ABSTRACTS in Alphabetical Order by Presenting Author

ABSTRACTS in alphabetical order by presenting author

6-9 July 2004

Index of Authors and Abstracts (in alphabetical order by presenter)

Allen, Simon Commercial platforms for marine science – Why re-invent the wheel? 13

Allen, Tim Finding a voice for Nemo – Opportunities for AMSA engagement in marine policy and public awareness 13

Ambo Rappe, Rohani & Maria J Schreider Possible consequences of fragmentation of seagrass bed on mobile epifauna 14

Anantharaman, Mohan Oil pollution regulations and oily water separator design to meet these requirements 14

Arendt, Michael D Data…Not just another bad, four-letter word when you have the right tools to manage it! 15

Awruch, CA, S Frusher & J Stevens Conventional and acoustic tagging studies on the draughtboard shark (Cephaloscyllium laticeps) in a scientiﬁc reserve in Tasmania 15

Baird, ME, PG Timko, JH Middleton & IM Suthers Biological response to wind forcing in the EAC 16

Bani, Ali, Natalie Moltschaniwskyj & Alan Jordan (Poster) Necessity of temporal and spatial management in recreational ﬁsheries, sand ﬂathead case 16

Bannister, Raymond, Christopher Battershill & Rocky de Nys Feeding biology of the tropical sponge Coscinoderma sp. on the Great Barrier Reef (GBR) 17

Barnes, Julia, Rhys Hauler & Chris Carter The effect of differing dietary protein:energy ratios on feed intake and growth of Atlantic salmon (Salmo Salar) at elevated temperature 17

Barnes, Peter Examination of processes affecting the distribution of the sponge, Suberites sp. in NSW coastal lakes 18

Bax, Nic & Piers Dunstan Evaluating management strategies for the Northern Paciﬁc seastar in Australia: A progress report 19

Beaumont, Karin Planktonic interactions and particulate ﬂux 19

Beckley, Lynnath E & Claire B Smallwood Marine reserve or marine caravan park? Assessment of recreational boating at Rottnest Island 20

Berly, Thomas Marine Sciences: Strong collaboration between France and Australia 20

Bidigare, Robert R (Keynote Address) Inﬂuence of Mesoscale eddies on plankton biomass, primary productivity and carbon export 21

Bird, James, Craig Steinberg & Tom Hardy Modelling sub-reef thermodynamics to predict coral bleaching: a case study at Scott Reef, WA 22

Blackweir, Dermot G & Lynnath E Beckley Beach usage and aerial surveillance for sharks in Perth metropolitan waters 22

Boxshall, Anthony Integrating science and management in Victorian Marine Protected Areas 23

Buchan, Steve High frequency near-seabed currents 23

Burdon, Jennifer Keeping buoyant in the Sea of Science: Making education a PFD 24

Butler, Alan (Poster) CSIRO Marine Research in Torres Strait 24 Index of Authors and Abstracts

Byrne, Maria (Keynote Address) Life history evolution in sea stars – insights into speciation in the sea 25

Chatwin, PG, IM Leggett & SL Hughes Observations of the slope current and shelf edge processes West of Shetland 25

Clark, Graeme & Emma Johnston Manipulating larval supply in the ﬁeld: a controlled study of marine invasibility 26

Coleman, Andrew Regional Marine Planning – the Economic Components 26

Coman, Frank E, Rod M Connolly & Nigel Preston Food sources of Acetes sibogae in prawn ponds in southeast Queensland 27

Condie, Scott & John Andrewartha Modelling the circulation on Australia’s North West Shelf: Global to coastal scales 27

Condie, Scott, Jason Waring , Jim Mansbridge & Madeleine Cahill Characterising marine connectivity patterns around Australia 28

Craig, Peter Internal wave relection – the career of Peter H 28

Crean, Angela, Steve Swearer & Heather Patterson Is larval supply a good predictor of recruitment in reef ﬁsh populations? 29

Cresswell GR, DA Grifﬁn & C Rathbone The Leeuwin Current, eddies, and subantarctic waters off southwestern Australia 29

Cresswell, G, P Tildesley, P Holloway, S Buchan & C Simpson4 Preliminary interpretation of RADARSAT scenes off NW Australia 30

Dagorn, Laurent Acoustic telemetry on tropical pelagic ﬁsh around FADs: The experience of IRD and collaborating partners 30

Dagorn, Laurent, Kim Holland, David Itano Residence time and movements of yellowﬁn and bigeye tuna in a network of FADs 31

Dambacher, Jeffrey, Klaas Hartmann & Alistair Hobday By your food and your enemies: Simplifying food webs using social network theory 31

Daniell, James¹, Michael Hughes², Peter Harris¹, Andrew Heap¹, Mark Hemer¹ Repeat seabed surveys in Torres Strait – mapping rates of sandwave migration and implications for the marine environment 32

Day, Robert, David Bardos, Cameron Dixon, Sylvain Huchette4 & Luke McAvaney Density dependence in abalone: how local populations respond to ﬁshing 32

Deagle, BE, DJ Tollit, SN Jarman, MA Hindell & NJ Gales Studying diet using genetic identiﬁcation methods: Analysis of prey DNA in scats from captive Steller’s sea lion 33

Dell, James & Alistair Hobday Long-term changes in the school composition of a declining tuna species 33

Douglas, J (Poster) Acoustic telemetry in Victorian fresh and estuarine waters-Overview of some current research 34

Dudgeon, Christine & Janet Lanyon (Poster) The ecology of the leopard shark Stegostoma fasciatum in southeast Queensland 34

Edyvane, Karen, Piers Dunstan & Craig Johnson Large-scale loss of giant kelp, Macrocystis pyrifera, forests off the east coast of Tasmania 35

Egli, Daniel, Russ Babcock & John Montgomery Monitoring long-term presence/absence and movement of temperate sparid Pagrus auratus in a no-take marine reserve 36

Elliott, Pam & Thomas Moore Australia’s oldest marine discovery centre offers world-class education opportunities involving students in scientiﬁc research 36

England, Matthew H & Stephanie K Moore Jervis Bay circulation and modelling: Some work inspired by the pioneering efforts of Peter Holloway 37

Abstracts - Page 2 Index of Authors and Abstracts

Feng, Ming Tracking two oppositely-rotating eddies off the Western Australian coast 37

Feng, Ming, Susan Wijffels, Stuart Godfrey & Gary Meyers Do eddies play a role in the momentum balance of the Leeuwin Current? 38

Fernandes, Milena, Peter Lauer & Anthony Cheshire Nitrogen ﬂows associated with tuna farming in Port Lincoln, South Australia 38

Lauer, Peter, Milena Fernandes, Jason Tanner, Peter Fairweather & Anthony Cheshire (Poster) Tuna farming and the seaﬂoor 39

Field, Iain C, Corey JA Bradshaw, Harry R Burton & Mark A Hindell (Poster) Seasonal use of oceanographic and ﬁsheries management zones by juvenile southern elephant seals (Mirounga leonina) from Macquarie Island 39

Forbes, S & C Macleod Development of quantitative visual assessment techniques for the evaluation of sediment condition 40

Forehead, HI, GA Kendrick, PA Thompson, A Waite Scratching the surface: Benthic microalgae and their effects on N cycling in WA coastal waters 41

Foster, Jacqui ‘MESA Facilitating Marine Monitoring- A Case Study’ 41

Fox, Nicola J & Lynnath E Beckley Hotspots, biogeography, complementarity and pragmatism: Priority areas for conservation of Western Australian coastal ﬁshes 42

Frusher, Stewart Behaviour: The missing ingredient in ﬁsheries assessment 42

Fulton, Elizabeth A, Randall Gray, L Rich Little, Vincent D Lyne, A David McDonald, Keith Sainsbury, Brian Hatﬁeld Marine ecosystem modelling and multi-sector monitoring on the Northwest Shelf of Australia 43

Gaston, Troy, Thomas Schlacher & Rod Connolly Are small estuarine plumes traceable on exposed open coasts? 44

Godfrey, J Stuart, Mai-Britt Kronborg & Detlef Quadfasel Links between tidal mixing and the Leeuwin Current 44

Golding, Rosemary (Poster) Morphological studies of Australian Amphibolidae (Gastropoda: Pulmonata) 45

Goldsworthy, Laurie & Tajima, Hiroshi Water injection for control of emissions of oxides of nitrogen from ship engines 45

Gray, RB, PJ Canﬁeld & TL Rogers The health status of the leopard seal, Hydrurga leptonyx, in Prydz Bay, Eastern Antarctica and NSW, Australia: A comparative study 46

Grifﬁn, D, I Barton, M Cahill, J Dunn, J Mansbridge, C Rathbone, K Ridgway, G Smith, K Suber, P Turner A selection of GLATs 46

Grose, Michael & Andrew McMinn (Poster) How much is in the east? Algal biomass in the East Antarctic pack ice 47

Grose, Michael, Andrew McMinn, Jill Cainey, Chris Lane, Guido Corno (Poster) Biogenic production of methyl halides by phytoplankton in Tasmanian Coastal waters 47

Guenther, Jana & Rocky de Nys Differential community development of fouling species on the pearl oysters Pinctada fucata, Pteria penguin and Pteria chinensis (Bivalvia, Pteriidae) 48

Guest, Michaela A, Rod M Connolly & Neil R Loneragan Movement of carbon among estuarine habitats and its assimilation by invertebrates 48

Bailleul, F, C Barbraud, M Biuw, C-A Bost, J-B Charassin, L Dubroca, M A Lea4, F Roquet, Y Park, M Fedak, M. Hindell, H Weimerskirch, C Guinet (Keynote Address) What can top marine predators tell us about the Southern Ocean? 49

Abstracts - Page 3 Index of Authors and Abstracts

Gurney LJ, C Mundy, MC Porteus & N Ogle New approach to an old problem: using stable oxygen isotope proﬁles to age abalone 50

Habeeb, Rebecca, Craig Johnson, Simon Wotherspoon & Jessica Trebilco Characteristic length scale estimates: Application to a marine system 50

Hallegraeff, Gustaaf M, Damian Grundle, Judith-Ann Marshall & Jo Dowdney Range extension of the red-tide dinoﬂagellate Noctiluca into Tasmanian waters 51

Hammond, Bethany K Post-settlement survival inﬂuenced by naturally occurring temperature changes in temperate benthic systems 51

Hanson, Christine E, Charitha B Pattiaratchi, Anya M Waite, Stéphane Pesant & Peter A Thompson Oceanographic forcing of phytoplankton dynamics off Western Australia 52

Hartmann, Klaas, Lance Bode & Paul Armsworth Marine reserves as a learning tool 52

Hay, Tracy, Michael Phelan, Neil Gribble, Steve Bailey, Christina De Vries, Malcolm Dunning & Karen Danaher (Poster) Methods for monitoring habitat and abundance of the mud crab Scylla serrata in northern Australia 53

Heap, Andrew D, James Daniell, Peter T Harris & Mark Hemer Sand movement and potential seagrass dieback in Torres Strait 53

Helidoniotis, Fay & Jonny Stark (Poster) Human impacts on benthic assemblages in Antarctica 54

Heupel, Michelle & Colin Simpfendorfer Analysis techniques from passive acoustic telemetry studies of coastal shark nursery areas 54

Poore, Alistair GB; Nicole A Hill & Eric E Sotka Evolutionary associations among herbivorous amphipods and marine plants 55

Evans, K, MA Hindell, R Warneke & R Thresher Cetacean strandings is climate a driving force? 55

Wheatley, Kathryn E, Mark A Hindell, Corey JA Bradshaw & Lloyd S Davis (Poster) Energy resource allocation of female Weddell seals (Leptonychotes weddellii) in years of contrasting quality 56

Hobday, Alistair & Ryo Kawabe Acoustic monitoring to determine nearshore migration paths of juvenile southern blueﬁn tuna in southern Western Australia 56

Hodgson, Kate E, George D Jackson & Jeremy M Lyle Tracking arrow squid movements with an automated acoustic telemetry system 57

Holl, Carolyn M, Joseph P Montoya & Anya Waite (Poster) Nitrogen ﬁxation by unicells: An investigation of vertical proﬁles and size fractions of the natural phytoplankton assemblage found in a warm and a cold core eddy 57

Holl, Carolyn M, Joseph P Montoya, Anya M Waite, Stéphane Pesant, Peter A Thompson Diazotroph activity in WA waters: comparative analysis of nitrogen ﬁxation in a warm core and a cold core Mesoscale Eddy 58

Holland, Kim, Laurent Dagorn & Tim Clark Pelagic Ecosystem Observing Systems: “Smart FAD”, FADIO and HULA programs 58

Holmes, Nick (Poster) Determining levels of mercury in subantarctic penguins on Macquarie Island 59

Hooge, Philip N, William M.Eichenlaub The Animal Movement Program: Integrating GIS with statistical analysis and modeling of animal movements 60

Hooge, PN , SJ Taggart & ER Hooge Site ﬁdelity in Paciﬁc halibut (Hippoglossus stenolepis) 60

Hughes, Lauren & Stephen DA Smith

“If you build it, they will come”. A sampling package for the rapid assessment of amphipod biodiversity 61 Hunter, Cass, Malcolm Haddon & Keith Sainsbury Lobster size: modelling its effect on trapment 61

Abstracts - Page 4 Index of Authors and Abstracts

Hunter, John & Mark Hemer Modelling the ﬂow under an Antarctic ice shelf using POM 62

Huveneers, Charlie & Rob Harcourt A new wobbegong species (Orectolobidae) in New South Wales: preliminary results 62

Ives, Matthew C, J Scandol, I Suthers & S Montgomery A quantitative analysis of prawn harvesting strategies 63

Ivey, GN & JP Antenucci Bottom intensiﬁed currents on the North West Shelf 63

Johnson, Colin CL & Natalie Moltschaniwskyj Behaviorally measured development of visual acuity in southern dumpling squid (Euprymna tasmanica L.). 64

Johnson, Craig (Keynote Address) Mechanisms of invasion, impact and options for environmental control of exotic marine species: Perspectives from Tasmania as a laboratory 64

Johnston, Emma L, Sean D Connell, Andrew D Irving, Edward Forbes, Kate Stuart, Adele J Pile & Bronwyn Gillanders Characterising shallow rocky-reef assemblages from the Windmill Islands coast, East Antarctica 65

Jones, Graham, Mike Harvey, John McGregor, Hilton Swan, Anke Schneider 4, Edward Abraham, Cliff Law, Murray Smith, Michael Ellwood5, Julie Hall5, Simon Wright6 The SOLAS Air-Sea Gas Experiment (SAGE) 2004 and effects of iron fertilisation on DMS gas exchange 65

Jordan, Alan & Andrew Bickers Development and application of seabed habitat mapping technologies 66

Kämpf, Jochen On the South Australian coastal upwelling system 66

Katsumata, Katsurou, Peter Holloway & Graham Symonds A numerical and observational investigation into the bottom boundary layer on North West Shelf 67

Kawaguchi, So, Steve Candy, Stephen Nicol & Mikio Naganobu Modelling Antarctic krill Growth: a new approach 68

Kelaher, Brendan, Jeff Levinton, Ruth Junkins & Bengt Allen (Poster) What does $100 million buy: an environmental restoration or an ecological disturbance? 68

Khou, Muoi, Nick Paul, Jeff Wright & Peter Steinberg Fragmentation as a strategy for expansion by Caulerpa ﬁliformis 69

Kildea, TN & AC Cheshire Comparison of the productivity, chlorophyll concentration and depth distribution of two species of Cystophora (Fucales) from West Island, South Australia 69

Kingston, Jennifer J, Christophe Guinet, Robert G Harcourt, Simon D Goldsworthy4 & Des W Cooper Sympatrically breeding fur seals do not use visual cues for species recognition 70

Koslow, J Anthony, J Strzelecki, H Paterson, S Pesant, A Begum, A Pearce & A Waite Seasonal and onshore-offshore patterns in the biophysical oceanography off SW Australia 71

Paterson, H , Band Ashraﬁ & AJ Koslow (Poster) Microplankton diversity in two contrasting mesoscale eddies 71

Paterson, H, S Pesant2, AJ Koslow, A Waite Herbivorous impact of microzooplankton in two contrasting eddies 72

Krause, Gunther (Keynote Address) From the Coorong to the Greenland Sea - Surprises on bottom water formation and ventilation in the Greenland Sea 72

Lansdell, Matthew, Craig Mundy & Alistair Hobday (Poster) Meager movements of abalone? The beneﬁts of studying small-scale ecology for ﬁsheries management 73

Lewis, John A Translocation of marine non-indigenous species: How important is ship hull fouling? 73

Hobday, Alistair, Tony Smith, Ilona Stobutzki, Scott Ling (Poster) Ecological risk assessment for effects of ﬁshing: A ﬂexible framework that works in data-poor situations to prioritize action 74

Abstracts - Page 5 Index of Authors and Abstracts

List, Kate Recent planktonic foraminifera in surface sediments 74

Longford, Sharon, Staffan Kjelleberg & Peter Steinberg Community ecology of epiphytic bacteria on a temperate red alga 75

Lyall, Luisa & Johnson, Craig (Poster) Use of ﬂuorochromes as markers for tracking larval dispersal of Heliocidaris erythrogramma 75

Magierowski, Regina & Craig Johnson How robust are surrogates of alpha diversity in marine communities? 76

Manson, FJ, NR Loneragan, BD Harch4, GA Skilleter5, L Williams6 Mangrove-ﬁsheries links at broad spatial scales 76

Mantel, Peter (Poster) Increasing the survivability of APEX Argo Proﬁlers 77

Margvelashvili, Nugzar, John Andrewartha, Scott Condie, Mike Herzfeld, John Parslow, Jason Waring Modelling suspended sediment transport on Australia’s North West Shelf 77

Martin-Smith, Keith & Amanda Vincent Wild horses run free: Abundance, distribution and movement in seahorses 78

McCauley, Robert D, K Jenner, S Curt, M-N Jenner, Christopher LK Burton, John L Bannister, & Chandra Salgado Kent Blue whales in the Perth Canyon 78

Ward, Tim M, Lachlan J McLeay, Wtjens F Dimmlich, Paul J Rogers, Sam McClatchie, Roger Matthews, Jochem Kämpf, Paul D van Ruth Do juvenile southern blueﬁn tuna aggregate in the Great Australian Bight to target high concentrations of sardines? 79

McKinnon, David Production, respiration and grazing in tropical Australian waters 79

McQuillan, Lea, Jane Fromont, Jackie Alder & Paul Lavery Differences in sponge assemblages on reef habitats off coastal Perth, Western Australia 80

Merriﬁeld, Mark, Peter Holloway, Shaun Johnston, Michelle Eich, Jerome Aucan, Nathalie Zilberman, & Yvonne Firing (Keynote Address) The rise and fall of internal tides in the deep ocean 80

Meyers, Gary, Peter McIntosh & Lidia Pigot The years of El Nino, La Nina and interactions with the tropical Indian Ocean 81

Middleton, Jason Topographic wakes 81

Middleton, John & Gennady Platov Weather-band circulation and upwelling off South Australia: a numerical study of the summer of 1999 82

Miller, Matt, Julia Barnes, Rhys Hauler Chris Carter & Peter Nichols The effect of variation in dietary energy and protein levels on the lipid class and fatty acid composition of Atlantic salmon (Salmo Salar) fed at elevated temperature conditions 82

Moltschaniwskyj, Natalie A & Michael A Steer Spatial and seasonal variation in reproductive characteristics and spawning of southern calamary: Spreading the mortality risk 83

Monro, Keyne, Robert Brooks & Alistair GB Poore Adaptive plasticity of foraging behaviour in a marine macroalga 83

Moore, Stephanie K & Iain M Suthers Stable isotopes of the pygmy mussel (Xenostrobus securis) as an indicator of catchment disturbance and estuarine nutrient enrichment 84

Moore, Thomas, John Marra, Richard Matear & Lesley Clementson Distribution of phytoplankton biomass off Western Australia: Role of mesoscale eddies in cross-shelf export 84

Moore, Thomas, Richard Matear & John Marra (Poster) Variability of phytoplankton biomass on the central Western Australian shelf: Characteristics and causes 85

Abstracts - Page 6 Index of Authors and Abstracts

Moritz, CM, AD McKinnon, JH Carleton (Poster) Summer variation in abundance and biomass of microzooplankton of the North West Cape, Australia 85

Muhling, Barbara A & Lynnath E Beckley Ichthyoplankton in two meso-scale Leeuwin Current eddies: preliminary results 86

Muhling, Barbara A, Lynnath E Beckley & Anthony J Koslow Preliminary analysis of ichthyoplankton assemblage structure in coastal, shelf and offshore waters of south-western Australia 86

Neil, KM & S McKenna Larval trap monitoring for pests in tropical Australia 87

Nelson, Vicki The National Marine Bioregionalisation: incorporating scientiﬁc uncertainty into oceans management 87

Newton, Gina M Communicating marine science and conservation through children’s literature: An inclusive approach 88

Nicol, S, S Kawaguchi & S Romaine Krill and currents 88

Nichols, Carol Mancuso, Sandrine Garon, John Bowman, John Gibson, Peter Nichols & John Guézennec (Poster) Exopolysaccharide production by Antarctic bacteria: Implications for nutrient cycling 89

Nichols, PD, JAE Gibson, JJ Plumb, MB Stott, HR Watling, PD Franzmann (Poster) Archaeal hyperthermophilic communities in marine sediments and vents of the Manus Basin and from nearby terrestrial environments: isolation, characterisation, lipid signatures and industrial potential 89

Nichols, P, P Mansour, I Bronwyn, S Robert, D Frampton, S Blackburn, S Singh & A Green (Poster) New single cell and crop plant sources of long-chain Omega-3 oils 90

Nichols, P, B Mooney & N Elliott Is farmed Australian seafood a better source of the good oil than wild-caught seafood? 90

O’Dor, Ron (Keynote Address) Where have all the Cephalopods gone? 91

O’Dor, Ron K, George D Jackson & Yanko Andrade Exploring the life styles of squid and cuttleﬁsh using ‘Hybrid’ acoustic/archival tags 91

Olivier, Frederique Sea ice extent and breeding performance variability of snow petrels (Pagodroma nivea) at Casey (East Antarctica): detecting local response to large-scale processes ? 92

Otway, Nick Pop-up archival tracking of the critically endangered grey nurse shark in SE Australian waters 92

Pal, Aji Ecologically sustainable developments in marine propulsion engines 93

Parker, Naomi, Jacinta Innes & Karina McLachlan The National System for the Prevention and Management of Marine Pests Incursions 93

Meuleners, Michael, Charitha Pattiaratchi & Gregory Ivey Numerical modelling of the mean ﬂow characteristics and eddies of the Leeuwin Current System 94

O’Callaghan, Joanne & Charitha Pattiaratchi The inﬂuence of diurnal tides on sediment re-suspension in a partially mixed micro-tidal estuary 94

Pattiaratchi, Charitha Physical oceanography off Western Australia 95

Woo, Mun & Pattiaratchi, Charitha Interaction between the Leeuwin Current and shelf currents along the Gascoyne continental shelf 95

Paul, Nick, Rocky de Nys & Peter Steinberg The chemical ecology of seaweeds: marine algae are not higher plants 96

Pecl, Gretta, Sean Tracey, Jayson Semmens & George Jackson Addressing spatial management issues of mobile species with acoustic telemetry 97

Abstracts - Page 7 Index of Authors and Abstracts

Pederson, Hugh G & Craig R Johnson Effects of lobster ﬁshing on the population dynamics of the sea urchin Heliocidaris erythrogramma on the east coast of Tasmania 97

Pesant, Stéphane (Poster) Investigating a homogeneous ﬂuorescence proﬁle covering the top 250m in a warm-core, downwelling-eddy off WA: Evidence of heterogeneity from photosynthesis vs irradiance experiments 98

Pesant, Stéphane, Christine E Hanson, Tony Koslow, Robert D McCauley, Charitha Pattiaratchi, Chandra Salgado Kent, Peter A Thompson4, Luke Twomey, Florence Verspecht, Anya M Waite Size-fractionated phytoplankton characteristics: A quick and easy approach to the ecology of pelagic marine systems off WA 98

Pesant, Stéphane, Holl, Carolyn M, Thompson, Peter A & Waite, Anya M Phytoplankton production in two contrasting eddies off WA 99

Pesant, Stéphane, Lindsay Pender & Mark Underwood (Poster) Dissection of two eddies off WA using the SeaSoar, an open ocean towed undulating data acquisition vehicle 99

Phillips, Helen, Susan Wijffels & Ming Feng Interannual variability in freshwater content NW of Australia from Argo 100

Pile, Adele J & Bethany K Hammond Pulsed-cold water events have a persistent negative impact at all levels of community structure 100

Piola, Richard & Emma Johnston (Poster) Comparative copper sensitivities of four species of four species of introduced marine bryozoans 101

Post, Alix & Will Howard

Biological production and the uptake of CO2 in the Southern Ocean: Evidence from planktonic foraminifera 101 Proctor, Craig, Tim Davis, John Gunn, Subhat Nurhakim, Wudianto, Gede Merta, Retno Andamari4 & Budi Iskandar Indonesia and Australia collaborate to develop Indonesia’s capacity to monitor and assess its Indian Ocean tuna and billﬁsh ﬁsheries, aiming for sustainability of shared-stocks 102

Provis, David Hydrodynamics of Port Phillip Heads, The Rip 102

Rathbone, Chris, Glen Smith, Ken Suber & Peter Turner 10 Years of Australasian Sea Surface Temperature 103

Reid, Anthony & Craig Johnson Utilisation of the New Zealand screwshell by native hermit crabs in Tasmania: Indications of potential impact 103

Rennie, Susan, Robert McCauley & Charitha Pattiaratchi Physical oceanography of the Perth Canyon 104

Ribbe, Joachim Linking Southern Ocean water masses and Australian rainfall variability 104

Ridgway, KR The 5500-km long boundary ﬂow off western and southern Australia 105

Newman, Stuart J, David Ritz & Stephen Nicol Behavioural reactions of Antarctic krill (Euphausia superba Dana) to ultraviolet and photosynthetically active radiation 105

Roberts, David A & Alistair GB Poore Experimental habitat fragmentation affects colonisation of epifauna in a marine algal bed 106

Gales, N & S Robinson (Poster) Tracking baleen whales: development of the e-D tag 106

Jarman, S, N Gales, B Deagle, A Passmore, S Robinson (Poster) DNA as a dietary biomarker 107

Roob, Ralph The effectiveness of hydro-acoustic techniques to characterise benthic habitats and communities in Port Curtis 107

Ross, Jeff, Mick Keough & Andy Longmore Interaction of marine pests and nutrient cycling in Port Phillip Bay 108

Abstracts - Page 8 Index of Authors and Abstracts

Roy, Craig CSIRO’s National Research Flagships- Wealth from Oceans Flagship 108

Runcie, John W Characterising the nutrient status of macroalgae with chlorophyll ﬂuorescence 109

Saint-Cast, Frederic, Scott Condie & Peter Harris Circulation in the Torres Strait marine ecosystem 110

Sala, Ridwan & Ron Johnstone (Poster) Size composition of skipjack (Katsuwonus pelamis L) taken from the northeastern waters of Indonesia 110

Salgado-Kent, C & R McCauley An analysis of blue whale (Balaenoptera musculus) call variations from south-western Australia 111

Sauer, Warwick Movement pattterns of an endemic sparid in South Africa 111

Saunders, Krystyna, Andrew McMinn, Dona Roberts, Dominic Hodgson & Henk Heijnis (Poster) Recent human-induced salinity changes in Ramsar-listed Orielton Lagoon, Tasmania, Australia 112

Semmens, Jayson, Julian Harrington & Matthew Inkson Why won’t my octopus come back: Utilizing passive telemetry to understand the dynamics of an octopus population 112

Serebryany, Andrey Intense internal waves on shelf 113

Seymour, Jamie, Teresa Carrette, Paul Sutherland, Glenda Seymour, Ameila Seymour & Ben Seymour The use of ultrasonic transmitters for determining movement patterns in the cubozoan Chironex ﬂeckeri 113

Shaw, Sylvie Aquaculture – the social context 114

Sherman, Craig, David Ayre & Karen Miller There’s no place like home: Localised adaptation of the intertidal sea anemone Actinia tenebrosa 114

Sherwood, John, Cheree Fenton & Julie Mondon Environmental ﬂows for highly stratiﬁed estuaries in SW Victoria, Australia 115

Skillington, Anna, Thomas A Schlacher & Troy F Gaston Response of mesozooplankton to estuarine plumes 115

Sliwa, Cath, Keith Hayes, Sasha Migus & Felicity McEnnulty Prioritising introduced species in Australia for management - Identifying target species 116

Smallwood, Claire B, Lynnath E Beckley & Neil R Sumner Recreational angling in the Rottnest Island reserve: Catch, effort and participation estimates 116

Smyth, Chris The role of science in Marine Protected Areas and regional marine planning 117

Stark, Jonathan S & Martin J Riddle Assessing the remediation of an Antarctic waste dump: biological and chemical monitoring of marine benthic communities 117

Grimshaw R, E Pelinovsky, Y Stepanyants & T Talipova Internal solitary wave dynamics in coastal seas 118

Stroud, Stan Importance of internal waves to stability of submarine pipelines off North-West Australia 118

Strzelecki, Joanna, Lidia Yebra Mora, Stéphane Pesant & J Anthony Koslow Assessment of zooplankton secondary production using egg production and aminoacyl –tRNA synthetases activity (AARS) method, off the south west coast of Western Australia 119

Sumby, Jon The science–policy gap in ocean governance 119

Kinloch, Martine, Rupert Summerson & Danielle Curran Domestic vessel movements and the spread of marine pests: risks and management approaches 120

Abstracts - Page 9 Index of Authors and Abstracts

Summerson, Rupert, Martine Kinloch & Danielle Curran The role of nodes in secondary invasions by introduced marine pests 120

Sumner, Michael (Poster) Mapping marine animal behaviour at-sea 121

Sutton, Caroline A & Chad L Hewitt Detection kits for community-based monitoring of introduced marine pests 121

Sutton, Caroline & Jeannie-Marie LeRoi Communicating science through art: As demonstrated by the science in Salamanca festival 122

Symonds, Graham Wave-driven currents on coral reefs 122

Tate, Peter M & Jason H Middleton The effect of internal waves on the trajectory and dilution of buoyant jets 123

Taylor, Alan H The International Maritime Organization (IMO) and the Marine Environment 123

Taylor, Alan, Geoff Rigby & Gustaaf Hallegraeff The International Ballast Water Management Convention and its implication for the marine environment and Australian shipping 124

Thompson, BAW, NW Davies, MJ Riddle, I Snape, JS Stark Oil degradation, infaunal recruitment and bioturbation in Antarctic sediments 125

Thompson, Peter, Anya Waite & Stéphane Pesant Pigment differences between a warm core and a cold core eddy off Western Australia 125

Thompson, Peter, Anya Waite & Stéphane Pesant (Poster) Pulse amplitude modulation (PAM) ﬂuorometry reveals signiﬁcant variation in photosynthetic parameters in a deep mixed layer within a warm core eddy 126

Thresher, Ronald E & Peter Grewe Development of a species-speciﬁc biocide for the control of Caulerpa taxifolia 126

Timko, Patrick G, Mark E Baird & Jason H Middleton Response of the East Australian Current to wind stress 127

Tovar-Ávila, Javier, Terence I Walker, Robert W Day (Poster) Rapid assessment for ecological risk of the Australian angel shark 127

Tracey, Sean R, Jeremy M Lyle, Guy Duhamel (Poster) Comparing somatic growth and otolith form of striped trumpeter (Latris lineata) from widely separated populations 128

Troy, Sally Marine science and Australian oceans management – steps towards an integrated approach 128

Tsotsobe, Sakhile, Hans Verheye & Mark Gibbons Spatio-temporal variation in the abundance and community structure of the major copepod species in northern Benguela 129

Twomey, Luke, V Pez, F Verspect, A Waite, C Pattiaratchi & P Thompson Nutrient limitation off Western Australia 129

Valentine, Joe & Craig Johnson Establishment of dense stands of the introduced kelp Undaria pinnatiﬁda in Tasmania depends on disturbance to native algal assemblages 130 van Polanen Petel, Tamara, Melissa Giese, Mark Hindell Behavioural responses of lactating Weddell seals (Leptonychotes weddellii) to human activity 130 van Senden, David Mixing in estuarine wetlands: The role of long waves 131

Davidson, Andrew T Tessa Vance, Paul G Thomson, Nina Cadman, Graham Jones (Poster) The effects of solar UV radiation on an Antarctic marine microbial community 131

Waite, Anya M Leeuwin Current meso-scale eddies: Death traps or nurseries? (A preliminary overview of the 2003 Eddy Voyage) 132

Abstracts - Page 10 Index of Authors and Abstracts

Waite, Anya M, Carrie Holl & Joseph Montoya Contrasting food webs in cold-core and warm-core eddies: evidence from δ15N and δ13C stable isotopes 132

Wang, XH Circulation and heat budget of the northern Adriatic Sea (Italy) due to a Bora event in January 2001: A numerical model study 133

Webster, Ian The Coorong – hydrodynamic features of a unique system 133

Welch, David & Jayson Semmens Developing a permanent continental-scale acoustic tracking array for marine ﬁsheries research: The goal and the strategy 134

West, Elizabeth J The role of anthropogenic activity in the fragmentation and dispersal of the invasive alga, Caulerpa taxifolia 134

White, Camille A, John AE Gibson & Kerrie M Swadling Pathways of community development following isolation from the marine environment: A case study in two Antarctic saline lakes 135

Wolkenhauer, Svea-Mara, Sven Uthicke , Timothy Skewes & Roland Pitcher Sea cucumber removal and its consequences for seagrass growth: a case study on commercially important sandﬁsh Holothuria scabra in shallow seagrass beds of Moreton Bay, Queensland 136

Wright, SW, HJ Marchant, AT Davidson, FJ Scott, R van den Enden, P Thomson, K Westwood (Poster) Microorganisms rule the Southern Ocean 137

Zacharek, Andrew Assessment of risks from multiple uses of oceans 137

Abstracts - Page 11

AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Allen, Simon CSIRO Marine Research, Castray Esplanade, Hobart, TAS 7000 [email protected] Commercial platforms for marine science – Why re-invent the wheel? Underwater sensor platforms have advanced rapidly in sectors of marine related industry other than marine science. Recent proposals for projects such as the bio-regionalisation of Australian waters require access to ground truth data sets on such a grand scale that collection from conventional multidisciplinary surface vessel based cruises is proving too expensive. The author wishes to present a review of existing commercial subsea data collection platforms and some innovative mission plans to allow cost-effective data collection for bio-regionalisation and marine protected area monitoring. ______

Allen, Tim National Coordinator – Marine and Coastal Community Network, 3rd Floor, 60 Leicester Street, Carlton Vic. 3053 [email protected] Finding a voice for Nemo – Opportunities for AMSA engagement in marine policy and public awareness Public surveys have highlighted that marine scientists are considered by the community as “trusted messengers” on marine biodiversity conservation issues. Marine scientists are well placed to inspire people to think about the marine environment, to urge the media to give matters public attention, and convince policymakers and others to make marine issues a priority. For the past 10 years the Marine and Coastal Community Network has worked at the interface of marine science, conservation policy and public marine education, successfully building strong links with members of Australia’s marine science community to progress numerous marine policy initiatives. What has been learned, and what opportunities might exist to increase AMSA’s role in the formation and implementation of marine conservation policies. ______

Abstracts - Page 13 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Ambo Rappe, Rohani* & Maria J Schreider School of Applied Science, Newcastle University, NSW, 2258 [email protected] Possible consequences of fragmentation of seagrass bed on mobile epifauna Fragmentation of seagrass habitat results in increase in the number of smaller patches and the distances among patches. Increase in the number of smaller patches leads to an increase in the ratio of the edge length to the interior area. These changes may affect distribution and abundance of species associated with seagrass. Some species prefer interior sections of habitats whereas others utilise the ecotone along the edge of the patch. For example, amphipods were often reported to prefer edges rather than interior sections of seagrass patches. This study assessed the potential effects of seagrass fragmentation on amphipods living in seagrasses by testing the following hypotheses: 1, Abundances of amphipods will be different in seagrass patches of different sizes; 2, Abundances of amphipods will be affected by the distance from potential source of colonists (natural beds of seagrass Zostera capricorni); 3, There will be a significant difference in abundances of amphipods at the edges of seagrass patches compared to their interior areas. To test these, artificial seagrass units (ASUs) were deployed around the natural seagrass beds in Tuggerah Lakes and Lake Macquarie (Central Coast, NSW) during September-October, January- February, March-April, and July-August in 2002/03. There was no significant difference in the abundance of amphipods in patches of different sizes. After four days of placing the ASUs, there also no difference in abundances of amphipods at any of the distances from natural seagrass beds. After one month, however, amphipods were significantly more abundant at the furthest distance from Z. capricorni. Contrary to many other findings, amphipods were significantly more abundant in the interior sections of patches than at the edges. Thus, fragmentation of seagrasses can influence distribution and abundance of amphipods, but the effects are likely to be species – specific and vary in different geographical areas. ______

Anantharaman, Mohan Australian Maritime College Oil pollution regulations and oily water separator design to meet these requirements What do we do with our waste can affect the quality and biodiversity of our seas and oceans. Australians are the second –highest producers of waste in the world behind the US. More than half the debris in Australia’s seas comes from land and up to 80 percent around cities. The Australian population’s proximity to and love of the seas make protecting the natural environment an important task. If we are to continue to enjoy our natural heritage and enviable life style, we must ensure that caring for our seas, oceans and coasts and diversity of marine life found there, continues to be a major priority for each and every one of us. Oil pollution from ships is a major contributory factor, which adversely affects marine life. Commercial shipping operation has transformed to a great extent in the past four decades. The gruelling bunker fuel oil prices have a great impact on commercial vessel operation. Present day merchant shipping vessel burn residual fuel oil in their engines. In very practical terms oil ingress into the ship’s engine room cannot be averted in total. Hence there is always going to be an oily water mixture in the ship’s engine room. Present day shipboard equipment provide means for pumping out this mixture overboard at high seas provided the oil content in water is only 15ppm. Also discharge is totally prohibited in some areas designated as special. The aim of this paper is to throw light on “ Oil Pollution Regulations and Oily Water Separator Design to meet these requirements”. These regulations are set up by IMO, The International Maritime Organisation, which is an agency of the United Nations. It becomes the Shipboard Marine Engineer’s duty and responsibility to comply with the IMO requirement and assist all Port State Control and associated bodies in our efforts to have clean seas and oceans. ______

Abstracts - Page 14 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Arendt, Michael D Marine Resources Research Institute, Marine Resources Division, SC Department of Natural Resources, Charleston, South Carolina 29412 [email protected] Data…Not just another bad, four-letter word when you have the right tools to manage it! The use of automated sampling devices to monitor for the presence of acoustically tagged animals at fixed locations over time (i.e., passive acoustic telemetry) provides a markedly improved ability to characterize distributional patterns than is typically achievable by actively tracking individual animal movements. Although initially expensive, the long-term cost per data point using this automated approach may be considerably cheaper than active data collection, due to increased sampling opportunities without the associated personnel or vessel charges. Because of increased sampling opportunities, very large datasets are often generated using this approach, which represents both a potential burden for data management and an opportunity for analysis of a large, continuous time series. As the use of automated sampling devices increases, there is an increased need to educate users of these types of devices regarding efficient management and analysis of the resulting data. In 2003, I created a template database (with a companion user manual) using a commercially available software package (Microsoft Access) for managing large, binomial (presence, absence) datasets generated by automated acoustic sampling devices such as the Vemco VR2 receiver. In this presentation, I will briefly discuss the design and application of this database, particularly as it relates to preparing data summaries for descriptive analyses (i.e., Fourier, Empirical Eigenfunction Analysis) that I have found to be useful for characterizing temporal trends in species occurrence. Other insights and comments regarding study design for future VR2 studies will also be provided. ______

Awruch, CA1,2, S Frusher1 & J Stevens2 1 Tasmania Aquaculture and Fisheries Institute, University of Tasmania. Nubeena Crescent, Taroona 7053, Tasmania, Australia. 2 CSIRO Marine Research, GPO Box 1538, Hobart Tas. 7001, Australia [email protected] Conventional and acoustic tagging studies on the draughtboard shark (Cephaloscyllium laticeps) in a scientific reserve in Tasmania The draughtboard shark Cephaloscyllium laticeps (Duméril, 1853) is the most common catshark in the coastal areas of southern Australia. We have been using a combination of acoustic and conventional tagging technology to give us a greater insight into the behavior of this species. The conventional tags have provided valuable information on growth and long-term movement. Between January 2000 and February 2004, 375 tagged sharks were released in Crayfish Point Reserve. To date, 121 sharks have been recaptured with 36% recaptured more than once. A high proportion of sharks remained within the reserve; others moved to the south-west and east coast of Tasmania. The longest period between tagging and recaptures was 39 months. The use of conventional tagging data to assess shark growth will be reported. The acoustic data have provided information on site fidelity, residency periods and behavior. Between January-July 2003, 25 sharks were fitted with Vemco V8SC acoustic tags. Vemco VR2 automatic acoustic receivers were deployed in the Crayfish Reserve, in the Derwent River and Storm Bay. Acoustic data showed that most sharks stayed within the reserve, supporting the finding from conventional tagging. Sharks were active during both day and night, although stationary behavior (lack of movement) of up to 4 days was also observed. The advantages of combining both acoustic and conventional tag information will be discussed.

