An organism that can create living contained in matter out of inorganic or inanimate matter. Bay Environmental Study : Final Productivity: The magnitude of a producer’s Report (Harris et al, 1996). activity. Port Phillip Bay Fisheries Management Plan: Recreational use: The harvesting of fish or any Background Paper (Fisheries Victoria, 1996). other aquatic resource for personnel use.

Anderson Inlet 17 Appendix 1—Fish Species

Fish and bait species captured by recreational fishers within Anderson Inlet Species name Common Name Comments 2001 Assessment Thyrsites atun (Euphrasen 1791) Barracouta or snoek rare Acanthopagrus butcheri (Munro 1949) Bream black Cyprinus carpio (Linneaus) Carp European Introduced, considered a pest species Anguilla spp Eel Callorhinchus milii (Bory de Saint‐Vincent 1823) Elephant fish Platycephalus bassensis Cuvier 1829 Flathead sand common Platycephalus fuscus Cuvier 1829 Flathead dusky Family PLEURONECTIDAE; Family Flounder or sole occasional BOTHIDAE; Family SOLEIDAE Hyporhamphus spp Garfish Mustelus antarcticus Günther, 1870 Gummy shark migratory Arripis georgianus Valenciennes 1831 Herring Australian or tommy common ruff or tommy rough Family MONACANTHIDAE Leatherjackets by‐catch Girella tricuspidata (Quoy & Gaimard 1824) Luderick minor Aldrichetta forsteri (Valenciennes 1836) Mullet yellow eye Argyrosomus hololepidotus (Lacépède 1802) Mulloway rare Macquaria colonorum (Günther 1863) Perch estuary in season Dinolestes lewini (Griffith 1834) Pike long‐finned rare Sphyraena novaehollandiae (Günther 1860) Pike short finned or snook rare Sardinops neopilchardus (Steindachner 1879) Pilchard bait SERRANIDAE Family Rock cod Arripis spp Salmon Australian RAJIIDAE Family Skate by‐catch Chrysophrys auratus (Schneider 1801) Snapper mainly pinkies as by‐ catch Notorynchus cepedianus (Péron 1807) Sevengill/broadnose incidental sevengill/Tasmanian tiger shark DASYATIDIDAE Family Stingray by‐catch Haletta semifasciata (Valenciennes, 1840) Stranger, blue rock whiting, rare blue‐arsed whiting Pomatomus saltator (Linnaeus 1766) Tailor rare TETRAODONTIDAE Family Toadfish by‐catch Pseudocaranx dentex (Bloch & Schneider 1801) Trevally silver Sillaginodes punctata (Cuvier 1829) Whiting King George

Family GRAPSIDAE Crab black minority/bait Ovalipes australiensis Stephenson & Rees 1968 Crab sand minority/by‐catch Family PENAEIDAE Prawn occasional visitor Leptomithrax gaimardii Milne Edwards 1834 Spider crab, big orange crab by‐catch Family CALLIANASSIDAE Yabby bass Collected for bait 2004 Assessment FAMILY NEREIDAE sandworms bait

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