Abstracts - Page 15 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Baird, ME1*, PG Timko1, JH Middleton1 & IM Suthers2 1 Centre for Environmental Modelling and Prediction, School of Mathematics, UNSW Sydney 2052 2 School of Biological, Earth and Environmental Sciences, UNSW Sydney 2052 [email protected] Biological response to wind forcing in the EAC A coupled physical-biological model is configured for the East Australian Current, and forced using idealised winds. The spatial and temporal trends in biological output is compared to a physical diagnostic ‘ideal age’, a measure of the average time a volume of water has been in the euphotic zone. Model output for a variety of winds is compared with remotely-sensed and in situ data. The most biologically dynamic regions are filaments of upwelled water which interact with the offshore eddy field. ______

Bani, Ali1*, Natalie Moltschaniwskyj1 & Alan Jordan2 (Poster) 1 School of Aquaculture, University of Tasmania, Locked Bag 1370, Launceston Tas. 7250

2 Marine Research Laboratories, Tasmanian Aquaculture and Fisheries Institute, Taroona Tas. 7053 [email protected] Necessity of temporal and spatial management in recreational fisheries, sand flathead case Understanding spatial and temporal variability of life history characteristics, as a function of environmental variability and fishing impacts, is critical in the prediction and sustainable management of fisheries. This study explored the life history traits of sand flathead, Platycephalus bassensis, populations targeted by recreational fishers. Fish were sampled from three locations around Tasmania; an estuary (Tamar River) and two embayments (Coles Bay & Georges Bay). Growth, age/size structure, mortality rates, and reproductive condition differed among the populations. No fish older than 4 years were caught in the Tamar estuary, whereas the maximum age of flathead in Coles Bay was 20 years. The Georges Bay population showed an average age 49 % older and 17 % younger than the Tamar River and Coles Bay populations respectively. Total mortality (Z) rates derived from catch curve analysis in Georges Bay were double that in Coles Bay. Gonadosomatic index (GSI) was significantly higher (value > 4) in Coles Bay during spring, which was more than double the average GSI seen at the other two locations. Duration of spawning in Georges Bay (September-November) was considerably shorter than Coles Bay (October-March). No reproductively mature fish were caught at any time of the year in the Tamar River. Differential removal rates of fast-growing individuals by fishing and/or differential spatial distribution of the population, related to maturation, may explain the variation among the populations. This research highlights the need to take care when assuming uniform demographic structures in exploited populations. This strongly suggests the use of temporally and spatially specific management of fishing activities. ______

Abstracts - Page 16 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Bannister, Raymond1*, Christopher Battershill2 & Rocky de Nys1 1School of Marine Biology & Aquaculture, James Cook University, Qld 4810 2Australian Institute of Marine Science, Qld 4810 [email protected] Feeding biology of the tropical sponge Coscinoderma sp. on the Great Barrier Reef (GBR) The consumption of planktonic particulate organic matter by benthic filter feeding invertebrates is an important pathway for the transfer of carbon and nitrogen in benthic ecosystems. Understanding this pathway has important implications for the aquaculture of sponges, including growth and survival, site selection, and impacts on the benthic community. Coscinoderma sp. is an abundant species in the Palm Island Group of the Great Barrier Reef (GBR), with strong potential as an aquaculture species. The distribution, abundance and feeding biology of Coscinoderma sp. was examined as part of a broader program investigating the biology and ecology of sponges and sponge aquaculture. Belt transects were used to estimate the abundance of Coscinoderma sp. with abundances ranging from 8 to 28 individuals per 250 m2. Ultraplankton consumption was measured using flow cytometry. Ultraplankton abundance and retention was highest in winter. Coscinoderma sp. selectively retains Prochlorococcus spp., Synechococcus spp., heterotrophic bacteria and picoeukaryotes with efficiencies from 40 to 70%. Pumping rates of Coscinoderma sp. were measured at 4-4.5 cm.sec-1 using microthermistor probes and remained constant over a 20-hour period. Combining these data allowed the calculation of carbon and nitrogen fluxes. Daily carbon and nitrogen consumption by Coscinoderma sp. was highest in winter with 1207 µg of carbon and 355 µg of nitrogen retained per m2 of reef per day compared to 75 µg of carbon and 22 µg of nitrogen retained per m2 per day in summer. ______

Barnes, Julia1, Rhys Hauler2 & Chris Carter1 1 School of Aquaculture, TAFI, University of Tasmania, Locked Bag 1370, Launceston Tas. 7250 2 Skretting, Cambridge [email protected] The effect of differing dietary protein:energy ratios on feed intake and growth of Atlantic salmon (Salmo Salar) at elevated temperature The optimal temperature for growth of large Atlantic salmon is thought to be between 10 and 14°C. During summer and autumn in Tasmania, growth can be compromised by temperatures rising to between 17 and 20°C, and there is little information available on the nutrient requirements of salmon at these temperatures. Higher temperatures result in an increase in metabolic and protein synthesis rates, though the processes will be less efficient. Protein and energy requirements will therefore increase, but probably not at the same rate. Fish eat firstly to satisfy their energy requirement, so the protein and energy balance of the diet needs to be formulated to optimise growth when salmon are experiencing sub-optimal temperatures. This experiment investigated the effect of different protein:energy ratios on the growth of Atlantic salmon at elevated temperature. Triplicate tanks of Atlantic salmon were fed to satiation one of four commercially made extruded diets, which differed in their protein:energy ratios. Each treatment also had two extra tanks; one fed to 60% of satiation and one to 30%. The treatments were different combinations of high or low protein content (HP or LP) and high or low fat content (HF or LF). The diets were therefore HP:HF, HP:LF, LP:HF. LP:LF. Feed intake was determined each day and tank biomass was obtained every three weeks. There was no significant difference between the diets for growth rate or feed efficiency by the satiation-fed fish. There was a significant difference (p = 0.022) in feed intake between the LP:LF and LP:HF diets; feed intake increased as the energy content of the diet decreased and the protein:energy ratio increased. There was no significant difference between these diets and the HP:LF and HP:HF diets. Growth (grams gained/g body weight/day) and energy intake (KJ/g body weight/

Abstracts - Page 17 AMSA2004 - Authors and Abstracts (alphabetically by presenter) day) data from all feeding levels were pooled and growth regressed against energy intake. The energy utilisation for growth was 14.085KJ/g gained, with energy intake explaining 92% of the change in body weight. This efficiency will be compared to literature values to evaluate how the efficiency of growth may be affected by high temperature. Although there was no significant difference found for growth and feed efficiency, a more detailed understanding of the interaction between nutrient balance and water temperature in terms of feed intake, growth and growth efficiency has been acquired. This information will allow more precise control over feeding regimes in changing production conditions. ______

Barnes, Peter School of Biological Sciences, University of Wollongong, NSW 2522 [email protected] Examination of processes affecting the distribution of the sponge, Suberites sp. in NSW coastal lakes The sponge, Suberites sp. is found in several saline coastal lakes in NSW. It is an upright sponge, contains cyanobacteria, may grow attached or unattached to the substratum and individuals can be moved around within lakes by wind-driven currents. Previous work found that Suberites sp. is patchily distributed within lakes, but when they do occur, are most common in areas with a mosaic of bare sediment and patchy seagrasses or macroalgae. Suberites sp. is rarely found in areas with a dense canopy of seagrasses (particularly Zostera). This study used manipulative experiments to examine four possible mechanisms which may explain the absence of Suberites sp. from areas with dense seagrasses; 1. shading by seagrass canopies, 2. reduced water flow amongst seagrass, 3. adult Suberites sp. do not arrive in dense seagrasses and 4. other mechanisms associated with areas of dense seagrasses. Individual sponges were tagged in situ in Smiths Lake. Sponges were then shaded, had currents reduced or were transplanted to areas with dense Zostera. In addition, appropriate untouched and procedural controls were included. There were no effects of shading nor reduced current on individual sponges. In contrast, sponges transplanted to seagrasses were absent or had dramatically reduced in size by the end of the study. Examination of the surviving sponges in seagrasses revealed numerous bite marks, typical of small fish. These results suggest that predation may be an important mechanism in determining the distribution of Suberites sp. within a lake. Although fish were not directly observed feeding on sponges in seagrasses, from the nature of the marks and the types of fish known to be in Smiths Lake at the time, small leatherjackets (Monocanthids) are most likely to be responsible. ______

Abstracts - Page 18 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Bax, Nic1* & Piers Dunstan1 1 CSIRO Marine Research [email protected] Evaluating management strategies for the Northern Pacific seastar in Australia: A progress report The threat of marine organisms arriving in Tasmania in ballast water sourced from Japan was first noted in 1973. Nothing was done. The Northern Pacific seastar Asterias amurensis was identified in Tasmania in 1992 and the population estimated at 28 million individuals. The threat of the seastar spreading to mainland Australia was recognised, but again nothing was done. Between 1995 and 1997 four adult seastars were collected in Port Phillip Bay, on the mainland 700km away. In 1998, 103 juveniles were collected from mussel ropes in Port Phillip Bay. By 2000, the population was estimated at 150 million individuals, with a biomass of ~3,000 tonnes. Total biomass of demersal fish in the Bay is ~4,000 tonnes. The Port of Melbourne in Port Phillip Bay is a major shipping hub for Australia and it is to be expected that the seastar will be spread throughout southern Australia. Can anything be done? Of course it can, but of all the management strategies available to us – ballast water regulation, biofouling reduction, population reduction through physical removal, biological control or genetic manipulation, early warning and emergency response – which will work best? And how will we know whether or not a strategy is working, or whether we are achieving the goals set by managers? Management Strategy Evaluation has been developed to answer these questions and applied to the harvest of marine fisheries and whales, and more recently to ecosystem management. In this paper, we present the first results of applying Management Strategy Evaluation to reducing the spread of the Northern Pacific seastar. ______

Beaumont, Karin School of Zoology, University of Tasmania, Box 5, Hobart 7001, Tasmania Australia * Australian Antarctic Division, 203 Channel Highway, Kingston Tas 7050 Planktonic interactions and particulate flux The Southern Ocean is one of the largest marine ecosystems in the world, and is a major sink for atmospheric carbon dioxide. Thus it plays a considerable role in the mitigation of the greenhouse effect and resultant global warming. Marine micro-organisms dominate the plankton biomass in Antarctic waters and are principal determinants of the transfer and vertical flux of photosynthetically-fixed carbon. I examined the composition and trophodynamics of a plankton community dominated by microzooplankton grazers (small copepods and protozoa), and their role in vertical carbon flux in Ellis Fjord, east Antarctica. The seasonal succession of the plankton community was similar to that commonly observed in the wider Southern Ocean; changing from dominance by microplanktonic diatoms and small herbivorous copepods during early summer to nanoflagellates and protozoa during late summer. Microplanktonic diatom blooms and herbivorous grazers are commonly regarded as contributing to carbon export in the Southern Ocean, while communities dominated by auto- and heterotrophic nanoplankton favour the retention and respiration of carbon in pelagic waters. However, in Ellis Fjord, there was little vertical flux to depth throughout the entire summer. Grazing by microzooplankton retarded the flux of phytoplankton by reducing their direct sedimentation, by producing faecal pellets of a morphology and ultrastructure that inhibited sinking, and by coprophagous degradation and recycling of pellets. Protozoan and small copepod pellets differed in morphology, ultrastructure and carbon content. Surprisingly, protozoan pellets that contained only empty diatom frustules contained more carbon per pellet than small oval copepod pellets. Despite their differences both types of microzooplankton contribute to the retention of new and regenerated production. This reduces the draw-down of atmospheric carbon in Antarctic waters and the capacity of these waters to ameliorate global climate change. ______

Abstracts - Page 19 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Beckley, Lynnath E* & Claire B Smallwood School of Environmental Science, Murdoch University, South Street, Murdoch 6150 WA [email protected] Marine reserve or marine caravan park? Assessment of recreational boating at Rottnest Island Western Australia has the highest recreational boat ownership per capita in Australia and, in Perth, there are more than 44 000 registered boats. Rottnest Island reserve, located 18 km offshore of Perth, is a favoured boating destination. In the embayments of the reserve, there are eight designated mooring areas with 35 rental moorings and 864 moorings which are licensed to private individuals on a long-term basis. Despite high annual fees, demand for moorings is high and, currently, there are more than 500 boat-owners on a waiting list. Nevertheless, prior to our survey of boating activity in reserve waters, conducted from January to December 2003, the Rottnest Island Authority had little information on occupancy of moorings, types of vessels visiting the reserve and what activities the passengers engage in. The majority of vessels were found to visit the reserve in summer and significantly higher numbers of all vessel types were recorded on weekends. One hundred percent occupancy was rarely attained, and then, only in some mooring areas on a few long weekends. Outside of mooring areas, SCUBA diving was the most popular marine recreational activity conducted from boats during the summer months and, during winter, surfing was the most frequently recorded activity. Fishing and crayfishing were also conducted at numerous sites around the island. Management concerns include equity of access to moorings, impacts of boating, waste management, provision of shore-based facilities, user-conflicts and spill-over of excess boats to other island reserves. ______

Berly, Thomas S&T section of the French Embassy, 6, Perth Avenue, Yarralumla ACT 2600 [email protected] Marine Sciences: Strong collaboration between France and Australia Ocean and marine resources have a huge economic and social impact in sectors including oil and gas, shipping industries and tourism. Marine research has increasing implications for policy areas such as fisheries, environment, agriculture and rural development with many users involved such as industry, scientific community and policy makers. Marine Science is one of the main research topics for cooperation between France and Australia. Both countries are willing to develop research in Marine Science and Technology. In 1991, was signed an agreement between the French and the Australian Government to reinforce collaboration in marine research. Under the MOU, the Joint Marine Sciences committee was created to enabling joint projects, promoting mobility of researchers and coordinating the use of infrastructures. As a result, each year, more than 100 collaborative projects are underway, bilaterally and multilaterally, between France and Australia in the fields of research related to coral reefs, geoscience, climate, fisheries and aquaculture. In the Southern Ocean research, Hobart is a major focus of cooperation for French research institutions such as IFREMER1, CNRS2, IRD3 and IPEV4 that have shown and received a strong interest in collaborating with their Australian colleagues from the Australian Antarctic Division (AAD), the CSIRO Marine Research, the CRC Antarctic Climate and Ecosystems and University of Tasmania. Hobart is also the base of the IFREMER vessel Astrolabe for Antarctic missions. Encouraging S&T cooperation (including Marine Sciences) between France and Australia is a prime goal for the French Embassy in Australia. In November 2003, FEAST-France, the French-Australian Research Network (www.ambafance-au.org/science) was initiated as a common platform on which research

Abstracts - Page 20 AMSA2004 - Authors and Abstracts (alphabetically by presenter) actors can build projects or networks on focussed research topics. Recently, the implementation of the French-Australian Science and Technology (FAST) programme is an example of the joint engagement by both Governments to support scientific and technological cooperation between Australian and French researchers in both public and private sectors. However, it’s up to the scientists to strive to provide new concepts into areas of policy, enhance the results of their work and structure themselves to intensify cooperation at bilateral and multilateral levels. In the field of Marine Sciences, identifying priorities and outlining future developments should become key objectives for the research community to enhance the quality and visibility of future action, specially when Marine research is foreseen to play an important role within the FP7. 1) IFREMER (Institut Français de Recherche pour l’Exploitation de la MER): National Institute for Oceanic Research and Exploitation (www.ifremer.fr) 2) CNRS (Centre National de la Recherche Scientifique) : National Scientific Research Centre (www. cnrs.fr) 3) IRD (Institut de Recherche pour le Développement) : Research Institute for Sustainable Development (www.ird.fr) 4) IPEV : Institut Paul Emile Victor (http://www.ifremer.fr/ifrtp/pages/inst.html) ______

Bidigare, Robert R (Keynote Address) Department of Oceanography, University of Hawaii, Honolulu, HI 96822 Influence of Mesoscale eddies on plankton biomass, primary productivity and carbon export Numerous studies have demonstrated that eddy activity generates mesoscale variability in physical, chemical and biological properties in surface waters of the Atlantic, Pacific, Indian and Southern Oceans. At least three different eddy types contribute to this mesoscale variability, and include first (cyclones and anticyclones) and second baroclinic mode eddies. Enhanced biological activities have been reported for each eddy type as evidenced by measurements of carbon fixation, nutrient uptake and oxygen production. New (and total) production rates within these features are generally thought to be stimulated by the input of growth-limiting nutrients that results from the upward displacement of nutrient-rich isopycnal surfaces, higher upwelling velocities, and/or larger vertical eddy diffusion coefficients. These higher rates of new production imply that rates of organic carbon export should increase when steady-state conditions are attained. Unfortunately, there are only a limited number of published sediment trap and 234Th measurements that document the latter. The paucity of export measurements for eddies is a consequence of their ephemeral nature as well as the time lags associated with biological responses. In the lee of the main Hawaiian Islands, local topography and prevailing northeasterly trade winds combine to generate a vigorous and continuous eddy field. The cold-core cyclonic eddies, in particular, serve as natural laboratories for investigating the influences of eddy pumping on phytoplankton community structure and rate processes in the subtropical Pacific. Here we report the results of a multidisciplinary study undertaken to quantify the effects of cyclonic eddies on phytoplankton biomass, primary productivity, microheterotroph biomass and carbon export in the lee of Hawaii. Microheterotroph biomass and 234Th- derived carbon export rates were 2 to 3 times higher than those observed for adjacent waters. If this eddy is representative of other cyclonic eddies that are frequently formed in the lee of Hawaii, then eddy activity may significantly enhance the areal efficiency of the biological pump and facilitate the transfer of organic carbon to organisms inhabiting the mesopelagic and abyssal-benthic zones of this subtropical ecosystem. ______

Abstracts - Page 21 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Bird, James1,2*, Craig Steinberg1 & Tom Hardy2 1 Australian Institute of Marine Science, PMB No. 3, Townsville 4810 2 James Cook University, Department of Civil & Environmental Engineering, Townsville 4810 [email protected] Modelling sub-reef thermodynamics to predict coral bleaching: a case study at Scott Reef, WA A clearer understanding of the oceanographic mechanisms that control coral bleaching will enable better reef management. Currently, the best method to detect bleaching-like conditions is through a time integration of sea surface temperatures observed by satellite. Unfortunately, these observations only reveal the thermal structure for the top millimetre of water averaged over large areas (presently 2500 square kilometres). The aim of this study is to use environmental physics to predict water temperatures at the reef and sub-reef scales. Scott Reef, WA presents an ideal test site as it experienced a severe bleaching event in 1998 that was well documented. Averaged coral cover in exposed sites dropped from 54% to less than 10% over the top 30 metres. A sophisticated turbulence model is used to determine the vertical temperature structure of the water column from radiative, latent, and sensible heat fluxes. In a novel approach, stratified waters from this 1D model can be well-mixed in zones identified by a 2D hydrodynamic model. There is a strong correlation between areas where bleached corals survived and locations which are predicted to have access to cooler well-mixed deep waters. ______

______

Blackweir, Dermot G* & Lynnath E Beckley School of Environmental Science, Murdoch University, Murdoch WA 6150 [email protected] Beach usage and aerial surveillance for sharks in Perth metropolitan waters During summer, many thousands of people visit beaches in the Perth metropolitan area to engage in a wide range of recreational activities. In November 2000, a swimmer was killed by a shark off Cottesloe Beach - the first shark attack fatality in 75 years. Since then, the Western Australian government has implemented aerial surveillance for sharks in coastal waters off Perth metropolitan beaches each summer during November, December and January. In the summer of 2003/04 an observer from Murdoch University flew with the aerial patrol to evaluate various aspects of the surveillance. Aerial patrols were conducted daily from 06:00 – 09:00 and from 09:30 to 12:30. The flight route was from Jandakot Airport northwards to Two Rocks Beach, then southwards along 140 km of coast to Avalon Beach, Mandurah and back to Two Rocks Beach. This flight pattern was repeated several times each day resulting in as many as eight passes over individual beaches. Marine animals such as dolphins were regularly sighted but sharks proved elusive. Environmental factors, such as glare, water clarity, seabed characteristics, weather and onset of the sea breeze, were found to influence the visibility of marine animals from the air. Beach usage patterns were also investigated by photographing beaches along the flight path and counting the numbers of people engaged in recreational activities such as swimming and surfing. Highest numbers were recorded on Boxing Day, when the total number of people observed on beaches during a north-south flight along the metropolitan coastline exceeded 12 000 persons. Repeated passes over popular beaches such as Cottesloe and Scarborough throughout the summer allowed detailed temporal information regarding beach usage to be obtained. ______

Abstracts - Page 22 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Boxshall, Anthony Manager, Marine National Park Research, Parks Victoria, 10/535 Bourke St, Melbourne, 3000 [email protected] Integrating science and management in Victorian Marine Protected Areas In November 2002, the Victorian Government gazetted a new system of marine protected areas. The 13 new Marine National Parks and 11 new Marine Sanctuaries consist of a representative example of Victoria’s marine environment and protect ~5.3% of Victorian waters. Since that time a large research and monitoring program has been developed and implemented across the state. The program has a number of major aims, including the collection of baseline biological data, the creation of marine habitat maps, the promotion of robust community involvement in biological monitoring and establishing a broad and relevant research program. This talk will detail the breadth of the program and make explicit the objectives and methods of a number of the components of the program. I will present early results from a number of monitoring and research projects, including preliminary biological monitoring information from a number of parks, early habitat mapping information for shallow water environments and details of the efforts to integrate the research and monitoring into the day to day management of Victorian Marine Protected Areas. With a new, broad park system starting simultaneously in 24 locations across the state, it has been important to ensure the science is integrated with the management of the system. A number of paths have been followed to help this process along. As well as presenting some preliminary data, I intend to critique the success of some of them to now and offer alternatives where needed. ______

Buchan, Steve MetOcean Engineers Pty Ltd, 31 Bishop Street, Jolimont WA 6014 High frequency near-seabed currents Since 1985, when Peter Holloway ﬁrst demonstrated the existence of near-seabed internal hydraulic jumps and solitons in current data from North Rankin location, MetOcean Engineers has been conducting long-term, high frequency, near-seabed current measurements at dozens of locations on Australia’s North West Shelf. Wherever near-seabed temperature stratiﬁcation is coupled with even moderate seabed slopes, episodes of intense benthic turbulence have been recorded. This presentation illustrates a range of internal wave activity, including solitons, breaking solitons and topographically enhanced seabed jets. Intermittant current pulses have been recorded with timescales of the order of 10 minutes and speeds exceeding 2 m/sec. ______

Abstracts - Page 23 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Burdon, Jennifer Interpretation & Education Ofﬁcer, Parks & Wildlife Service, Hobart, Tas [email protected] Keeping buoyant in the Sea of Science: Making education a PFD This session will provide practical strategies for communicating your key messages more effectively to the wider community. Public awareness of your research is a vital step in gaining public support. Jenni is the Vice President of the Marine Education Society of Australasia - a national organisation which provides a forum for sharing ideas and facilitating leading environmental education programs. MESA promotes the sustainable use of marine and coastal environments through education. ______

Butler, Alan (Poster) CSIRO Marine Research, Hobart [email protected] CSIRO Marine Research in Torres Strait The economic and social reliance of the Torres Strait people on the marine environment is perhaps the strongest of any community in Australia. This poster outlines current work by CSIRO Marine Research aimed to help achieve ecological sustainability and conservation of the Torres Strait ecosystem while providing for the socio-economic needs of its people. CSIRO has a long history of research in the Torres Strait. Our work has been focused on the management of certain fisheries, particularly tropical rock lobster and bêche de mer, but it is now broadening, in collaboration with other partners through the CRC-Torres Strait (www.crctorres.com). Current projects integrate skills and expertise across a range of disciplines including ecology, fisheries science, ocean circulation, biogeochemistry and ecosystem modelling. Tasks include habitat mapping and characterization using a novel combination of methods, stock assessments for key species, biophysical modeling incorporating hydrodynamics and sediment dynamics, studies of the effects of certain fisheries on the ecosystem, and evaluation of alternative management strategies. Our aim is to move towards more comprehensive modeling of the ecosystem, to enable multiple-use management strategy evaluation. ______

Abstracts - Page 24 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Byrne, Maria (Keynote Address) Department of Anatomy and Histology, University of Sydney, NSW 2006 [email protected] Life history evolution in sea stars – insights into speciation in the sea One of the most pervasive influences on the diversity and structure of animal populations is life history mode. Evolutionary change in life history has played a major role in speciation in the sea. We use the comparative approach with echinoderm genera that exhibit an array of larval forms and modes of development to investigate the influence of life history evolution on generation of marine biodiversity. The Asterinidae is a species-rich asteroid family in Australia with the full array of mating systems, larval types and developmental habitats seen in marine invertebrates. Using Patiriella and Cryptasterina as model systems the features of maternal provisioning and development that are labile for change and those that are conserved are being determined. The similar adult phenotypes of these sea stars on one hand, and their contrasting developmental phenotypes on the other, highlight the influence of life history evolution on species divergence. Careful attention to the phenotypic expression of life history traits has revealed the presence of cryptic species, potential hybridising species complexes and hitherto undetected biological diversity that can be separated by molecular sequence data. This is an important consideration particularly for research involving morphospecies with wide geographic ranges. ______

Chatwin, PG1, IM Leggett1 & SL Hughes2 1 Shell U.K. Limited, 1 Altens Farm Road, Nigg, Aberdeen, AB12 3FY, UK 2 FRS Marine Laboratory, Po Box 101, Victoria Road, Aberdeen, AB11 9DB, UK [email protected] Observations of the slope current and shelf edge processes West of Shetland During 1990s the offshore industry extended its activities from the North Sea continental shelf (<200m) out to the deeper waters of the continental slope, West of Shetland (300m – 1000m). At this time the complexity of oceanographic processes were poorly understood and reports of extreme current events lead to the industry embarking on an extensive measurement campaign in support of critical operations. Observed extreme current events are associated with the combined effects of large and smaller scale processes. These events occur infrequently and are difﬁcult to predict. This paper gives an initial overview of a tidal and residual currents derived from 5.7 ‘current’ years of rig-mounted ADCP data collected by the North West Approaches Group (NWAG) during the period 1994-2000. Deployment periods range from 20 days to 226 days, in water depths ranging 330m to 940m. Results compare favourably with long-term ADCP data collected in the region by the FRS Marine Laboratory, Aberdeen. This paper also describes observations of mesoscale variability at the shelf-edge, derived from hydrographic and AVHRR satellite data collected during FRS Scotia research cruise 1600S, 5-19 October 2000. The results complement previous studies commissioned by NWAG, suggesting that remotely sensed observations could be used as a tool to provide advance warning of extreme currents, West of Shetland. ______

Abstracts - Page 25 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Clark, Graeme & Emma Johnston School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052 Manipulating larval supply in the field: a controlled study of marine invasibility Continued advances in the field of invasion biology are vital to the protection of global biodiversity. Recent studies have tested for invasibility in grassland habitats by manipulating community traits in replicate plots, and seeding plots with a controlled supply of propagules. These studies have produced the first empirical evidence of the influence of community traits on invasibility, yet the consistent use of terrestrial plants limits our ability to generalize the findings across all ecosystems. We developed a larval dosing technique to allow marine experimental units to be dosed with a controlled supply of live propagules under field conditions. Using this technique, we conducted a manipulative field experiment to test the relationship between common human disturbances and invasibility in hard-substrate epifaunal communities. Six month old assemblages were exposed to three fully-crossed factors: physical disturbance, chemical disturbance, and timing of larval dose relative to the disturbances. Physical disturbance was shown to increase the invasion success of the dosed species, Bugula neritina, up to 30 days following the disturbance. This was mainly through an increase of recruitment onto primary space, however physical impacts with an anti-foulant surface also led to increased recruitment on secondary space. After 15 days, B. neritina recruits on primary space were found to be larger than recruits on secondary space, suggesting a heightened threat of invasion through primary recruitment. Natural recruitment of barnacles, ascidians, and sedentary polychaetes was also increased by the physical disturbance, although these effects were weaker and varied between taxa and sampling times. This study supports the theory that human disturbance facilitates invasions in marine epifaunal communities, and contributes a new technique of manipulating propagule supply in the marine environment. ______

Coleman, Andrew National Oceans Office [email protected] Regional Marine Planning – the Economic Components Australia’s oceans are a significant contributor to our economy and society. Australia’s marine industries contribute over $70 billion to the national economy each year and employ, both directly and indirectly, around nine hundred thousand Australians. A substantial proportion of this activity occurs in remote and regional Australia - areas where there may be limited alternative employment opportunities. Australia’s Oceans Policy released in 1998 is neither solely an environmental protection policy nor simply an economic development policy, it is both. It is a policy for the Ecologically Sustainable Development of our oceans. This places a requirement on managers and uses and those with a stake in the long term health of our oceans and the communities that depend upon them to understand the implications of proposed actions. As a result, access to relevant biological, economic and social information is paramount. The National Oceans Office’s National Socio-economic Work Program is building the information and processes required to assess the Ecological Sustainable Development implications of current and proposed activities. Work is currently concentrated on the mapping of marine activities, socio-economic risk assessment, performance system development, valuing the economic contributions of Australia’s marine industries and developing guidelines for assessing the socio-economic impacts of proposed actions. ______

Abstracts - Page 26 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Coman, Frank E*1,2, Rod M Connolly2 & Nigel Preston1

1 CSIRO Division of Marine Research, PO Box 120, Cleveland, 4163, Australia 2 Centre for Aquatic Processes and Pollution, and School of Environmental & Applied Sciences, Gold Coast campus, Griffith University, PMB 50, Gold Coast Mail Centre, Queensland, 9726, Australia [email protected] Food sources of Acetes sibogae in prawn ponds in southeast Queensland A combination of stable isotope measurements and gut contents analysis were used to determine the major food sources of Acetes sibogae in commercial prawn ponds at two farms in southeast Queensland. Slight differences were observed between farms but overall the results were consistent. Although gut contents analysis gave a good indication of the range and temporal occurrence of food items consumed by the Acetes, it was difficult to ascertain the contribution each item made to the diet. This was mainly due to the large proportion of unidentifiable material in the guts. Only resilient items such as crustacean remains and diatoms were commonly identified from the guts. Stable isotope signals were measured for Acetes and likely food sources including pelleted prawn feed, zooplankton and macroalgae. The pattern of changes in isotopic signals of Acetes across the season showed that zooplankton were a primary food source. Changes in the signals of zooplankton were reflected by changes for Acetes, but the changes in Acetes signal were less pronounced. At both farms, the Acetes were more enriched in 13C & 15N than the zooplankton, across the whole season. The absolute difference between the δ13C value of Acetes and zooplankton was greater than might be expected based on fractionation over a single trophic level. Furthermore, laboratory feeding trials showed that fractionation could not explain the greater than expected enrichment of the Acetes signal compared to that measured for zooplankton in the ponds. This, together with evidence from gut contents analysis, showed that a food source other than zooplankton must also be important to Acetes. The results indicate that the macroalgae that colonise pond substrates are the most likely additional source. ______

Condie, Scott & John Andrewartha CSIRO Marine Research, GPO Box 1538, Hobart Tas. 7001 [email protected] Modelling the circulation on Australia’s North West Shelf: Global to coastal scales Modelled circulation across Australia’s North West Shelf is described on time scales from hours to years, and space scales from 10 km over the entire shelf to 1 km in a selected focus area around the Dampier Archipelago. A series of nested circulation models have been developed with forcing by realistic winds, tides, and large-scale regional circulation. The simulations covered a period of more than six years, allowing the tidal, seasonal, and interannual characteristics to be investigated. Model results confirm that instantaneous current patterns are strongly dominated by the barotropic tide and its spring-neap cycle. However, longer-term transports over the inner- and mid-shelf are mainly controlled by wind- driven flow, which follows the seasonal switch from summer monsoon winds to southeasterly trades in winter. Over the outer-shelf and slope the large-scale regional circulation, provided by a global model, had a major influence. Results are shown to be relatively insensitive to adjustable model parameters and sub-model structures. However, model performance depends strongly on the quality of the forcing fields. For example, the prediction of low-frequency inner-shelf currents was improved substantially when the relatively coarse resolution global winds where replaced by locally observed winds in the Dampier Archipelago model. Inferior prediction of low-frequency currents on the outer-shelf can be largely attributed to errors in the global circulation model.

Abstracts - Page 27 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Condie, Scott1*, Jason Waring 2, Jim Mansbridge 1 & Madeleine Cahill 1 1 CSIRO Marine Research, GPO Box 1538, Hobart Tas. 7001 2 CSIRO Marine Research, Private Bag No 5, Wembley, Western Australia 6913 [email protected] Characterising marine connectivity patterns around Australia The Australian Connectivity Interface or Aus-ConnIe has been developed as a web-tool for marine scientists and managers to investigate the large-scale patterns of spatial connectivity around Australia associated with ocean currents. Specifically, it provides an estimate of the probability that any two regions of the upper water column are connected over a user specified dispersion period. Results generally compare favourably with observed trajectories of satellite-tracked ocean drifters. Aus-ConnIe is expected to find applications in areas such as larval dispersion and recruitment studies, and the development of scenarios and preliminary risk assessments for contaminant dispersion. It is publicly accessible through www.per. marine.csiro.au/aus-connie ______

Craig, Peter CSIRO Marine Research [email protected] Internal wave relection – the career of Peter H This talk will be a short reﬂection on the work of Peter Holloway. There were two main scientiﬁc themes to Peter’s research, internal waves and mixing, and 3 main geographic foci, the North West Shelf, Jervis Bay and the Hawaiian Ridge. It is probably fair to say that internal waves on the North West Shelf were his research passion. His curiosity was sparked (as was mine at around the same time), when he was a postdoc at UWA, by the spectacular current and temperature signals Woodside was collecting at various locations on the shelf edge. He was drawn to the perverse nonlinearity of the internal tides, and developed a taste for KdV (Korteweg-de Vries) modelling. Later, he moved to more conventional modelling (by my standards, anyway), pushing POM (the Princeton Ocean Model) to reproduce the nonlinear behaviour and reveal the spatial variability of the internal waves. Towards the end of his career, he combined his internal wave, mixing and modelling skills on the Hawaiian Ridge – but that is the subject of another talk. ______

Abstracts - Page 28 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Crean, Angela*, Steve Swearer & Heather Patterson Department of Zoology, University of Melbourne, Vic. 3010 [email protected] Is larval supply a good predictor of recruitment in reef fish populations? The decoupling of local production and recruitment in marine populations has led to considerable debate over what factors drive variation in reef fish recruitment. Although many studies have addressed this issue, the use of contrasting methods, taxa, and scales have led to conflicting results. Therefore, this study focused on two main aims: (1) to determine if larval supply is a good predictor of reef fish recruitment at a local scale; and (2) to trial artificial reef units as a method of estimating reef fish recruitment. Larval supply and recruitment were measured simultaneously using light traps, artificial reef units, and visual censuses. Overall, larval supply was not a good predictor of reef fish recruitment at the scale examined. However, the relationship between spatial patterns of larval supply and recruitment was complex, and varied substantially between species. Artificial reef units were found to be a useful method of estimating recruitment of cryptic species. However, the alternative traps were biased toward different taxa. These results have implications for the design of future studies and the development of management strategies for conservation initiatives such as marine parks. ______

______

Cresswell GR, DA Griffin & C Rathbone CSIRO Marine Research, Hobart Tasmania Australia The Leeuwin Current, eddies, and subantarctic waters off southwestern Australia A research vessel in late 1994 and several years of satellite observations revealed complex interactions of ocean features off southwestern Australia. The ship measurements showed that the Leeuwin Current (LC) commonly ran at 0.5 ms-1 above the upper continental slope and extended down to about 250 m. South of the continent a 200km-diameter anticyclonic eddy depressed the ocean structure in the upper 1000 m. The eddy showed influences of the LC, deep mixing in winter, and summer heating. The subantarctic water around the eddy was cooler, fresher, and richer in nutrients and oxygen than both the eddy and the LC. Satellite thermal and topographic measurements showed that cyclonic eddies accelerated the LC along the southern upper continental slope, while anticyclonic eddies diverted it out to sea and then back again. The images suggested that weak eddies originating east of the Great Australian Bight migrate westward, first encountering the continental slope off the Recherche Archipelago. There the anticyclonic eddies take on warm water from the LC and strengthen. Several anticyclonic eddies were followed westward beyond the archipelago for 18 months as they drifted at up to 5 km per day and interacted with the LC and with one another. ______

Abstracts - Page 29 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Cresswell, G1, P Tildesley1, P Holloway2, S Buchan3 & C Simpson4 1 CSIRO Marine Research, Box 1538, Hobart Tas. 7001. 2 Deceased. Late of University of New South Wales/Australian Defence Force Academy. Honoured by this Symposium 3 MetOcean Engineers Pty Ltd, 31 Bishop Street, Jolimont WA 6014 4 Department of Conservagtion and Land Management, 47 Henry Street, Fremantle WA 6160 [email protected] Preliminary interpretation of RADARSAT scenes off NW Australia The synthetic aperture radar on RADARSAT enables images to be made of the roughness of the sea surface. Such images have been used around the world as part of studies of, inter alia, Antarctic ice, oil seeps, internal waves, and river plumes. We present images off NW Australia that can be interpreted to show internal waves, possible coral spawning slicks, and a plankton bloom. We acknowledge the generosity of the Canadian Space Agency / Agence spatiale canadienne in providing the images. ______

Dagorn, Laurent Institut de Recherche pour le Développement – France, IRD PO Box 570 – Victoria (Seychelles) [email protected] Acoustic telemetry on tropical pelagic fish around FADs: The experience of IRD and collaborating partners The « Institut de Recherche pour le Développement » (IRD) has been using acoustic telemetry on pelagics for the last 20 years, as first sonic tracking experiments started in the mid 80’s. In the last couple of years, IRD has developed new researches using acoustic telemetry, i) through a strong collaboration with the University of Hawaii and funds from the Pelagic Fisheries Research Program (‘Smart FAD’ project), and ii) through a european collaboration on a research project funded by the European Union (DG Research) called ‘FADIO’ (www.fadio.ird.fr). These current collaborative projects involve acoustic telemetry in different aspects : • development of an array of listening stations (VEMCO VR2) on FADs moored off Oahu (Hawaii) to study movements and residence times of tagged tunas • tagging tuna and other pelagics around drifting FADs equipped with VR2s, in the western Indian Ocean • development with VEMCO of the new VR3, a listening station with ARGOS uplinks • active tracking of pelagics (dolphinfish, yellowfin tuna) for homing experiments around FADs ______

Abstracts - Page 30 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Dagorn, Laurent1, Kim Holland2, David Itano3 1 Institut de recherche pour le développement (IRD, France), Seychelles, Indian Ocean 2 Hawaiian Institute of Marine Biology (HIMB), University of Hawaii, USA 3 Pelagic Fisheries Research Program (PFRP), University of Hawaii, USA [email protected] Residence time and movements of yellowfin and bigeye tuna in a network of FADs Adjacent FADs surrounding the island of O‘ahu (Hawaii) have been equipped with automated fish monitoring receivers (VEMCO VR2). Approximately 100 yellowfin and bigeye tuna have been surgically implanted with coded sonic transmitters that record fine scale presence/absence data at each FAD location. Size and species specific movement and residence patterns have been continuously monitored since August 2002. Most tagged fish have remained at the same FAD where they were tagged or visited a few adjacent FADs. However, others have moved extensively throughout the FAD network over a period of several months. Some FADs appear to function as aggregative subsets of the whole array with fish repeatedly moving between a pair or small group of FADs. Arrival times and distances between FADs suggest that these animals might be well aware of the location of adjacent FADs and can travel directly from one to the next. A great variability of residence time of fish at FADs has emerged from the data (from a few minutes up to several weeks), which might be explained by differences in local environments. ______

Dambacher, Jeffrey*, Klaas Hartmann & Alistair Hobday CSIRO Marine Research, GPO Box 1538, Hobart Tas. 7001 [email protected] By your food and your enemies: Simplifying food webs using social network theory The increasing popularity of input-output (or compartment-flow) models, such as Ecopath, is based in part on the practicality of converting stomach content and food-web data into a common currency of biomass pools and flows. Compartments are linked by trophic relationships with the goal of accounting for total biomass flow in the system. While the majority of models, especially those of marine ecosystems, represent myriad species, most have compartments numbering only in the tens. Thus, one of the first, and we argue, most important stages of model development is to aggregate species based on some measure of similarity. Typically, ‘trophic similarity’ is based on a comparison of diets, with some degree of restriction based on phylogeny, biology, and topical interests. While intuitively appealing, this approach can potentially lead to alternate models with contradictory behaviour. Recently, the notion of trophic similarity has been extended by a network approach pioneered by social scientists in the 1960’s. Here it is important to know not only who you eat (or manage), but also who eats (or manages) you. Based upon a recursive graph/matrix algorithm, it is possible to provide a reduced-complexity view of a system that accounts for its entire set of interactions. We use this approach as a means of exploring the implications of community structure to the problem of model aggregation, and as a basis for comparing both qualitative (i.e. loop analysis) and quantitative models (i.e. Ecopath). We develop the notion of ‘aggregation error’ and present a refinement of the network algorithm that considers additional information within the aggregation process, such as population turnover rates or spatial structure. We believe food web simplification is a critical step in the development of model ecosystems, and by providing a more rigorous approach, we hope to better support frameworks for management decisions. ______

Abstracts - Page 31 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Daniell, James¹, Michael Hughes², Peter Harris¹, Andrew Heap¹, Mark Hemer¹ ¹ Geoscience Australia, GPO Box 378, Canberra, ACT 2601 ² School of Geosciences, University of Sydney NSW 2006 [email protected] Repeat seabed surveys in Torres Strait – mapping rates of sandwave migration and implications for the marine environment Two high-resolution bathymetric surveys were undertaken using a shallow-water multibeam sonar at two locations of ~1.5 km2 near Turnagain Island, Torres Strait. The purpose of the repeat surveys was to calculate the rate and volume of sand transport and migration direction of bedforms (sandwaves) in the two study areas. The initial survey revealed that the sandwaves were up to 3-4 m in height and spaced up to 200 m apart. In both survey areas the sandwaves were initially asymmetric and oriented towards the east with a full to starved, 3-dimensional morphology. This initial morphology is consistent with the sandwaves being shaped by water movements during the monsoon season. The second survey revealed that the sandwaves had begun to reverse their asymmetry and move towards the west. Signiﬁcant volumes of sediment were moved at both sites between the two surveys, with maximum volumes attaining up to ~0.09m³/m²/day. Over the 17 days, the sand-wave crests moved a net distance of between 6-10 m to the west. Although the sandwaves did not completely reverse their asymmetry, the change in morphology was associated with a change to SE winds and waves. It is likely that during the SE trade wind season the residual westerly water movements would further alter the morphology of the sandwaves. The high- resolution multibeam sonar surveys will be repeated in October 2004 to calculate sediment transport rates and examine the degree to which the sandwaves are affected by the change in residual water movements between Monsoon and SE trade wind seasons. These measurements will provide crucial data for estimating the effects of sediment transport on seagrass survival, dieback and recovery in Torres Strait. ______

Day, Robert1*, David Bardos2, Cameron Dixon1,3, Sylvain Huchette1,4 & Luke McAvaney1 1 Zoology Department, University of Melbourne, Parkville, Vic. 3010 2 School of Physics, University of Melbourne, Parkville Vic. 3010 3 SARDI Aquatic Sciences, PO Box 120 Henley Beach SA 5022 4 LEMAR, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Brest, France [email protected] Density dependence in abalone: how local populations respond to fishing Abalone are very valuable on Asian markets, they are sedentary, and they emerge from crevices on reaching maturity. Thus divers can exert very high fishing pressure on stocks. As populations’ densities are reduced, we know that compensatory density dependent (DD) processes must increase population growth rate. The fishery would not be sustainable if this were not so. But the mechanisms that change population growth rate and their relative importance are not known. We have experimentally manipulated the density of Haliotis laevigata at all life history stages, and found DD effects at almost all stages, especially on growth. Settlement of larvae was not significantly affected by larval density, but post-larval growth and mortality was DD. In seeded cryptic juveniles mortality appears to be somewhat related to density, growth was strongly DD and the timing of first gonad development was related to growth rate. In thinned adult aggregations the growth of smaller adults and the fecundity of larger adults increased. Matrix model simulations based on available abalone population parameters show that DD growth has different effects from the DD fecundity or mortality that is implicitly assumed in standard fishery models. DD growth effects stabilise at much longer time scales. This suggests fishery management models may need modification. DD growth may also render local stocks progressively more vulnerable to fishing as they are fished down.

Abstracts - Page 32 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Deagle, BE1,2*, DJ Tollit3, SN Jarman2, MA Hindell1 & NJ Gales2 1 Zoology Department, University of Tasmania, Box 252-05, Hobart Tas. 7000 2 Australian Antarctic Division, Channel Highway, Kingston Tas. 7050 3 Fisheries Centre, University of British Columbia, Vancouver, Canada [email protected] Studying diet using genetic identification methods: Analysis of prey DNA in scats from captive Steller’s sea lion Recent studies show it is possible to detect prey DNA in the scats of predators, indicating genetic methods may be a useful tool for diet analysis. Currently, pinniped diet is primarily studied by morphological identification of bones found in scats. However, the data are biased since bones from some species can readily survive digestion whereas bones from other species are destroyed. In order to determine if prey DNA can be reliably recovered from sea lion scats and if this genetic data could be used to reconstruct diet, a captive feeding trial was set up. No previous studies have looked at the recovery of prey DNA from scats in captive mammals. A diet including fish (5 species) and squid (1 species) was fed to 2 captive sea lions over a six week period and scats were collected. DNA was extracted from soft parts of the scats and tested for presence of prey DNA using specifically developed PCR tests. DNA from the prey species feed throughout the trial is detected in ~90% of the tests (640 tests carried out). Squid was reliably detected even though it represented only 6% of the daily diet. Diet items fed for 1 day then removed from the diet were only detected in scats collected within 48 hours of ingestion. Preliminary analyses indicate that the amount of prey DNA present in the scat is proportional to the mass of prey item consumed. Future directions of this research will be discussed. ______

Dell, James & Alistair Hobday Sustainable Pelagic Fisheries and Ecosystems, CSIRO Marine Research/ University of Tasmania, Castray Esplanade Hobart Tasmania 7001 [email protected] Long-term changes in the school composition of a declining tuna species Southern Bluefin Tuna (SBT) are a valuable commercial fish species which have experienced an estimated 90% decline in parent biomass over the last 40 years. Juvenile SBT, which school in the Great Australian Bight during the austral summer, have been the subject of 40 years of tag-recapture studies. The data from these tagging studies are used in a novel investigation to determine if schooling behaviour can be used as an abundance indicator of the juvenile population. Biases and caveats associated with the data collection, method of analysis and biological changes over time were considered and where possible removed. Summary metrics describing school composition were calculated and compared between schools from different years and decades. These metrics describe the mean, maximum, minimum, variance and the degree of size structure of the fish sizes within a school. Significant trends were found in these metrics over the 40 year period; increasing by 14 - 74%. These metrics suggest changes in schooling behaviour over a 40 year period were inversely related to the population decline. Monitoring population changes using metrics of school composition may be used to indicate further decline or recovery of SBT and, therefore, have important applications to the future precautionary management strategies for this species. ______

Abstracts - Page 33 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Douglas, J (Poster) Primary Industries Research, Private Bag 20, Alexandra Vic. 3714 [email protected] Acoustic telemetry in Victorian fresh and estuarine waters- Overview of some current research Researchers from the Victorian Department of Primary Industries are currently undertaking three separate studies to investigate the movement and habitat use of selected native fish species using acoustic telemetry. The species include golden perch (Macquaria ambigua), Australian bass (Macquaria novemaculeata) and estuary perch (Macquaria colonorum). Golden perch are a popular angling species native to the Murray Darling basin and have been stocked into Lake Eildon in north-east Victoria to enhance recreational angling. However, anglers have not been able to catch many of the fish even though surveys have shown relatively large numbers are present in the lake. Acoustically tagged golden perch were observed regularly over several months and were found to have home ranges but did not necessarily frequent the areas where anglers were targeting the species. Australian bass movement is currently being monitored in the Snowy River in eastern Victoria. Adult Australian bass are catadromous and little information is known in the Snowy River system regarding the specific timing, triggers or extent of the downstream migration of bass or, where they spawn. Adult Australian bass have been implanted with acoustic tags and strategically deployed listening stations spaced out along the river to the estuary to track the movement of the tagged fish. Estuary perch are a closely related species to Australian bass but are generally restricted to the estuarine sections of rivers. The large-scale seasonal movement, small scale daily movement and habitat preferences of estuary perch in the lower Snowy river and estuary are being investigated by utilising a combination of fixed listening stations and real time tracking to monitor movements of estuary perch. Bathymetric mapping of the estuary is being undertaken to assist in identifying key estuarine habitat factors. So far the fish have been found to be largely nocturnal, cover oriented during daylight and highly mobile throughout the estuary and lower river. ______

Dudgeon, Christine* & Janet Lanyon (Poster) School of Life Sciences, University of Queensland, St. Lucia Qld 4072 [email protected] The ecology of the leopard shark Stegostoma fasciatum in southeast Queensland The leopard shark is a unique demersal species found in the shallow coastal waters of the tropical and subtropical western Pacific and Indian Oceans. More commonly found alone in and around rocky and coral reefs, adult leopard sharks are known to form temporal aggregations at various locations throughout their range. One of the largest known aggregations occurs annually in the oceanic coastal waters of southeast Queensland over the summer months with over 30 adult leopard sharks seen within an approximate two- hectare region. To date, leopard sharks have not been studied in the wild and the duration and function of these aggregations is unknown. This project will investigate the ecology and population dynamics of the leopard shark focusing upon the temporal southeast Queensland aggregations using techniques that include mark-recapture tagging, sonic telemetry and genetic analysis. We report here on progress of the project at the conclusion of the first field season (November 2003 to March 2004). 119 leopard sharks have been individually identified in the aggregation through photo-identification and tagging. The aggregation appears to be composed entirely of reproductively mature adults with a strong female bias. We have commenced the investigation of seasonality and site-fidelity through the deployment of sonic tags and listening stations as well as developing a leopard shark specific microsatellite library for population and kinship genetic analysis. ______

Abstracts - Page 34 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Edyvane, Karen1, Piers Dunstan2 & Craig Johnson3 1 School of Geography and Environmental Studies, University of Tasmania, Tasmania 7001 2,3Department of Zoology, School of Biological Sciences, University of Tasmania, Tasmania 7001 [email protected] Large-scale loss of giant kelp, Macrocystis pyrifera, forests off the east coast of Tasmania World-wide, kelp ecosystems face the threat of large-scale deforestation from herbivory (usually from sea urchins) and climate change. Following anecdotal reports of kelp loss, a temporal analysis was undertaken of the distribution of Macrocystis pyrifera forests off the east and south coast of Tasmania, focussing on 9 specific regions. Results from a GIS-based analysis of aerial photographic data (the longest dataset), indicate an average decline of ~47% of dense M.pyrifera surface canopies in eastern Tasmania over the 1944-2000 period. Despite considerable annual fluctuations, overall rates of canopy loss varied from ~18% (Port Arthur) to >90% (Maria Island). In all 9 regions examined, kelp forests have been unable to fully recover to their original historical extent. Greatest losses occurred along the north east coast. Major kelp canopy loss episodes coincided with strong El Niño events in 1972, 1982-83 and 1987.Historical oceanographic and meteorological data reveal significant ENSO-related changes along the east coast of Tasmania over the period 1944-2000, including declining rainfall (post-1979), a 1.5-2oC rise in minimum temperatures, reduced inter-annual variability in SSTs, and a declining influence of subantarctic waters. Major threats to M.pyrifera include: increased sea temperatures (due to increased influence of EAC eddies on the east coast of Tasmania); increased mortality from storms (due to increased frequency and severity of El Niño episodes); and increases in sea urchin populations. Kelp loss has possibly been exacerbated by the low diversity of kelp ecosystems and their southerly geographic position, which precludes range retraction during El Niño events. Patterns of kelp canopy loss off eastern Tasmania and elsewhere (ie. King Island, southern NSW) supports evidence for a large-scale, inter-decadal change in ocean climate and ecological regime shift in south eastern Australia, similar to the 1976-1977 regime shift in the California Current. If so, then there are potential large-scale consequences for the region’s pelagic ecosystems, fisheries and biodiversity. ______

Abstracts - Page 35 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Egli, Daniel1*, Russ Babcock2 & John Montgomery1 1 Leigh Marine Laboratory, University of Auckland, P.O. Box 349, Warkworth 1241, New Zealand 2 CSIRO Marine Research, PO Box 5, Wembley WA 6913 Australia [email protected] Monitoring long-term presence/absence and movement of temperate sparid Pagrus auratus in a no-take marine reserve Depletion of fisheries worldwide calls for new approaches in fisheries management. It has been widely proposed that no-take marine reserves might benefit adjacent fished stocks. However, models of interactions between marine reserves and non-reserve areas have generally made simplistic assumptions about fish behaviour. While the understanding of movement patterns is absolutely central to the effectiveness of marine reserves, information relating to such movements is sparse, particularly at scales relevant to (often small) marine reserves. Results from long-term ultrasonic monitoring of New Zealand Snapper (Pagrus auratus) within the Cape Rodney to Okakari Point marine reserve in NE New Zealand from October 2001 to present revealed large variability in individual behaviour. The range of movement patterns observed includes some fish being resident for the entire tracking period, while others were more mobile. Some mobile fish left the receiver array permanently and others have returned after varying periods. Nearly all fish showed some level of site fidelity for varying periods of the time they were tracked. Fish activity peaked in the summer, and the highest densities of fish were also recorded during this time. Relative fish density on reefs in the marine reserve varied by over 200% between summer and winter, most likely due to seasonal migrations. The present study suggests that fish do not display uniform behaviour, even within a single species. Therefore, using random diffusion models would not be appropriate to examine marine reserve effects and model crossboundary movements. Examining such complex range of behaviour may be a key component for achieving desirable outcomes for both conservation and fisheries. ______

Elliott, Pam1 & Thomas Moore 1 Marine Discovery Centre, Channel Highway, Woodbridge,Tas 7162 2 CoastView Enterprises, South Hobart, TAS 7004 [email protected] Australia’s oldest marine discovery centre offers world- class education opportunities involving students in scientiﬁc research Set on the shores of Tasmania’s D’Entrecasteaux Channel the Woodbridge Marine Discovery Centre (WMDC) challenges students of all ages to learn about, discover and care for the marine environment through diverse shore and sea-based programs. The oldest of its kind in Australia, in the 25 years since the WMDC opened, approximately 125,000 students, teachers and parents, have had the opportunity to ‘pat’ the sharks, play with the stars and hermit crabs and ‘go to sea’ on the RV Penghana. In 2004 the WMDC is moving in an exciting new direction; involving students in authentic scientiﬁc research. With the support of state and federal government departments, local university students, and, in particular, with the support and donations of Tasmanian and international private enterprise we will have the capacity to record and download all data using modern marine science instrumentation. Biodiversity and meteorological data will also be recorded daily. The project aims to provide the facility for on-line access of data products by students and the public. Ultimately this will enable Tasmanian students to play a direct role in studies of seasonal and inter-annual variability vital to understanding the impacts of climate change, introduced species, and other anthropogenic effects. Together this should give a comprehensive picture of the complex marine environment in the D’Entrecasteaux Channel. ______

Abstracts - Page 36 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

England, Matthew H1 & Stephanie K Moore2 1 Centre for Environmental Modelling and Prediction, School of Mathematics, University of New South Wales NSW 2052 Australia 2 School of Biological Earth and Environmental Sciences, University of New South Wales NSW 2052 Australia [email protected] Jervis Bay circulation and modelling: Some work inspired by the pioneering efforts of Peter Holloway Peter Holloway pioneered our understanding of the circulation and hydrography of Jervis Bay, a coastal embayment on the south coast of New South Wales. Peter undertook extensive observational and modelling analyses in Jervis Bay, leading to much of our present-day knowledge of its oceanography. Here we will review some of Peter’s pioneering efforts in this regard, as well as presenting a model analysis of thermally- driven summertime flow regimes in the bay. Of particular interest is the extent to which overnight cooling can induce a density-driven outflow and result in ventilation of the bay. To this end, a series of experiments is studied with different initial ocean temperature conditions. The model is then forced using one of two typical summertime diurnal air temperature fields. The first case is that associated with warmer north to northeasterly air masses, whereas the second is more typical of a southerly wind system. The prescribed air temperature is based on summertime meteorological observations. Model results suggest that diurnal cooling can be sufficient to produce a significant density-driven circulation in Jervis Bay during summer. The circulation strength is sensitive to the offshore temperature field and to the minimum of the diurnal air temperature cycle. In particular, overnight air temperatures must be cooler than the temperature of waters at depth at the mouth of the bay to initiate a density-driven circulation. During upwelling favourable winds (north-easterlies) warmer air temperatures and denser offshore waters see a reduced thermal component of circulation. Conversely, southerly winds tend to be accompanied by cooler air temperatures, deeper mixed layers and less dense deep water at the mouth of the bay; these factors conspire to yield an enhanced thermal circulation. Using an idealised tracer we estimate ventilation rates for the thermal component of circulation in Jervis Bay. Ventilation of the bay by thermal forcing alone can be as rapid as about 7-14 days during south-easterly wind periods. After upwelling events, in contrast, summertime thermal forcing is too weak to induce any substantial ventilation, in which case coastal-trapped waves provide the only likely ventilation mechanism. In this scenario, enhanced stratification in the bay provides a medium on which internal waves can propagate around the bay, and also a barrier to overnight convective cooling. ______

Feng, Ming CSIRO Marine Research, Floreat WA 6014 [email protected] Tracking two oppositely-rotating eddies off the Western Australian coast A multi-disciplinary R/V Southern Surveyor cruise was conducted in October 2003 to quantify upper ocean productivity within two adjacent oppositely-rotating mesoscale eddies. In this study, satellite altimeter data, shipboard Acoustic Doppler Current Profiler (ADCP) and Conductivity-Temperature-Depth (CTD) measurements during the cruise, and Argo profiling float data are used to track the temporal evolution and spatial structure of the two eddies. Results show that the two eddies detached from the Leeuwin Current during late August to early September, and reached their mature stages during the cruise time. Fitting the ADCP data with a Gaussian shape, the anticyclonic (warm-core) eddy has a peak azimuthal velocity of 65 cm/s at the radius of 63 km, and the cyclonic (cold-core) eddy is slightly smaller and has a peak azimuthal velocity of 60 cm/s at the radius of 49 km. Both eddies have deep-reaching structures, and the peak azimuthal velocity at 1000 m is estimated to be about 20 cm/s for the cyclonic eddy. The water-properties in the two eddies are quite stable over the cruise time. From temperature-salinity diagrams, the mixed layer water in the core of the anticyclonic eddy is suggested to contain mostly the Leeuwin Current water, and the mixed layer water in the cyclonic eddy is rather similar to surrounding Indian Ocean open ocean water. These analyses set the scene for the ocean productivity research using the cruise data.

Abstracts - Page 37 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Feng, Ming1, Susan Wijffels2, Stuart Godfrey2 & Gary Meyers2 1 CSIRO Marine Research, Underwood Avenue, Floreat 6014 WA Australia 2 CSIRO Marine Research, Castray Esplanade, Hobart 7000 Tas. Australia [email protected] Do eddies play a role in the momentum balance of the Leeuwin Current? The Leeuwin Current is a poleward flowing eastern boundary current off the Western Australian coast, and longshore momentum balance in the current has been hypothesized to be among the southward pressure gradient force, the northward wind and bottom stresses. In this study, the longshore momentum balance of the Leeuwin Current is revisited, using a high-resolution upper ocean climatology to determine the longshore pressure gradient, and altimeter and mooring observations to derive the eddy induced Reynolds stress. North of the Abrolhos Islands (situated near the shelf break between 28.2-29.3°S), the pressure gradient is weak and the longshore momentum balance is between the pressure gradient and wind stress. South of the Abrolhos Islands, the Leeuwin Current is highly unstable and strong eddy kinetic energy is observed offshore of the current axis. The longshore momentum balance on the offshore side of the current reveals an increased longshore pressure gradient, weakened longshore wind stress, and a significant Reynolds stress exerted by the mesoscale eddies. The eddy Reynolds stress has a -0.5 Sv correction to the Indonesian Throughflow transport estimate from Godfrey’s island rule. The mesoscale eddies draw energy from the mean current through mixed barotropic and baroclinic instability, and the pressure gradient work overcomes the negative wind work to supply energy for the instability process. Hence the large scale pressure gradient in the East Indian Ocean drives the strongest eddy kinetic energy in the Leeuwin Current among all the mid-latitude eastern boundary currents. ______

Fernandes, Milena1*, Peter Lauer1,2 & Anthony Cheshire1 1 South Australian Research and Development Institute and Aquafin CRC, Aquatic Sciences Centre, PO Box 120, Henley Beach SA 5022 2 Flinders University of South Australia and Aquafin CRC, GPO Box 2100, Adelaide SA 5001 [email protected] Nitrogen flows associated with tuna farming in Port Lincoln, South Australia The past decade has seen considerable expansion of the aquaculture industry in Australia, with the value of production almost trebling from $256 million in 1991/1992 to $733 million in 2001/2002. Farming of southern bluefin tuna (Thunnus maccoyii) alone contributes to more than 30% of this total value. As aquaculture expands, there is a continuing need to ensure that any environmental effects are minimised. In this project we are interested in assessing inputs and environmental pathways of nitrogen supplied with fish feed to commercial tuna pens in Port Lincoln, South Australia. Preliminary results from samples collected in the first month of the farming season suggest that less than 10% of nitrogen supplied to the pens as feed is actually retained by the fish, with more than 90% being lost to the environment. The bulk of the environmental loss occurs in dissolved form, released primarily as ammonia from fish metabolism. The flux of sinking particulate matter, composed essentially of faecal matter, might convey as much as 22% of the environmental loss to the seafloor. Bacteria and infauna in the sediments rapidly break down the organic matter that reaches the seafloor to reintroduce nutrients into the water column. This sedimentary flux of nitrogen significantly increased only two weeks after the pens were stocked and might transfer as much as 25% of the sedimented nitrogen back to the overlying water as dissolved inorganic nitrogen. This process reduces the amount of nitrogen that is actually buried in the sediments to less than 15% of the original feed input with the rest being assimilated by biota, taken up by scavenger organisms or flushed out of the system. This study constitutes a first step in the assessment of nutrient flows associated with tuna farming in open waters off the South Australian coast.

Abstracts - Page 38 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Lauer, Peter1,2, Milena Fernandes1, Jason Tanner1, Peter Fairweather2 & Anthony Cheshire1 (Poster) 1 South Australian Research & Development Institute, Aquatic Sciences, and Aquafin CRC, PO Box 120 Henley Beach SA 5022 2 Flinders University of South Australia and Aquafin CRC, GPO Box 2100, Adelaide SA, 5001 Tuna farming and the seafloor Environmental research on southern bluefin tuna (SBT, Thunnus maccoyii) aquaculture near Port Lincoln, South Australia, seeks to better understand ecosystem processes. This is necessary to assess potential impacts of SBT aquaculture on the environment and ensure industry sustainability. Measurements of sediment condition form part of this assessment. Sediment biogeochemical characteristics change within a few weeks of the stocking of tuna pontoons, coincident with increased sedimentation rates. Nearly all commercial SBT farms use baitfish as the primary feed source, with at least 2 companies testing pelleted feed. This study investigates baitfish and pellet feed types, using commercial and research pontoons. Sedimentation rates in March 2004 were 92 g dry weight m-2d-1 directly adjacent to a stocked tuna pontoon fed baitfish, which was four times higher than values recorded at control sites 1 km away. Increased sedimentation rates were associated with shifts of seafloor mineral grain size towards finer fractions (silts and fine sands <125 µm) with higher water content. Phosphate in seafloor porewater (0.04 µmolcm-3) was about seven-fold higher than at control sites. Phosphate and ammonium fluxes measured adjacent to active tuna pontoons using shipboard core incubations (227 and 583 µmolm-2h-1) were 18 and 6 to 10 fold higher than control sites, respectively. However, no difference in NOx fluxes was found. Studies during 1996 in Port Phillip Bay, Victoria, yielded sediment ammonium fluxes in the range of 4 to 500 µmolm-2h-1, with the highest rates recorded during summer. As this study has had only one sampling event at the start of autumn, it is expected that subsequent winter samples may yield lower nutrient fluxes. Farming of SBT clearly generates changes in sediment processes, but it is likely that these are reversible given that the sites are fallowed for part of each year. ______

Field, Iain C, Corey JA Bradshaw, Harry R Burton & Mark A Hindell (Poster) University of Tasmania, Hobart Tas. 7000 Seasonal use of oceanographic and fisheries management zones by juvenile southern elephant seals (Mirounga leonina) from Macquarie Island The foraging distribution of marine predator populations is important for effective modelling and management of pelagic marine systems. We tracked 31 juvenile southern elephant seals from Macquarie Island (158º 57’E, 54º 30’S) over their annual post-moult and mid-year trips to sea. We calculated the amount of time spent in regional fisheries management areas and within bounded oceanographic regions. During the austral summer, juvenile seals spent over 90 % of their time south of the Antarctic Polar Front and ~ 80 % within fisheries management regions (CCAMLR and Exclusive Economic Zones). In winter, seals spent ~ 75 % of their time in the region bounded by the Antarctic Polar Front and the southern boundary of the Antarctic Circumpolar Current, and ~ 60 % within fisheries-management regions. The time spent per region differed significantly between summer and winter. Our results demonstrate that juvenile southern elephant seals from Macquarie Island spent more time south of the Antarctic Polar Front and within fisheries management areas than previously suspected. ______

Abstracts - Page 39 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Forbes, S1* & C Macleod1 1 Tasmanian Aquaculture & Fisheries Institute and Aquafin CRC, University of Tasmania, Hobart, 7001 [email protected] Development of quantitative visual assessment techniques for the evaluation of sediment condition Deposition of waste feed and faeces from finfish culture can result in organic enrichment of sediments. This in turn can result in alterations in sediment biochemical properties (including production of methane and hydrogen sulphide gas) and changes in benthic macrofaunal communities which are visually recognizable on the sediment surface. Video assessment has been used in many places worldwide to assess environmental impact and in several countries is used by regulatory bodies as part of their environmental monitoring of finfish farms. At present, assessment is largely qualitative, comprising detailed written descriptions of the video content. This is time consuming to prepare and review and makes temporal comparisons difficult. This study aimed to define a more quantitative approach for video assessment thereby reducing the subjectivity of these assessments. Previous research, background information and the benthic community structure also suggest that there are distinctive and easily recognisable infaunal characteristics indicative of differing levels of impact. Observations of sieved benthic samples collected for infaunal analysis suggested that analysis of photographs of these samples could be used to distinguish and categorise these levels. Consequently, in this study two quantitative visual assessment techniques were developed: i) video of epibenthic characteristics ii) photographs of benthic infauna. Results indicated that quantitative assessment of sediment video footage can not only clearly differentiate between unimpacted and impacted conditions, but can also distinguish levels of impact. Visual characterisation of benthic samples also showed promising results, clearly distinguishing impacted from unimpacted conditions. Both approaches correlate well with the analysis of benthic community structure and relate strongly to farm production levels. These techniques are simple and inexpensive and could be easily incorporated into regular monitoring programs to provide a rapid assessment of sediment condition, identifying key transition stages in the sediment degradation / recovery processes which would assist in planning and help to ensure environmental sustainability. ______

______

Abstracts - Page 40 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Forehead, HI1,2*, GA Kendrick1, PA Thompson2, A Waite3 1 Department of Plant Biology, University of Western Australia, Crawley WA 6009 2 CSIRO Division of Marine Research, Castray Esplanade, Hobart Tas. 7000 3 Centre for Water Research, University of Western Australia, Crawley WA 6009 Scratching the surface: Benthic microalgae and their effects on N cycling in WA coastal waters The west coast of Australia is dominated by warm, oligotrophic waters, shallow carbonate-rich sediments and little terrigeneous nutrient input. Irradiance and light penetration are generally high so that benthic primary production is substantial and can equal that in the water column. Microphytobenthos has been shown to have a major influence on nutrient cycling elsewhere, but little work has been published examining the Western Australian marine environment. This presentation focuses upon anthropogenic impacts on microphytobenthos and sediment-water column nitrogen cycling. The effects of artificial enclosures (harbours) on microphytobenthic communities and nitrogen cycling were examined over an annual cycle at 2 locations in Cockburn Sound, Western Australia. Core and bulk sediment samples were taken from bare sandy areas in water 6-7m deep at sheltered and exposed sites. Ex-situ core incubations were used to determine rates of N2 fixation, denitrification, fluxes of macronutrients and oxygen. Bulk sediment samples were analysed for pigments, fatty acids, neutral lipids, organic C and N content and isotopic composition. Significant differences were found in both flux and biomarker data between the 2 areas, inside and outside the harbours and between summer and winter. Biomarker data gave information about the algal, bacterial and faunal composition of the sediments and how it changed across the same temporal and spatial scales as the fluxes. The combination of process studies and biomarker information promises to be a powerful tool for resolving a range of questions on the magnitude and mechanisms of nitrogen inputs and exports from these shallow ecosystems. ______

Foster, Jacqui MESA Tasmanian State Representative, c/o Marine Discovery Centre, Channel Highway, Woodbridge Tas. 7162 [email protected] ‘MESA Facilitating Marine Monitoring- A Case Study’ MESA (Marine Education Society of Australasia) provides a forum for the sharing of information and ideas to facilitate the development of leading environmental education and interpretation programs with a marine and coastal focus. MESA is currently working alongside schools from Victoria, King Island and north-west Tasmania to initiate an environmental monitoring program spanning Bass Strait. A forum on the MESA website will facilitate the exchange of data and other information on the ecology of the marine and coastal environments which students have been monitoring. Marine and coastal monitoring projects executed by school and community groups provide an invaluable ‘early warning’ system through which changes (adverse or otherwise) within the environment can be seen. Community groups, government bodies and members of the scientiﬁc research community will be able to log into the site to access data, share hypotheses and link studies with a common goal, aiding in raising levels of awareness and cohesion between the scientiﬁc and education communities. ______

Abstracts - Page 41 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Fox, Nicola J* & Lynnath E Beckley School of Environmental Science, Murdoch University, WA 6150 [email protected] Hotspots, biogeography, complementarity and pragmatism: Priority areas for conservation of Western Australian coastal fishes Western Australia has an extensive coastline ranging from the tropical north to the temperate south but, along its length, there are only seven multiple use marine parks and one marine reserve (no take). With the global trend towards the establishment of marine reserves and development in the science of their selection, the opportunity was taken to compare a range of reserve selection methods for Western Australia. Species richness and endemism richness hotspots, biogeographic regions and complementarity analysis were used to determine priority areas for conservation of Western Australian neritic fishes (n = 1 855). There was found to be a general decline in species richness from north to south, with all the species richness hotspots located on the Northwest Shelf. There was no overlap with the species richness and endemism hotspots as the latter all occurred on the south and southwest coasts. The regions highlighted by the biogeographic and complementarity analyses occurred around the entire coastline. However, the complementarity analysis proved to be the most efficient method, as >95% of all fish species could be protected in six, appropriately located, 100 km long sections of coastline. As Western Australia currently has a system of existing and proposed marine protected areas, it was considered pragmatic to include these in the complementarity analysis. This reduced the efficiency and indicated that some of the protected areas may not be well situated for the conservation of neritic fishes. The analysis also highlighted gaps in conservation effort on the Kimberley and south coasts of Western Australia. ______

Frusher, Stewart Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Tas 7001 [email protected] Behaviour: The missing ingredient in fisheries assessment The difficulty in working in the marine environment has resulted in establishing many ‘defacto’ measures of animal abundance. In fisheries, fish abundance is often related to catch rates such that changes in catch rates reflect relative changes in the abundance of fish in the ecosystem. While fishery scientists agree that such a relationship is simplistic, most fisheries are still dependent on catch rate data for their annual assessments. Recent research evaluating the relationship between catch rates and animal abundance of lobsters has identified that behaviour of both the fisher and the species being fished are important for correct interpretation of catch rate data. Intraspecies interactions would result in changes in the size structure of the population that is not reflected in catch rate data and, in the case of lobster fisheries, may have underestimated declines in recruitment. Changes in the behaviour of fishers, or fleet dynamics, due to management change has resulted in catch rate changes that are independent of changes in the abundance of lobsters. ______

Abstracts - Page 42 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Fulton, Elizabeth A, Randall Gray, L Rich Little, Vincent D Lyne, A David McDonald, Keith Sainsbury, Brian Hatfield CSIRO Marine Research, PO Box 1538, Hobart Tas. 7001 [email protected] Marine ecosystem modelling and multi-sector monitoring on the Northwest Shelf of Australia The management of marine resources on the Northwest Shelf (NWS) of Australia has been associated with the successful implementation of monitoring programs in combination with the use of ecosystem and natural resource models. A key part of this has been the use of management strategy evaluation (MSE). MSE has been effective in resolving the multiple and conflicting objectives of the many stakeholders within Australian fisheries and so the approach has been extended to multiple-use management of the entire regional ecosystem of the Northwest of Australia. This shift in focus from a single to multiple sectors has also required a shift in the breadth of monitoring reports that must be brought together, as well as necessitating a shift in the complexity of the models used to represent the system. A spatially explicit agent-based biophysical simulation model was developed as the basis of the NWS multi- sector MSE. This model (NWS-InVitro) employs a mix of classical dynamic models and individual-based model structures. This hybrid form facilitates the handling of multiple scales and allows for consideration of the links between the ecosystem dynamics and cumulative impacts of human activities related to fishing, conservation, coastal development and the extraction of oil and gas. Investigation of the implication of uncertainty is a central part of the MSE framework. Uncertainty in system behaviour, developmental trajectories and management decisions (e.g. the form of monitoring schemes) have all been considered in this multi-sector MSE. Numerous lessons have been learnt as part of the MSE process, such as the crucial role of monitoring – not only for learning and scientific enquiry (e.g. basis for model development and validation), but also in the on-going management of multiple uses. A well structured monitoring regime, for example, can ensure that the levels of contaminants in highly mobile species can be detected and appropriate management responses determined. ______

Abstracts - Page 43 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Gaston, Troy1*, Thomas Schlacher1 & Rod Connolly2 1 Faculty of Science, University of the Sunshine Coast, Maroochydore DC, Qld 4558 2 School of Environmental and Applied Sciences, Griffith University, Gold Coast, Qld 9726 [email protected] Are small estuarine plumes traceable on exposed open coasts? Coastal seas trap much of the material exported from land, with most of the matter transported by rivers to the sea being deposited fairly close to shore. This riverine-and estuarine conduit may be visually observable in the form of prominent plumes which push from estuaries into the nearshore zone. Such plumes and their interaction with the nearshore marine environment are mostly documented for large systems (e.g. Mississipi, Congo, Amazon), but on the Australian East Coast the setting is different: rivers are much smaller, estuaries discharge directly onto an exposed coast, and distinct plumes are only evident after substantial rainfall events. Our principal goal was to measure some fundamental characteristics for two small plumes originating from the Mooloolah and Maroochy Estuaries on Australia’s East Coast. Estuarine out-welling is evident in the nearshore zone after rainfall with substantially elevated nutrient levels (DIN increases by ~330%, Si by ~530% ), increased phytoplankton stocks (chlorophyll a up by 20%) and a less saline and more turbid water column. These changes to water chemistry are often confined to surface layers: the plumes are ‘buoyant’. Carbon of suspended particulates in the visible plume shifts from approximately marine source-dominance during dry weather (δ13C ~ -21.5‰) to a stronger influence of estuarine, out-welled material following rain (δ13C ~ -23.0‰). The δ13C value of organic material in the sediments below plumes became enriched (~ 3.2‰) after rainfall indicating a non-estuarine/terrestrial carbon source to nearshore seafloor areas. However, Cu concentration of sediments increased (~ 0.7 mg/kg) after rainfall indicating an estuarine source. Trophic subsidy of nearshore food webs by plumes was assessed by comparing carbon isotope signals and Cu concentration in key consumers distributed both in areas of direct plume influence and in offshore/reference areas. 3-spot sand crabs (Portunus sanguinolentus) from plume areas have significantly depleted δ13C values (-17.7 ± 0.2‰) and higher Cu concentrations (~ 38 mg/kg) compared with conspecifics caught offshore (–16.8 ± 0.1‰ and 12 mg/kg, respectively), indicating that some carbon carried by the plume is incorporated by marine consumers. ______

Godfrey, J Stuart1, Mai-Britt Kronborg2 & Detlef Quadfasel3

1 CSIRO Marine Research, Hobart Tas. 7000 2 Danish Centre for Earth System Science, Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Denmark 3 Detlef Quadfasel, Universität Hamburg, Zentrum für Meeres- und Klimaforschung, Institut für Meereskunde, Bundesstr. 53, D-20146 Hamburg, Germany [email protected] Links between tidal mixing and the Leeuwin Current A combination of data from a year-long mooring deployment enclosing the region of most active barotropic tides in the Timor Sea, plus altimeter data, have been used to explore the mass budget of seasonal mean water flow into and out of this region. In winter, geostrophic flow out of the region appears balanced to within error bars by Ekman inflow. In summer, however, Ekman outflow is significantly less than the measured geostrophic inflow in the top 125m (which does not include possible outflows in “bottom triangles”). It is postulated that excess outflow may occur in the bottom mixed layer, and be due to tidal mixing of surface water with deeper, colder water. Peter Holloway’s studies of the Northwest Shelf have been a major guide in the planning of this work. ______

Abstracts - Page 44 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Golding, Rosemary (Poster) Department of Anatomy and Histology, University of Sydney, Sydney, NSW 2006 Australia and Australian Museum, 6 College Street, Sydney, NSW 2010 [email protected] Morphological studies of Australian Amphibolidae (Gastropoda: Pulmonata) The morphology of two Australian species of the intertidal marine pulmonate family Amphibolidae is described. The anatomy of Salinator solida and Salinator fragilis are discussed, with comparison to the type species of the family, the New Zealand Amphibola crenata. Although the shell, opercular and external morphology of both Salinator species show some similarities, aspects of the reproductive anatomy of these species were substantially different. The conﬁguration of the terminal genital apparatus of S. fragilis was found to be monaulic, as in A. crenata, with an undivided hermaphrodite duct and a single structure (possibly a combined penis/ovipositor) at the genital aperture. The gonoduct of S. solida diverges, with a separate muscular vagina and an unusual male copulatory organ uniting at a single genital aperture. Scanning electron micrographs of radulae from S. fragilis, S. solida and A. crenata also provide evidence of divergence between the species, both within and between the current generic concepts. Plesiomorphic pallial structures include a pair of opposed ciliated bands found in A. crenata and S. fragilis, but these are absent in S. solida. The substantial anatomical differences observed between the two Australian amphibolids suggest that a separate genus should be created to include S. solida. Work is continuing on the morphology and histology of these animals. ______

______

Goldsworthy, Laurie1 & Tajima, Hiroshi2 1 Australian Maritime College, Launceston, Tasmania; 2Kyushu University, Kyushu, Japan [email protected] Water injection for control of emissions of oxides of nitrogen from ship engines Oxides of nitrogen (NOx) emissions produced by the international oceangoing merchant fleet have been estimated at about 20 million tonnes per annum, equivalent to almost 20% of global NOx emissions from fossil fuels. NOx emissions participate in the formation of photochemical smog and acid rain, and contribute to greenhouse warming and eutrophication. The Air Pollution Annex to Marpol (Annex VI) aims to limit NOx emissions for a standard test cycle to 17g/kWh for the large, slow speed marine diesels, and less for smaller engines. This measure will take some time to significantly impact on total emissions due to the slow turnover of marine engines. It is likely that further restrictions will occur. Most marine engine manufacturers can achieve the required Marpol Annex VI levels by measures such as engine tuning and modified fuel injectors. To achieve much lower emissions levels, measures such as water injection, fuel-water emulsions and after-treatment using selective catalytic reactors are employed. Computational Fluid Mechanics (CFD) is utilised to optimise the injection of water into the burning fuel spray, to reduce burnt gas temperature and thus NOx formation rates. Computed results are compared with measurements of flame extent and temperature in a visual test engine. The configuration of the diesel spray in the test engine models that of slow speed marine diesel engines, which provide the bulk of the propulsive power for global shipping and produce the majority of the NOx emissions. The challenge is to locate the injected water in the limited regions where NOx forms, without increasing soot emissions or interfering in the ignition and efficient combustion of the fuel. It is shown that coincident water and fuel sprays, with water injection commencing at the same time as fuel injection, provides an effective strategy.

Abstracts - Page 45 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Gray, RB1*, PJ Canfield2 & TL Rogers1 1 Australian Marine Mammal Research Centre PO Box 20 Mosman NSW 2088; 2 Faculty of Veterinary Science University of Sydney NSW 2006 [email protected] The health status of the leopard seal, Hydrurga leptonyx, in Prydz Bay, Eastern Antarctica and NSW, Australia: A comparative study As upper trophic species, leopard seals, Hydrurga leptonyx, are an important indicator species of the Antarctic ecosystem and long-term monitoring of this species may be useful for the assessment of the marine ecosystem they inhabit. Whilst the majority of leopard seals are confined to the circumpolar pack ice, there is some north-south movement of individuals, the majority of which are immature non-breeding seals, to the sub-Antarctic islands and the Australian coast in winter. The presence of these seals along the Australian coastline poses important considerations for personnel involved in their management. A comparative study of the health status of leopard seals in Antarctica and in NSW was conducted. The health status of the leopard seal in Antarctica was assessed by an integrated study of body condition, clinical examination, parasite studies, and commonly utilised blood values including haematology, serum biochemistry and serum proteins. The majority of these seals were in good body condition, and although clinical disease was observed in these seals, it was not considered to be of sufficient severity to affect health status. Obvious differences in body condition, incidence of clinical disease, and differences in haematology, biochemistry and serum protein concentrations were observed in leopard seals hauled out in NSW compared to those in Antarctica. The majority of the seals hauled out in NSW were in poor body condition, and the differences in their blood values were attributed to differences in health status and differing environmental and dietary influences for the two populations. A practical outcome of the present study is the development of reference ranges for haematology, serum biochemistry and serum protein values in the leopard seal in Antarctica. These will serve as important baseline values for comparative studies of the health status of leopard seals in Antarctica, the sub- Antarctic and leopard seals hauled out along the Australian coast. ______

Grifﬁn, D, I Barton, M Cahill, J Dunn, J Mansbridge, C Rathbone, K Ridgway, G Smith, K Suber, P Turner CSIRO Marine Research, Hobart, Tasmania A selection of GLATs* BlueLINK is a CSIRO/BoM/RAN project to implement an operational ocean forecasting system for Australia. One component of BlueLINK is the Regional Analysis, which has the goal of assembling, synthesizing and ‘analysing’ (in both senses of the word) the many data sets which will be either assimilated into the hydrodynamic model, or used for testing its performance. While the ultimate goal of BlueLINK is to develop a forecasting ability, the ﬁrst step will be to do a hindcast of the last decade, in order to develop and test the modelling. Accordingly, the Regional Analysis includes focii on both the real- time and delayed-mode data streams. In this talk I will outline what we are doing within the Regional Analysis project and illustrate it by stepping through a selection of interesting ocean events that have occurred in the Australasian region over the last decade, some of which have probably gone unnoticed. I will also introduce our website, www.marine.csiro.au/remotesensing/oceancurrents/, from where some oceanographic images and data are already available. This talk is dedicated to Peter Holloway. * “Gee, look at that” ______

Abstracts - Page 46 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Grose, Michael1 & Andrew McMinn1 (Poster) 1Institute of Antarctic & Southern Ocean Studies (IASOS), University of Tasmania How much is in the east? Algal biomass in the East Antarctic pack ice The total pack ice algal biomass in the eastern Antarctic pack ice zone (30-150°E) was assessed using chlorophyll a measurements from ice cores, calibrated observations of ice colour and biomass transects through surface communities. Remote sensing data was used to individually calculate the habitat extent of each type at each time. The total pack ice algal biomass was 7.9 Tg C on 20 Nov 2000, 80% of which was in the bottom community. Using an extrapolation, the maximum standing crop of algae is 8.51 Tg C, (95% in pack ice), which is ~14% of the Antarctic ice algal biomass. These results suggest that the bottom communities in East Antarctic sea ice are more important than previously thought. ______

______

Grose, Michael1, Andrew McMinn1, Jill Cainey2, Chris Lane1, Guido Corno1,3 (Poster) 1 Institute of Antarctic & Southern Ocean Studies (IASOS) 2 Cape Grim Baseline Air Pollution Station (CG-BAPS), Bureau of Meteorology 3 Oregon State University, USA Biogenic production of methyl halides by phytoplankton in Tasmanian Coastal waters

Methyl halides (CH3Br, CH3I, CH3Cl) produced in the ocean are important carriers of active forms of iodine, bromine and chlorine to the atmosphere. In the atmosphere, they play important roles in ozone destruction, and iodated species have been suggested as necessary initiators of new particle formation in the marine environment. This new particles can act as cloud condensation nuclei and hence have a role in climate modification. Biogenic production and emission by marine phytoplankton are among many natural and anthropogenic sources of methyl halide gases. However, the characteristics of this production are poorly understood. Here, we present ongoing work at the Cape Grim Baseline Air Pollution Station (CG-BAPS), and a field site at Couta Rocks, 50 km south of Cape Grim, investigating the relationship between phytoplankton ecology and methyl halide production. Preliminary results suggest that there is a significant relationship between nitrate limitation and methyl bromide production in coastal waters, and diatoms are just as likely as prymnesiophytes to be responsible for methyl halide production. Also, work at Couta Rocks indicates that the species composition of the local plankton communities has a critical role in controlling the levels of methyl halides in surface waters and in the air above these waters. Work is ongoing, and future directions are discussed. ______

Abstracts - Page 47 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Guenther, Jana & Rocky de Nys School of Marine Biology and Aquaculture, James Cook University, Townsville, Qld 4811 [email protected] Differential community development of fouling species on the pearl oysters Pinctada fucata, Pteria penguin and Pteria chinensis (Bivalvia, Pteriidae) The community development of fouling organisms and the presence of fouling-resistant surfaces on the shells of the pearl oysters Pinctada fucata, Pteria penguin and Pteria chinensis were investigated. In situ experiments were carried out to document the development of fouling communities on two shell regions (lip and hinge) of these pearl oysters. While there was no signiﬁcant difference in total fouling cover between shell regions of P. fucata and Pt. chinensis after 16 weeks, the hinge of Pt. penguin was signiﬁcantly more fouled than the lip. The most common fouling species (the hydroid Obelia sp., the bryozoan Parasmittina sp., the bivalve Saccostrea sp. and the ascidian Didemnum sp.) showed differential fouling patterns. Obelia sp. almost exclusively settled on the lip of P. fucata and Pt. penguin, whereas Parasmittina sp. and Saccostrea sp. only settled on the hinge of Pt. penguin and Didemnum sp. almost exclusively settled on the hinge of Pt. chinensis. The periostracum at the lip and hinge of all three pearl oyster species was investigated using scanning electron microscopy. The periostracum of P. fucata lacked regular features, whereas the periostracum of Pt. penguin and Pt. chinensis consisted of regular structures with a mean amplitude of 0.84 µm and 0.65 µm, respectively. The periostracum was mainly intact at the lip of all three pearl oyster species, while the periostracum at the hinge was abraded and bored. The relationship between the presence and surface microtopography of the periostracum of P. fucata, Pt. penguin and Pt. chinensis and differential community development of fouling species is discussed. ______

Guest, Michaela A1,3*, Rod M Connolly1,3 & Neil R Loneragan2,3 1 Centre for Aquatic Processes and Pollution, and School of Environmental and Applied Sciences, Gold Coast Campus, Griffith University, Qld 2 CSIRO Marine Research, Cleveland, Qld 4163 3 The Cooperative Research Centre for Coastal Zone, Estuary and Waterway Management, Qld m.guest@griffith.edu.au Movement of carbon among estuarine habitats and its assimilation by invertebrates The large-scale movement of carbon from inshore estuarine environments to offshore systems has been the focus of much research, but for some estuaries there is evidence that more limited movement of carbon between adjacent estuarine habitats occurs. The spatial extent of carbon movement may also be influenced by the habitat patch size and this is yet to be examined in estuarine systems. We measured the fine-scale movement of carbon and its assimilation by resident invertebrates between saltmarshes of different sizes adjacent to mangrove habitats in an Australian estuary, using carbon isotope analysis of animals at different distances into adjacent patches of habitat. Carbon isotope values of crabs and slugs in large saltmarsh patches closely matched those of saltmarsh grass. In mangroves, δcarbon isotope values of crabs and slugs were enriched relative to those of mangroves but were more similar to those of microphytobenthos. The carbon isotope values of crabs and slugs, especially those in large patches of saltmarsh habitat, clearly indicate that the movement and assimilation of carbon between adjacent saltmarsh and mangrove habitat is restricted to just a few metres, although some contribution from unmeasured sources elsewhere in the estuary is possible. In small patches of saltmarsh (< 0.3 ha) carbon isotope values of crabs were more depleted in 13C than those collected from large patches, indicating the assimilation of allochthonous carbon sources. We also examined three alternative models potentially explaining the observed pattern in carbon isotope values of crabs: 1) crab movement, 2) particulate carbon movement, and 3) a combination of 1 and 2. A mark-recapture program showed that movement was limited to 1 m or less from the place of initial capture for the majority of crabs (> 90%). The trend in carbon isotope values of detritus supports the model of particulate carbon movement across the saltmarsh-mangrove interface.

Abstracts - Page 48 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Bailleul, F1, C Barbraud, M Biuw2, C-A Bost1, J-B Charassin3, L Dubroca1, M A Lea4,1, F Roquet3, Y Park3, M Fedak2, M. Hindell3, H Weimerskirch1, C Guinet1 (Keynote Address) 1 Centre d’Etudes Biologiques de Chizé-CNRS, France 2 Sea Mammal Research Unit, University of St Andrews, Great Britain 3 Laboratoire d’Océanographie Physique, Museum d’Histoire Naturelle, France 4 University of Tasmania, Hobart, Australia [email protected] What can top marine predators tell us about the Southern Ocean? Over the last several decades a number of Southern Ocean predators species have exhibited large interannual variation in breeding performances major changes in population numbers. The focus of our research was first to investigate if these demographic changes were related to short and longer term variations in oceanographic conditions and second to investigate how these top marine predators adjust their foraging behaviour in relation to variations in the oceanographic conditions that they encounter when foraging. The demographic studies have shown that the major population decline of elephant seals, wandering albatrosses and emperor penguins in the Indian and Pacific sector of the Southern Ocean coincides with an increase in sea-surface temperature and a decrease in the extent of sea ice conditions. Studies of the inter-annual variation in the foraging ecology of king penguins and Antarctic fur seals have shown how these species adjust several aspects of their feeding behaviour in relation to the change in oceanographic condition. A recent collaboration between biologists and oceanographers in Australia, France and Great Britain is aiming to obtain detailed physical oceanographic data associated with foraging in the southern elephant seal. These deep, continuously diving and wide ranging animals were equipped with new ARGOS satellite CTD tags developed by the Sea Mammal Research Unit. Temperature and salinity data can now be collected from elephant seals, while simultaneously providing biologists with vital information about the oceanographic characteristics associated with successful foraging in these animals. Instruments are deployed simultaneously on seals from major colonies throughout the elephant seal distribution maximizing the spatial coverage of the Southern Ocean.This innovative method, which after less one year has already provided more data than the whole archived information on the ice edge oceanographic conditions, is an extremely cost-efficient enhancement of the traditional ship-based oceanographic sampling and ARGOS CTD buoys. ______

Abstracts - Page 49 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Gurney LJ, C Mundy, MC Porteus & N Ogle [email protected] New approach to an old problem: using stable oxygen isotope profiles to age abalone Age and growth estimates are fundamental to understanding the biology and ecology of a species, and are also essential for management of exploited species. To date, techniques used to obtain age and growth data for abalone include age from shell layers, growth from tag-recapture growth increment data, and modal shifts in population length frequencies. While each of these techniques have provided much needed data, none are completely satisfactory and/or fully validated. In organisms with calcareous body parts or shells, stable isotopes of oxygen from the seawater are incorporated into the structural skeleton. The ratio of stable isotopes varies with temperature, thus in instances where the oxygen is incorporated into the shell at isotopic equilibrium with the seawater, the stable isotope ratios from the shell reflect the water temperature at which the shell was laid down. When seasonal fluctuations are of great enough amplitude for annual cycles to be observed, isotope data can be used to determine age and growth of the specimen. Stable oxygen isotopes ratios have been used in many studies of molluscan age and growth, but this technique has not been applied to haliotids. Here we apply this technique to the blacklip abalone Haliotis rubra in south-east Tasmania. Serial samples of calcium carbonate from seven shells of H. rubra were collected at approximately 1mm – 4mm intervals along the growth direction of each shell. A seasonal temperature cycle was apparent in the results of the stable oxygen isotope ratios for each specimen and from these oscillations, estimates of age and growth were obtained. Specimens ranged in maximum shell length from 64mm to 141mm and were found to be between 3.5 and 7 years old. At shell length greater than 20mm, the average growth rate for these specimens was 20.2mm.yr-1. The results are compared to the shell growth layer technique and the findings are discussed. ______

Habeeb, Rebecca, Craig Johnson1, Simon Wotherspoon2 & Jessica Trebilco1 1 School of Zoology and Tasmanian Aquaculture and Fisheries Institute 2 School of Mathematics and Physics, University of Tasmania, Hobart Tas. 7001 [email protected] Characteristic length scale estimates: Application to a marine system The scale at which an ecosystem is viewed strongly influences the patterns and underlying processes that are detected. Characteristic length scales (CLSs) have been defined as spatial scales at which the non-trivial deterministic signal in a system’s temporal dynamic is maximized relative to stochastic fluctuations. Determining CLSs may provide a useful solution to the significant applied problem of choosing an appropriate scale at which to observe marine systems to detect real trends. Two similar approaches (Keeling et al. 1997; Pascual & Levin 1999), both based on attractor reconstruction from nonlinear time series analysis, have been developed to estimate CLSs of simple dynamical model systems. We first investigated the robustness of these techniques, examining their sensitivity to (1) the parameters used in the reconstruction process, (2) changes in species identity and initial conditions, and (3) model complexity. Our analyses focused on spatial multispecies models of varying complexity generated with the COMPETE software, and showed that one approach (Pascual & Levin 1999) was notably more robust than the other. However, although the method of Pascual & Levin was robust, its application requires unrealistic time series data. Accordingly, we modified the method, using very short time series of spatial arrays instead of long time series. We show that CLSs can be estimated with a series of only three highly resolved ‘landscapes’ through time, rather than tens of thousands of time steps. This modification allows CLSs to be more realistically applied to real ecological systems. We will present an application of this new technique to show that it can be used to identify CLSs in a real marine ecosystem, namely a natural marine fouling community.

Abstracts - Page 50 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hallegraeff, Gustaaf M, Damian Grundle, Judith-Ann Marshall & Jo Dowdney School of Plant Science, University of Tasmania, Private Bag 55, Hobart Tas. 7001 [email protected] Range extension of the red-tide dinoflagellate Noctiluca into Tasmanian waters Red tide blooms by the large phagotrophic dinoflagellate Noctiluca scintillans have dramatically increased in frequency and duration in southeastern Australian coastal waters, starting in the early 1990s in New South Wales (blooms at 19-24oC) and more recently in 2001-2004 in Tasmania. Available satellite evidence suggests that this nuisance species may represent a recent East Australian Current driven range extension into Tasmanian waters, where it now has established permanent overwintering populations (thriving at temperatures of 12-17 oC). Through a combination of culturing experiments and field surveys, we seek to define Noctiluca bloom conditions in Tasmanian waters with respect to estuarine seed populations, temperature tolerance, prey preference and grazing rates. Dinoflagellate abundance off Nubeena in the period Oct. 2003-April 2004 exhibited a boom and bust cycle with irregular population crashes at 4-10 wk intervals most likely triggered by depletion of phytoplankton food. Noctiluca poses a potential threat to the Tasmanian salmonid fish farm industry through gill irritation from unionized ammonia and reduced oxygen concentrations in dense shoreline slicks. Noctiluca’s voracious grazing pressure on larval fish, zooplankton and phytoplankton could also result in impacts on wild fisheries and shellfish aquaculture. ______

Hammond, Bethany K The University of Sydney, School of Biological Sciences (A08), Sydney, NSW 2006 [email protected] Post-settlement survival influenced by naturally occurring temperature changes in temperate benthic systems Temperature changes are well known mechanisms for altering the effect of biotic controls in marine environments as well as exerting their own abiotic effects. At Point Avoid, South Australia, temperature profiles differ dramatically between two adjacent benthic communities. This change affects only Point Avoid South, where, at low tide, pulsed cold water events decrease temperature markedly from 14oC to 6oC for a period of ten minutes. Conversely, only meters to the north, ambient water temperature is maintained throughout the tidal cycle. Community structure differs significantly between these two sites, where the impacted is dominated by resilient algal species, and, in complete contrast, the unimpacted site maintains high benthic biodiversity typical of temperate marine environments. I examined the effect of pulsed water events on newly recruited invertebrates and algae with laboratory and field experiments. Exposure to this highly stochastic temperature regime increases mortality of newly settled invertebrates that are not found at the impacted site by up to 50%. Conversely, co-occurring organisms, such as sea lettuce, do not have as high mortality when newly settled. In conclusion, this difference in post-settlement mortality ultimately drives benthic community structure by reducing recruitment of organisms to the location impacted by cold water intrusions. These results highlight the importance of investigating post-settlement processes of benthic organisms when researching settler-recruit analogies for community structure. ______

Abstracts - Page 51 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hanson, Christine E1*, Charitha B Pattiaratchi1, Anya M Waite1, Stéphane Pesant1 & Peter A Thompson2 1 Centre for Water Research, University of Western Australia, Crawley WA 6009 2 CSIRO Marine Research, Hobart Tas. 7001 * Current affiliation: CSIRO Marine Research, Floreat WA 6014 [email protected] Oceanographic forcing of phytoplankton dynamics off Western Australia This work represents the first large-scale biological oceanographic study to be undertaken off the northwest (Exmouth Peninsula to the Abrolhos Islands) region of Western Australia. The study area is dominated by the Leeuwin Current (LC), an anomalous eastern boundary current that transports tropical water poleward and prevents deep nutrients from reaching the surface by creating large-scale downwelling. Indeed, LC and offshore waters were consistently associated with low nitrate concentrations and low phytoplankton biomass and production (< 200 mg C m-2 d-1). However, the physical forcing of the LC was offset, during the summer months, by upwelling associated with wind-driven inshore countercurrents (Ningaloo and Capes Currents), which provided a mechanism to access high nutrient concentrations normally confined to the base of the LC. Production rates in these countercurrents were significantly higher than expected (~ 700 – 1300 mg C m-2 d-1) along this otherwise oligotrophic coast. Furthermore, phytoplankton biomass within the Leeuwin Current was largely confined to the base of the LC’s mixed layer, forming a deep chlorophyll maximum (DCM). Between 10 and 40 % of total water column production was attributable to the DCM. Coupling between nutrients at depth and the DCM indicate that the balance between light and nutrient availability is critical in controlling primary productivity in the LC. Pelagic ecosystem structure was quite distinct between LC/offshore and shelf/countercurrent regions. Smaller sized phytoplankton (including cyanobacteria and prochlorophytes) dominated the Leeuwin Current waters, and were primarily dependent on regenerated forms of nitrogen at both the surface and DCM. In upwelling regions, where larger phytoplankton (including diatoms) were more abundant, production was still heavily reliant on regenerated forms of nutrients. Thus, both in the DCM and upwelling countercurrents, nitrogen recycling via heterotrophy appears to play a critical role in sustaining primary and secondary productivity. This investigation provides fundamental knowledge on physical-biological coupling off Western Australia, with implications for fisheries management in view of seasonal and inter-annual variability in the strength of both the Leeuwin Current and inshore countercurrents. ______

Hartmann, Klaas1,2, Lance Bode1 & Paul Armsworth3 1 James Cook University, Queensland, Australia 2 currently at CSIRO Marine Research, Hobart, Australia 3 Stanford University, Stanford, USA Marine reserves as a learning tool Marine reserves are an emerging tool for the management of marine resources. Many of the benefits associated with marine reserves have been widely investigated and the field is currently an active area of research in theoretical ecology. One benefit of reserves that has remained overlooked is their value as a tool for learning about the population dynamics of a system. This benefit of a marine reserve is investigated using both a Monte Carlo simulation and stochastic dynamic programming framework. These methods have been used to demonstrate that in some situations the value of learning from a reserve may be significant. This value may be sufficient to make the creation of a reserve purely for learning about a system economically optimal. ______

Abstracts - Page 52 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hay, Tracy1*, Michael Phelan1, Neil Gribble2, Steve Bailey2, Christina De Vries3, Malcolm Dunning3 & Karen Danaher3 (Poster) 1 NT Fisheries Group, Department of Business Industry and Resource Development Darwin NT 2 Northern Fisheries Centre, Queensland Department of Primary Industries and Fisheries, Cairns QLD 3 Queensland Fisheries Service, Queensland Department of Primary Industries and Fisheries, Brisbane [email protected] Methods for monitoring habitat and abundance of the mud crab Scylla serrata in northern Australia The mud crab, Scylla serrata, is an important “icon” species, found in Northern Australian estuarine and inshore waters throughout the year. Recreational, commercial and traditional fishers all covet the species and the combined interest results in consistently high fishing pressure. Stock assessment based on commercial and recreational catch statistics and estimates has not proved informative, as the underlying assumptions required for assessment methods and models based on such data cannot be met. High variability in growth rates and/or mortality has also made length-based assessment methods difficult and as yet, no stock estimates are available for Australian mud crab fisheries. Two priority areas will be addressed in the current study; 1. Mapping of critical mud crab habitat. Critical habitat such as tidal mangrove creeks, mudflat/foreshore areas, and saltmarsh areas will be mapped across northern Australia using satellite imagery aerial photography and ground truthing. 2. Assessment of appropriate techniques for mud crab abundance estimation. Techniques combining mark- recapture and depletion and trapping web studies will be assessed. The aims of the project are: • The identification and quantification of critical mud crab habitat; • To develop and assess techniques for estimating mud crab abundance; and • Provide advice on future monitoring methods for northern Australian mud crab stocks. ______

Heap, Andrew D, James Daniell, Peter T Harris & Mark Hemer Geoscience Australia, GPO Box 378, Canberra, ACT 2601 [email protected] Sand movement and potential seagrass dieback in Torres Strait Large, mobile sandwaves cover the seabed in Torres Strait. A high-resolution swath sonar survey and detailed sampling program of the sandwaves were undertaken in two study areas next to Turnagain Island to reveal bathymetry, sediments and habitats. The main focus of the survey was to understand the movement of the sandwaves and changes to water turbidity as possible mechanisms for seagrass dieback events. The movement of sand along the seabed was mostly in the form of “pulses” caused by wind waves. The movement of sand was widespread at sites with seagrass and at the barren sites. Suspended sediment concentrations at the bed attained >30 mg l-1 and were highest at barren sites. Repeat sonar surveys three weeks apart revealed that the sandwave crests had moved west up to 6-13 m, and coincided with a change from NW winds and waves to SE winds and waves. The orientations and migration directions of the sandwaves and ridges are effected by the different wind-driven currents between the summer monsoon and winter trade wind seasons. A second survey will be completed at the end of the 2004 trade wind season to determine how far the sandwaves have moved and assess any effects on seagrass distribution. Given the widespread movement of sandwaves observed in our study, it is likely that the movement of sand has contributed to the observed seagrass dieback events. Data collected from both surveys will assist in characterising seabed ecosystems, and provide crucial information on the nature of the seabed in Torres Strait for developing models of physical and biological processes for input into management strategies. The surveys are part of a larger program managed by the CRC Reef based in Townsville to understand the biophysical processes inﬂuencing seagrass dieback and the potential implications for dugong, green turtles and juvenile rock lobster.

Abstracts - Page 53 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Helidoniotis, Fay1* & Jonny Stark2 (Poster) 1 Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Tasmania 7005 2 Australian Antarctic Division, Tasmania 7050. [email protected] Human impacts on benthic assemblages in Antarctica Antarctica currently has 35 scientific research stations operating along the coast. Their establishment has led to the development of waste disposal sites, raising widespread concern about their uncertain ecological ramifications. At Casey, the presence of a waste tip in the Thala Valley has prompted extensive monitoring of the nearby shallow water marine community. The waste tip was in use for 21 years since 1965, and lay disused and derelict since 1986. Since then, all waste has been returned to Australia. A photoquadrat survey was conducted on the shallow water hard-substratum community around Casey Station in the austral summer of 1997/98 to investigate how human impacts influence communities of organisms. The scope of this study was to examine spatial variability of epi-benthic communities, known to receive contaminated melt-water from the nearby disused waste tip. Three locations were surveyed around Casey Station: 1 putatively impacted location adjacent to the tip and two control locations. A hierarchical nested sampling design resolved spatial variability at a range of spatial scales; locations (103 m apart), sites (102 m apart), plots (2 - 10 m apart). From a total of 209 photoquadrats, 72 taxa were found making the area species rich. Multivariate analyses by nMDS ordination and cluster analysis indicate that all locations significantly differ in biotic assemblages. Shannon-Weiner diversity index, species richness (Margalef’s index) and Pielou’s evenness reveal that the control locations in this study have high variability of benthic assemblages and low level of dominance by singular species. In contrast, the low value of all indices at the putatively impacted location is evidence of anthropogenic contamination. Qualitative descriptions of benthic assemblages reveal differences between control and impacted locations. For example, slow growing sponges, indicative of a stable environment, were present at control locations and absent at the impacted location. The results suggest that for broad taxonomic categories of the Antarctic marine benthos, reliable estimates of spatial variability can be obtained from non-destructive photoquadrat surveys. ______

Heupel, Michelle* & Colin Simpfendorfer Center for Shark Research, Mote Marine Laboratory, Sarasota, Florida USA 34236 [email protected] Analysis techniques from passive acoustic telemetry studies of coastal shark nursery areas Arrays of acoustic receivers deployed in Florida estuaries have been used to study the movement and behavior of sharks within their nursery areas. Initial studies in Terra Ceia Bay used an array of 25 receivers to study the movement of 127 new-born blacktip sharks (Carcharhinus limbatus) between 1999 and 2002. Data from this array was originally designed to determine residence time and philopatric behavior. However, additional analysis techniques extended this study to include determination of survival rates, home range size and interactions of individuals. The investigation of intra-speciﬁc interactions included both dynamic interaction and nearest neighbor techniques, and has shown that there may be coordinated movement patterns within the population. Later research in Pine Island Sound used an array of up to 41 receivers to study the movements of several species of sharks during 2002 and 2003. Data from this study site has been used to examine home range sizes and examine inter-speciﬁc differences in the effect of changes in salinity on movement and distribution. A third study site has used 20 receivers in a linear arrangement to study the movements of new-born bull sharks (Carcharhinus leucas) in the Caloosahatchee River during 2003 and 2004. Data from this study site have being used to examine nursery area utilization patterns relative to salinity levels within the lower reaches of the river and over-wintering patterns. Correlations between movement patterns and changes in salinity are being used to make inferences about the possibility of behavioral osmoregulation in this species. These examples of analysis techniques will be discussed to show the utility of acoustic monitoring as a tool for better understanding a wide range of movement and behavioral patterns in highly mobile aquatic organisms.

Abstracts - Page 54 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Poore, Alistair GB1; Nicole A Hill1* & Eric E Sotka2 1 School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052, Australia. 2 Hopkins Marine Station, Stanford University, 120 Oceanview Boulevard, Paciﬁc Grove, CA 93950, U.S.A. [email protected] Evolutionary associations among herbivorous amphipods and marine plants Most insect herbivores are highly specialized, consuming only a few of the plant taxa available to them. On evolutionary time scales, host plant use is commonly conservative leading to strong historical associations between herbivore and plant taxa. These associations between insects and their hosts have been used to examine possible co-evolution, host plant shifts, and the evolution of specialization. In marine environments, herbivores are generally considered to be less specialized, but such studies are hindered by a poor understanding of the associations between herbivores and their hosts. In our study, we determine whether host use differs among the genera of the amphipod family Ampithoidae, and whether these patterns could be attributed to a historical association between amphipods and their hosts. Ampithoids are herbivorous amphipods common in algal and seagrass beds throughout the world. Their ecological role has been likened to that of terrestrial insects on higher plants. A literature search yielded 74 studies providing host-use data for 99 out of the 131 ampithoid species. Occurrence on algal and seagrass taxa was contrasted among the four most species-rich genera using multidimensional scaling and analysis of similarities. The multivariate analyses indicated that host use differed among the amphipod genera when hosts were considered at the level of genus, family and order, but not division. Differences in host use could not be assigned to geographical location, or tropical versus temperate zones (with the exception of hosts at the level of division). The number of host taxa used differed among the amphipod genera when accounting for the increase in diet breadth associated with the increasing number of studies done on a given amphipod species. These differences among amphipod genera indicate a strong historical component to the current pattern of host use in these herbivorous amphipods. ______

Evans, K1, MA Hindell1, R Warneke2 & R Thresher3 1 Antarctic Wildlife Research Unit, School of Zoology, University of Tasmania, Private Bag 5, Hobart Tas. 7001 2 Blackwood Lodge, 1511 Mt. Hicks Rd, Wynyard Tas. 7325 3 CSIRO Marine Research, GPO Box 1358, Hobart Tas. 7001 [email protected] Cetacean strandings is climate a driving force? Ascertaining the causes of cetacean strandings has perplexed scientists for many years. Theories abound, but little quantitative research has been conducted into this, one of the most puzzling of biological mysteries. We analysed a long term data set of whale strandings in south-east Australia (Tasmania and Victoria) and observed a clear circa-10 year periodicity in the number of whales stranded each year. This quasi-decadal cycle in the number of whales that strand occurred across all groups of whales and coincides with a major climatic cycle - the yearly regional persistence of strong zonal westerly winds (ZWW). The ZWW belt or Antarctic circumpolar vortex varies in intensity on annual, quasi-decadal and longer time scales reflecting long-term and large-scale shifts in hemispheric sea level pressure, in general, and the position of the Sub-tropical Ridge, in particular. Colder nutrient rich waters are driven closer to Tasmania and water column productivity is increased during periods of persistent ZWW, periods which coincide with times of maximum whale strandings. These findings suggest that these climatic events may provide powerful distal influence which results in a greater propensity for whale strandings to occur. Our study provides the first clear test of existing hypotheses for this mysterious behaviour, and provides managers with a powerful predictive tool to enable them to prepare for years of peak stranding activity. ______

Abstracts - Page 55 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Wheatley, Kathryn E1,*, Mark A Hindell1, Corey JA Bradshaw2 & Lloyd S Davis3 (Poster) 1 Antarctic Wildlife Research Unit, School of Zoology, University of Tasmania, GPO Box 252-05, Hobart Tas. 7001 2 Key Centre for Tropical Wildlife Management, Charles Darwin University, Darwin NT 0909 3 School of Zoology, University of Otago, P.O. Box 56, Dunedin, New Zealand [email protected] Energy resource allocation of female Weddell seals (Leptonychotes weddellii) in years of contrasting quality Lactation is the most energetically demanding period faced by female mammals. Phocid seals are one of the few mammals capable of meeting these energetic requirements through stored body nutrients. A female’s mass and condition at parturition will therefore influence how energy is allocated to support both maintenance metabolism and energy transfer to pup. In turn, pup growth during lactation will have consequences on its prospects of survival to nutritional independence. Weddells seals (Leptonychotes weddellii) are an ideal candidate to study this process, as they must achieve this in one of the most extreme environments, and in a relatively short period of time. We examined the changes in body mass and body composition of adult female Weddell seals during lactation, in relation to initial body size, in two years (2002 & 2003) with very different environmental conditions. Post-partum mass ranged from 410 to 503 kg (mean: 451.6 ± 33.1 kg) in 2002 and from 279 to 480 kg (mean: 393.1 ± 54.7 kg) in 2003, with a significant difference between years (p < 0.001). In contrast, pup birth mass was not significantly different (2002: 27.4 ± 3.91 kg, 2003: 27.0 ± 4.83 kg; p = 0.725). Near the end of lactation (34 days), female mass differences diminished and were no longer significantly different (p = 0.062). This suggests that heavier females, from 2002, had a proportionately higher energetic output than the smaller females in 2003, which resulted in significant differences in pup mass (2002: 96.8 ± 10.94 kg, 2003: 76.6 ± 15.31 kg; p < 0.001). We also examine changes in body composition (between years) which reveal individual variations in the energetic contribution of lipid and protein to mass loss. ______

Hobday, Alistair1 & Ryo Kawabe2

1 CSIRO Marine Research & University of Tasmania 2 Nagasaki University, Japan [email protected] Acoustic monitoring to determine nearshore migration paths of juvenile southern bluefin tuna in southern Western Australia Southern Bluefin Tuna (SBT) are considered to be at historically low population levels; despite this, intense Australian and international fishing continues. Monitoring trends in the population through development of a fishery independent abundance index remains a key goal for the managers of the species. Fishery- independent surveys on which the indexes are based are carried out in fixed areas, and rely on the assumption that the fraction of the SBT population entering the survey area to be counted is constant from year-to-year. Recent declines in the abundance index derived from the southern Western Australian survey area have been questioned: one competing hypothesis for an apparent juvenile SBT decline is a change in the timing or location of the alongshore migration route. An acoustic monitoring project was established under the Japan Australia Recruitment Monitoring Program to investigate the nearshore movements of age-1 SBT, in particular to examine potential migration routes. An acoustic monitoring system suitable for continental shelf deployments has been developed and tested and provides sufficient resolution to examine the speed and position of alongshore movements of these “pelagic” animals. Listening stations (VR2’s) have been deployed in the region for three years, with cross-shelf lines and hotspots monitored. Results from these experiments have shown that acoustically tagged SBT move quickly alongshore and relatively close to shore, with limited overlap with the survey area and timing. The movement of tagged SBT has important implications for the timing and the location of the abundance surveys. Results suggest that the timing and migration behavior of juvenile SBT may be earlier and closer inshore compared with the late 1990’s, perhaps as a result of changes in population size or environment conditions.

Abstracts - Page 56 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hodgson, Kate E*1,2, George D Jackson1 & Jeremy M Lyle2 1 Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Private Bag 77, Hobart, Tasmania, Australia, 7001 2 Marine Research Laboratories, Tasmanian Aquaculture & Fisheries Institute, University of Tasmania, Private Bag 49, Hobart, Tasmania, Australia, 7001 [email protected] Tracking arrow squid movements with an automated acoustic telemetry system Few studies on the movement ecology of cephalopods have utilised acoustic tracking technology, even though migrations and movement dynamics are known to be key processes for many cephalopod species. This is the ﬁrst application of an automated acoustic telemetry system to studying movement in a squid, Nototodarus gouldi (Cephalopoda: Ommastrephidae). The main aims of the study were to investigate the spatial usage and movement of N. gouldi between the adjoining bays and inlets around Storm Bay in southeastern Tasmania, and their behaviour and activity patterns. The system comprised sixty-four automated acoustic receivers (VR2’s) that were deployed as ‘curtains’ across the entrances to bays and inlets in the study area, and small uniquely coded transmitters that were attached to squid. Twelve tagged squid were detected for up to 37 days over an area of more than 300 km2. Tagged squid moved widely between Storm Bay and the Derwent Estuary, but none were detected moving into the adjoining bays or the D’Entrecastreaux Channel. Tagged squid appeared to move out of Storm Bay throughout the study period, suggesting a highly dynamic population. There was evidence of a relationship between level of activity and photoperiod, with visits to receivers being longer and more variable in duration in the night compared to the daytime. Schooling or group movement was not observed. Speed calculations based on straight-line movements between non-adjacent receivers varied widely with speeds over distances of 10 km or more ranging from 0.06 to 1.46 mantle lengths per second (ML.s-1), and one instance of an average speed of 3.6 ML.s-1 over 9.3 km. ______

Holl, Carolyn M1*, Joseph P Montoya1 & Anya Waite2 (Poster) 1 Georgia Institute of Technology, School of Biology, Atlanta, GA USA 2 Center for Water Research, University of Western Australia [email protected] Nitrogen fixation by unicells: An investigation of vertical profiles and size fractions of the natural phytoplankton assemblage found in a warm and a cold core eddy A warm core and a cold core eddy were investigated during a research expedition off the coast of WA in 15 13 October 2003. Nitrogen fixation ( N2 uptake) and carbon fixation (H2 CO3 uptake) rates were measured in vertical profiles of the natural phytoplankton assemblage to ascertain the potential of diazotrophy as a source of new nitrogen to the upper water column. We also compared fixation rates in the 100µm and 10µm size fractions as well as in whole water to determine the size of the diazotrophs present and their relative rates of activity. Our vertical profiles show volumetric rates of nitrogen fixation in the upper 100m of the water column ranging from 1.3 x 10-7 to 9.6 x 10-6 µmol N•L-1•h-1 with a mean of 4.3 x 10-6 ± 1.6 x 10-6 µmol N•L-1•h-1 (mean ± SE, N = 10) without any obvious vertical structure. Though highly variable, nitrogen fixation rates tend to be higher below 100m depth. Size fractionation experiments showed the highest nitrogen fixation rates in whole water samples and lower rates in the 100 µm and 10µm size fractions. In contrast, we found no significant difference between size fractions in volumetric carbon fixation rates. Comparisons between the focal points in each eddy (center, body and periphery) will be presented and discussed in the context of the nutrient supply necessary to support phytoplankton production in these waters. ______

Abstracts - Page 57 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Holl, Carolyn M1*, Joseph P Montoya1, Anya M Waite2, Stéphane Pesant2, Peter A Thompson3 1 Georgia Institute of Technology, School of Biology, Atlanta, GA USA 2 Center For Water Research, University of Western Australia 3 CSIRO Hobart, Tasmania [email protected] Diazotroph activity in WA waters: comparative analysis of nitrogen ﬁxation in a warm core and a cold core Mesoscale Eddy

15 13 Nitrogen fixation ( N2 uptake) and carbon fixation (H2 CO3 uptake) rates were measured in the natural phytoplankton assemblage of a warm core and a cold core eddy off the coast of Western Australia in October 2003. We believe these to be the first measurements of diazotrophic activity in unicellular phytoplankton in this region. Day and night incubations on samples from both the surface and the chlorophyll maximum were performed at 10 stations across each eddy with focal points in the center, the body, and periphery of each eddy. The mean daytime nitrogen fixation rate was 3.3 x 10-5 ± 1.6 x 10-5 µmol N•L-1•h-1 (mean ± SD, N=18) in the warm core eddy and 2.1 x 10-5 ± 1.2 x 10-5 µmol N•L-1•h-1 (mean ± SD, N=20) in the cold core eddy. We found a significant difference in daytime nitrogen fixation rates with depth in the warm core eddy, but not in sample incubated at night. In general, nitrogen fixation rates were higher in the body and periphery and lower in the center of the warm core eddy. In contrast, we found no significant difference in nitrogen fixation rate among any of the treatments in the cold core eddy and no distinct spatial trend. The depth integrated mean areal nitrogen fixation rate in the warm core eddy was 42.9 µmol N•m-2•d-1 ± 14.1 (mean ± SD, N=9), which was 2.5 times higher than that of the cold core eddy, 17.1 µmol N•m-2•d-1 ± 8.1 (mean ± SD, N=10). Simultaneous carbon fixation rate measurements suggest that nitrogen fixation could support only about 2% of total production in the warm core eddy and only 0.6% in the cold core eddy. Though measurable, nitrogen fixation in these eddies does not appear to be the primary source of nitrogenous nutrients to the phytoplankton. ______

Holland, Kim1, Laurent Dagorn2 & Tim Clark1 1 Hawaii Institute of Marine Biology, University of Hawaii 2 IRD, France [email protected] Pelagic Ecosystem Observing Systems: “Smart FAD”, FADIO and HULA programs Advances in acoustic telemetry techniques and increasing sophistication of active acoustic survey methods have opened up the possibility of an improved understanding of open ocean pelagic ecosystems. Three inter-related research projects are at various stages of implementation in attempting to develop autonomous or semi-autonomous systems for observing pelagic animals and the ecosystem within which they move. Within this general theme, particular emphasis is being placed on describing the dynamics the pelagic communities that associate with both anchored and drifting fish aggregating devices (FADs). In Hawaii, the Smart FAD project has two components. First, development of a rotating (360°) sonar system to monitor the waxing and waning of aggregations of fishes associated with anchored FADs and, second, development of new types of electronic “ecology” tags. These tags might be used to monitor the social milieu of pelagic fishes or to determine feeding activity. We are testing a prototype tag that will collect and store acoustic signatures generated by schools of fish (thereby indicating if the tagged fish is alone or with a group of conspecifics) and we are developing tags that will telemeter stomach pH and thereby indicate feeding periodicity.

Abstracts - Page 58 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

In complementary experiments, two research cruises have been completed in the Indian Ocean where the FADIO project is attempting to characterize the dynamics of the association and aggregation of various pelagic ﬁshes with drifting FADs of the type used by commercial purse seiners operating in that area. Active sonic tracking, passive acoustic telemetry and ship-borne acoustic surveys have been completed and good preliminary data acquired. More cruises are planned. HULA (Hawaii Undersea Listening Array) is in the planning stage. Conceptually, it will consist of a variety of active and passive acoustic monitoring devices that will be both “stand alone” and hard wired in an array deployed along the Kona coast of Hawaii. An existing array of passive acoustic monitors deployed in the same area to monitor the movements of manta rays is already demonstrating the potential utility of the HULA concept. In addition to providing long term and detailed data on the movements of manta rays, the existing array is being used to detect the movements of jacks, tiger sharks and turtles. ______

Holmes, Nick (Poster) School of Geography and Environmental Studies, University of Tasmania, 7001 [email protected] Determining levels of mercury in subantarctic penguins on Macquarie Island Mercury is one of the most critical metal pollutants in marine environments, representing an environmental health risk to both human and wildlife populations (Fowler 1990). Mercury naturally occurs in air, land and water; however the amount of mercury cycling through these environments has risen since the industrial age. The transformation of inorganic mercury to the more toxic methylmercury in low-oxygen environments (i.e. deep water column), allows this metal to bioaccumulate through the food chain to top predators via target prey. Seabirds represent ideal monitors of mercury in marine environments because age-related differences in mercury accumulation recorded in mammals and ﬁsh are not present – an artefact of mercury deposition in feathers (Furness 1993). Feathers can represent a relative snapshot of mercury accumulation subsequent to the last moult sequence, with this information providing an indication of mercury levels present in seabird populations, and also of mercury levels in foraging zones utilised during that period. Mercury levels have been assessed for several subantarctic and Antarctic seabird species however little research has been published concerning subantarctic penguin species. Here we detail the background, methodologies and ﬁeldwork to date for determining the levels of mercury present in feathers of King Aptenodytes patagonicus, Gentoo Pygoscelis papua, Rockhopper Eudyptes chrysocome and Royal Eudyptes schlegeli penguins on Macquarie Island (54°30’S 158°57’E). Fowler, S. W. (1990). Critical review of selected heavy metals and chlorinated hydrocarbon concentrations in the marine environment. Marine Environmental Research, 29: 1-64. Furness, R. W. (1993). Birds as monitors of pollutants. In Birds as monitors of environmental change, eds. R. W. Furness &J. J. D. Greenwood, Chapman & Hall. London, pp. 86-143.

______

Abstracts - Page 59 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hooge, Philip N1, William M.Eichenlaub2 1 United States National Park Service, Denali National Park & Preserve, P.O. Box 9, Denali Park, Alaska 99755 2 National Park Service, Glacier Bay National Park, P.O. Box 140, Gustavus, Alaska 99826 [email protected] The Animal Movement Program: Integrating GIS with statistical analysis and modeling of animal movements In response to the lack of tools for analyzing the movements of animals within a GIS environment we developed software that integrates a commonly used GIS program (ARC View) with a large collection of analysis tools. This application can be loaded as an extension under multiple operating system platforms (PC, Unix, Mac OS). The extension contains over 45 functions, including parametric and nonparametric home range analysis, random walk models, habitat analysis functions, point and circular statistics, tests of complete spatial randomness, autocorrelation, sample size tests, point and line manipulation tools and animation tools. Several functions have not been implemented previously as computer algorithms or represent new analysis methods. We will demonstrate the use of these functions to analyze the movements of animals. The extension is available at http://www.absc.usgs.gov/glba/gistools/index. htm. ______

Hooge, PN1 , SJ Taggart2 & ER Hooge1

1 Denali National Park & Preserve, P.O. Box 9, Denali Park, Alaska, USA 99755 2 USGS, Glacier Bay Field Station, 3100 National Park Road, Juneau, Alaska, USA 99801 [email protected] Site fidelity in Pacific halibut (Hippoglossus stenolepis) Pacific halibut are thought to be a widely migrating and panmictic species, yet communities in Alaska have experienced declining harvests from nearby areas. This “local depletion” has been occurring despite evidence from population models that Pacific halibut in the North Pacific can sustain harvests much higher than current levels. We placed wire tags (N = 1598) and sonic-tags (N = 110) on Pacific halibut in Glacier Bay, Alaska to determine the degree of within and between year site fidelity of this species. We found that most halibut exhibit site fidelity and home range behavior. Home range sizes were often small, in nearly all cases less than 0.9km2 for the 95% kernel utilization distribution. Home range size decreased with increasing age, and older individuals exhibited increased site fidelity. Sonic-tracking over multiple years demonstrated that many halibut return to the same areas in subsequent years. Data from wire tags corroborated the results from the sonic-tracking study with 96% of fish tagged in Glacier Bay recaptured within the same statistical unit. Many halibut returned to Glacier Bay for two or more years, often returning to the same area as previously used. The limited movements of Glacier Bay halibut indicate good potential for marine reserves to be an effective tool in the management of this species and that these restricted movements should be taken into account in harvest models. ______

Abstracts - Page 60 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hughes, Lauren* & Stephen DA Smith University of New England, Armidale NSW 2350 & National Marine Science Centre, PO Box J321 Coffs Harbour NSW 2450 [email protected]

“If you build it, they will come”. A sampling package for the rapid assessment of amphipod biodiversity Artificial Substrate Units (ASUs) have been successfully used in quantitative and manipulative experiments within many marine settings. In monitoring and biodiversity research, ASUs have been applied as a means of collection to assess invertebrate communities at local, regional and global scales. This project tested a range of ASU types to develop a rapid assessment sampling package specifically aimed at cataloguing regional amphipod biodiversity. Four sites within the Solitary Islands Marine Park (SIMP) were used to trial six ASU types including novel materials and those successful in previous studies. Deployment was tested over two weeks, one month and four months, with one month proving optimum for both abundance and number of species. Different ASU types supported different diversities of species and community composition. Unique recruitment to each ASU type made all ASUs valuable as part of a final sampling package to determine regional amphipod biodiversity. ASUs sampled more amphipod fauna than the general collection of natural habitats. To further test the use of this artificial sampling package, an additional deployment was made at Bare Island, Botany Bay. This tested the use of the package outside the SIMP, in cooler temperate waters. Under a different benthic environment and physical conditions the artificial sampling package again proved successful in cataloguing amphipod species diversity. This ASU sampling package represents a tested and efficient means of rapidly assessing amphipod biodiversity for use in regional marine management. ______

Hunter, Cass1,2, Malcolm Haddon1 & Keith Sainsbury2 1 Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Nubeena Crescent, Taroona Tas. 7000 2 CSIRO Division of Marine Research, GPO Box 1538, Hobart Tas. 7001 [email protected] Lobster size: modelling its effect on trapment Environmental and biological factors are known to affect the catchability of crustaceans in pots. The behavioral interaction arising from larger crustaceans deterring smaller crustaceans from entering pots has been identified as one of the important factors influencing the probability of trapping crustaceans. Simulation modelling was used to evaluate this behavioral effect on the trapping dynamics within the Tasmanian rock lobster (Jasus edwardsii) fishery. The present work investigates methods for evaluating the influence lobster size has on the catchability and the selectivity of pots for lobster. The effect of lobster size was simulated by developing a set of trapping rules that combine fishery information with monte- carlo modelling to determine the number and size of lobsters that are expected to enter and remain in a pot. The optimum set of trapping rules were determined by minimising the difference between the predicted size frequency of captured lobsters with that observed in the fishery. In the context of an individual based model the trapping rules includes a threshold size measure that determines whether a lobster is classified as a small or large sized lobster and it accounts for the probability of smaller sized lobsters entering and remaining in the pot when larger sized lobsters are already present. A spectrum of alternative trapping rules were investigated with respect to the degree of interaction between different sized lobsters. These ranged from complete independence of individual lobsters to very strong influence of large lobsters on small lobsters. The sensitivity of the trapping rule to the size threshold of what is defined as a large lobster was also investigated. ______

Abstracts - Page 61 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hunter, John1* & Mark Hemer2 1 Antarctic Climate & Ecosystems CRC, Sandy Bay, Tas 7000. 2 Geoscience Australia, Canberra, ACT 2601. [email protected] Modelling the ﬂow under an Antarctic ice shelf using POM The Princeton Ocean Model (POM) has been modiﬁed to simulate the circulation under ice shelves. The resultant model has been applied to the cavity under the Amery Ice Shelf, Antarctica, in order to investigate the patterns of currents, melting and freezing, and the way in which these might change under conditions of global warming. I will describe some of the interesting oceanography associated with such cavities, why understanding these systems is important, and the dependence of the model results on tidal currents and grid size. I will also indicate some of the problems encountered in modifying POM for high surface pressure loadings, which exceed 200 atmospheres at the base of some parts of the Amery Ice Shelf -- equivalent to a rather impressive anticyclone! ______

Huveneers, Charlie & Rob Harcourt Graduate School of the Environment, Macquarie University, Sydney NSW 2109 [email protected] A new wobbegong species (Orectolobidae) in New South Wales: preliminary results Orectolobidae taxonomy has been described as problematic. In Australian waters, there are currently six accepted species but as many as three new species and an undescribed one have recently been proposed. In New South Wales, two species of wobbegongs are found, the spotted wobbegong (Orectolobus maculatus) and the ornate wobbegong (O. ornatus). However, anecdotal observations from divers and fishers, combined with, admittedly limited, biological data, have lead to the possibility that there may be a third species. Although its external appearance is similar to O. ornatus, the ‘dwarf’ ornate wobbegong seems to mature at a significantly smaller size. Morphometric measurements of five specimens of both ‘dwarf’ and normal ornate wobbegong were undertaken to investigate morphological differences. Spiral valves were also counted to look for internal dissimilarities. Preliminary results obtained from the ten specimens measured indicated that ‘dwarf’ and ornate wobbegong were morphological different. Distinctive measurements include: snout to anal insertion length, preorbital length, prespiracle length, head, mouth and trunk width, pectoral, dorsal, anal and caudal fins and snout to vent length. The likelihood of two different species was confirmed by a highly differentiated spiral valve count where the ‘dwarf’ wobbegong has only 20-23 spiral valves, compared to an average 30-32 for the ornate wobbegong. Further investigation will include an increase in sample size of distinctive measurements and spiral valve counts, predorsal and precaudal vertebrae count, teeth morphology and denticle morphology. A side project using DNA analysis will also be undertaken to quantitatively describe speciation between ‘dwarf’ and ornate wobbegong. Orectolobidae taxonomy needs to be resolved as soon as possible in order to appropriately regulate the fishery in NSW. O. maculatus and O. ornatus have recently been added as ‘Vulnerable’ to the IUCN Red list within NSW as a result of a decreasing catch rate. Their status could be worse if a third species is confirmed. ______

Abstracts - Page 62 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Ives, Matthew C1, J Scandol2, I Suthers1 & S Montgomery2 1 Fisheries and Marine Environmental Research Lab, School of Biological, Earth and Environmental Sciences, University of the New South Wales 2 NSW Fisheries [email protected] A quantitative analysis of prawn harvesting strategies Prawns are targeted by fisheries in NSW, with a commercial value of around $35 million dollars per annum, and a recreational fishery of cultural and social significance. A crucial component in the sustainable management of such marine resources is the discipline known as ‘stock assessment’. The most recent innovation in this field, gaining global prominence, is Management Strategy Evaluation (MSE) that involves computer simulation of biological and management systems to investigate the impact of various management strategies on the sustainability of harvested stocks. Monthly commercial prawn catch and effort data from 1984 to 2000 will be utilised to develop biological models of two key prawn species, eastern king prawn (Penaeus plebejus) and school prawn (Metapenaeus macleayi). The models developed will be tested using 2001+ catch data. Those models that demonstrate satisfactory predictive quality will be employed as MSE-style heuristic tools for the investigation of hypotheses on various strategies to improve the management of the prawn fisheries in NSW. Various indicators, including those derived from length composition data and tagging studies, as well as physical predictors (such as water temperature and river flow data), will be tested for their ability to improve management outcomes for the commercial fisheries. Finally, additional socio-economic data and algorithms will be added to the models for the purposes of evaluating the likely biological and socio- economic implications of alternative effort-allocation strategies on the various sectors of the fisheries. ______

Ivey, GN* & JP Antenucci Centre for Water Research, University of Western Australia, Nedlands WA 6907 [email protected] Bottom intensiﬁed currents on the North West Shelf Long term measurements of current and temperature collected at 6 depths in 302 metres of water off the North West Cape of Western Australia revealed several periods of extreme near-bed currents. The dominant forcing frequencies at the site are due to the M2 and M4 tides, with energy levels generally decreasing as the bottom is approached. There is, however, an increase in energy for all frequencies in excess of the M4 tidal frequency between 80 m and 10 m above the sea bed. Waves in this frequency bandwidth are critical to the local bottom slope, with dissipation estimates revealing energetic motions with dissipation rates of approximately 10-4 . m2 s-3. Spectral analysis of the data shows incident waves of horizontal wavelength in the range 200 to 2000 m. Superimposed on this ambient state, three energetic events can also be detected with duration varying between 8 and 24 hours. These events are characterized by large increases in energy levels in the high frequency range and peak speeds at 10 m above the sea bed of 1.9 ms-1. These events appear to be driven by direct local energy inputs at high frequencies. ______

Abstracts - Page 63 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Johnson, Colin CL & Natalie Moltschaniwskyj School of Aquaculture, Locked Bag 1370, Launceston Tas. 7250 [email protected] Behaviorally measured development of visual acuity in southern dumpling squid (Euprymna tasmanica L.). Visual resolution of E. tasmanica was measured from hatching to adults using two behavioural techniques: (i) optomotor and optokinetic responses and (ii) reactive distance. Both methods were used to calculate visual acuity expressed as a minimum separable angle (MSA). MSAs determined by optomotor or optokinetic responses were significantly smaller than those determined by reactive distance for all ages of animals. Visual acuity increased significantly with ontogenetic development from MSA of 30.78’ at hatching to 7.66’ in adults. Adult acuity was reached by seven weeks post-hatch and prior to this time acuity was primarily determined by age. Visual acuity determined by reactive distance also improved significantly from a MSA of 2°55.36’ at hatching to 1°55.99’ at seven weeks of age. Reasons for the discrepancy between calculated MSA for the two methods are discussed and optomotor derived visual acuities compared to published examples for finfish to provide insights into the ecological ramifications of these results. ______

Johnson, Craig (Keynote Address) School of Zoology and Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Private Bag 5, Hobart Tas. 7001 [email protected] Mechanisms of invasion, impact and options for environmental control of exotic marine species: Perspectives from Tasmania as a laboratory As an island receiving frequent inocula of exotic marine species, either through intentional introductions or unintentional incursions as a result of shipping activities or range extension, Tasmania offers particular advantages as ‘natural laboratory’ to study the invasion dynamics of exotic species. The majority of work on the invasion dynamics of exotic marine species worldwide has focused on case histories. While this is instructive, a higher goal of invasion ecology is to derive a broader synthetic theory that provides a robust foundation to a more general understanding of invasion processes, impacts, and options for ‘environmental’ control of exotic species. The talk will outline work in Tasmania on a range of introduced plants and animals which indicates that any general framework will be complex because invasion dynamics, impacts and options for control depend to a large extent on the particular properties of the invader and recipient community and their interaction as a system. Speciﬁc conclusions include that (1) the likelihood of invasion cannot be predicted from aggregate properties of the recipient community such as species richness; (2) impacts of a given species are habitat dependent and even within habitats can be highly variable in space and time depending on local ecologies; (3) indirect impacts from ‘ﬂow-on’ effects in an ecosystem can be as important as direct impacts; (4) environmental control, where it is possible at all, requires management at the community and ecosystem level, and thus a clear understanding of community and ecosystem dynamics; and (5) that impacts and options for control are often tightly linked to the mechanisms of invasion. I suggest that a useful framework to integrate considerations of invasions dynamics, impacts and control is to determine whether an exotic species ‘tracks’ or ‘drives’ community dynamics. ______

Abstracts - Page 64 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Johnston, Emma L1, Sean D Connell2, Andrew D Irving2, Edward Forbes3, Kate Stuart3, Adele J Pile3 & Bronwyn Gillanders2 1 School of Biological, Earth and Environmental Sciences, University of New South Wales NSW 2052 2 School of Earth and Environmental Science, University of Adelaide SA, 5005 3 School of Biological Sciences, University of Sydney NSW, 2006 [email protected] Characterising shallow rocky-reef assemblages from the Windmill Islands coast, East Antarctica Antarctic marine assemblages exist in consistently cold waters with relatively constant nutrient levels. Environmental factors such as day length, ice-cover, ice-disturbance, and sedimentation rates are thus likely to affect the distribution of these plants and animals. We quantitatively characterised assemblages at two exposed island sites and two sheltered bays from the Windmill Islands coast of Antarctica. We used replicated 30 m line transects for macroalgal cover and quadrats for invertebrate and encrusting algae. Small boulders were also collected from the dominant habitat types within each exposure and depth category and censused for flora and fauna. Results showed a dramatic effect of extended ice cover in bays. Island sites were dominated by macroalgae and we observed a distinct depth zonation. Immediately below the ice-foot zone at six m, the area was dominated by foliose red (Palmaria decipiens) and foliose brown (Desmarestia sp.) algae, at 12 m the large kelp Himantothatlus grandifolia dominated. Bay sites featured large areas of diatom/sediment film and no canopy forming macroalgae. Percent cover of invertebrates was similar across sites and depths however, filter feeders dominated assemblage in bays while grazers occurred around islands. Surveys of small boulders revealed complex relationships between algae and bryozoans. The dominant bryozoan Inversiula nutrix competed for space with small turfing algae at island sites. Bryozoan diversity was reduced in deeper bay areas and this is hypothesized to be due to increased fine sediment reducing the availability of cryptic habitat (under boulders) and smothering small recruits (top of boulders). Climate variability that affects the extent or duration of ice-cover will have a rapid and marked affect on the distribution of rocky reef organisms in Antarctic coastal waters. ______

Jones, Graham1, Mike Harvey2, John McGregor2, Hilton Swan3, Anke Schneider1, 4, Edward Abraham2, Cliff Law2, Murray Smith2, Michael Ellwood5, Julie Hall5, Simon Wright6 1 School of Environmental Science & Management, Southern Cross University, Lismore, NSW 2480 2 National Institute of Water & Atmospheric Research, Kilburnie, Wellington, New Zealand 3 Australian Government Analytical Laboratories, Pymble, NSW 2073 4 Institute for Marine Chemistry & Biology, Carl von Ossietzky University, Oldenburg, Germany 5 National Institute of Water & Atmospheric Research, Auckland, New Zealand 6 Australian Antarctic Division, Kingston, Tasmania [email protected] The SOLAS Air-Sea Gas Experiment (SAGE) 2004 and effects of iron fertilisation on DMS gas exchange The SOLAS Air-Sea Gas Experiment (SAGE) was an iron fertilisation patch-tracer experiment conducted to the east of New Zealand in sub-Antarctic waters around an eddy at 46o 45’S, 172o 15’E between 24 March and 10 April 2004. Background dissolved iron concentrations in the region were around 0.11 -1 2+ 3 nmol L . In the initial fertilisation, approximately 225 kg of Fe were added as FeSO4.7H2O in 7.5 m of acidified seawater over an area of 6 km by 6 km along with dissolved SF6 tracer gas to mark the patch. Dissolved iron concentrations were initially raised to 1.3 ± 0.8 nmol L-1 and generally kept above 0.2 nmol L-1 by 3 subsequent infusions over the following 15 days. Phytoplankton showed a rapid physiological response within 48 hours of the first iron addition through an increased photosynthetic competence Fv/ Fm measured by fast repetition rate fluorometry. However, the biological response was slow and limited; after 15 days chlorophyll-a levels and phytoplankton cell numbers in the patch had approximately doubled. Dissolved DMS was measured every 14 minutes throughout the experiment with an automatic purge and trap assembly designed at NIWA. Dissolved DMS levels were most affected by the high wind stress that occurred throughout most of the experiment, but during the fourth infusion during calm conditions a slight increase in dissolved DMS did occur. These results are compared and contrasted with other iron fertilisation experiments.

Abstracts - Page 65 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Jordan, Alan1 & Andrew Bickers2 1 Tasmanian Aquaculture and Fisheries Institute, Marine Research Laboratories, University of Tasmania, Private Bag 49, Hobart 7000 2 School of Plant Biology, University of Western Australia, 35 Sterling Highway, Crawley WA 6009 [email protected] Development and application of seabed habitat mapping technologies Mapping of seabed habitats is an important component of the overall research required to describe the distribution and structure of Australia’s coastal and marine ecosystems for conservation planning and multiple-use ecosystem management. Recent advancements and application of technologies such as aerial remote sensing, vessel based single and multibeam acoustics, differential GPS, Geographic Information System software and cost-effective underwater video has resulted in an increase in mapping throughout Australia. Aerial remote sensing techniques are either airborne (photography, lasers, multi-spectral and hyper-spectral scanners) or satellite based (multispectral and hyperspectral scanners), which vary in spectral and spatial resolution and classification procedures. Hydroacoustic methods such as single beam and multibeam echosounders (side-scan sonar and swath mappers) vary dramatically in cost, resolution capabilities and the need for data processing and expertise. Single-beam sounders obtain information on the roughness and hardness of the seabed directly below the vessel and there are various acoustic substrate classification systems (e.g. Roxanne and Questa Tangent) that use these parameters to classify seabed substrates. Side-scan sonar provides a considerably wider coverage to produce a mosaic of imagery of the seabed that is used to classify and map texturally different regions. Multibeam sounders (swath mappers) acquire bathymetric and backscatter (surface roughness) across a wide swath of seabed using a collection of acoustic beams with the large volume of data requiring considerable post-processing to generate habitat maps. Further development of backscatter analysis techniques will allow identification of a broad range of seabed habitat types and finer detail on the dominant benthic community. Video is commonly used to groundtruth classifications and obtain detailed information on macrofauna and flora and physical parameters. Single cameras can also be used measure objects when fitted with paired laser beams and the application of stereo cameras has allowed more precise measurements of marine biota and physical parameters. These range technologies will be discussed and examples of their application to mapping seabed habitats in Tasmania will be presented. ______

Kämpf, Jochen School of Chemistry, Physics and Earth Sciences, Flinders University, Adelaide SA 5000 Jochen.Kaempf@flinders.edu.au On the South Australian coastal upwelling system I will discuss findings of our recent explorations of the South Australian Upwelling System that will be published shortly in Geophysical Research Letters (Kämpf et al., in press). Foci of my talk will be a) to summarise what is known about this seasonal upwelling system that establishes in summer and extends from Ceduna to Portland, and b) to identify gaps of knowledge to foster more coastal oceanographic research to be undertaken along South Australian southern shelves. Despite its great ecological significance, this region is heavily understudied ______

Abstracts - Page 66 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Katsumata, Katsurou1*, Peter Holloway2 & Graham Symonds1 1 School of Physical, Mathematical, and Environmental Sciences, University of New South Wales/Australian Defence Force Academy, ACT 2600 2 Deceased. Late of University of New South Wales/Australian Defence Force Academy. Honoured by this Symposium [email protected] A numerical and observational investigation into the bottom boundary layer on North West Shelf Turbulence and sediment concentration in the benthic boundary layer are studied using a numerical simulation and in situ observations on the Australian North West Shelf. The numerical simulations were done using the Princeton Ocean Model, configured with one-way nesting to achieve a horizontal grid resolution of 800 m by 800 m. The model is forced with a prescribed surface semidiurnal tide (M2 only) along the boundary. A parameterisation of the sediment dynamics is incorporated into the model. The in situ observations were obtained from a three-dimensional tripod, approximately 3 m wide and 3 m high, equipped with three 3-dimensional acoustic Doppler velocimeters sampling at 8 Hz and three optical backscatter sensors and an acoustic Doppler current profiler. The tripod was deployed on the seabed at a depth of 125 m on 3 March 2004 and approximately three weeks of turbulent data were obtained. An energy analysis from the last tidal period of a four-day model run shows that the region is a sink for the baroclinic energy which flows from both shallower and deeper regions. The energy is dissipated predominantly as the bottom friction. The horizontal velocity is dominated by the tidal flow and the tidal ellipses agree well with previous observations. The vertical velocity within 10 m from the bottom fluctuates with a period of 2 to 4 hours, suggesting some form of nonlinear dynamics. The turbulent kinetic energy near the bottom is strongest when the surface elevation starts to rise, while the sediment concentration is greatest just prior to the minimum in the surface elevation. Some of these features show good qualitative agreement with the in situ observation. The observed peak in the turbulent kinetic energy occurs at a similar tidal phase as the numerical model and the observed non-turbulent vertical velocity shows fluctuations with shorter periods than the semidiurnal tide. However, the sediment concentration does not show any clear relation to the tidal phase. ______

Abstracts - Page 67 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Kawaguchi, So1*, Steve Candy1, Stephen Nicol1 & Mikio Naganobu2 1 Australian Antarctic Division, Channel Hwy, Kingston TAS 7050 2 National Research Institute of Far Seas Fisheries, 5-7-1, Shimizu-Orido, Shizuoka, Japan 424-8633 [email protected] Modelling Antarctic krill Growth: a new approach Antarctic krill is a keystone species of the Antarctic marine ecosystem. Krill growth is one of the most important parameters essential for ecosystem management under CCAMLR (Commission for Conservation of Antarctic Marine Living Resources) regime. The traditional length-frequency analysis of repeated sampling have generally been used, however, this method is based on the assumption that the series of krill sampled are from the same population, which is difficult to verify for pelagic organisms. The “instantaneous growth rate” (IGR) method utilises data on size change from living krill. The advantage of this method is that it is based on actual growth of the individuals measured at moulting, and also can be related to environmental conditions. The IGR technique is beginning to provide a large amount of data on growth, however, modelling krill growth trajectories using IGR data has not yet been attempted. The aim of this study is 1) to generate a growth model based on IGR measurements, and 2) to see how factors such as sex, temperature, and season affect krill growth. Data from the Indian Sector during 1991/92 to 2002/03 season for December to April, and the Atlantic Sector from November to February of 1999/2000 season were used. IGR, expressed as a percentage of total length, was fitted using a linear mixed model (LMM) using total length, area, month and sex as independent factors and cruise as a random factor. Juveniles and males showed similar IGR-length curves, however, females of >36 mm showed significantly lower growth rates compared to males and juveniles, suggesting that larger females during this period are putting their effort into reproduction rather than growth. Growth trajectories were generated using an intermoult period-temperature function, average monthly temperatures, and a predictive model for IGR. This exercise will allow us to test the effect of environmental factors such as temperature variations on the growth trajectory. Discussion will be extended to the comparison of these results with existing growth models. ______

Kelaher, Brendan1*, Jeff Levinton2, Ruth Junkins2 & Bengt Allen2 (Poster) 1 Department of Environmental Sciences, UTS, Broadway, NSW, Australia 2 Departments of Ecology and Evolution, SUNY Stony Brook, NY, USA. [email protected] What does $100 million buy: an environmental restoration or an ecological disturbance? We investigated the effects of removing cadmium-polluted sediments on the benthos of Foundry Cove, New York. From 1953 to 1979, the cove was polluted by wastewater from the production of nickel- cadmium batteries, but was recently restored at a cost of ca. $ 100 million USD. Prior to the clean-up, concentrations of Cd in the sediment ranged from 500 ppm – 10,000 ppm. Surprisingly, the structure of macrobenthic communities in Foundry Cove did not differ signiﬁcantly from those in uncontaminated coves, which in part can be explained by the evolution of resistance by the dominant oligochaete, Limnodrilus hoffmeisteri. A massive environmental restoration from 1993 to 1996 was affective in reducing Cd concentrations in the sediment to less than 20 ppm, stimulating reverse evolution of some Cd resistant species. Changes in sediment characteristics associated with restorative dredging, however, negatively affected macrofaunal assemblages. In future restorations, such impacts could be minimized by paying greater attention to maintenance of sediment properties important to infaunal communities. ______

Abstracts - Page 68 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Khou, Muoi1, Nick Paul1, Jeff Wright2 & Peter Steinberg1 1 School of Biological, Earth & Environmental Sciences, and, Centre for Marine Biofouling and Bio-Innovation, University of New South Wales 2052 2 Department of Biological Sciences, University of Wollongong 2522 [email protected] Fragmentation as a strategy for expansion by Caulerpa filiformis Asexual reproduction by fragmentation is an important method of propagation for many marine organisms. In algae, the ability to fragment and disperse appears to be significant for range expansion and establishment. This is particularly evident for two invasive species from the genus Caulerpa, Caulerpa taxifolia and Caulerpa racemosa. Wide-scale invasions of these species in the Mediterranean is mainly attributed to vegetative fragmentation. First documented in South-East Australia in 1927, Caulerpa filiformis is believed to have replaced many native species, often attaining 100% cover at some localities. However, to date the mechanisms underlying its expansion are poorly understood. As sexual reproduction has rarely been documented in Caulerpa genera, this study focuses on fragmentation as a mechanism for recolonisation in C. filiformis. Growth and attachment of C. filiformis fragments were examined to determine the success of different fragment types and sizes. These fragments were chosen based on field sampling and consisted of three major morphologies. In the laboratory, fragments were able to survive, grow and produce re-attachment structures (rhizoids) independent of size and type. Fragments without stolons were most successful in producing growth of rhizoids and thalli. Attachment success of fragments was also scored for all fragment types and sizes in the laboratory, however fragments could only attach if rhizoids were present. In field experiments, fragments with rhizoids successfully attached on coralline turf. Rhizoids are therefore essential for fragment attachment in the field. However, laboratory experiments indicate that rhizoids cannot be produced while fragments are suspended, and production only occurs once the fragment has settled on substrata. This result accounts for the lack of fragments with rhizoids found during the field sampling. These results suggest that asexual fragmentation is important in the successful expansion of C. filiformis populations. ______

Kildea, TN1 & AC Cheshire2 1 Australian Water Quality Centre, PMB 3 Salisbury SA 5108 2 South Australian Research Institute, PO Box 120, Henley Beach SA 5022 [email protected] Comparison of the productivity, chlorophyll concentration and depth distribution of two species of Cystophora (Fucales) from West Island, South Australia The relationship between changes in photosynthetic pigment content and productivity as a function of water depth were measured in two species of Cystophora, C. moniliformis and C. subfarcinata, to examine whether their differences in depth distribution were dependent upon the individual species’ ability to utilise light. Both species are commonly found in subtidal macroalgal communities along the southern Australian coastline to a depth of six metres, but C. moniliformis can occur to a depth of 28 metres. At shallower depths (3 and 5 metres) there were no significant differences in chlorophyll a and c concentrations and in situ net 24hr productivity between the two species. It was therefore proposed that C. subfarcinata did not occur at depths below 6 metres, due to an inability to adapt its pigment system. To investigate this theory, individuals of both species were transplanted from 5 to 10 metres for a period of seven days before chlorophyll concentrations were remeasured. Concentrations of chlorophyll a and c significantly increased from 0.45 to 0.56 mg.g-1 f wt and 0.07 to 0.10 mg.g-1 f wt respectively in C. moniliformis. There were however no significant changes in chlorophyll concentrations in C. subfarcinata (chl a 0.35 to 0.38 mg.g-1 f wt and chl c 0.06 to 0.06 mg.g-1 f wt). Species of Cystophora have been shown to accumulate carbohydrate reserves and it is proposed that the utilisation of such reserves may allow for the production of chlorophyll when net 24hr productivity is reduced. If C. moniliformis has the ability to store carbohydrates and C. subfarcinata does not, this may explain why C. subfarcinata is not found at depth.

Abstracts - Page 69 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Kingston, Jennifer J1, Christophe Guinet2, Robert G Harcourt3, Simon D Goldsworthy4 & Des W Cooper1 1 Department of Biological Sciences, Macquarie University, Sydney 2109, NSW, Australia 2 Centre d’Etudes Biologiques de Chizé; CEBC-CNRS, UBR 1934; 79360 Villiers en Bois, France 3 Graduate School of the Environment, Macquarie University, Sydney 2109, NSW, Australia 4 Department of Zoology, LaTrobe University, Melbourne 3086, VIC, Australia [email protected] Sympatrically breeding fur seals do not use visual cues for species recognition Fur seals of the genus Arctocephalus were heavily exploited during the 18th and 19th centuries, only recently recovering and recolonising their former habitats. Seven fur seal species inhabit the southern hemisphere. Most species have discrete breeding ranges, but sub-antarctic fur seals (SFS) breed sympatrically with other species at three sites. Hybridisation between SFS and other species has been recorded at two sites and this study aimed to determine the frequency of hybridisation, if any, at the 3rd site, Îles Crozet. We sampled and genotyped 364 individuals across 10 polymorphic microsatellite loci and identified hybrids using an assignment test. If random mating were occurring, we would expect hybrid frequency to be 52%. Our results indicate that only 2.5% of the population are hybrids. The significantly low frequency of hybrids suggests that a mechanism for species recognition may discourage hybridisation. Male SFS exhibit unique features not found in other fur seals, namely a conspicuous pelage with a creamy-yellow ventral surface, dark dorsal fur and a prominent saggital crest. We asked: do females use pelage as a visual cue for species recognition? Fur seals are highly polygynous and males aggressively defend territories during the breeding season. We performed a mate choice experiment in 2001/02 at one sympatric site, by manipulating 8 male SFS to resemble other fur seal species. Similar treatment was given to a group of 8 control males to remove any handling bias. Untreated males were classified as ‘other’. We measured individual male reproductive success using genotypic data and recorded the number of females in each territory to determine the number of expected paternities for experimental, control, and ‘other’ males. Males, females and offspring were genotyped at 10 microsatellite loci and were able to assign paternity to 28 pups. There was no significant difference between the expected and actual number of pups sired by experimental, control and ‘other’ males (χ2=619; p = 0.96) showing that females do not exhibit choice for conspecific mates based on pelage characteristics. However, evidence that fur seals avoid hybridising suggests that there is an alternative mechanism for species recognition. ______

Abstracts - Page 70 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Koslow, J Anthony,1 J Strzelecki1, H Paterson1, S Pesant2, A Begum3, A Pearce1 & A Waite2 1 CSIRO Marine Research, Floreat WA 6014 2 Centre for Water Research, University of Western Australia, Perth WA 6000 3 River and Waters Commission, Perth WA 6000 [email protected] Seasonal and onshore-offshore patterns in the biophysical oceanography off SW Australia The oceanography off the west coast of Australia is unique, dominated by the world’s only poleward flowing, downwelling eastern boundary current, the Leeuwin. Yet the region’s biological dynamics remain undescribed. Since February 2002, we have regularly occupied a cross-shelf transect north of Perth. From the coastal ‘lagoon’ to 1000 m depth, we obtain CTD profiles of temperature, salinity and chlorophyll, as well as samples of nutrients, phytoplankton, micro- and mesozooplankton. Primary production, microzooplankton grazing and copepod production are examined at selected stations. The water column is highly stratified in summer, leading to undetectable nitrate in the mixed layer and a deep cholorophyll maximum layer, which lies just over the bottom on the shelf and extends to ~100 m depth offshore. In April/May the Leeuwin Current intensifies. Although it is a low-nutrient current, the breakdown of stratification mixes nutrient into the mixed layer and leads to autumn/winter blooms across much of the shelf and slope. This pattern does not apply within the coastal lagoon, and there is considerable interannual variability. Results of this field study will be incorporated within biogeochemical models that should lead to an understanding of the links between El Nino, the strength of the Leeuwin Current, and recruitment variability in the region’s major fisheries. ______

______

Paterson, H1 , Band Ashrafi2 & AJ Koslow3 (Poster) 1 Animal Biology, University of Western Australia, Perth WA 6000 2 Department of Environment, Perth WA 6000 3 CSIRO Marine Research, Perth WA 6000 [email protected] Microplankton diversity in two contrasting mesoscale eddies Abundance and species community structure of large, protists (acantharians, radiolarians) and diatoms was investigated in October 2003 in two contrasting mesoscale eddies, 300 nm off the central western coast of Australia. Between 50 and 60 L of seawater was filtered through a 0.2 μm filter, air dried and prepared for scanning electron microscopy. The microplankton community in the upwelling eddy was dominated by large diatoms, thus detecting heterotrophic protists was difficult. The upwelling eddy, on the other hand, was sparsely populated, allowing the identification of large protists. This experiment has demonstrated the high abundance and importance of diatoms in the downwelling eddy, and their scarcity in the upwelling eddy. In addition the diversity of protists from the upwelling eddy has been evaluated. ______

Abstracts - Page 71 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Paterson, H1, S Pesant2, AJ Koslow3, A Waite2

1 Animal Biology, University of Western Australia, Perth Western Australia, [email protected] 2 Centre for Water Research, University of Western Australia, Perth 3 CSIRO Marine Research, Perth, Australia Herbivorous impact of microzooplankton in two contrasting eddies Grazing rates by microzooplankton on picophytoplankton and total phytoplankton were estimated from dilution experiments in October 2003 in two contrasting mesoscale features, 300 nm off the central western coast of Australia. Each eddy was sampled at the centre, body and at the edge. In the downwelling eddy the abundance of microzooplankton was between 900 and 3000 cell L-1, and in the upwelling eddy between 1000 and 2200 cell L-1. Microzooplankton biomass was generally higher in the downwelling eddy, as was phytoplankton biomass. Microzooplankton grazing on total chlorophyll a standing crop and phytoplankton production ranged from 0 to over 100 % in both eddies. Turnover rates of the small cyanobacteria, Synechococcus, ranged from 0 - 29% and 0- 41% in the downwelling and upwelling eddies respectively. Eukaryotic picoplankton had high rates of growth and grazing, with turnover rates between 10 and 53 % for the downwelling eddy and 67 and 85% for the upwelling eddy. This increased herbivory on eukaryotic picoplankton in the upwelling eddy, suggests that the microbial food web is a more important component of the trophic dynamics in this system than in the downwelling eddy. ______

______

Krause, Gunther (Keynote Address) Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany From the Coorong to the Greenland Sea - Surprises on bottom water formation and ventilation in the Greenland Sea The author witnessed Peter Holloway’s development from a young BSc student to a successful and respected marine scientist. As A Ph.D. candidate of the author at the Flinders University of South Australia he performed the field work for his thesis on the vertical temperature structure in the shallow waters of the Coorong lagoon in Australia. Sixteen years later he brought his greatly expanded knowledge of the upper layers of the water column to a polar expedition in to the Greenland Sea. This article is thus a personal account of our close association from 1974, in a chronological sequence, and include some science from that collaboration. As such it does not cover all his scientific career and achievements. The scientific part is a presentation of results of yearly expeditions in to the Greenland Sea between 1989 and 2003. It deals with the components of the forcing mechanisms of the global thermo-haline circulation which are at work in the Greenland Sea. It is shown that – in contrast to many theories since Fridjof Nansen – the bottom water was not directly linked to the surface after 1991. The observed increase of bottom water temperatures was found to be not an effect of “global warming”, but resulted from vertical advection which moved the water column downwards at a rate of approximately 100 m/year. ______

Abstracts - Page 72 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Lansdell, Matthew1*, Craig Mundy2 & Alistair Hobday1,3 (Poster)

1 School of Zoology, University of Tasmania, GPO Box 252-05, Hobart Tas. 7001 2 Tasmanian Aquaculture & Fisheries Institute, University of Tasmania, Private Bag 49, Hobart Tas. 7001 3 CSIRO Marine Research, GPO Box 1538, Hobart Tas. 7001. [email protected] Meager movements of abalone? The benefits of studying small-scale ecology for fisheries management Valuable commercial abalone fisheries worldwide have depleted resources to the point of collapse, due to over-exploitation and inadequate fishery and catch management practices. In Tasmania, the relatively healthy fishery and well-managed abalone industry brings significant economic benefit to the state, accounting for 25% of the world catch. However, ongoing and new research into abalone ecology, as well as improved management techniques and practices, is essential for the Tasmanian fishery to avoid a similar fate to fisheries elsewhere. One area of research that has received less attention is movement of abalone at small spatial and temporal scales. Small-scale movements are important for abalone aggregation and reproduction, and from a fishery perspective, to prevent complete removal of viable populations. Commercial fishermen report areas of ‘good recovery bottom’ that may be re-fished heavily after a few weeks. The resilience of abalone populations in these areas relates to small-scale movement. While variation in movement can be significant between species, this project will concentrate on the blacklip abalone (Haliotis rubra Leach), which is the main commercial species in Tasmania. Anecdotal evidence shows emergent blacklip abalone move in and out of cryptic habitats, however, the time-scale, distance and frequency of these movements are unknown. This project will utilise minimal disturbance techniques to tag abalone and record movement at a frequency sufficient to permit the resolution of movement patterns over small temporal scales. I am specifically seeking to answer questions about home-site use, daily movements and aggregation composition and dynamics. A clearer understanding of abalone behaviour and the interaction/influence upon their environment over small spatial/temporal scales will improve existing assessment and management techniques, namely: more accurate abundance and density estimates; improved understanding of the dynamics of re-population of exploited sites; and the role of homing scars in movement and aggregation. ______

Lewis, John A Maritime Platforms Division, DSTO, Melbourne, Vic. [email protected] Translocation of marine non-indigenous species: How important is ship hull fouling? Recent invasions of Australian inshore waters by invasive pests, notably the Japanese seastar Asterias amurensis, the Mediterranean fanworm Sabella spallanzanii, the Japanese kelp Undaria pinnatiﬁda, and the invasive strain of Caulerpa taxifolia, have highlighted the threat posed to our ecosystems and marine industries by exotic species. Shipping is recognised as a primary vector for the international translocation of non-indigenous species but the mode of transport is not as clearly resolved. Hull fouling is considered to have been the major transport mode for non-indigenous species (NIS) through the 19th and early 20th centuries, but developments in antifouling technology in the latter part of the 20th century were considered to have minimised this risk. The emphasis thus shifted to ballast water, culminating in the adoption by the International Maritime Organization earlier this year of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments. However, hull fouling has re- emerged as a vector not to be ignored in the management of NIS translocation. Recent observations on the incidence and composition of fouling communities on ship hulls and within ship pipe work will be presented, and management options and the implications of increasing restrictions on the use of toxic antifouling paint systems discussed.

Abstracts - Page 73 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Hobday, Alistair1, Tony Smith1, Ilona Stobutzki2, Scott Ling1 (Poster) 1 CSIRO Marine Research 2 ICLARM Ecological risk assessment for effects of fishing: A flexible framework that works in data-poor situations to prioritize action Broader ecological impacts of fisheries, on non-target species, habitats, and marine communities, are leading to growing public concern and pressure for action. This pressure often precedes the scientific methodology and data required to assess such impacts. Risk assessment techniques have been used to bridge this gap in several countries. In Australia an ecological risk assessment framework has been developed and applied to federally-managed fisheries. This Ecological Risk Assessment for the Effects of Fishing (ERAEF) framework involves a 3-level hierarchical approach. It moves from a comprehensive but largely qualitative analysis of risk (Level 1), through a more focused and semi-quantitative approach (Level 2), to a highly focused and fully quantitative “model-based” approach (Level 3). This is efficient because many potential but minor risks are screened out at Level 1, so the more intensive analyses at Level 2 (and Level 3) are limited to higher risk activities. It also enables rapid identification of high- risk activities, enabling immediate management action. The ERAEF approach evaluates five ecological components; (1) Target species, (2) By-product and by-catch species, (3) Threatened, endangered and protected species, (4) Habitats, and (5) Ecological communities. We adapted classical risk assessment methods to the complexities and uncertainties involved in assessing ecological risks from fishing. The aim is to be comprehensive and rigorous while also realistic, with regard to the time and resources available for assessing a fishery, and the data and expertise available to address specific issues. We developed a flexible approach applicable to all types of fisheries. Over 15 individual fisheries have been assessed, including demersal trawl, set net and pelagic longline fisheries. Results from these case studies show the success and flexibility of the ERAEF approach and describe general patterns of ecological risk in these fisheries. ______

______

List, Kate The University of New South Wales at the Australian Defence Force Academy, School of PEMS, Northcote Avenue, Campbell ACT 2600 [email protected] Recent planktonic foraminifera in surface sediments Paleoceanographic interpretation of fossil assemblages relies heavily on an understanding of the distribution of recent foraminifera in surface sediments. Planktonic foraminiferal data collected from south-eastern Australian continental shelf surface sediment correlate signiﬁcantly with speciﬁc indicator species chosen from living planktonic foraminiferal distributions. The separation of the Tasman Sea and the Coral Sea (Tasman Front) is apparent in the post-mortem distributions of planktonic foraminifera in surface sediments on the shelf. It may be possible to record paleoceanographic changes in the position of the Tasman Front down-core using this simple technique. A regional model for paleodepth determination using planktonic/benthic ratios in the surface sediment is proposed for the south-eastern Australian continental shelf. A threshold value of 100m paleodepth (50% planktonic tests) to distinguish between shallow coastal, and outer shelf environments is suggested. ______

Abstracts - Page 74 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Longford, Sharon1,2*, Staffan Kjelleberg2,3 & Peter Steinberg1,2 1 School of Biological, Earth and Environmental Sciences, 2 Centre for Marine Biofouling and Bio-Innovation, 3 School of Microbiology, University of New South Wales, Sydney 2052 [email protected] Community ecology of epiphytic bacteria on a temperate red alga The community structure of epiphytic bacteria inhabiting the temperate marine red alga Delisea pulchra was investigated focusing on stability and succession patterns for the algal tip community. D. pulchra is distinctive in that it produces biologically active secondary metabolites (furanones) known to interfere with bacterial signaling systems which coordinate expression of multicellular phenotypes. Culturing of bacterial isolates indicates that well-deﬁned bacterial assemblages are present along the thallus of D. pulchra – a trend that correlates with a gradient of furanone production across the plant. This pattern is stable in both space and time and is not present on co-occurring macroalgae. The bacteria community was investigated on the tip regions of D. pulchra where the furanone concentration is the highest. Bacterial succession of the alga was investigated using antibiotic treated plants transplanted into D. pulchra’s natural environment and destructively sampled over time. Denaturing gradient gel electrophoresis (DGGE) was used to detect temporal shifts in community structure and identify primary and subsequent bacterial colonisers appearing throughout the succession process. The time taken for bacteria to colonise a disturbed plant and reach a stable community is approximately 12 d. Analysis of a 16S rRNA gene clone library based on a stable/climax community reveals an assemblage showing high species richness, with more than 120 restriction fragment length polymorphism (RFLP) types and over 80 different bacterial species/strains present. The ability of such a diverse assemblage to stabilize in a short time frame after disturbance is fundamental to understanding the community structure and functioning of this dynamic system. ______

______

Lyall, Luisa & Johnson, Craig (Poster) School of Zoology, University of Tasmania, Tas 7001 [email protected] Use of fluorochromes as markers for tracking larval dispersal of Heliocidaris erythrogramma Planktonic larval dispersal plays a crucial role in maintaining connectivity between populations of marine benthic species that might otherwise be relatively isolated. Evaluation of the pattern of larval dispersal is necessary to ascertain the level of connectivity between populations and the impact of dilution of dispersing larvae on population dynamics. For lecithotrophic species with a short planktonic duration, direct tracking of marked larvae is possible. In this context, the ideal properties of a suitable marker are 1) that the marker is retained post metamorphosis so that dispersal to the point of settlement can be estimated, and 2) that the marker does not affect the survivorship, development, morphology or visual appearance of the larva or post metamorphic individual. We investigated the effectiveness of two fluorochromes (Nile Red and calcein) for marking larvae of the sea urchin Heliocidaris erythrogramma and their potential application for tracking larval dispersal. A marking protocol was developed for each fluorochrome that produced readily detectable marks in larvae of the sea urchins whilst having no adverse effects on larval development or the ability of the larvae to settle and complete metamorphosis. Markers were retained through larval metamorphosis and were still detectable in juvenile sea urchins after a period of 8 weeks. These fluorescent markers show great potential for use in tracking larval dispersal of H. erythrogramma as they are easy to apply, inexpensive, have no affect on larval development, are retained through metamorphosis and are unambiguous to detect whilst not changing the appearance of the larvae or juveniles to visual predators.

Abstracts - Page 75 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Magierowski, Regina & Craig Johnson School of Zoology University of Tasmania, Private Bag 05, Hobart Tas . 7001 [email protected] How robust are surrogates of alpha diversity in marine communities? The usefulness of surrogates to estimate complex variables describing community structure, such as the various components of biodiversity, is long established. Most attention has been given to surrogates of species richness and species diversity, and has focussed on identifying a subset of taxa from a community as a surrogate of total richness or diversity. In adopting a surrogate measure, it is assumed that the relationship between the surrogate(s) and total richness or diversity is consistent in both space and time. These assumptions are rarely examined explicitly. We examined the robustness of potential surrogates of familial richness and multivariate community structure for macrofauna communities inhabiting artificial kelp holdfasts by comparing among communities of dissimilar ages and among communities established at different times of the year. This is important because most benthic ‘landscapes’ will be a mosaic of patches reflecting different intensities, frequencies and timing of disturbances. Irrespective of the age of the community, the total abundance of organisms and familial richness of crustaceans were good predictors of total familial richness (R2 > 0.8). In contrast, while the richness of other groups such as molluscs and echinoderms were well correlated with total familial richness for communities at an early stage of development, the strength of these relationships declined with community longevity. For multivariate community structure, carefully selected subsets of ~10% of the total taxa yield similar patterns to the total suite of taxa irrespective of the age of the community. For different communities of identical age, the identity of surrogate communities changes with the time of the year that artificial holdfasts are deployed, but these differences were more pronounced in newly developed communities than in long standing ones. Thus, useful surrogates of both familial richness and multivariate community structure can be identified for this type of community, however careful selection is required to ensure that surrogates perform consistently across different aged communities and for different starting conditions. ______

Manson, FJ1,2,3, NR Loneragan3, BD Harch4, GA Skilleter5, L Williams61

1 CRC for Coastal Zone, Estuary and Waterway Management, 80 Meiers Road, Indooroopilly, Queensland, Australia 2 School of Geography, Planning and Architecture, University of Queensland, Brisbane, Queensland, 4072, Australia 3 CSIRO Marine Research, PO Box 120, Cleveland, Queensland, 4163, Australia 4 CSIRO Maths and Information Sciences, Queensland Bioscience Precinct, 306 Carmody Road, Brisbane, QLD 4067, Australia 5 Marine & Estuarine Ecology Unit, School of Life Sciences, University of Queensland, Brisbane, Queensland, 4072, Australia 6 Queensland Department of Primary Industries, 80 Ann Street, Brisbane, QLD 4001, Australia fi[email protected] Mangrove-fisheries links at broad spatial scales There is a widely-held paradigm that mangroves are critical for sustaining production in coastal fisheries because they act as important nursery areas for fisheries species; this paradigm has been used as the basis for important management decisions on habitat conservation and restoration. Support for the paradigm comes from previous studies that have found correlations between the extent of mangroves and the catch in nearby fisheries. However, these analyses have often included a mix of species that used mangroves in different ways, rather than individual species; fishing effort has not been taken into account; other environmental variables that may explain variation in the catch have not been included in the analysis; and the spatial scales at which the mangrove and fisheries data have been collected have not been considered. Our study evaluated whether links between mangrove extent (area and length of the water interface) and fisheries catch can be detected by correlation and multiple regression analyses at a broad regional scale (1000’s km) in Queensland. Both catch and catch-per-unit-effort were investigated and a number of fish and crustacean species were examined. We also identified environmental parameters, other than mangrove extent, that may influence fisheries catch and incorporated these variables into the analyses. The results showed that this type of analysis can detect links between mangrove extent and the commercial catch of some species at a broad scale. Other outcomes of the study were the identification of the limitations of the correlative approach and recommendations for how it can be improved in the future.

Abstracts - Page 76 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Mantel, Peter (Poster) CSIRO Marine Research, Castray Esplanade, Hobart, Tasmania 7000 [email protected] Increasing the survivability of APEX Argo Profilers CSIRO Marine Research have been involved with Argo profilers since 1998. The Marine Instrumentation group has considerable experience in testing and preparing APEX profilers manufactured by Webb Research. The APEX-260, version 8b profiler was found to be susceptible to failure during automatic adjustments of hydraulic ballast while at depths greater than 1600 metres. CSIRO engineered a solution for this problem, which has since been adopted by the manufacturer. It has been estimated that this engineering will increase the reliability of APEX profilers, over a four-year lifespan, from 73 to 95 percent. ______

Margvelashvili, Nugzar*, John Andrewartha, Scott Condie, Mike Herzfeld, John Parslow, Jason Waring CSIRO Marine Research, GPO Box 1538, Hobart Tas 7001. [email protected] Modelling suspended sediment transport on Australia’s North West Shelf A three-dimensional sediment transport model has been developed to simulate fine sediment transport over the North West Shelf. The model solves advection-diffusion equations for the mass conservation of suspended and bottom sediments, taking into account the bottom exchanges by resuspension and deposition. The time-dependent sediment resuspension, transportation and deposition are simulated as responses to wind waves and currents. Simple empirical formulation is employed to estimate surface wave characteristics. Water circulation is modelled using a three-dimensional non-linear hydrodynamic model (MECO). The sediment model is initialised using field data for the grain-size distribution on the shelf. The hydrodynamic and the wave models are driven with realistic tides, winds, temperature, and salinity fields. According to simulations, one year average sediment fluxes were directed southwest along the shelf and off the shelf. While there were significant uncertainties associated with these fluxes, the results suggested that sediment losses from the shelf exceeded the mean annual river loads by at least a factor of three over the simulation period. The model also predicted major sediment transport events during tropical cyclones. Modelled off-shelf loads during cyclone Bobby (February 1995) exceeded both annual river loads and annual loads during non-cyclone conditions. The simulations demonstrated how cyclone generated eddies could capture large quantities of suspended sediments and carry them offshore to be deposited within highly localised patches in the deep ocean. ______

______

Abstracts - Page 77 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Martin-Smith, Keith1* & Amanda Vincent2 1 Project Seahorse, School of Zoology, University of Tasmania, Tas 7001 2 Project Seahorse, Fisheries Centre, University of British Columbia, Canada V6T 1Z4 [email protected] Wild horses run free: Abundance, distribution and movement in seahorses Seahorses are flagship species for marine conservation but we know little about basic population biology for many species. In order to make informed conservation decisions we need to understand seahorse temporal and spatial dynamics. We conducted quantitative underwater visual surveys of populations of the big-bellied seahorse, Hippocampus abdominalis, in the Derwent River, Tasmania from 2000-2004. Over this period, seahorse density declined significantly. We also undertook mark-recapture studies in Hobart and Sydney to estimate population size and follow individual seahorses. There were significant differences in abundance, sex ratio and size-frequency distributions between the two populations. In Hobart, we found seahorses at lower density, the sex ratio was significantly female-biased and the majority of individuals were large adults, while in Sydney we found greater density of seahorses, equal sex ratio and more juveniles. In both populations, big-bellied seahorses were generally found singly, although they were occasionally aggregated on underwater structures. In contrast to other species of seahorse we did not find seahorses in pair-bonded couples and we found no evidence of small home ranges. On the contrary, we observed marked seahorses traveling considerable distances in short periods of time – up to 2.5 km in 28 days. Implications of these findings for conservation initiatives such as the design of marine protected areas will be discussed. ______

McCauley, Robert D1, K Jenner, S Curt2, M-N Jenner2, Christopher LK Burton3, John L Bannister3, & Chandra Salgado Kent1 1 Centre for Marine Science and Technology, Curtin University of Technology, Bentley WA 6102 2 Centre For Whale Research (Western Australia) Inc. 3 WA Museum, Perth [email protected] Blue whales in the Perth Canyon The Perth Canyon harbours seasonal aggregations of pygmy blue whales during November to June with most animals present during February to May. Based on aerial surveys, upwards of 50 blue whales per day may be present at peak times. Several sets of observations confirm that while in the Canyon whales actively feed on krill. The presence of sufficient quantities of krill to sustain large numbers of feeding whales suggest the Canyon is a biological hotspot along what is conventionally considered a nutrient poor coastline. A multifaceted program has studied the Canyon through oceanography, productivity, krill abundance and whale biology. Blue whales in the Canyon show distinct behavioural patterns and engage in deep feeding dives, which have been observed via echosounder during daytime, to target scattering layers at 200-400 m depth. These layers were sampled during a Southern Surveyor National Facility vessel cruise in early 2004 and found to harbour krill and myctophid fishes. The compacted daytime layers disperse upwards at night, when we believe whales continue feeding. This suggests different day / night, whale feeding strategies. One of the tools used in studying whales in the Canyon is passive acoustics. Blue whales produce powerful low frequency signals. Passive acoustic studies run year round in the Canyon have revealed a suite of great whale species which use or transit the Canyon plus regular choruses believed produced by myctophid fishes. Signals unique to pygmy and true blue whales are used to census the animals. Grids of hydrophones deployed adjacent the Canyon rim enable tracking of calling whales. Tracking grids, visual observations and satellite tagging allow determination of migratory routes and local whale behaviour. Combining the Perth Canyon acoustic data sets with others available or in progress, will allow us to map the movement patterns of hitherto little known great whales, along large stretches of the WA coast. ______

Abstracts - Page 78 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Ward, Tim M1, Lachlan J McLeay1, Wtjens F Dimmlich1, Paul J Rogers1, Sam McClatchie1, Roger Matthews2, Jochem Kämpf2, Paul D van Ruth1 1 South Australian Research and Development Institute (Aquatic Sciences), PO Box 120, Henley Beach 5022 SA 2 School of Earth Sciences, Flinders University of South Australia, GPO Box 2100, Adelaide 5001 SA [email protected] Do juvenile southern bluefin tuna aggregate in the Great Australian Bight to target high concentrations of sardines? Coastal upwelling at several locations in the eastern Great Australian Bight (GAB) during the austral summer-autumn results in localised increases in surface chlorophyll-a concentrations and downstream enhancement of zooplankton biomass. Sardine (Sardinops sagax) and anchovy (Engraulis australis) eggs and larvae were abundant and widely distributed in shelf waters of the eastern and central GAB during summer-autumn, with high densities occurring in areas with high zooplankton biomass. Summer egg densities and distributions support previous evidence suggesting that the spawning biomass of sardine in South Australia is an order of magnitude higher than elsewhere in southern Australia, and an order of magnitude lower than in the eastern boundary current systems. Sardine from the GAB have a high lipid content during summer-autumn and comprised >50% by weight of the identified prey species of juvenile southern bluefin tuna (SBT, Thunnus maccoyii) collected during this period. These findings suggest that juvenile SBT migrate into the eastern and central GAB during each summer-autumn to access the high densities of sardines that are available in the region during the upwelling period. ______

McKinnon, David Australian Institute of Marine Science, PMB 3, Townsville MC Qld 4810 [email protected] Production, respiration and grazing in tropical Australian waters Plankton community metabolism measurements in the waters of the Great Barrier Reef, Ningaloo Reef, Darwin Harbour, the Timor Sea and the Gulf of Papua allow a regional comparison of the balance between pelagic autotrophy and heterotrophy. Overall, these waters are net autotrophic, though respiratory demand can be high despite great differences in plankton standing stocks and in light climate. Gross production frequently exceeded 5 g C m-2 d-1, and P:R ratios were as high as 5. Net production in excess of 3 g C m-2 d-1 was not unusual. Surprisingly, heterotrophy occurred in the clearest waters – those of the central Gulf of Papua, and in the Timor Sea after the decay of a plankton bloom. The general predominance of autotrophy over heterotrophy implies that considerable amounts of carbon are available to grazers. Dilution experiments conducted on the same cruises indicate that overall ~60% of phytoplankton production is consumed by microzooplankton when chlorophyll is used as an indicator of phytoplankton standing stocks. Flow cytometric estimates of grazing pressure on picoplankton are even higher – 80-100% of primary production being grazed daily. The predominance of microbial processes and the complex trophic interactions in the lower end of pelagic food webs may explain the poor tertiary yields of Australian waters despite episodically high primary production. ______

Abstracts - Page 79 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

McQuillan, Lea*, Jane Fromont, Jackie Alder & Paul Lavery Centre For Ecosystem Management, Edith Cowan University, 100 Joondalup Drive, Joondalup, Western Australia 6027 [email protected] Differences in sponge assemblages on reef habitats off coastal Perth, Western Australia Sponge assemblages were compared on three habitat types across six sites, in Marmion Lagoon, Western Australia, to determine if there were differences in assemblages among the habitat types, reef wall, reef underhang, and reef flat. Assemblages were sampled in June and December 2000. In each habitat, the sponge assemblages in 11 quadrats (0.25 m2) were recorded using digital video and sponge density and cover were measured from analysis of the video footage. Sponges were important benthic components of the reef environment off Marmion Lagoon. They were the dominant faunal group and occupied 30-50 % of the limestone reef surface area. Density of sponge individuals was up to 28 per m2 and species assemblages were highly diverse (>200 sponge species). Sponge assemblages in the study area varied significantly according to habitat type. Reef underhang habitats had higher density and cover of sponges when compared to reef walls. Reef walls, in turn, had a higher density and cover of sponges when compared to reef flats. nMDS and ANOSIM analysis showed sponge density and cover across reef walls and underhangs were similar, and the paucity of sponges on reef flats resulted in significant differences among habitats. These trends persisted even when the assemblages were analysed at higher taxonomic levels (order level). This study highlighted differences among reef habitats, which may be explained by differences in several key ecological variables, such as, light, sedimentation, predation and abrasion. The uniqueness, diversity and species composition of the sponge assemblages at this location suggests Marmion Lagoon, is biologically important and needs to be protected. ______

Merrifield, Mark1, Peter Holloway2, Shaun Johnston3, Michelle Eich1, Jerome Aucan1, Nathalie Zilberman1, & Yvonne Firing1 (Keynote Address) 1 Department of Oceanography, University of Hawaii, Hawaii USA 2 Deceased. Late of University of New South Wales/Australian Defence Force Academy. Honoured by this Symposium 3 Scripps Institution of Oceanography, University of California, San Diego [email protected] The rise and fall of internal tides in the deep ocean The generation and dissipation of internal tides in the deep ocean are examined using three-dimensional numerical simulations made with the Princeton Ocean Model. The generation of internal tides is considered for two types of deep ocean topography: 1) a chain of steep seamounts, ridges, and islands that form the Hawaiian Ridge, and 2) the rough, irregular flanks of the Mid-Atlantic Ridge. Model validation results using field observations from the Hawaii Ocean Mixing Experiment (HOME) are presented. The dissipation of internal tides is examined at the Kauai Channel, the site of the intensive HOME Nearfield study, and at distant seamounts in the path of the low-mode internal tides that radiate from Hawaii. The magnitude and spatial distribution of diapycnal mixing associated with internal tide dissipation are considered. ______

Abstracts - Page 80 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Meyers, Gary, Peter McIntosh & Lidia Pigot CSIRO Marine Research, GPO Box 1538, Hobart Tas 7001 [email protected] The years of El Nino, La Nina and interactions with the tropical Indian Ocean The Indian Ocean Dipole (IOD) has been a subject of increasing interest and sometimes scientific debate since 1999 when the first papers on it were published in Nature. This paper is concerned with identifying the IOD and its relationship to the El Nino Southern Oscillation phenomenon (ENSO). The physical oceanographic characteristics of IOD are identified by reviewing selected, recently published papers. Upwelling on the Indian Ocean coasts of Java and Sumatra is identified as a key controlling process in IOD, generating the cold eastern pole observed in XBT and altimeter measurements during recent decades. Then, the relationship between IOD and ENSO is characterized by carefully classifying each year of the 20th century as a year of El Nino, La Nina or neither; and positive IOD, negative IOD or neither. The classification is based on the latest version of the GISST data set. The method of classification is critically dependent on recognizing the important role of upwelling in both the Pacific equatorial cold tongue and off the Java/Sumatra coast. The relationship between IOD and ENSO is then described in terms of global SST patterns for cases when particular phases of the two phenomena occur together or independently. Finally the impact of IOD and ENSO acting together and separately on Australian rainfall is determined. ______

Middleton, Jason University of New South Wales Topographic wakes Ocean wakes and eddies have been known since the days of Greek mythology, and were reputed to appear in the Straits of Messina between Italy and Sicily. Other early observations and use of island wakes was made by the fishermen of Palau. Aerodynamic studies between the first and second world wars also provided a valuable guide to the nature of wakes in undisturbed free streams. Recent observations and theories suggest that the structures of wakes (and bulk quantities such as the total drag) depend significantly on the existence of upstream turbulence in the incident flow. In this presentation, a range of observations of oceanographic wakes are presented, and the dynamics interpreted in terms of new theories predicting non-normal instabilities. Applications in the meteorological boundary layer are also discussed. ______

Abstracts - Page 81 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Middleton, John1 & Gennady Platov2 1 School of Mathematics, University of New South Wales, NSW 2005 2 Center for Computational and Geophysical Mathematics, Novosibersk, Russia Weather-band circulation and upwelling off South Australia: a numerical study of the summer of 1999 A preliminary numerical study of the shelf and slope circulation between Esperance and Portland is presented. The model is forced with 6 hourly LAPS winds and NCEP fluxes of heat and freshwater. A coarse resolution model (CRM) that extends to 48 S is adopted to provide transports along the open boundaries of the fine resolution model. In particular, the CRM transports at 39 S are equatorward and of a magnitude consistent with Sverdrup dynamics. The equatorward transport is crucial to the formation of the westward flowing Flinders Current that is expected to flow along the shelf slope at depths of order 300-500 m. The FRM is forced with these transports as well as by a first mode CTW paddle at Esperance. The amplitude of the paddle is varied using (adjusted) sea level observations obtained at Esperance. The FRM results are in reasonable agreement with coastal sea level data obtained along the shelf and within the Gulfs. The model SST is in poor agreement with observed SST within the Bight due to the poor NCEP fluxes which over-estimate cooling. Within the Gulfs and off Kangaroo Is., better agreement is found. The model results suggest that upwelling is periodically driven by a plume to the south-east of Kangaroo Is and Robe, and from depths of 150 m or so. This water is advected to the north-east and appears at the surface off the western tip of the Bonney coast, Kangaroo Is and the Eyre Peninsula. Future plans will be discussed. ______

Miller, Matt1,3, Julia Barnes1, Rhys Hauler2 Chris Carter1 & Peter Nichols3 1 School of Aquaculture, TAFI, University of Tasmania Australia, 2 Skretting, Cambridge 3 CSIRO Marine Research, GPO Box 1538, Hobart Tas. 7000 [email protected] The effect of variation in dietary energy and protein levels on the lipid class and fatty acid composition of Atlantic salmon (Salmo Salar) fed at elevated temperature conditions The influence of higher water temperatures, as encountered in Australia, on tissue fatty acid composition has not previously been assessed in detail. Most Atlantic salmon nutrition research occurs in the northern hemisphere (Scotland, Scandinavia and Canada), under conditions not comparable to the Australian environment. The influence of higher water temperatures encountered in Australia has not been assessed. Cold water fish have a distinct dietary requirement for ω3 polyunsaturated fatty acids (PUFA) where as warm water fishes have a less well defined but lower dietary requirement. This difference has been explained due to the structure of ω3 PUFA allowing a greater degree of unsaturation which is necessary for the membrane phospholipid to maintain flexibility and permeability at low temperatures The PUFA requirement of salmon may depend on the environmental temperature. An increase in water temperature leads to an increase in saturation of gill lipids to ensure optimal membrane fluidity. The composition and integrity of fatty acids in the gill epithelial membranes is crucial to the maintenance of effective osmorgulation by salmon. Our experiment aimed to provide information on possible effects of elevated temperature on the Atlantic salmon. We have examined changes in the lipid class and fatty acid composition of Atlantic salmon under different protein and energy diets with fish held at elevated temperature (20oC). The research findings will be significant to Tasmanian aquaculture producers who encounter high water temperatures during summer and autumn months, and need to optimise growth, fish health and dietary lipid content in this relatively higher temperature environment. ______

Abstracts - Page 82 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Moltschaniwskyj, Natalie A & Michael A Steer School of Aquaculture, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Locked Bag 1370, Launceston Tas. 7250 [email protected] Spatial and seasonal variation in reproductive characteristics and spawning of southern calamary: Spreading the mortality risk Southern calamary in Tasmania form spawning aggregations in Great Oyster Bay on the central east coast of Tasmania during spring/summer, which are targeted by commercial fishers. However, it is not known if similar aggregations occur further south in Tasmania or at other times of the year, especially since this species lives for less than a year. Therefore, the aim of this study was to describe and identify differences in reproductive ecology of southern calamary on the east and south-eastern coast of Tasmania. This was achieved by sampling adults and surveying egg masses during 2001 at inshore sites in both regions. Inshore populations of southern calamary in both regions showed a consistent seasonal trend of large gono-somatic index, reproductive output and body size, and greatest abundance during spring, and lowest in autumn. The number of egg masses found was higher on the east coast, where mature animals formed large spawning aggregations during the spring and summer. Such aggregations however were not observed during winter or autumn. Along the south-east coast spawning activity was sporadic, resulting in isolated, low density, egg patches deposited over broader spatial areas during spring, summer, and winter. There was no evidence of areas of seagrass or macroalgae with large depositions of egg masses at any time in the south-east. It appears by adopting different spawning behaviours in different locations and seasons that southern calamary may spread the mortality risks in both space and time. The biological significance of this is unclear, particularly with respect to understanding the mechanisms that drive the development of spawning aggregations. Both spatial and seasonal spawning patterns appear to be the result of very specific use of inshore sites at certain times of the year. Consequently, any management concerns about fishers targeting spawning aggregations in the south-east may be unfounded. ______

Monro, Keyne*, Robert Brooks & Alistair GB Poore School of Biological, Earth and Environmental Sciences, University of New South Wales, Kensington, Sydney 2052 [email protected] Adaptive plasticity of foraging behaviour in a marine macroalga In clonal plants, light-induced plasticity that maximises resource acquisition is generally termed foraging behaviour. This trait is considered adaptive in terrestrial habitats that vary in light, but remains unexplored for marine habitats. Previously, we demonstrated that manipulations of light quantity induce foraging-like plasticity in the marine macroalga, Asparagopsis armata. Suites of correlated morphological traits underlie a fundamental growth strategy characterised by the production of compact, highly-branched (phalanx) and elongate, sparsely-branched (guerilla) phenotypes in light and shade environments respectively. We now consider whether such plasticity is adaptive (i.e., whether it evolves by natural selection). This firstly requires sufficient phenotypic variation for selection to act and secondly, that such variation has fitness consequences. We tested these requirements using multivariate selection gradient analysis and reciprocal transplants of phenotypes among light and shade environments. We found significant levels of linear and nonlinear selection acting on phenotypes in light and shade populations and further, that each pattern of selection differed between environments. Our reciprocal transplant showed that guerilla phenotypes are fitter than phalanx phenotypes in shaded habitats, but phalanx phenotypes are fittest in habitats with more light. These results suggest that the genotypic ability to produce alternate phenotypes in response to environmental heterogeneity is a selectively important strategy that optimises fitness. ______

Abstracts - Page 83 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Moore, Stephanie K*1 & Iain M Suthers1 1 Fisheries and Marine Environmental Research Laboratory, School of Biological, Earth and Environmental Sciences, University of New South Wales, NSW 2052. [email protected] Stable isotopes of the pygmy mussel (Xenostrobus securis) as an indicator of catchment disturbance and estuarine nutrient enrichment Large temporal variability in water quality may hinder estuarine management. Filter feeding bivalves can integrate temporal patchiness in nitrogen and carbon stable isotope ratios by accumulating and incorporating elements into their tissues from the large volumes of water they filter while feeding, making them suitable bio-indicators of diffuse nutrient sources. The pygmy mussel, Xenostrobus securis, found abundantly amongst mangrove pneumatophores, was used to trace the movement and assimilation of anthropogenic nutrient sources in the Manning, Wallamba and Wallingat Rivers, NSW. Previous computer modelling showed that the abundance and filtering by this mussel has the potential to remove phytoplankton blooms (>50 mg L-1 of chlorophyll) within 7 d. d15N composition of adult pygmy mussels collected during the summer months from December 2002 to April 2003 significantly increased near tertiary treated sewage effluent and near run-off collected from cattle grazing land. d13C composition was able to define an estuarine gradient consistent with mixing of river inputs and marine waters. The ability to tolerate a large range of salinities (5-30 ppt) and its abundance in mangroves throughout southern Australia make the pygmy mussel a promising long-term indicator of nutrient enrichment in estuaries. By providing habitat for a potent manipulator of phytoplankton biomass, mangroves are an important component of water quality. ______

______

Moore, Thomas1, John Marra2, Richard Matear3 & Lesley Clementson3 1 IASOS & ACE, University of Tasmania, Hobart Tas. 7000 2 Lamont-Doherty Earth Observatory, Columbia University, USA. 3 CSIRO Marine Research, Hobart Tas. 7000 [email protected] Distribution of phytoplankton biomass off Western Australia: Role of mesoscale eddies in cross-shelf export The eastern Indian Ocean and the waters off Western Australia (WA) are unique in terms of both their biological and physical oceanographic character. While the productivity of the region does not compare with other eastern boundary current regions, significant spatial and temporal variability in phytoplankton biomass does exist. The region supports commercially important fisheries and it has been suggested that a factor controlling recruitment off WA is the distribution of phytoplankton. We utilize 6 years of remotely sensed phytoplankton biomass estimates and the targeted sampling of mesoscale eddies during the TIP2000 cruise to identify the character and dynamics of phytoplankton variability on and off the WA shelf. We find that, contrary to canonical ideas on eddy pumping, satellite estimates of surface chlorophyll off WA show low concentrations of phytoplankton biomass in cyclonic eddies and high concentrations in anti-cyclonic eddies. Anti-cyclonic eddies, formed adjacent to the shelf, entrain shelf waters and, as they propagate westward, export coastal phytoplankton communities offshore. Off-shelf we find two types of phytoplankton communities; modified coastal communities in anti-cyclones and offshore communities concentrated in the deep chlorophyll maximum of the cyclonic eddies. ______

Abstracts - Page 84 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Moore, Thomas1, Richard Matear2 & John Marra3 (Poster) 1 IASOS & ACE, University of Tasmania, TAS. 2 CSIRO Marine Research, Hobart, TAS. 3 Lamont-Doherty Earth Observatory, Columbia University, USA. [email protected] Variability of phytoplankton biomass on the central Western Australian shelf: Characteristics and causes The eastern Indian Ocean and the waters off central Western Australia (WA) are unique in terms of both their biological and physical oceanographic character. Driven by an oceanic pressure gradient, the eastern boundary current is poleward-flowing and downwelling conditions prevail. While the phytoplankton productivity of the region does not compare with other eastern boundary current regions, significant spatial and temporal variability in phytoplankton distribution does exist and the region supports commercially important fisheries. A feature of the phytoplankton biomass variability is a seasonal signal on the central WA shelf. The cause of the seasonal signal is not clear but we hypothesize it may be related to a number of potential nutrient inputs through: upwelling from off-shelf, rainfall and associated runoff, transport related to the Leeuwin current, shallowing of the nutricline, and benthic supply. Using both in-situ data and remotely sensed data products we explore these hypotheses and place bounds on possible drivers for the seasonal variability of phytoplankton on the central WA shelf. ______

______

Moritz, CM1, AD McKinnon2, JH Carleton2 (Poster) 1 Accédez au courrier électronique de La Poste, 3615 LAPOSTENET: www.laposte.net: tél: 0892681350 2 Australian Institute of Marine Science, PMB 3, Townsville, Qld 4810 Summer variation in abundance and biomass of microzooplankton of the North West Cape, Australia The biological oceanography of waters adjacent to Australia’s North West Cape (21º 49’S, 114º 14’E) was studied during the austral summers 1997/1998 and 1998/99. We estimated microzooplankton abundance and biomass at a shallow (~20m) station in the mouth of Exmouth Gulf, and at a shelf-break station (~80m). We categorised microzooplankton into six categories: dinoflagellates, Strombidium spp, Strobilidium spp., tintinnids, “other ciliates” and radiolarians. Total microzooplankton abundances ranged between 144 and 3412 l-1 . The most abundant groups were the dinoflagellates (mean 459 ± 73 SE l-1) and Strombidium spp mean (334 ± 42 SE l-1 ). Total microzooplankton biomass ranged between 0.027 and 1.7 µg C l-1 (mean 0.329 ± 0.049 SE l-1). Redundancy analysis showed differences in microzooplankton community composition between Station B and E, between the two sampling years, and strong relationships between dinoflagellates and chlorophyll. The microzooplankton community shows considerable variability between adjacent sampling dates, reinforcing the conclusion that this area is a very dynamic environment. ______

Abstracts - Page 85 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Muhling, Barbara A & Lynnath E Beckley School of Environmental Science, Murdoch University, Murdoch WA [email protected] Ichthyoplankton in two meso-scale Leeuwin Current eddies: preliminary results In many coastal oceans, eddies and jets occur predictably under certain conditions, and are a common mechanism for entraining coastal water across the continental shelf. Eddies may therefore act as transport mechanisms for planktonic organisms and larvae. In October 2003, a cruise was undertaken on the RV Southern Surveyor to investigate the dynamics of two eddies located more than 500km off the Western Australian coast. Primary production patterns, nutrient cycling, oceanographic and biological characteristics of both eddies (one cold-core upwelling, and one warm-core downwelling) were investigated over a 23 day period, using oblique and depth stratified plankton tows, continuous physiochemical samplers (“Seasoar”), sediment traps and other methods. Larval fish were collected from plankton samples taken in the centre, body and perimeter of each eddy, during both day and nighttime, with both oblique bongo, and depth stratified EZ Net tows. Preliminary analysis shows that the larval fish assemblage was mostly composed of offshore and oceanic families, such as the Myctophidae, Phosichthydae and Gonostomatidae. The cold-core eddy showed few differences between its centre, body and perimeter in terms of larval density, and species assemblage. The warm-core eddy, however, showed much lower densities of larvae in the centre, compared to both the body and perimeter, and to the cold-core eddy. This was particularly apparent at night, suggesting that the dynamics of the centre of the warm-core eddy were affecting the presence, and/or the vertical migration of larger larvae in the eddy at night.

Muhling, Barbara A1, Lynnath E Beckley1 & Anthony J Koslow2 1 School of Environmental Science, Murdoch University, Murdoch, Western Australia. 2 CSIRO Marine Research, Floreat Laboratories, Western Australia. [email protected] Preliminary analysis of ichthyoplankton assemblage structure in coastal, shelf and offshore waters of southwestern Australia As part of the SFRME Biophysical Oceanography Program, this project is examining the structure and composition of ichthyoplankton assemblages in waters off Western Australia. Larvae are sampled using replicated oblique bongo net tows at three stations (18m, 40m, 100m depth) every month, and five stations (18m, 40m, 100m, 300m, 1000m) every quarter. The samples from the 355µm mesh nets are sorted to remove all larval fish which are then identified to family and species, where possible. Larval assemblages have been characterised, inter-seasonal and inter-annual trends identified, and related to dominant oceanographic and ecological processes. Samples from 18 months of cruises have been examined thus far, and larvae from 70 teleost families and approximately 160 species have been identified. Assemblages appear distinct between seasons at the inshore station (18m), and the two offshore stations (300m and 1000m), but the shelf stations (40m and 100m) show considerable variation throughout the year. Larval densities show peaks inshore in summer, and mid-shelf in autumn, and are possibly related to variation in strength of the Leeuwin and Capes Current, or climatic events. Additionally, preliminary correlations have been made with larval fish density and fluorescence peaks, and with the depth of the mixed layer on larval composition and abundance. ______

Abstracts - Page 86 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Neil, KM1,2 & S McKenna2,3

1 Cooperative Research Centre for the Great Barrier Reef World Heritage Area, Townsville, Qld. 2 Department of Primary Industries, Cairns, Queensland, Australia 3 Department of Marine Biology and Aquaculture, James Cook University, Townsville, Queensland, Australia Larval trap monitoring for pests in tropical Australia A key component of an effective integrated pest management plan includes a strategy for monitoring, both for new introductions and for the spread of previous introductions. In Australia larval settlement traps are currently being utilised to monitor ports, marinas and other shipping areas for the presence of a number of known marine pests that have been introduced to our coastal waters: the Asian green mussel (Perna viridis), the black striped mussel (Mytilopsis salleii) and the Caribbean tube worm (Hydroides sanctaecrucis) among others. In northern Australia much of this monitoring is undertaken by various industries in a haphazard fashion. Currently there is little standardised effort in the design of a larval trap, type of substrate utilised, frequency with which plates are examined and expertise of staff examining the plates. As such there is little opportunity for comparison of results across different monitoring programs, and in some cases, little conﬁdence such programs are effective. This study was undertaken to compare and contrast different settlement substrates immersed for different periods of time to develop a settlement plate monitoring program suitable for implementation in tropical Australia that was able to be efﬁciently utilised in a standardised fashion by the industries who undertake the monitoring. Results of this study and the applications to industry will be discussed. ______

______

Nelson, Vicki Project Manager, Science, National Oceans Office The National Marine Bioregionalisation: incorporating scientific uncertainty into oceans management Under Australia’s Oceans Policy, the Australian Government is committed to taking an ecosystem-based approach to oceans management. This approach requires that planning and management be based on ecosystem boundaries rather than on sectoral or jurisdictional boundaries. Bioregionalisation is one way of defining ecosystem boundaries as areas are delimited based on similarities in physical and biological structure, understanding of ecosystem processes and connectivity between adjacent systems. While data on biological distributions and diversity for bioregionalisation is relatively abundant in coastal waters, both the quantity and quality of data decline with distance from shore. In deep water habitats, particularly, biological data are spatially and temporally patchy. The distribution of data has profound consequences for the confidence managers can have in ecosystem-based boundaries for planning and management. Does this uncertainty matter for management decisions? We argue that managers and scientists both must take a pragmatic approach to uncertainty. While acknowledging that the knowledge is incomplete, and will remain so for the foreseeable future, managers also need to make decisions now in an adaptive framework. We illustrate the use of incomplete biological data augmented by physical parameters for defining ecosystem boundaries and potential ways of communicating the consequences of uncertainty for planners and managers. ______

Abstracts - Page 87 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Newton, Gina M Australian Academy of Science, GPO Box 783, Canberra, ACT 2601 [email protected] Communicating marine science and conservation through children’s literature: An inclusive approach Globally, science communication is becoming increasingly important. A recent Government report stated that Australia’s success as a 21st Century knowledge society will depend on having a science literate community. However, in Australia recent trends have shown a dramatic decline of science as a pursuit at both secondary and tertiary level education; there are also serious concerns with science teaching at primary school level. In America, less than one in five people meet a minimal standard of civic scientific literacy – in the Australian community the status is unknown. The literary story offers an effective and versatile means by which to communicate science. Therefore, to achieve higher levels of science literacy across our community, it may beneficial for the scientific professions to consider a greater involvement in the production of children’s books as part of their communication activities. In addition to the production of the encyclopaedic, fact-finding types of science books for children there is a strong need for more creative and imaginative approaches to convey deeper understanding. The blending of non-fiction and fiction ie. ‘faction’, may be a useful approach to break down the stereotypic barriers of traditional non- fiction and increase the ‘readability’ and ‘enjoyability’ of science books for both children and adults. My presentation will cover aspects of the importance of science literacy, storytelling and the power of story, and characteristics of good science books for children. In particular I will highlight the important role that children’s literature can serve, not only in improving science literacy, but also in the recovery process for threatened (marine) species. ______

Nicol, S1*, S Kawaguchi1 & S Romaine2 1 Australian Antarctic Division, 203 Channel Highway , Kingston Tas. 7050 2 Institute of Ocean Sciences Sidney, B.C. Canada [email protected] Krill and currents The results of two multidisciplinary surveys conducted as part of the Southern Ocean GLOBEC Program off Mawson station, East Antarctica, indicate that variability of krill distribution and abundance occurs on a number of temporal and spatial scales. Some of this variability is attributable to behavioural effects such as diurnal vertical migrations, and in other cases the variability is more likely to be physically mediated. Most of the variability observed, however, is likely to be the result of interactions between the krill population and their physical and biological environment. The relationship between the distribution of krill and the three dimensional current structure is not a simple one and because of this complexity, simple models utilising generalised ﬂow ﬁelds are unlikely to provide a realistic assessment of the forces that govern krill distribution locally or regionally. Our results also show that observed changes in local krill distribution and abundance can have marked effects on populations of land-based predators, particularly when they are rearing young. ______

Abstracts - Page 88 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Nichols, Carol Mancuso1*, Sandrine Garon2, John Bowman1, John Gibson3, Peter Nichols3 & John Guézennec2 (Poster) 1 University of Tasmania, Hobart Tas. 7000 2 Institute Français de Recherche pour l’Exploitation de la Mer, Centre de Brest, Plouzané, France 3 Commonwealth Scientific and Industrial Research Organization, Marine Research, Hobart Tas. 7000 Exopolysaccharide production by Antarctic bacteria: Implications for nutrient cycling This study was undertaken to investigate the ecological role of exopolysaccharides (EPS) produced by marine bacteria from the Antarctic environment. Ten EPS-producing bacterial strains were isolated from particulate material sampled from seawater and sea-ice in the Southern Ocean. Analyses of 16S rDNA sequences and whole cell fatty acids were used to identify these isolates as members of four genera including Pseudoalteromonas, Shewanella, Polaribacter and Flavobacterium. The yield of EPS from batch cultures from one isolate incubated at three temperatures was at least 30 fold higher at –2oC and 10oC than at 20oC. Crude chemical studies of EPS produced by these ten isolates in liquid culture showed that they were composed primarily of neutral sugars and uronic acids. Fourier transform-infrared spectroscopic analysis of EPS from four Pseudoalteromonas strains showed the presence of sulfate functional groups. In addition, nuclear magnetic resonance spectra of EPS from one of these Pseudoalteromonas isolates revealed a succinyl functional group as well. Gas chromatography of monosaccharides released from the EPS confirmed these gross compositional findings, and molar ratios of monosaccharides showed distinct differences between EPS from the ten isolates. EPS produced by Antarctic bacterial isolates examined in this study appear to be polyanionic and, therefore, a sink for cations such as trace metals. Since the availability of iron as a trace metal is of critical importance in the Southern Ocean where it is know to limit primary production, the production of these bacterial EPS in the Antarctic marine environment has important ecological implications.

Nichols, PD1, JAE Gibson1, JJ Plumb2, MB Stott3, HR Watling3, PD Franzmann2 (Poster) 1 CSIRO Marine Research, Hobart Tas. 7001, Australia 2 CSIRO Land and Water, Floreat, Western Australia 6014, Australia 3 AJ Parker CRC for Hydrometallurgy, CSIRO Minerals, Waterford, Western Australia, Australia [email protected] Archaeal hyperthermophilic communities in marine sediments and vents of the Manus Basin and from nearby terrestrial environments: isolation, characterisation, lipid signatures and industrial potential A CSIRO team from four Divisions - Minerals, Land and Water, Marine Research and Molecular Science - was established in 2000 to develop new hyperthermophilic organisms for use in mineral processing. The team drew together skills in processing chemistry, microbiology, biochemistry and molecular biology. Initial bioprospecting for hyperthermophilic microorganisms occurred in the Manus Basin, with further material collected from a geothermally-heated gold mine on Lihir Island and from volcanic areas near Rabaul. Signature lipid profiling was used to characterise the hyperthermophilic microorganisms. High concentrations of Archaeal-derived tetraether (TE) lipids, including highly cyclised TE indicative of the family Sulfolobales, indicated that hyperthermophilic Archaea were present. Novel thermophilic archaeal strains and mixed archaeal cultures, with the ability to oxidise sulfide minerals at temperatures greater than 80oC, were isolated from these samples. Strains were characterised using molecular methods, including signature lipid and 16S rRNA gene sequencing; all strains were phylogenetically related to Sulfolobus spp. and contained distinctive cyclised TE lipids. Their physiological requirements and mineral leaching capabilities have also been characterised. Isolates were able to oxidize both Fe2+ and sulphur, and grow on both pyrite and chalcopyrite under autotrophic conditions. Leaching experiments showed that the isolates were capable of rapidly leaching a chalcopyrite concentrate (up to 91% Cu release in 108 hour). These unique strains have the ability to oxidise sulfides over a wide temperature range and are potentially suited to leaching applications where temperature fluctuations limit the growth of non- thermophilic bioleaching microorganisms. Based on progress to date, Manus Basin vents and related geothermal environments provide source material containing novel hyperthermophilic microorganisms that have applications in industrial processes, including mineral leaching.

Abstracts - Page 89 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Nichols, P1, P Mansour1, I Bronwyn1, S Robert1, D Frampton1, S Blackburn1, S Singh2 & A Green2 (Poster)

1 CSIRO Marine Research, Australia, 2 CSIRO Plant Industry, Australia [email protected] New single cell and crop plant sources of long-chain Omega-3 oils Long-chain omega-3 polyunsaturated fatty acids [LC-PUFA, e.g. EPA, 20:5(n-3) and DHA, 22:6(n-3)] have health benefits against coronary heart disease, inflammatory diseases such as rheumatoid arthritis, hypertension, and are essential for infant nutrition (e.g. brain and retina development). Omega-3 LC- PUFA also may have beneficial effects against some cancers as well as various mental disorders such as schizophrenia, ADHD and Alzheimer´s disease. Fish oils are the main commercial source of the beneficial omega-3 LC-PUFA. However, global fisheries have been reported to be unsustainable, indicating a need for new sustainable and commercially viable sources of such oils. In addition, fish do not synthesis these oils, rather microalgae and other marine microorganisms (e.g. thraustochytrids and some bacteria) are the primary source of omega-3 LC-PUFA which are incorporated in higher marine animals, and ultimately in humans through consumption of seafoods. Microalgae and related heterotrophic organisms are a renewable `clean and green´ resource which is amenable to high density culturing using photobioreactors and fermentors for biomass production. They are also a source of novel genes for PUFA biosynthesis which may be transferred to terrestrial crop and oil-seed plants. Our research is targeting microalgae and other microorganisms with high levels of LC-PUFA. We also aim to identify, isolate and characterise omega-3 LC-PUFA biosynthesis genes (desaturases and elongases from microalgae; PKS genes from thraustochytrids and bacteria) and transfer these to oil-seed crop plants (e.g. Canola, flaxseed). Omega-3 LC-PUFA oils from these plants may be able to be used in human nutrition and aquaculture feeds. ______

Nichols, P1, B Mooney2 & N Elliott1

1 CSIRO Marine Research, GPO Box 1538, Hobart, Tas. 7000 2 Institute of Molecular Biosciences, University of Queensland, St Lucia, Qld 4072 [email protected] Is farmed Australian seafood a better source of the good oil than wild-caught seafood? Nutritionists and medical authorities encourage seafood consumption because the oils contain nutritionally important omega-3 long-chain polyunsaturated fatty acids (LC-PUFA), termed the “Good Oil”. Wild-caught seafood is promoted as an ideal source of the two important long-chain omega-3 LC- PUFA – EPA [eicosapentaenoic acid, 20:5(n-3)] and DHA [docosahexaenoic acid, 22:6(n-3)]. The human body manufactures only small amounts of these LC-PUFA, so we need them from our diet. Two volumes of the FRDC-funded Guide “Seafood the Good Food” have been produced and detail the oil and PUFA composition of Australian seafood, with species examined largely from the wild. Omega-3 LC-PUFA oils are also a prerequisite for survival and development of many marine finfishes, molluscs and crustaceans. The Guides also provide an indication to PUFA levels required in farmed species if their marketing for human consumption is to utilise or maximise on the beneficial omega-3 oil factor. Concern has been expressed in recent times nationally and internationally that cultured (farmed) fish contain lower oil and omega-3 content than wild-harvested seafood. We examined the current state of play with cultured Australian seafood. We found that, under current feeding practices, farmed Australian finfish (e.g. Atlantic salmon, barramundi, barramundik cod, striped trumpeter) have higher oil and omega-3 content than the same species from the wild. Other cultured species, jade perch, silver perch and Murray cod, also contained attractive PUFA levels. In general, farmed finfish contain higher oil and omega-3 content than many wild-caught species. Furthermore, oil content and composition in aquafeeds can be tailored to influence PUFA profiles in farmed finfish. Blue mussel contained similar oil and PUFA content to the more publicized New Zealand green lip mussel. In contrast to finfish, cultured banana prawns, whilst containing higher oil content, contained lower levels of omega-3 PUFA, in particular DHA, relative to wild specimens. The PUFA profiles of cultured seafood are particularly important for consideration in aquaculture feeds and also for value-adding market opportunities from current harvests.

Abstracts - Page 90 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

O’Dor, Ron (Keynote Address) Census of Marine Life, CORE, 1201 NewYork Ave., Washington, DC20003, USA [email protected]. Where have all the Cephalopods gone? Don’t worry this is not a lament for another collapsed fishery: cephalopods continue using their brains and mobility to occupy niches opened by fishing down the food chain. The question is where do they execute their complex life styles? It is hard to census or catch animals constantly on the move. Fortunately, cephalopod technology has proved compatible with human technology, so we have not only been tracking them for over twenty years, they even send us telemetric messages about what they are doing there. Squid, cuttlefish, octopus and nautilus around the world have revealed their secret lives in details we never imagined possible. Pressure records from jetting and just breathing can characterize and measure the energy costs of activities hundreds of meters beneath the sea. From 10g to 50kg, and larger if we could catch them, coastal acoustic receiver arrays and satellites can follow their migrations. Adult squid travel thousands of kilometers to spawn where currents will transport eggs to complete a life cycle, but is a mobile feast really a migration? Bioenergetics say that squid do it differently from fish and birds, compensating for minimal reserves with cannibalism. On a smaller scale we can track movements meter by meter while recording every breath. Who knew that squid can soar? Who knew male cuttlefish not only work harder having sex than females, they do their deep breathing before copulation? Who knew that octopuses could train people to use gillnets to catch fish for them? Who knew that slow, stupid nautilus have one of the most efficient search strategies imaginable - monitoring hundreds of square kilometers by vertically moving across currents. Maybe that’s why they are still living fossils? ______

O’Dor, Ron K1, George D Jackson2 & Yanko Andrade3 1 Census of Marine Life, CORE, 1201 New York Ave., Washington, DC 20036 2 IASOS, University of Tasmania, PO Box 252-77, Hobart Tas. 7001 3 Biology Department, Dalhousie University, Halifax, NS, Canada B3H 4J1 [email protected] Exploring the life styles of squid and cuttlefish using ‘Hybrid’ acoustic/archival tags This study demonstrates the simultaneous use of acoustic and archival tags for obtaining data for nearshore species. Australian giant cuttlefish Sepia apama (off Whyalla, South Australia) and the tropical squid Sepioteuthis lessoniana (off Magnetic Island, Queensland, Australia) were tagged using a ‘hybrid’ tag consisting of a Vemco V8 acoustic tag potted with a Vemco Minilog temperature-depth archival tag. All of these animals were released and monitored inside radio-acoustic positioning and telemetry (RAPT) buoy system arrays. All were subsequently located out of RAPT range, and half of the archival tags were recovered. Tags could easily be pinpointed using a boat-mounted hydrophone and VR 60 receiver, and recovery was aided by a diver operating a hand-held VUR 96 receiver. A similar approach could be used after identification of animals tagged with codes detected by arrays of VR-2s as used in the Pacific Ocean Self Tracking project. This technology provides a cost-effective alternative to expensive satellite pop- up tags and is suitable for much smaller species that return to near-shore environments. Such detailed information can be important in identifying critical habitats for breeding and feeding that may limit the recovery of fished stocks and aid in the selection of Marine Protected Areas. ______

Abstracts - Page 91 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Olivier, Frederique Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Hobart [email protected] Sea ice extent and breeding performance variability of snow petrels (Pagodroma nivea) at Casey (East Antarctica): detecting local response to large-scale processes ? Snow petrels Pagodroma nivea are the smallest resident flying seabird in the Antarctic region, foraging in open or broken sea-ice within the marginal ice zone where they feed predominantly on fish, cephalopods and krill. Being an obligate associate of the sea ice, they are likely to be directly affected by its variations, potentially providing useful signals to monitor the effects of climate change. Demographic parameters were estimated for snow petrels nesting at the study colony of Reeve Hill near Casey station between 1984 and 2003. Within this period, 12 years of complete data on breeding success were available. Breeding effort, hatching, fledging success and breeding success were subject to a high interannual variability. Previous work demonstrated that large-scale climatic events (ENSO, Antarctic Circumpolar Wave) and the related sea-ice cover around the Antarctic influence the lower trophic levels of the marine environment and consequently food availability for snow petrels. The influence of regional sea-ice extent on the breeding performance of snow petrels at Reeve Hill was examined. Fewer birds were breeding when sea- ice had been extensive during April-May. Overall breeding success and fledging success were improved during years with extensive sea-ice cover in winter. Successful breeding effort and breeding success were depressed when there was extensive sea-ice cover during January-February. However, before drawing ecological conclusions on the effect of sea ice extent on snow petrel breeding success, attention is brought onto the spatial scale considered: correlations are the strongest with sea ice extent averaged over 10° of longitude. A systematic comparison with the long-term study conducted in Terre Adélie, 600 miles away from Casey, also suggests that the nature of the correlation of sea-ice extent with snow petrel breeding performance differed substantially between locations, probably because of the overriding effects of other environmental factors acting at the local scale (local weather, habitat quality). ______

Otway, Nick Department of Primary Industries, Port Stephens Fisheries Centre, Taylors Beach Road, Taylors Beach NSW 2316 Nick.Otway@ﬁsheries.nsw.gov.au Pop-up archival tracking of the critically endangered grey nurse shark in SE Australian waters This study used pop-up archival satellite (PAT) tags to document the movements of the critically endangered Grey Nurse shark in the coastal waters of SE Australia. These tags recorded the water temperature, depth and light levels at hourly intervals, and then stored this information in the tag’s memory. The tags were pre-programmed to pop-up the shark after deployments of 3, 4 and 6 months, respectively. Once free, the tag ﬂoated to the sea’s surface where the archived data were transmitted via the Argos system to NOAA satellites. Once decoded, the data were used to identify the proportion of time spent in shallow and deeper waters and to examine whether the movements were related to water temperature and /or depth. Results from a preliminary analysis of the data are presented and show that the sharks spent in excess of 70% of their time in waters 30 metres or less. The time spent in deeper waters was generally associated with movements between aggregation sites. Localised movements at aggregation sites also showed pronounced diurnal patterns in relation to variation in depth. ______

Abstracts - Page 92 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Pal, Aji Department of Maritime Engineering, Australian Maritime College, Launceston, Tasmania [email protected] Ecologically sustainable developments in marine propulsion engines The threat of ecological disturbance caused by greenhouse effect and Ozone depletion and resulting into wide spread natural disasters is so serious that all sectors of economy are taking steps to minimise the environmental pollution, maximise the energy efficiency, utilise the bye-products, recycle and ascertain the healthy service life. The marine transport sector is an important sector of international significance contributing to environmental pollution and resource ( fuel ) exhaustion.. The regulatory bodies such as International Maritime Organisation alongwith National Administrations have made concerted efforts to minimise environmental pollution through regulatory framework such as MARPOL 73/78. The designers of marine propulsion engines have responded well to this challenge by focussing their attention on ecologically sustainable designs .1980s saw the application of advanced and sophisticated technological developments in maximising the energy efficiency , while 1990s onwards environmental concerns became the prominent design and operating factors for marine propulsion engines. The factors responsible for fuel economy being somewhat contrary to those responsible for clean environment, the optimum engine designs complemented with external measures are being adopted for the current and future engines. The new marine engines have been developed to have maximum fuel efficiency and minimum permissible

NOx emissions by manipulating intrinsic engine factors such as injection timing and compression ratio, outside factors such as exhaust gas recirculation (EGR), primary methods such as maximising combustion pressures, injecting water into combustion chamber and secondary methods such as SCR , NIXHAUST and

MACT. SOX emissions are being minimised by using low-sulphur fuel oils and scrubbers. The new focus is for the developments of engines with minimum CO2 and particulate emissions by using minimum emission fuels such as natural gas, emission-less fuels such as hydrogen, Fuel Cell ( FC ) technology and scrubbers such as Eco-silencer. The paper outlines some of these latest Ecologically Sustainable Developments in marine propulsion engines , and evaluates their efﬁcacy regarding ecological sustainability. ______

Parker, Naomi, Jacinta Innes & Karina McLachlan Australian Government Department of Agriculture, Fisheries and Forestry, Barton ACT 2601 [email protected] The National System for the Prevention and Management of Marine Pests Incursions The National System for the Prevention and Management of Marine Pest Incursions is a nationally coordinated holistic approach to marine pest management that aims to address all potential vectors. It is currently being developed through a collaborative effort between the Australian and the State/Northern Territory Governments, industry representatives and other stakeholders. The System is designed to provide strategies to combat pests at each stage of their introduction through three management elements: prevention of introductions to and translocations within Australia; emergency preparedness and response to deal with new incursions; and ongoing management and control to contain established populations. Vector management is crucial to all three elements and work is currently underway to develop cross- jurisdictional, and cross-sectoral management actions to address the risks posed by ballast water and biofouling. These actions will consist of a range of regulatory and voluntary guidelines. The National System will be underpinned by a range of research and development which cut across all three System elements, and can be broadly grouped into the categories of governance systems; vector management; species and ecological information for management; information, communication and education; and evaluation and review. Research focussed on these broad areas is critical to the successful development and implementation of the National System. ______

Abstracts - Page 93 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Meuleners, Michael, Charitha Pattiaratchi & Gregory Ivey Centre for Water Research, University of Western Australia, Crawley WA 6009 [email protected] Numerical modelling of the mean flow characteristics and eddies of the Leeuwin Current System In this paper, the oceanic circulation of the region between Carnarvon (latitude 25ºS) and Jurien Bay (latitude 31ºS) is examined using observational and remotely sensed data in conjunction with a detailed numerical modelling study. The numerical model, Regional Ocean Model (ROMS v1.8), is validated using in situ ADCP and CTD data and the results re-produce the spatial and temporal scales of the observed mean surface flow, particularly of the eddy features. In addition, the results provide an insight into the annually averaged alongshore transport of the Leeuwin Current and the mean flow characteristics of the Leeuwin Undercurrent. Analysis of the model results, between the latitudes 26.8˚S and 30.8˚S, the annually averaged alongshore transport across the southern boundary of the Leeuwin Current was found to be 5.7 Sv, of which the northern boundary contributed 3.60 Sv or 63%. The inflow of water through the western boundary due to geostrophic balance was estimated to be 2.1 Sv or 37% and was found to vary meridionally. Similar to the Leeuwin Current, the Leeuwin Undercurrent is driven by a geopotential gradient, estimated to be 1.9×10-7 and acting towards the equator. The core of the Undercurrent, located at depths between 250 and 600m, was characterised as an energetic flow with meso-scale variability that is strongly influenced by the more energetic surface current. The coupling is evident in the region adjacent to the western boundary of the Abrolhos Islands (latitude 29˚S). A surface meander, initiating the onset of a warm core eddy, induces a response preferentially downwards, coupling with the Undercurrent, before a surface response is observed. During the growth phase the eddy splits in two, forming a surface and subsurface eddy. The surface eddy intensifies, detaches and moves offshore, whilst the subsurface eddy remains attached to the topography for ~115 days. It appears that the re-occurrence of the surface meander maintains the subsurface eddy. ______

O’Callaghan, Joanne & Charitha Pattiaratchi Centre for Water Research, University of Western Australia, Crawley WA 6009 [email protected] The influence of diurnal tides on sediment re-suspension in a partially mixed micro-tidal estuary South-western Australian estuaries experience a diurnal tidal range which exhibit different characteristics when compared to semi-diurnal estuaries. For example, the highest tidal range ‘spring’ tides) do not follow the lunar cycle (ie spring tides do not always occur during the full moon, new moon cycle). In semi-diurnal estuaries, the first harmonic of the dominant astronomical constituent plays an important role governing the net sediment transport. For diurnal systems, the amplitude of these harmonics are small and dominated by the semi-diurnal astronomical constituents that have a similar period. As the diurnal and semi-diurnal astronomical constituents oscillate at slightly different frequencies, inequalities exist at the spring-neap and tidal time scales. Over a 24 hour period, the inequality between the diurnal and semi-diurnal tides, is manifested as a double high water on the flood tide. Time series of water levels currents and turbidity in the upper Swan River estuary during 2001/02, were used to examine the behaviour of diurnal tides and their effect on sediment re-uspension. The highest turbidity concentrations were measured during these double high water events, and not when current flows were maximal as is predicted from sediment transport theory. Near-bed currents were less then 5cms-1, with corresponding shear stresses being low over the 24h tidal cycle. This suggests that the mechanism responsible for increased turbidity during the double high water event is not simply related to bottom shear stress generated from the mean flow. However, Reynolds stresses, obtained from measurements of horizontal and vertical turbulent fluctuations, exceeded the critical threshold of erosion and the turbulent kinetic energy was at a maximum during the double high water event. Turbulence generated around the double high water caused an upward transfer of mass, despite the characteristic low speeds of micro-tidal estuary. ______

Abstracts - Page 94 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Pattiaratchi, Charitha Marine Science and Engineering Program, Centre for Water Research, The University of Western Australia, Crawley 6009 [email protected] Physical oceanography off Western Australia The circulation of the continental shelf and offshore regions off Western Australia is dominated by the presence of the anomalous Leeuwin Current, which transports warm, nutrient poor water poleward and has a strong influence on the local climate and biology. The Leeuwin Under Current flows northward beneath the Leeuwin Current at depths of 250 and 600m. Processes in the Pacific Ocean control the inter-annual variability of the current and hence, the local climate and biological variability is also controlled by those processes. A common feature associated with the Leeuwin Current is the generation of both anticyclonic (warm core) and cyclonic (cold core eddies) and the eddy generation appears to be correlated with the strength of the Leeuwin Current and seabed topography. Eddy generation is generally observed at two main locations: (a) the Shark Bay region between latitudes 24-26°S; and, (b) the Abrolhos Island region between latitudes 28-31°S. The continental shelf circulation is mainly forced by wind. In the summer months, the Capes Current, driven by prevailing southerly winds, enhanced by strong sea breezes, flows northward along the continental shelf and exits the north-west Cape as the Ningaloo Current. There is localised upwelling due to Ekman dynamics and interaction with topographic features such as Rottnest Island and Perth Canyon. Further north, the continental shelf width controls the northward current and its interaction with the Leeuwin Current. In this presentation, an overview of the Leeuwin Current System and associated eddies will be presented. ______

Woo, Mun & Pattiaratchi, Charitha Centre for Water Research, University of Western Australia, Crawley WA 6009, Australia [email protected] Interaction between the Leeuwin Current and shelf currents along the Gascoyne continental shelf In 1995, Peter Holloway published a paper on ‘Leeuwin Current observations on the Australian North West Shelf, May-June 1993’ (Deep-Sea Research, 42, pp. 285-305) which provided a snapshot of the structure of the Leeuwin Current on the North West Shelf over the continental slope region of the NWS at latitudes of approximately 17o and 19oS. The study concluded that at least some of the Leeuwin Current water originates from the North West Shelf and identified a broad, deep and slow moving Leeuwin Current on the North West Shelf in the region. In this paper, we investigate the region immediately to the south of Peter Holloway’s study region. The Gascoyne continental shelf is located along the north-central coastline of Western Australia between latitudes 21o and 28o S. This paper presents CTD and ADCP data collected in November 2000, aboard RV Franklin, together with concurrent wind and satellite imagery, to provide a description of the summer surface circulation patterns along on the Gascoyne continental shelf and slope. It is shown that the region comprises of a complex system of currents that are influenced by offshore eddies, wind stress, varying shelf-widths, coastal topography and outflow from the hypersaline Shark Bay. Four different water types and currents systems were identified from the field measurements. The Leeuwin Current is the major current flowing through the region. It transports lower salinity, warmer water along the 200 m isobath, poleward. The signature of the Leeuwin Current gradually transformed from a warm (24.7oC), lower salinity (34.6) water in the north to a cooler (21.9oC), more saline (35.2) water in the south resulting from geostrophic inflow of offshore waters. The width and depth of the current also changed continuously responding to the changing bottom topography and the orientation of the coastline: in the northern section under the influence of the narrow shelf and steep slope, the current was strong (~75 ms-1) and extended deeper into the water column. In contrast, the current decelerated (to ~0.2–0.4 ms-1) when flowing past wider continental shelf offshore of Shark Bay and then

Abstracts - Page 95 AMSA2004 - Authors and Abstracts (alphabetically by presenter) accelerated along the southern section along the steep continental slope. Downwelling events were persistently associated with the Current. The Ningaloo Current flowed along the northernmost coast of the Gascoyne shelf, less than 35 km from the shore. Although upwelling was detected along the northern section of the study region, adjacent to the Ningaloo coral reef, water properties there suggests a recirculation of Leeuwin current water from the south. Changes in the shelf width at Point Cloates have a significant influence on the Ningaloo current resulting in bifurcation of the northward current. The higher salinity outflow from Shark Bay influences the continental shelf region immediately offshore of the main entrances to the Bay through the mixing of the higher salinity outflow water with the shelf waters. The Capes Current, a wind-driven current originating to the south of the study region was identified as a cooler, more saline water mass flowing northward. ______

Paul, Nick1*, Rocky de Nys2 & Peter Steinberg1 1 School of Biological, Earth & Environmental Sciences, and, Centre for Marine Biofouling & Bio-Innovation, University of New South Wales, Sydney 2052 2 School of Marine Biology & Aquaculture, James Cook University, Townsville 4811 [email protected] The chemical ecology of seaweeds: marine algae are not higher plants Chemical ecology theory developed for terrestrial plants is commonly applied to the ecology and evolution of chemical defences in marine algae. These theories attempt to explain the distribution of secondary metabolites, with an assumption that the production of ecologically-important metabolites is costly. The red alga Asparagopsis armata is an ideal organism for directly testing the predictions of chemical ecology theory. This alga has a simple ﬁlamentous growth form, and produces high levels of secondary metabolites that are stored in gland cells. We varied resource (light) levels and examined the effect on growth and levels of secondary metabolites. At the high light level growth was positively correlated with metabolite production, however, at low light levels a negative relationship was found. These results are consistent with predictions of resource-based models and a cost for metabolite production when resources are limiting. In addition, we used a novel method to test the predictions of resource-based models by examining the variation in the size of gland cells (storage structures which measure metabolite load) and their associated vegetative cells. In mature regions, gland cells were larger in the high light level than in low light, however when expressed as a relative size of the associated vegetative cell, showed no difference between light levels. Interestingly, for actively growing regions the relative size of gland cells was largest for high-light plants, again demonstrating a resource tradeoff. These results have important implications for testing chemical ecology theory in algae, as they demonstrate that algal ultrastructure, growth form and growth stage strongly inﬂuence the predictive ability of terrestrial models in the marine environment. ______

______

Abstracts - Page 96 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Pecl, Gretta1*, Sean Tracey1, Jayson Semmens1 & George Jackson2 1 Marine Research Laboratories, Tasmanian Aquaculture & Fisheries Institute, University of Tasmania, Hobart 7001 2 Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Hobart 7001 [email protected] Addressing spatial management issues of mobile species with acoustic telemetry In 2003 management concerns about escalating catch and effort levels for southern calamary led to the introduction of a three-month block closure of the two main regions, separated by 25-35km, where calamary aggregate to spawn and are therefore targeted by the ﬁshery. As calamary are a predatory and highly mobile species, questions have been raised concerning the relationship between populations within the adjacent areas of Great Oyster Bay and Mercury Passage, and the degree of protection that closing these areas may be providing to spawning animals. Eighty-three VR2 receiver stations moored throughout the east coast were used to detect detailed movements of 46 acoustically tagged squid, where each receiver could detect and record the date, time and unique ID number of an acoustically tagged squid every time it swam within 300-500m of the receiver. The receivers were placed along the boundaries of Great Oyster Bay and Mercury Passage, across smaller bays within these areas, and on individual seagrass beds. Over 118,000 ‘hits’ were obtained on the VR2’s with the data clearly demonstrating that calamary are very active during the spawning season, with many squid easily travelling a minimum of 100’s of km within a few weeks. Although most squid were travelling distances much greater than the 25-35km gap between Great Oyster Bay and Mercury Passage, movement of squid between these two areas was not detected. The placement of the receivers also allowed an estimate of the percentage of time that squid were staying within the closed area, and therefore protected from commercial ﬁshing. Squid were detected on the boundaries of the closed areas, however, most squid were detected again on other receivers within the closed area, indicating that although squid had moved within the vicinity of the boundary they had not actually left the closed, and therefore protected area. ______

Pederson, Hugh G & Craig R Johnson School of Zoology and Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Private Bag 5, Hobart Tas. 7001 [email protected] Effects of lobster fishing on the population dynamics of the sea urchin Heliocidaris erythrogramma on the east coast of Tasmania Formation of sea urchin ‘barrens’ occurs widely in temperate regions of both northern and southern hemispheres. Understanding the mechanisms leading to the formation of sea urchin barrens is an important management issue because the associated decline in primary and secondary production and loss of habitat structure underpins major changes in community structure and function. These changes can include loss of commercial fisheries for crustacean and abalone species. We examined whether fishing of rock lobster (Jasus edwardsii) and/or demersal reef fishes on rocky reefs in Tasmania could account for population increases of the sea urchin Heliocidaris erythrogramma to the point where there is significant risk of overgrazing of native macroalgae to form sea urchin barrens. Our previous work, involving both surveys at multiple spatial scales and a manipulative experiment in a marine reserve, indicated that rock lobsters are much more important as predators of this sea urchin than are fishes. Thus, we assume that the difference we measured in relative predation rates on sea urchins inside and outside reserves is due largely to differences in the size and abundance of rock lobsters. Estimates of age-specific mortality rates and age frequency distributions derived for several distinct sea urchin populations enabled construction of matrix models of urchin population growth. Using empirical estimates of mortality rates of H. erythrogramma outside reserves (derived from age-frequency distributions) and inside reserves (derived from age-frequency distributions and empirical estimates of differences in relative mortality inside and outside reserves), we were able to estimate and compare sea urchin population dynamics inside and outside reserves. This provides the basis to estimate the effect of exploitation of lobsters in regulating sea urchin population density. The modelling suggests clearly that the reduction in biomass of legal-sized lobsters on the east coast of Tasmania due to fishing is sufficient to account for increases in populations of H. erythrogramma to the point where formation of sea urchin barrens may occur.

Abstracts - Page 97 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Pesant, Stéphane (Poster) Centre for Water Research, The University of Western Australia, WA 6009 [email protected] Investigating a homogeneous fluorescence profile covering the top 250m in a warm-core, downwelling-eddy off WA: Evidence of heterogeneity from photosynthesis vs irradiance experiments A pair of warm- and cold-core eddies were studied for 23 days in October 2003, on board the RV Southern Surveyor. To our great surprise, in the center of the warm-core, downwelling eddy, the fluorometer attached to the CTD revealed a homogeneous profile of chlorophyll a from the surface down to 250m, well below the euphotic zone (90m). Size fractionated chlorophyll a and microscopic observations made on board showed that roughly 20% of the phytoplankton responsible for that fluorescence were diatoms. Several hypotheses were generated about the physiological adaptation of these diatoms to their vertical excursion through a deep nutrient deplete water column, i.e. undetectable nitrate down to130m. These led to a series of ad hoc experiments and the poster presents one of these. Natural assemblages of phytoplankton from 0, 50, 100, 150, 200 and 250m were incubated under 6 different light intensities for 24h. The resulting Photosynthesis vs. Irradiance (Pvs.I) curves tell us about the photosynthetic ability of these assemblages under a range of light conditions, similar to those experienced during a vertical excursion from the surface down to 250m. ______

Pesant, Stéphane1, Christine E Hanson1, Tony Koslow2, Robert D McCauley3, Charitha Pattiaratchi1, Chandra Salgado Kent3, Peter A Thompson4, Luke Twomey1, Florence Verspecht1, Anya M Waite1 1 Centre for Water Research, The University of Western Australia, WA 6009 2 CSIRO Marine Research, Floreat WA 6913 3 Centre for Marine Science and Technology, Curtin University, WA 6845 4 CSIRO Marine Research, Hobart Tas. 7001 [email protected] Size-fractionated phytoplankton characteristics: A quick and easy approach to the ecology of pelagic marine systems off WA Phytoplankton come in a wide range of sizes, from half a micron to several hundred microns and up to a few millimeters in the case of chain/colony forming species. Generally speaking, “LARGE” and “SMALL” phytoplankton correspond to distinct taxonomic groups, i.e. diatoms, dinoflagellates and coccolithophores on the one hand and autotrophic nanoflagellates and cyanobacteria on the other. The threshold used to separate the two size fractions varies from 3 to 20 microns, depending on the filters used to collect the particulate matter. Phytoplankton characteristics that are typically size fractionated are (1) extracted chlorophyll a (fractionation occurs before extraction) and (2) photosynthesis (any method that uses particulate matter tracers, e.g. 14C, 13C, 15N). The two characteristics provide information on the structure and functions of the phytoplankton community. The advantages of the size fractionation approach are its simplicity, replicability, low cost and rapidity to obtain results in the field. Most importantly, the approach is ecologically meaningful since the two size fractions differ in physiology and are adapted to contrasting environmental conditions. Moreover, the two fractions play distinct roles in marine food webs. While the “LARGE” phytoplankton is associated with the classic algae-copepod-fish food web, the “SMALL” phytoplankton is associated with the microbial food web. Hence the extent of “LARGE” vs. “SMALL” phytoplankton should reflect the extent of herbivorous vs microbial food webs in marine systems. We present the first set of size-fractionated data collected off WA. Sampling efforts on the coast of WA has been intense during 2002-2004 owing to the Strategic Research Fund for the Marine Environment (SRFME) and to the marked research effort of the RV Southern Surveyor in 2003. We present results from over 130 sampling times and locations, covering lagoon, shelf, offshore, and deep canyon environments.

Abstracts - Page 98 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Pesant, Stéphane1, Holl, Carolyn M2, Thompson, Peter A3 & Waite, Anya M1 1 entre for Water Research, The University of Western Australia, WA 6009 2 Georgia Institute of Technology, School of Biology, Atlanta, GA USA 3 CSIRO Marine Research, Hobart, TAS 7001 [email protected] Phytoplankton production in two contrasting eddies off WA Phytoplankton production depends on the uptake of inorganic nutrients such as nitrate, nitrite, ammonium and urea. The latter two nutrients can be “REGENERATED” in surface waters by pelagic organisms, whereas nitrate and nitrite are formed in deep waters and are slowly diffusing to the surface, at a much lower rate than their uptake by phytoplankton. Unless these “NEW” nutrients are brought to the surface by upwelling (typical of productive, eutrophic coastal systems), phytoplankton production in oceans is typically low (then called oligotrophic systems). Off Western Australia (WA), upwelling is largely suppressed by the Leeuwin Current and generally leads to oligotrophy. Mesoscale eddies modify the vertical structure of pelagic systems and the proximity of nutrient-rich deep waters to the surface. Eddies are common features on the coast of WA and are expected to signiﬁcantly modify the local ecology of pelagic systems where they develop. We hypothesized that warm-core, downwelling-eddies develop into “DESERTS”, whereas cold-core, upwelling-eddies develop into “OASES”. We went on testing that hypothesis on board the RV. Southern Surveyor in October 2003 and studied a pair of warm- and cold-core eddies for 23 days. Results are not exactly as expected and offer a different perspective on the ecology of eddies on the coast of WA. ______

Pesant, Stéphane1, Lindsay Pender2 & Mark Underwood2 (Poster) 1 Centre for Water Research, The University of Western Australia, WA 6009 2 CSIRO Marine Research, Hobart, TAS 7001 [email protected] Dissection of two eddies off WA using the SeaSoar, an open ocean towed undulating data acquisition vehicle A pair of warm- and cold-core eddies were studied for 23 days in October 2003, on board the RV Southern Surveyor. In addition to the traditional CTD-proﬁle approach to describing physical and biological oceanographic features, we towed an open ocean undulating vehicle (SeaSoar), which carried a CTD and a ﬂuorometer. The SeaSoar proved to be an extremely useful dissecting tool. The poster is a stunning 2D post card of the eddies and the jet created by their combined circulation. Beyond its mapping utility, the SeaSoar provides high-resolution data that will be used in coupled biological-physical models. We will be happy to discuss the next step of our analysis; a 3D matrix of the eddies. Come see what Lindsay and Mark did during their spring break in 2003! ______

Abstracts - Page 99 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Phillips, Helen1*, Susan Wijffels1 & Ming Feng2 1 CSIRO Marine Research, Hobart Tas. 7000 2 CSIRO Marine Research, Floreat WA 6014 [email protected] Interannual variability in freshwater content NW of Australia from Argo The region northwest of Australia, the Indo-Australian Basin, was the focus for the first Argo profiler deployments around Australia. We now have almost 2000 Argo profiles (temperature and salinity to about 2000 metres) recorded between 1999 and today in this region. For comparison, shipboard CTD profiles between 1989 and 2004, of much higher vertical resolution and extending to the sea floor, number only 894. The time series from each Argo profiler, with 10-day sampling, reveal an incredible richness of temporal variability from intraseasonal to interannual. The data reveal a massive freshening of upper thermocline waters of 0.2 psu averaged over the top 180 metres of the region 100ºE-125ºE, 25ºS-5º, during 1999 to 2002. Excessive rainfall over the Indo-Australian Basin associated with the La Nina event of mid-1998 to early-2001 appears to be the primary cause of the freshening. We compare the Argo results with historical CTD sections dating back to 1989, thermosalinograph data during 1999-2002, and surface freshwater flux time series from NCEP and ECMWF. Together these show strong interannual variability in the upper ocean freshwater content of the region and that the recent freshening is unprecedented in the last 20 years. ______

______

Pile, Adele J & Bethany K Hammond The University of Sydney, School of Biological Sciences (A08), Sydney NSW 2006 Pulsed-cold water events have a persistent negative impact at all levels of community structure Internal waves and tidal bores are common coastal oceanographic phenomena that impact coastal ecosystems. In general they are believed to have a positive impact on near shore communities as they are a known mechanism for shoreward larval transport. We have discovered a pulsed cold water event at Point Avoid, Eyre Peninsula, South Australia, which may be driving near shore benthic community structure. At Point Avoid two adjacent communities, within meters of each other, have differed significantly over five years in their macroalgal and macroinvertebrate species diversity and overall levels of abundance. Only the community with the lowest levels of species diversity and abundance, experiences these pulsed water events that drop the temperature from 19-20oC to 6-7oC. These events occur on the falling tide, have a mean duration of 10 minutes, and large interannual variability in intensity. In addition to differences at the community level there are also significant differences between co-occurring organisms. The photobiology of Ulva lactuca on the impacted side suggests that these events lead to photoinhibition. Our results lead us to speculate that large-scale pulsed water phenomena may be negatively impacting benthic communities at sites along the entire coastline of southern Australia. ______

Abstracts - Page 100 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Piola, Richard & Emma Johnston (Poster) School of Biological, Earth & Environmental Sciences, University of New South Wales, NSW 2052, Australia [email protected] Comparative copper sensitivities of four species of four species of introduced marine bryozoans Sessile marine invertebrates in bays and estuaries are among the marine communities most vulnerable to invasion, due not only to the abundance of invasive propagules (or larvae) supplied via shipping, but also due to the high levels of anthropogenic disturbance that occurs in these same areas. Anthropogenic disturbances may weaken and alter the structure of local invertebrate communities, allowing introduced species to gain a foot-hold, proliferate and spread. Copper is a toxicant commonly discharged into estuaries, embayments and streams and at higher concentrations it is considered one of the three most toxic heavy metals to marine invertebrates of several trophic groups. In this study we tested the whether larval exposure to varying concentrations of copper (between 10 and 500 μg.L-1) had any short- or long-term effects on four introduced bryozoan species (Bugula neretina, Watersipora subtorquata, Schizoporella errata and Tricellaria occidentalis) by examining settlement success, survival and growth rates under laboratory conditions, then transplanting the colonies into the field. In addition, field-based larval exposure experiments provided an in situ comparison to the laboratory studies. In the laboratory, settlement and survival rates indicated considerable differences in copper sensitivity among the four species. However, once an individual managed to attach and metamorphose survival rates were generally high, though reductions in subsequent growth rates were recorded with increasing copper concentrations. Laboratory colonies transplanted into the field exhibited similar growth rate patterns as observed in the laboratory, though mortality rates did increase. Field-based larval exposure experiments yielded similar results to the laboratory experiments, though greatly reduced recruitment was observed. This research is important for better understanding the sensitivity and tolerances of introduced marine invertebrate species to copper disturbance events. ______

Post, Alix1 & Will Howard2 1 Geoscience Australia, Canberra, ACT 2601 2 Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart 7001 [email protected]

Biological production and the uptake of CO2 in the Southern Ocean: Evidence from planktonic foraminifera Planktonic foraminifera were collected in year long sediment traps deployed at 5 sites, spanning Subtropical to Polar Frontal environments. The carbon isotopic composition was analysed for Globigerina bulloides, providing a record of the surface water composition. Offsets between the δ13C for G. bulloides and measured δ13C of dissolved inorganic carbon can be corrected by applying a laboratory-derived temperature correction (Bemis et al., 2000). Comparison between the corrected foraminiferal δ13C composition and mass ﬂux to the sediment traps reveals the close coupling between biological production and changes in foraminiferal δ13C. The consistency of this relationship demonstrates the usefulness of foraminiferal δ13C records for tracing changes in biological production in down- core sedimentary records.

13 Since the industrial era, the δ C of atmospheric CO2 has become progressively lighter due to the addition of δ13C-enriched carbon from the burning of fossil fuels and forest clearance. Measurements of δ13C in the surface ocean also reﬂect this enrichment, with greatest enrichment in areas with the strongest atmospheric CO2 uptake. Understanding CO2 uptake by the oceans is an important constraint on CO2 models. In this study we compare the δ13C composition of foraminifera from the sediment traps to those in nearby surface sediments, which primarily represent accumulation since prior to the industrial revolution. In our transect the strongest uptake of CO2 in surface waters is found in the Subantarctic Zone, with a change in δ13C since pre-industrial times of up to 0.70‰. ______

Abstracts - Page 101 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Proctor, Craig1*, Tim Davis1, John Gunn1, Subhat Nurhakim2, Wudianto3, Gede Merta3, Retno Andamari4 & Budi Iskandar2 1 CSIRO Marine Research, G.P.O. Box 1538, Hobart Tas. 7001 2 Research Centre for Capture Fisheries, Jl. Pasir Putih I, Anchol Timur, Jakarta 14430 Indonesia 3 Research Institute for Marine Fisheries, Kompleks Pelabuhan Perikanan Samudra, Jl. Muara Baru Ujung, Jakarta 14440 Indonesia 4 Research Institute for Mariculture (Gondol), P.O. Box 140, Singaraja 81101, Bali Indonesia [email protected] Indonesia and Australia collaborate to develop Indonesia’s capacity to monitor and assess its Indian Ocean tuna and billfish fisheries, aiming for sustainability of shared-stocks Indonesia is one of the most important countries that fish tuna and tuna-like species in the Indian Ocean. The most recent estimate by Indian Ocean Tuna Commission (IOTC) of combined industrial and artisanal catch for Indonesia was 177,384 tonnes (year 2000). Around 60,000 tonnes of this is attributed to commercial longline vessels, with around 1000 to 1500 vessels thought to be operating in the Indian Ocean at that time. For almost 30 years Indonesia has had a national system of fisheries statistics, but data collected and reported is unsuitable for science-based stock assessments. As a result, Indonesia has been unable to meet the reporting requirements to regional fisheries management agencies such as IOTC and Commission for the Conservation of Southern Bluefin Tuna. In recent years, Indonesia’s tuna fishing industry have voiced strong concerns about declines in catch rates and mean fish size, and forced changes to fishing behaviours to achieve profitability. However, there is currently insufficient CPUE data to allow effective evaluation of these worrying trends. Since1992, CSIRO has collaborated with Indonesia’s principal fisheries research institutes in monitoring longline tuna landings at port of Benoa (Bali), primarily to enable annual assessments of Indonesia’s catch of SBT for the Commission for Conservation of Southern Bluefin Tuna. In 2002 the program was extended to two other major landing ports - Muara Baru (Jakarta) and Cilacap (Central Java), and now includes full monitoring of landings of other species (yellowfin, bigeye, albacore, marlins, and sailfish). With funding from Australian Centre for International Agricultural Research (ACIAR) a detailed review of Indonesia’s Indian Ocean tuna fisheries was done and a strategy developed for improving Indonesia’s capacity for fisheries stock assessments and independent reporting to the regional fisheries management agencies. The long-term goal is to achieve sustainability of shared-stocks for mutual benefit of both Indonesia and Australia. ______

Provis, David Lawson and Treloar Pty Ltd, 93 Normanby Rd, Notting Hill Vic. 3168 [email protected] Hydrodynamics of Port Phillip Heads, The Rip The Port of Melbourne Corporation is examining a proposal to deepen the shipping channels into the Port of Melbourne. This includes some deepening in Port Phillip Heads, the area known as The Rip. As part of the investigations for this project, measurements and modelling of the hydrodynamics of the heads has been undertaken. The Heads includes shallow banks with water depths of about 20 m intersected by a canyon with depths close to 100 m and near vertical walls. The result is an area of currents in excess of 3.5 m s-1, with complex ﬂow patterns. It is shown to be the major control for water movements in and out of the bay. Measurements indicate strong and persistent eddies and large gradients in the sea-surface elevation as well as very strong vertical-variations in the currents. The eddies are believed to play an important role in the exchange of water from Bass Strait with that in the bay. The major features are well reproduced by models with both two and three-dimensional modelling being used. ______

Abstracts - Page 102 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Rathbone, Chris, Glen Smith, Ken Suber & Peter Turner CSIRO Marine Research, Castray Esplanade, Hobart, Tas. 7000 [email protected] 10 Years of Australasian Sea Surface Temperature Sea Surface Temperature (SST) maps covering the region 10N to 65S and 80E to 170W at a spatial resolution of approximately 4km have been compiled for the period starting on the 6th October 1993 and ending in mid June 2003. The maps have been derived using infrared data from the Advanced Very High Resolution Radiometer (AVHRR) which are onboard the NOAA TIROS-N series polar orbiting satellites. The methodology used to derive the SST is described including, geo-location, calibration, cloud detection and the unique histogram based compositing technique. The maps are produced as 1, 3, 6, 10 and 15 day composites and form a fundamental dataset, unprecedented as a high-resolution, long-term time series of SST for the Australasian region. Examples are shown to illustrate the detail in the data. The data are available on the web and offer opportunity for the study of a wide variety of climate change and marine applications. ______

Reid, Anthony & Craig Johnson School of Zoology, University of Tasmania, Hobart 7005 [email protected] Utilisation of the New Zealand screwshell by native hermit crabs in Tasmania: Indications of potential impact Defining the associations between native and introduced species can help elucidate potential impacts of exotic species. We examined utilisation of the introduced New Zealand screwshell Maoricolpus roseus (Quoy & Gaimard 1834) by native hermit crabs in eastern Tasmania. A survey spanning the east coast of Tasmania indicated that empty M. roseus shells are utilised by at least 7 hermit crab species, but in particular Paguristes tuberculatus, Pagurixus handrecki and Micropagurus acantholepis. The level of occupancy of M. roseus by hermit crabs was highly variable among sites (14% - 85% occupancy of available shells). Small hermit crab species (largely P. handrecki and M. acantholepis) also utilised a variety of native shell species, and occupancy patterns reflected the relative availability of the different shell species. In contrast, the larger hermit crab, P. tuberculatus, only occupied M. roseus as no native shell species were similar in size to M. roseus. Moreover, occupancy rates were strongly positively correlated with the density of empty shells. Laboratory-based experiments indicated that P. handrecki shows clear preferences for small M. roseus shells over native shell species of similar size indicating a potential shift in shell species preferences of this hermit crab. Other laboratory experiments revealed clear preferences by P. tuberculatus for M. roseus shells exhibiting low levels of damage to the spire and aperture and low levels of epibiont fouling, despite no evidence of these preferences in the field. Discrepancies of this kind between the field and laboratory observations might be reconciled by considering how the pattern and distribution of empty shells influences availability and choice of shells by relatively sedentary hermit crabs. Our overall conclusion is that the arrival of M. roseus has provided an important resource for a number of hermit crabs, suggesting a shift in shell utilisation patterns and preferences of several crab species to utilise shells of this exotic species. In particular, there is convincing evidence that the introduction of M. roseus has facilitated very substantial increases in the populations of P. tuberculatus in eastern Tasmania. The flow-on effects of accumulations of P. tuberculatus at high densities on soft- sediment communities is unknown. ______

Abstracts - Page 103 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Rennie, Susan1, Robert McCauley1 & Charitha Pattiaratchi2 1 Centre for Marine Science and Technology, Curtin University of Technology, Bentley, WA 6102 2 Centre for Water Research, University of Western Australia, Crawley, WA 6009 [email protected] Physical oceanography of the Perth Canyon Situated west of Perth, the Perth Canyon is the foremost feature of the continental shelf between the Abrolhos Islands and Cape Leeuwin. It is a deep, narrow canyon which starts at the 200m contour, and extends to the bottom of the shelf. The canyon would be expected to have a significant influence on the oceanography of the region. Some evidence of this influence is the recurring presence of pygmy blue whales for feeding around the rims of the canyon during summer. Two field cruises, undertaken in October/November 2003 and January/February 2004 on the NF RV Southern Surveyor, included surveys of the Perth canyon where physical oceanographic data was acquired. The available processed data from these cruises are presented here, including ADCP current data, and CTD transects of the canyon. The aim of the fieldwork is to identify processes related to the canyon, such as upwelling and predominant circulation, particularly with the aim of determining why the canyon supports feeding blue whales, despite the general barrenness of the WA coast. Canyons in upwelling-favourable circumstances will tend to enhance the upwelling, increasing the productivity of the region. However, the Leeuwin current that flows over the Perth canyon is not upwelling favourable, making this particular system atypical. Complementing the fieldwork is a numerical simulation of the current interaction with the canyon. This is in the final developmental stages, and is hoped to be able to clarify some key processes associated with the Perth Canyon. ______

______

Ribbe, Joachim Department of Biological and Physical Sciences, University of Southern Queensland, Toowoomba Qld 4350 [email protected] Linking Southern Ocean water masses and Australian rainfall variability Rainfall in Australia and indices developed to monitor climate variability exhibit distinct pattern of multi- decadal variability. It is possible that physical mechanisms operating in the Southern Ocean are a driver of this behaviour. In particular, the formation of water masses within deﬁned geographical regions links the global ocean and the atmosphere. In the Southern Ocean, two large volumes of water are Subantarctic Mode Water (SAMW) and Antarctic Intermediate Water (AAIW), which are created by exchanges of heat and freshwater with the atmosphere and interior oceanic mixing. These sink below the surface of the Southern Ocean and move northward at depth of about 300-800 m. In this presentation, I present some arguments and evidence in support of possible linkages between Australian rainfall and Southern Ocean water mass formation processes via the equatorial ocean. ______

Abstracts - Page 104 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Ridgway, KR CSIRO Marine Research The 5500-km long boundary flow off western and southern Australia The path of the shelf-edge flow off southwestern Australia is documented using results from satellite altimetry and sea surface temperature and a climatological in situ analysis. During winter a continuous current is shown to extend from its origin at North West Cape to the southern tip of Tasmania, a total distance of 5500-km. Satellite SST observations and surface buoy tracks confirm the location and continuity of the current trajectory. While the Leeuwin Current is forced by the strong alongshore pressure gradient associated with the meridional portion of the Western Australian coastal boundary, our results suggest that the essentially zonal shelf edge flow along the southern Australian coast is driven by the winter westerly wind. The timing of these two different forcing mechanisms means that the west coast pressure gradient delivers the Leeuwin Current to the south coast just as the winds reverse and are thus able to maintain the eastward passage of the current. The shelf-edge flow consists of two main water masses. A low-salinity, warm water type of tropical origin associated with the Leeuwin Current and a high-salinity, warm water inflow formed on the western end of the Great Australian Bight continental shelf. A naming convention is proposed for the boundary flow, the Leeuwin Current representing flow from North West Cape to the Great Australian Bight (GAB), The South Australian Current, between the eastern GAB and western Bass Strait and the Zeehan Current located off western Tasmania. ______

Newman, Stuart J*, David Ritz1 & Stephen Nicol2 1 Department of Zoology, University of Tasmania, GPO Box 252-05, Hobart Tas. 7001 * present address: Food Standards Agency, Aviation House, 125 Kingsway London WC2B 6NH UK 2 Australian Antarctic Division, Channel Highway, Kingston Tas. 7050 [email protected] Behavioural reactions of Antarctic krill (Euphausia superba Dana) to ultraviolet and photosynthetically active radiation We used horizontal and vertical aquarium tanks to examine the behavioural responses of Antarctic krill (Euphausia superba) to photosynthetically active radiation (PAR) and ultraviolet (UV) radiation. Groups of animals were exposed to different levels of radiation and to gradients of radiation and their mean position in the tanks recorded photographically. Results from the horizontal tank (length 2.4 m) showed that krill move from areas of exposure to high levels of UVA (320 nm – 400 nm) to areas of low exposure. In addition, krill moved from areas of high exposure to PAR to areas of low exposure. There was no observed reaction to UVB (280 nm – 320 nm) wavelengths. Krill in the vertical tank (height 1.5 m) were evenly distributed throughout the tank when exposed to both high and low levels of PAR. Addition of UVA wavelengths caused krill to signiﬁcantly increase their depth in the tank, presumably to areas of lower irradiance. Addition of UVB radiation had no effect on the mean position of krill in the tank. The implications of these ﬁndings are that under ‘normal’ conditions, krill would avoid regions of high UVA or PAR and consequently would gain protection from high UVB. But the ‘ozone hole’ has elevated the ratio of UVB:UVA radiation reaching the ocean surface and thus potentially increases the risk of damage. ______

Abstracts - Page 105 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Roberts, David A1* & Alistair GB Poore1 1 School of Biological Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia [email protected] Experimental habitat fragmentation affects colonisation of epifauna in a marine algal bed Habitat fragmentation is a recognised threat to the preservation of both terrestrial and marine biodiversity. Few studies have considered how the two processes that cause fragmentation — reductions in the size of habitat patches and increases in the isolation of patches — affect the abundance of marine organisms. In this study, sampling and manipulative approaches were utilised to examine the how variation in the size and isolation of habitat patches affect mobile invertebrates inhabiting the brown alga Sargassum linearifolium in subtidal rocky reefs. Variation in the size of naturally occurring patches did not affect the abundance of any major taxonomic groups except polychaetes. When habitat was manipulated to mimic further habitat fragmentation, the total abundance and the abundance of isopods increased with increasing isolation of habitat patches. Small patches had signiﬁcantly greater abundance of amphipods and ostracods than did large patches. These ﬁndings are contrary to traditional predictions of declining abundance with increasing isolation and decreasing patch size. It is likely that traditional predictions of the effects of fragmentation do not apply consistently to marine systems and the processes underlying the patterns are fundamentally different in marine and terrestrial environments. ______

Gales, N & S Robinson (Poster) Applied Marine Mammal Ecology Group, Australian Antarctic Division, Channel Highway, Kingston Tas. 7050 Tracking baleen whales: development of the e-D tag Studies of at-sea movements of large cetaceans have been limited due to the difﬁculty of reliably attaching radio tags, yet knowledge of their medium to large scale movements is fundamental for informed debate on the diverse manner in which we interact with whales. By contrast, knowledge of the movements and behaviour of the more tractable marine predators (particularly seals and penguins) has increased rapidly in concert with advances in micro-electronics. Here we describe the development of several versions of the e-D (electronic-Discovery) tag; a small, biologically inert, blubber-implantable radio tag. The tags were designed and built through a collaboration of biologists and engineers from the Australian Antarctic Division, Sirtrack Ltd, New Zealand and Wildlife Computers, USA. Two Mark I e-D and one Mark II e-D tags have been successfully deployed on blue whales, and the Mark III e-D tag is currently being developed. ______

Abstracts - Page 106 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Jarman, S, N Gales, B Deagle, A Passmore, S Robinson (Poster) Applied Marine Mammal Ecology Group, Australian Antarctic Division, Channel Highway, Kingston Tas. 7050 DNA as a dietary biomarker The prey species that any predator consumes are a key aspect of its ecology. Estimation of the identity, diversity and relative abundance of prey proves to be a surprisingly difficult problem. DNA-based species identification has only recently been applied to this area. As a species identification tool, DNA has many advantages over morphological or other biomarker methods and may provide a better means of estimating the diet of predator populations than existing methods. Our research on the diet of Antarctic krill, penguins, whale sharks, giant squid and whales has proven that prey DNA identity can be readily determined from a diverse range of predators. Design of PCR primers for overcoming the problem of targeting prey DNA amongst the mixture of DNA present in dietary samples is described. ______

Roob, Ralph University of Melbourne, Geomatics, 2 St Andrews Street, Queenscliff Vic. 3225 [email protected] The effectiveness of hydro-acoustic techniques to characterise benthic habitats and communities in Port Curtis This study aims to generate geo-spatial layers of benthic habitats and communities throughout Port Curtis on the Central Queensland coast. Information from a benthic study of Port Curtis, designed and implemented by the Central Queensland University to provide a baseline that will assist in ongoing assessments of ecosystem health, will be used to verify and train data collected by single beam sonar. Quantitative approaches to post processing acoustic backscatter data has given sonar technology greater potential to survey physical attributes of the seafloor over broad areas with a method that is both efficient and economically feasible. Physical attributes of the seafloor may be used as a surrogate to determine the types of biological communities associated with them. It is therefore reasonable to hypothesise that quantitative measures derived from sonar technology will provide an effective means of identifying the spatial extent of certain biological communities. How effectively though, can information generated by sonar equipment be used as a surrogate to estimate the spatial extent of benthic habitats and communities? The effectiveness of hydro-acoustic techniques in mapping benthic habitats and identifying the communities they support will be determined. The study will examine the technical limits of these techniques in a variety of marine environments and will investigate the spatial resolution and detail that marine benthic communities can be classified. Geo-spatial analytical techniques will be applied to this data to generate a seamless map representing the distribution of benthic communities. A significant potential benefit of this study will be the capacity to predict the spatial distribution of epi-benthic and macro-benthic communities based on physical attributes of the seafloor. Hydro-acoustic surveys may also provide an insight into the magnitude and persistence of impacts on benthic communities caused by disturbances such as dredging and trawling as well as natural events such as extreme storm activity. ______

Abstracts - Page 107 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Ross, Jeff1,2, Mick Keough1 & Andy Longmore2 1 Zoology Department, The University of Melbourne 2 Marine and Freshwater Systems, Department of Primary Industries, Victoria [email protected] Interaction of marine pests and nutrient cycling in Port Phillip Bay Nutrients inputs are one of the most significant risks to coastal waters around the world, including waters around the Australian coast. The nutrient of key concern for most marine waters is nitrogen, and excessive nitrogen can result in eutrophication, with loss of biodiversity in benthic habitats, and consequent threats to fisheries. Whether or not eutrophication occurs depends most obviously on the level of nutrients, but also, critically, on the processes that remove nitrogen from the water. For semi- enclosed water bodies such as Port Phillip Bay, the key process is denitrification, which effectively transfers nitrogen from the water to the atmosphere. The exact mechanism for denitrification is not known, but our current understanding is that organisms living in soft sediments play a very important role in the denitrification process. While nutrients have been viewed as a major threat to urban coastal waters, in recent years, we have been increasingly aware of the threat posed by introductions of marine pests. Nutrients and pests have largely been treated as independent threats, but pests could interfere with denitrification processes if they cause substantial changes to the organisms living in soft sediments. In this study we are testing whether this occurs using an experimental ecological approach, examining ecological changes resulting from pests, coupling this with in situ nutrient assay chambers to measure denitrification. The results of this study will provide key information for managers devising nutrient management strategies. Results will be presented on spatial variability in the effects of one important pest, the European Fan Worm Sabella spallanzanii on soft sediment assemblages and nutrient fluxes. ______

Roy, Craig Director, CSIRO Wealth from Oceans Flagship, PO Box 93, North Ryde NSW 1670 CSIRO’s National Research Flagships- Wealth from Oceans Flagship CSIRO’s National Research Flagships are Australian science aiming high – the toughest challenges, the strongest teams, the most audacious goals. They are about delivering the best future we can envisage, in a practical, efficient and sustainable way. The Flagships initiative takes a scientific and commercial partnership approach to deliver real impact. Flagships will initially focus on six primary areas, namely: Preventative Health, Food, Water, Light Metals, Energy and Oceans, with each having strong alignment with the Federal Government’s National Research Priorities. Australia’s future lies with its oceans as much as the land itself – 70 per cent of the nation’s sovereign territory is sea, and the remainder is affected by its climatic influence. Australia has a fundamental interest in ensuring that the value of our oceans is identified and unlocked responsibly. With ocean spaces spanning Antarctica to the Tropics, Australia has some unique challenges and opportunities. The national Wealth from Oceans Flagship will aim to assist Australia in understanding and effectively utilising our last frontier – the oceans. Whilst the Flagship is still relatively young, its science program is underway and it will grow rapidly throughout FY 2004/05 – the total value of the R&D for the upcoming fiscal year will be approximately $20M. Initial projects include physical ocean and climate modelling, with outputs such as BlueLink (http:// www.marine.csiro.au/remotesensing/oceancurrents/) that publishes daily-updated images of ocean surface temperature and current – the Commonwealth Bureau of Meteorology and the Royal Australian

Abstracts - Page 108 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Navy are BlueLink partners. Additionally a new coastal / shelf environmental modelling suite that incorporates improved hydrodynamics, and coupled sediment dynamics and biogeochemical modules, is being developed and tested for SW West Australia. Three new science Themes will be established in FY 2004/05: Ocean-based forecasts of Australian climate – Oceans to Rains, sustainable management of marine resources – the Marine Nation and generating Blue GDP. Oceans to Rains aims to identify, understand, and predict the ocean processes driving Australian climate variability and change. It will maximise the benefits from good years and minimise the losses in bad years for Australia’s climate sensitive industries by providing reliable climate predictions. The Marine Nation will develop a program of research designed to build and deliver practical scientific knowledge and support for integrated marine multiple-use management, regional development and conservation policies. Whilst Blue GDP projects will target high impact areas of national significance and will focus on creating economic wealth and jobs creation. Opportunities include the oil and gas industry, offshore aquaculture, proteins and oils and smart sensors, instruments and knowledge systems. Strong partnerships and great science are critical to the success of all these Themes. The presentation will provide an overview of the National Flagship initiative with a focus on the Wealth from Oceans Flagship. ______

Runcie, John W1,2 1 Hawaii Institute of Marine Biology, P.O. Box 1346, Kaneohe, HI 96744 USA 2 Present address: Institute for Water and Environmental Resource Management, University of Technology, Sydney, NSW 2065 Characterising the nutrient status of macroalgae with chlorophyll fluorescence Estimating nutrient concentrations of coastal marine waters is important for predicting algal blooms and defining water quality, and macroalgae are ideal biological monitors of nutrient pollution as they incorporate nutrients directly from the water column. Under certain conditions nutrient-starved and nutrient-enriched macroalgae can be distinguished using chlorophyll fluorescence-based light response curves. In this study the chlorophyte macroalgae Ulva fasciata and Dictyosphaeria cavernosa were subjected in vivo to nutrient enrichment or starvation, and biochemical attributes and light response curves were examined. From these experiments a protocol was developed for the deployment of D. cavernosa in the field with and without accompanying nutrient enrichment. In situ fluorescence measurements over a 13 month period showed seasonal and site-specific patterns in ambient nutrient availability in Kaneohe Bay, Hawaii. The benefits and limitations of this technique for monitoring ambient nutrient concentrations is discussed. ______

Abstracts - Page 109 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Saint-Cast, Frederic1,2, Scott Condie1 & Peter Harris2 1 Torres Strait marine resources, CSIRO Marine Research, TAS 7001. 2 Marine and Coastal Environment Group, Geoscience Australia, ACT 2601. [email protected] Circulation in the Torres Strait marine ecosystem This study focuses on developing calibrated numerical models to investigate important ocean processes operating in the Torres Strait marine and coastal ecosystem between Papua New Guinea and the northernmost extremity of Australia. Early results on the circulation in this region, driven either by wind or by tide, are presented hereafter. Tides are the main forcing that drive ﬂows in the Torres Strait on a short-term (daily) base. Results compared with tidal signals given by the Admiralty System for a set of 14 ports show quite good agreement at most stations, with an averaged correlation of 0.77 and an averaged ratio of measured and modelled tidal elevation of 0.95. In the Strait, tides are dominated by the O1, K1, M2 and S2 components. Energy is found to be drastically redistributed within the 50 km zone covering the shallow ridge, with the S2 component vanishing almost completely on the western side. These results are well correlated with data recorded by Wolanski et al. (1988). Simulations proposed for the future will include sediment transport and allow impacts of physical processes on the evolution of important seabed communities to be investigated. ______

Sala, Ridwan* & Ron Johnstone (Poster) Centre for Marine Studies, The University of Queensland, St Lucia Qld 4072 [email protected] Size composition of skipjack (Katsuwonus pelamis L) taken from the northeastern waters of Indonesia Description of the size composition of catch can provide useful information for understanding the structure of fish stock that may be vulnerable to the fishing activities. A study on the size composition of skipjack in the Northeastern waters of Indonesia has been undertaken based on time series landed catch data with the objective to examine the spatial, temporal and gear type effects on the size of fish caught and the trend in size composition over time. It was found that skipjack taken by pole and line fishery showed a similar size distribution and no clear change in size composition during period 1993-2000. By comparison, the size composition of skipjack taken by purse seine fishery indicated that the composition of small skipjack (≤ 1 kg) was significantly higher in the western sites of the study region compared to that observed in the eastern sites. This result has significance for the long-term sustainability of the skipjack fishery in the study region and highlights the need to include such assessments in strategic planning for the management of such stocks. ______

Abstracts - Page 110 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Salgado-Kent, C* & R McCauley Centre for Marine Science and Technology, Curtin University of Technology, GPO Box U 1987, Perth WA 6845 [email protected] An analysis of blue whale (Balaenoptera musculus) call variations from south-western Australia Underwater acoustic monitoring is a powerful technique for identifying cetacean species present, identifying populations with regional dialects, and monitoring relative numbers and seasonal occurrence and movement patterns. To employ these techniques, calls must first be identified and described. This study identifies temporal variation in blue whale (Balaenoptera musculus) calls in the Perth Canyon, Western Australia, and relates these calls to those recorded elsewhere in the world. Seven call variations were identified from a sub-sample of recordings made between February to June, 2003. The most common occurred 52% of the time, while 4-part calls occurred 27%, 2-part calls occurred 9%, 2-part sinuous calls occurred 6%, 1-part calls occurred 5%, and 2-part upsweep calls occurred 1% of the time. The 1-part call was attributed to true blue whales, while all other calls were likely to be produced by pygmy blue whales. The two most common calls occurred throughout the study period, while the other calls occurred usually for 3 days, and appeared only once or twice during the study period. An analysis of call sound similarity showed that many sounds produced from the same population are similar to each other, but are just as likely to be similar to populations far removed as populations close by. The results of this study suggest that although blue whale calls and sounds from calls can be helpful in distinguishing populations, there may be limitations in their use in assessing how closely related one population is to another. ______

Sauer, Warwick Rhodes University, Ichthyology and Fisheries Science, PO Box 94, Grahamstown South Africa 6140 [email protected] Movement pattterns of an endemic sparid in South Africa Understanding the movement behaviour of fishes is crucial for fisheries management, especially in the context of marine reserve design. The size of the area that needs to be closed to the fishery in order to function effectively as a refuge largely depends on the movement patterns of the species. This study investigates the spatial distribution of Roman Chrysoblephus laticeps in two South African marine reserves. It focuses on the intensive study of the movement behaviour and the habitat utilisation of this species in relation to its biological parameters and oceanographic conditions and the consequences for management efforts. A combination of mark and recapture, boat based and SCUBA manual tracking, VRAP telemetry and direct observation was employed. All tagging and implantation methods were tested in controlled tank experiments and the accuracy of the position recording for the different methods established in preliminary field tests. The natural behaviour of the animals with implanted transmitters was confirmed through diver observations A preliminary analysis of the data suggests that • animals reside in an area less than 10000 m2, regardless of age or sex • the area is shared by other Romans (320 per 10000 m2 ), competition is limited to feeding and to courtship rituals by females during the spawning season • this area is reduced during the night and during sudden drops in sea temperature caused by coastal upwelling • the area is extended to at least 100000 m2 for females during the spawning season • a small percentage (~10%) of fishes leave their resident area and travel significant distances (4 km confirmed) A preliminary IBM of a Roman population in a small marine reserve scenario suggests, that • even small marine reserves will offer protection to spawning stock of Romans, provide a recruitment source for surrounding areas and therefore provide the most efficient management tool for the protection of this and other species with similar degrees of residency. ______

Abstracts - Page 111 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Saunders, Krystyna1, Andrew McMinn1, Dona Roberts1, Dominic Hodgson2 & Henk Heijnis (Poster) 1 Institute for Antarctic and Southern Ocean Studies, University of Tasmania, Hobart Tas. 7001 2 British Antarctic Survey, Natural Environment Research Council, Cambridge United Kingdom CB3 OET 3 Australian Nuclear Science and Technology Organisation, Menai, NSW 2234 [email protected] Recent human-induced salinity changes in Ramsar-listed Orielton Lagoon, Tasmania, Australia Over the last 200 years the ecology of many coastal lagoons in eastern Australia has changed as a result of human activities. However, it is often difficult to distinguish natural from human-induced changes and to determine their ecological implications. Orielton Lagoon (south-east Tasmania, Australia) is a Ramsar-listed coastal wetland of international importance for conservation. A palaeolimnological study was undertaken at the site to determine whether man-made hydrological modifications to the lagoon had influenced its salinity, ecology and compromised its Ramsar status. A diatom-salinity transfer function was constructed from a training data set of 96 diatom taxa from 34 sampling sites in 19 lagoons along the east coast of Tasmania. Results showed that the salinity of Orielton Lagoon has changed in response to known engineering events, which have transformed the lagoon from an open marine environment to an enclosed, virtually stagnant brackish water body. These changes have compromised the protected coastal wetland status of Orielton Lagoon. Environmental remediation attempts have since partially restored the natural hydrology of the lagoon and it is now returning towards its original state. ______

Semmens, Jayson1*, Julian Harrington1 & Matthew Inkson2 1 Marine Research Laboratories, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Private Bag 49, Hobart Tas. 7001 2 School of Computing, University of Tasmania, Private Bag 100, Hobart Tas. 7001 [email protected] Why won’t my octopus come back: Utilizing passive telemetry to understand the dynamics of an octopus population Traditional tag-recapture studies have long been used to examine movement of marine animals and provide an understanding of population dynamics. However, the disadvantage of these types of studies is the animals have to be recaptured to provide information. A tag-recapture program was undertaken to examine the movement and population structure/dynamics of the maori octopus Octopus maorum on an inshore temperate reef in Tasmania, Australia. During monthly sampling over the period of a year 49 octopus were captured in baited lobster traps and tagged with PIT tags and released. Of these tagged animals, however, only 7 were recaptured, with 6 recaptured within a few days of their initial capture and 1 in the following month. This posed the question: Why were there no long-term recaptures? To help answer this question, a complex-array of passive acoustic ‘listening stations’ was established on the reef, such that individually tagged octopus could be identiﬁed and recorded as they moved around the reef. 20 octopus were tagged with uniquely coded acoustic tags and tracked passively. This talk presents preliminary data from this study, which suggests that Octopus maorum may only be a short-term resident on reefs, explaining the low recapture rate in the initial tag-recapture study. ______

Abstracts - Page 112 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Serebryany, Andrey N.N. Andreyev Acoustics Institute, Moscow, Russia [email protected] Intense internal waves on shelf Peter Holloway discovered for the world oceanographic society intense internal tides and solitons on the Australian North West Shelf. One of his most significant contribution into physical oceanography was connected with a progress in understanding of the processes of internal solitons generation during propagation of strong internal tide on shelf. In the paper it will be shown that transformation of internal tides to soliton-like waves is a dominant mechanism which gives main input into shallow water internal wave spectrum. Review on observations of intense internal waves on Russian shelves and their main properties will be reported based on author’s long-term experience in the field. Main processes leading to generation of soliton-like internal waves on shelf revealed from the observations in closed (free-tidal), semi-closed and opened seas (internal tide propagated above shelf, shoaling quasi - inertial internal waves, local fronts of upwelling and downwelling origin, moving surface intrusion) and evidences of their efficiency will be presented. Widespread manifestation of nonlinear effects in observed internal waves (vertical asymmetry of wave profile - existence of wave depressions and elevations, change of internal wave polarity during passing of depression wave trough “overturning point”, horizontal asymmetry of internal waves – feature of “breaking solitons”, generation of underwater ambient nose by large-amplitude internal wave) will be shown. Examples of internal bores and large-amplitude internal waves measured in different sites by line temperature sensors as well as ADCP (shelves of the Caspian, Black and Barents Sea, the Sea of Japan, Pacific shelf of Kamchatka) are presented. The work was partially supported by Russian Foundation for Basic Research (RFFI) under grant 02-02-17325. ______

Seymour, Jamie, Teresa Carrette, Paul Sutherland, Glenda Seymour, Ameila Seymour & Ben Seymour School of Tropical Biology, James Cook University, Cairns Smithfield 4878 [email protected] The use of ultrasonic transmitters for determining movement patterns in the cubozoan Chironex fleckeri With the use of small ultrasonic transmitters, daily patterns of movement in the cubozoan Chironex fleckeri were elucidated. Transmitters where attached to the external surface of the bell of adult medusae (greater than 15cm in bell width) using a medical super-glue, histoacryl. Although tracking of any one animal was restricted to a maximum of twenty four hours (due to transmitter loses), distinctive diurnal patterns of movement where obvious. During daylight hours (from approximately 0600 hrs to 1500 hrs) animals moved an average of 212 m ever hour. However, from approximately 1500 to 0600 hrs, animals moved only an average of less than 10m ever hour. During these periods of “inactivity”, animals where observed to lie motionless on the sea floor, with no bell pulsation occurring and tentacles relaxed and in contact with the sea floor. These species of cubozoans are active vertebrate predators, relying presumably on visual images for prey location. Periods of inactivity when light levels are low and hence times when prey location may be limited, may allow these organisms to decrease energy usage for locomotion (which is high in comparison to other cnidarians) and redirect resources to growth. Increased periods of tracking are required to further elucidate the movement patterns of these organisms and this may be obtainable by securing of transmitters inside the medusal bell and hence decreasing abrasive forces resulting from contact with the sea floor and the transmitter. ______

Abstracts - Page 113 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Shaw, Sylvie Faculty of Fisheries and Marine Environment, Australian Maritime College, Tas. [email protected] Aquaculture – the social context ‘We need aquaculture and we need to do it right’. This quote from Seaweb highlights the need for sustainable aquaculture in this country. My paper explores the range of social issues surrounding the growth of aquaculture. It discusses the costs and benefits in social terms and outlines, using case studies, some of the concerns raised by communities affected by proposed and active fish farms, as well as those raised by commercial and recreational fishing organizations and environmental groups. In Tasmania particularly, concerns have been expressed over the expansion of ‘feral’ oyster leases as well as the perceived damage from salmon farms. Community unease relates mainly to environmental harm, the effect on local seal populations, as well as to the potential harm to visual amenity and property values. However, currently there is growing consumer concern over food safety and public health issues related to the use of pesticides, dyes and antibiotics in farmed fish. As well as community protests, recreational and commercial fishers have opposed the development of finfish farms due to their impact on targeted species, the problem of farm escapees, the spread of disease, and the potential impact on ocean and coastal environments. Responses from the industry are discussed along with issues of ‘eco-labelling’, ‘wild fish’ campaigns and benefits to the nation in terms of the ‘clean and green’ image. ______

Sherman, Craig*, David Ayre & Karen Miller Institute For Conservation Biology, University of Wollongong, NSW 2522 [email protected] There’s no place like home: Localised adaptation of the intertidal sea anemone Actinia tenebrosa While the life cycle of most marine invertebrates involves the use of sexual reproduction, many are also capable of asexual reproduction. Ecological and evolutionary theory predicts that organisms with a mixed mode of reproduction will use sexual reproduction for the widespread dispersal of genotypically diverse offspring, and asexual reproduction for the proliferation of locally adapted genotypes. This should lead to populations of locally adapted clones with restricted distributions. Indeed, for the intertidal sea anemone Actinia tenebrosa, local populations match this expected pattern with different headlands often dominated by different clones. Furthermore, transplant experiments from different geographic areas (i.e. NSW vs. Victoria) and between adjacent headlands have shown evidence of localised adaptation. However, the scale over which site-specific selection is acting is still not known as previous studies have been limited in their ability to identify the distributions of clones within a headland. The recent development of highly variable microsatellite markers has allowed us to test the true scale over which site-specific selection may be acting and test for evidence of localised adaptation within a single headland. We conducted genetic surveys to determine the distribution of clones within and between habitats on a headland (rock platform vs. boulder shore). We found very few genotypes shared between sites within habitats or between habitats suggesting clones are restricted to small areas of rocky shore within a headland. Reciprocal transplant experiments were carried out between boulder and rock pool habitats within the same headland and the fitness (measured as survivorship, growth and fecundity) of native and transplanted anemones monitored over a two-year period. We found that native anemones were significantly fitter in terms of survivorship (F=8.77; p= 0.001), growth (F=4.77; p=0.014) and fecundity (F=5.43; p=0.028) than transplanted anemones. This work provides strong evidence that clones of the intertidal sea anemone A. tenebrosa are locally adapted to different habitats within a single rocky headland. ______

Abstracts - Page 114 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Sherwood, John*, Cheree Fenton & Julie Mondon School of Ecology and Environment, Deakin University, Warrnambool Vic. 3280 [email protected] Environmental flows for highly stratified estuaries in SW Victoria, Australia Pierson et al (2002) have reviewed the literature on determination of environmental flows for Australian estuaries. They found such studies to be “relatively scarce” and identified only two substantial investigations – for the Derwent River (Tasmania) and Richmond River (N.S.W.). We have recently investigated the environmental flow requirements of the Barham River estuary (Victoria) in response to plans for increased water diversions to meet a growing population in Apollo Bay township. Our study adopted a field-based methodology to determine flow requirements for critical stages of the estuary’s annual hydrodynamic cycle: a) Minimum flows to flush salt water completely from the estuary in winter/early spring. b) Minimum flows to maintain an open estuary entrance in summer/autumn. Maintenance of these key features of the annual hydrodynamic cycle is crucial for the life cycle of estuarine organisms such as copepods (Newton, 1996) and fish (Sherwood and Backhouse, 1982). It is also necessary to maintain estuarine circulation and so reduce the frequency of deepwater anoxia and eutrophication associated with prolonged episodes of mouth closure. This paper will assess the strengths and weaknesses of our approach to environmental flow determination and review alternatives suggested in the literature. ______

Skillington, Anna*, Thomas A Schlacher & Troy F Gaston Faculty of Science, University of Sunshine Coast, Maroochydore DC 4558 Qld [email protected] Response of mesozooplankton to estuarine plumes A central premise in coastal ecosystem energetics is that estuaries produce more material than is internally consumed or stored. This excess production outwells to the nearshore marine zone in the form of estuarine plumes and enhances primary production and numbers and biomass of consumers in the nearshore area. This study aimed to determine how small plumes affect the physical structure and chemical conditions of nearshore waters and what flow-on effects these environmental changes may have on phytoplankton and mesozooplankton. The effect of plumes was assessed by following the temporal trajectory of a small estuarine plume – The Mooloolah Estuary (SE-Queensland, Australia) – over 7 months (August ’03 to February ’04) that encompassed both low-flow periods and significant rainfall events. Spatial coverage included the plume area just off the estuarine inlet, the lower estuary (3km in from the inlet) and a ‘control’ station located 2.5km offshore. Over the sampling period, two distinct buoyant and shallow (2-3m depth) plumes were encountered following rainfall bouts in December ’03 and February ’04. Phytoplankton biomass was positively correlated with freshwater inflow and thus higher during plume events. Suspended particulate organic matter (SPOM) in the December plume was depleted in 15N but enriched in 13C, reflecting the contributions of the large bloom of cyanobacterium Trichodesmium 15 13 spp. (N2 fixing organisms with depleted δ N but enriched δ C signals). By contrast, SPOM in the February plume had both depleted δ15N and δ13C values, reflecting estuarine-derived material. Zooplankton tended to track isotopic changes in the carbon pool during plume events, however, their abundance and biomass were substantially reduced following rainfall spikes. This decrease in mesozooplankton was more pronounced in the estuary followed by the nearshore plume area. No changes in zooplankton abundance and biomass spectra were recorded in offshore waters, therefore responses are driven by estuarine discharge and not confounded by marine processes. Thus, small plumes do significantly change the structure of nearshore waters by enhancing primary production whilst reducing mesozooplankton abundances and biomass. ______

Abstracts - Page 115 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Sliwa, Cath1*, Keith Hayes1, Sasha Migus1 & Felicity McEnnulty1 1 CSIRO Marine Research [email protected]; [email protected] Prioritising introduced species in Australia for management - Identifying target species Over the last ten years, CSIRO Marine Research (CMR) personnel have been collecting information on species that have been introduced to, or are known as cryptogenic in, Australian marine and estuarine environments. We discuss here our approach to define which introduced species, of those already present in Australia, should be prioritised for management action. In the past the process for selecting these species was loosely defined. Criteria for determining target species include invasion status, current distribution, date of introduction, and amenability to control (e.g. via ballast water exchange). Prioritising species for management action is becoming increasingly important with development of the National System for the Prevention and Management of Marine Pest Incursions. This study identified 23 out of 133 non-native species, and 5 out of 175 cryptogenic species, that may satisfy the definition of a domestic target species for ballast water management. These species represent potential domestic target species, and will be evaluated by regulatory authorities, industry and other groups to determine their significance before determining a target species for national control planning purposes. ______

Smallwood, Claire B1,2*, Lynnath E Beckley1 & Neil R Sumner2 1 School of Environmental Science, Murdoch University, South Street, Murdoch 6150, WA. 2 Department of Fisheries, P O Box 20, North Beach 6920, WA. csmallwood@fish.wa.gov.au Recreational angling in the Rottnest Island reserve: Catch, effort and participation estimates The Rottnest Island reserve, located off south-western Australia, is considered to be one of the most popular recreational fishing locations in Western Australia. A roving creel survey of shore-based recreational angling in the reserve was conducted from January to December 2003. In total, 1 053 anglers were intercepted which included individuals, families, school groups and angling clubs. The total annual shore-based angling effort for Rottnest Island was calculated at 23 899 angler outings and the total catch estimated at 53 994 retained fish. The highest levels of catch and effort were recorded in April, May and July. During the survey, 33 fish species were identified. However, 60% of the catch was Arripis georgianus, with an estimated weight of 7.3 tonnes. Shore-based anglers caught and released a large proportion of non-target species. Some anglers retained undersized fish which indicates a need for further education and enforcement of recreational fishing regulations. The total number of shore anglers who fished at Rottnest Island during the study period was estimated to be about 10 000. The survey has provided data that are being used to support decision making by the Rottnest Island Authority and Department of Fisheries with respect to the management of shore-based recreational angling in the Rottnest Island reserve. ______

Abstracts - Page 116 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Smyth, Chris Marine Campaign Ofﬁcer – Australian Conservation Foundation, 3rd Floor, 60 Leicester Street, Carlton Vic. 3053

The role of science in Marine Protected Areas and regional marine planning Australia has embarked upon the regional implementation of Oceans Policy through regional marine plans, and within these, the continuing role out of the National Representative System of Marine Protected Areas. What is, and what could be the role of sciences and other disciplines, and especially the marine sciences in the development and implementation of the plans and marine protected areas (MPAs)? This session will explore the opportunities for marine scientists and the conservation sector to collaborate to ensure a robust scientiﬁc basis to marine planning and MPAs, and to promote the need for a strategic increase in marine research and communictaion aimd at ocean protection. ______

Stark, Jonathan S* & Martin J Riddle Australian Antarctic Division, Channel Highway, Kingston, Tas. 7050 [email protected] Assessing the remediation of an Antarctic waste dump: biological and chemical monitoring of marine benthic communities In the 2003/2004 austral summer the Australian Antarctic Division began the ﬁrst remediation of a contaminated waste dump at an Australian Station, at Casey in East Antarctica. To evaluate the remediation process, ecological ﬁeld experiments and environmental monitoring are being conducted. There are three components that will provide information at different time-scales to answer different questions with the focus on impacts in the marine benthic environment, as the waste dump is situated on the sea-shore. Short-term monitoring over the period of the cleanup operation (several months) was used to provide information to direct or modify the clean-up operation and asses its immediate, short term effects. An Antarctic amphipod crustacean (Paramoera walkeri) was used as a biological sentinel to monitor water quality adjacent to the dump site in comparison to control locations. The concentration of dissolved metals in seawater were also measured using diffusive gradient gel techniques (DGT’s) which integrate metal concentrations in seawater over the same period of time. Medium-term monitoring (cleanup ± one year) will determine whether disturbance from the clean-up operation has created additional environmental impacts. Sediment traps are being used to measure contaminant dispersal into the sea before, during and after the clean-up. Field experiments have been deployed adjacent to the dump site and at control locations to determine whether colonization of infauna changes as a consequence of clean-up. A beyond-BACI design will determine if communities colonizing defaunated sediment at the dump site change over the period of the cleanup in comparison to controls. Monitoring over the longest temporal scale, (cleanup ± several years), will determine whether the effort invested in the clean-up remediates and restores the natural biological and environmental conditions. Changes in sediment chemistry and the diversity and composition of soft-sediment and hard substrata communities near the dump site and at several control locations is being monitored. ______

Abstracts - Page 117 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Grimshaw R, E Pelinovsky, Y Stepanyants* & T Talipova Nuclear Analysis Section, Nuclear Technology Division, ANSTO, Lucas Heights Science and Technology Centre PMB- 1, Menai , NSW 2234, Australia [email protected] Internal solitary wave dynamics in coastal seas Internal solitary wave dynamics in coastal seas is considered within the framework of the generalised Korteweg-de Vries (gKdV) equation which includes both quadratic and cubic nonlinearities, Boussinesq and Coriolis dispersion, various types of dissipation and spatial inhomogeneity (that is, variability of density stratification and ocean depth). The derivation of the equation is described for arbitrary stratification and background shear flow, and the range of applicability of gKdV equation is discussed. Typical solitary wave profiles are presented for different relationships between the quadratic and cubic nonlinearities. The possibility of the existence of nonstationary solitary waves, that is, breathers, is pointed out. The coefficients of the gKdV equation for the Australian North-West shelf are calculated and presented as functions of distance from the coastline. The peculiarities of these coefficients which affect the structure of solitary waves are discussed. The dynamics of semidiurnal tides and internal solitary waves on the Australian North-West and Portuguese shelves are modelled numerically, and the results obtained are presented versus in situ observations. The World Atlas of the kinematic and nonlinear parameters of gKdV equation has been created. This allows one to judge qualitatively about possible scenario of internal solitary wave dynamics in different regions of the world’s oceans. ______

Stroud, Stan Principal Metocean Engineer and Team Leader Ocean Engineering, Woodside Energy Ltd Importance of internal waves to stability of submarine pipelines off North-West Australia The presence of internal waves off the north-west coast of Australia is well known. However, only in very recent years has it been recognised that these waves produce unusually large currents near the seabed in water depths of 80m to 800m, and control the stability of submarine pipelines at existing and proposed oil and gas facilities off the North-West Cape, off Dampier, about Scott Reef, in the Timor Sea and on the south side of the Timor Trench. Woodside Energy Limited have undertaken many current measurements directed at investigating the nature of the internal waves and the associated bottom boundary layer currents. This work has identiﬁed waves of various scales (period 12 hours to 5 minutes), and the necessity to undertake research work to further investigate their nature and to allow determination of realistic loadings on submarine pipelines. This Woodside funded research work is now in progress. Elements include data interpretation, theoretical development and capacity building at University of Western Australia; and deployment of an “L” shaped array of 13 current measurement moorings March to May 2004, adjacent to the North Rankin A production platform in 125 m water depth. The aims of the array measurements were to investigate the near-seabed internal wave lengths, associated currents and the wave short-crestedness. The research programme is on-going and funded until 2007. ______

Abstracts - Page 118 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Strzelecki, Joanna1, Lidia Yebra Mora2, Stéphane Pesant1 & J Anthony Koslow1 1 CSIRO, Marine Research, Perth WA 6913 2 Plymouth Marine Laboratory, Plymouth PL1 3DH United Kingdom [email protected] Assessment of zooplankton secondary production using egg production and aminoacyl –tRNA synthetases activity (AARS) method, off the south west coast of Western Australia At present there is no single routine method to measure secondary production, such as is used to estimate primary production. One method is based on measuring the egg production of adult female copepods. Copepods are the most numerous and important group within the zooplankton, and many species cease somatic growth as adults, so all surplus production is expressed through egg production. Unfortunately the method requires incubation of individual adult female copepods, which is tedious to perform. As a consequence, zooplankton researchers have sought a biochemical index suitable for use in the ﬁeld. AARS activity is directly related to protein synthesis and is positively correlated with zooplankton growth rate under laboratory conditions (Yebra and Hernandez-Leon, 2004). To test this method in the ﬁeld, we are comparing its results with the results of the standard egg production method. We present results obtained from cruises off southwestern Western Australia, based upon sampling at stations along a transect from nearshore (15 m depth) across the shelf to 1000 m depth. ______

Sumby, Jon School of Government, Locked Bag 22, The University of Tasmania, Hobart 7001 [email protected] The science–policy gap in ocean governance As the management of the human use of marine ecosystems turns more toward multi-species ecosystem- based adaptive management, science is becoming central to policy-making. How policy-makers interpret and value scientiﬁc advice, and how that advice is presented, can be a major impediment for ocean governance. This is particularly true in regard to the frequently documented degradation of marine systems. This paper will explore the symptoms and underlying causes of the gap between scientiﬁc advice and policy decisions in relation to ocean governance. Understanding and addressing the science–policy gap is important for the effective management of human use of the marine environment which goes some way toward reaching social ideals such as biodiversity preservation and ecologically sustainable development. ______

Abstracts - Page 119 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Kinloch, Martine, Rupert Summerson* & Danielle Curran Bureau of Rural Sciences, GPO Box 858, Canberra, ACT 2601 [email protected] Domestic vessel movements and the spread of marine pests: risks and management approaches A recent report prepared by the Bureau of Rural Sciences reviewed the potential for non-trading vessels to act as vectors for the spread of marine pests around Australia. Vessel types from 23 government, industry and community sectors were examined in the review, together with their associated voyage nodes. The report estimates that close to a million non-trading vessels comprise the combined fleet of all 23 sectors. While the vast majority of these are privately owned recreational boats such as yachts and cabin cruisers, almost 15 000 vessels are owned and operated by government agencies, community associations or the private sector. Most of the vessels are based permanently in Australia but some, such as cruise ships and seismic survey vessels, are occasional visitors to our waters and belong to a multinational global fleet. The aim of the review was to identify sectors that pose the highest risk of translocating marine pests from one site to another, and to suggest ways of managing and mitigating risks across all sectors. Existing sources of information published on the World Wide Web, in the scientific literature or obtained through interviews with government and community stakeholders and industry representatives were drawn together to provide an information base that was used to assess the threats posed by each sector and rank them relative to one another (i.e. on a scale of 1 – 23) for risk. Ranking was done on the basis of 10 factors. Six of these pertained to the potential for entrainment of marine pests (vessel size, maintenance regimes and availability of refugia) and four factors related to the operating profile of the sector. Industry vessels, including commercial fishing boats, were ranked as being the highest risk while small recreational craft were considered the lowest risk. ______

Summerson, Rupert*, Martine Kinloch & Danielle Curran Bureau of Rural Sciences, GPO Box 858, Canberra, ACT 2601 [email protected] The role of nodes in secondary invasions by introduced marine pests Nodes are both the origin and destination points of voyages, as well as places or features where vector pathways (vessel routes) intersect. Examples include ports, marinas, slipways and boat ramps. These sites have the potential to act as distribution centres, where marine pests can be picked up or deposited by vectors, and are termed nodes to reﬂect the fact that they are points in a transport network. Secondary invasions by marine pests are where organisms are moved (translocated) from the site of the original (primary) invasion into the country to one or more new sites. The recently discovered colony of northern Paciﬁc seastar (Asterias amurensis) at Inverloch, Victoria, for example, is thought to be the product of a secondary invasion from Port Phillip Bay by means of an anthropogenic vector and not an expansion of its range by natural dispersion. Recent research and the development of conceptual models of the secondary invasion process suggest that the role of nodes in the successful establishment of a marine pest is more important than previously thought. The biology of the organism, the environment at receiving node and the numbers and types of vectors using the node are critical, but interwoven factors in the success of a secondary invasion. This paper will describe these concepts and present the results of an assessment of the risk of establishment by marine pests at twelve types of nodes. ______

Abstracts - Page 120 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Sumner, Michael (Poster) University of Tasmania, Hobart Tas 7000 [email protected] Mapping marine animal behaviour at-sea The at-sea behaviour of marine animals can be measured using satellite trackers and geolocation instruments, but the locations must be ‘filtered’ and ‘smoothed’ to give reasonable estimates of, for example, time spent. Simple speed filters that remove suspect locations, and various spatial gridding or other smoothing methods that rely on point density and/or time between points fail to use all the available information or incorporate the inherent uncertainty. Using a Bayesian statistical approach, we have developed a framework to use the researcher’s prior knowledge, all of the available data, including environmental and behavioural restrictions. The outputs of this approach include a behavioural summary in the form of probability distributions that incorporates all of the location uncertainty. Here we present an example of this approach, applied to the filtering of an at-sea satellite track. We apply a simple behavioural model, given the data from the satellite track, to restrict the animals speed of travel to physically realistic limits. This model takes the form of a probability distribution on the distances between successive location estimates, allowing us to generate estimates of location for times other than those provided directly from the instrument. We expand the sequence of locations by introducing intermediate points that correspond to locations of the tagged individual at some intermediate time. We then assume that the animal travels in a great circle path, and by imposing a distribution of possible distances on the total path length we can determine the distribution of the intermediate locations. ______

Sutton, Caroline A1* & Chad L Hewitt2 1 CSIRO Marine Research 2 Ministry of Fisheries - Te Tautiaki i nga tini a Tangaroa Detection kits for community-based monitoring of introduced marine pests The Community Detection Kit was designed to support Australia’s national strategy for the management of introduced marine species by providing early detection. Traps, beach walks, settlement plates, sediment trays and spat collectors were assessed for detection sensitivity and sampling efﬁcacy, and for their use by community groups. These detection methods were assessed against traditional surveys (where available) such as long term trapping surveys, video surveys, diver transect surveys and the Exotic Marine Pest Survey for the Port of Hobart. None of the Community Detection Kit methods (expect perhaps the spat-bags) were effective at detecting species at low densities without employing a large search effort. For example, our standardised beach walks inconsistently detected species washed ashore beaches with low (estimated) offshore densities, suggesting a high detection threshold. However, by including community reports, thus effectively increasing the search effort, species such as the green crab, Carcinus maenas were found in areas undetected by traditional methods (trapping). Trapping was also found to have a high detection threshold for Asterias amurensis where only 2 seastars were trapped from an estimated (by diver transect) population of 910-1700 seastars and a total catch of 684 individuals during a community collection. Settlement plates relative to pile scrapings were as effective at detecting the common fouling species, many of which were introduced species! However, our results suggest that the plates have a high detection threshold for ‘rare’ species (i.e. species with low frequency on the pile scrapings). All the methods had relatively high detection thresholds and their use as an early warning system would need to be coupled with an extensive ﬁeld program that ideally could include community groups. However the successful inclusion of community participation in a monitoring program is highly dependent on its implementation, and the resources available to provide ongoing support and training. ______

Abstracts - Page 121 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Sutton, Caroline1 & Jeannie-Marie LeRoi2 1 CSIRO Marine Research 2 University of Tasmania Communicating science through art: As demonstrated by the science in Salamanca festival Science in Salamanca was a festival celebrating art and science held during National Science Week 2002. Its primary goal was to increase public awareness of science through artistic interpretation. Five scientiﬁc themes relating to the environment of Salamanca and incorporating the expertise of 10 Tasmanian scientists formed the backbone of the festival and inspiration for all artworks. The same science was interpreted through professional and student artists in three exhibitions, an outdoor installation and a science art trail. Students were encouraged to learn about the science via the Festival website, talk with scientists via email and class visits and participate by creating artistic interpretations for presentation in their very own exhibition, Synergy Too, simultaneously with the professional artists’ exhibitions Synergy and Binding Synergy. The feedback received from students and teachers was extremely positive. The students were not only motivated to learn about science in order to create their artworks but, they gained conﬁdence and self esteem by participating in a program where their contributions were exhibited publicly in their own exhibition. ______

Symonds, Graham School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Australian Defence Force Academy, Canberra 2600 [email protected] Wave-driven currents on coral reefs Coral reefs are often subjected to high waves, dissipating the wave energy and protecting the lagoon, reef flat and island beaches behind the reefs. These breaking waves can drive significant mean currents that play a role in the on/off reef exchange of water, nutrients and planktonic larvae. It has also been suggested the magnitude of these currents, and associated bottom stress, affects nutrient uptake rates of benthic communities on coral reefs. Field observations of waves and currents on a coral reef are presented and compared with models of wave set-up and longshore currents, modified to allow depth integrated cross-shore flow when the reef crest is submerged. Measurements of waves and currents were made across the surf zone on the windward side of One Tree Island in the Great Barrier Reef, Australia, January 10-27, 2003, covering a spring-neap tidal cycle. At low tide the reef crest is exposed around the entire perimeter of the lagoon causing the water level in the lagoon to be up to a metre higher than the open ocean at Spring low tide. At Spring high tide the depth over the reef crest is about one metre. Mean cross-reef currents were generally weak (<0.1m/s) while along-reef currents were stronger (0.1m/s to 0.6m/s), consistent with forcing by oblique incident waves. Using the longshore current model developed by Thornton and Guza (1986) reasonable agreement between predicted and observed currents can be obtained using a linear friction coefficient, r~.003-.01, and wave height to depth ratio, γ > 0.8. ______

Abstracts - Page 122 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Tate, Peter M1* & Jason H Middleton2 1 Sydney Water Corp., Science and Technology, PO Box 73, West Ryde NSW 2114 2 Department of Aviation, The University of NSW, Sydney NSW 2052 [email protected] The effect of internal waves on the trajectory and dilution of buoyant jets Coastal cities often treat and discharge their municipal effluent as buoyant jets through deepwater ocean outfalls. The trajectory and dilution of the buoyant jets can be easily modelled and are largely governed by the current speed and the stratification of the water column. However, in addition to the intensity of the stratification, the shape of the density profile also plays a major part in determining the trajectory and dilution of the buoyant jet. When the pycnocline lies low in the water column, the trajectory and dilution of the buoyant are low. The opposite occurs when the pycnocline lies high in the water column. Internal waves may travel along the pycnocline resulting in its vertical movement and a subsequent change in the shape of the density profile. To date, buoyant jet models have ignored the effect of internal waves. This is probably because it is tacitly assumed that the time scales associated with internal waves are significantly greater than those associated with the rise of a buoyant jet. For discharges through deepwater outfalls, this assumption may not be valid. Off the coast of Sydney, high- frequency internal waves (with periods 10-15 minutes and trough-to-crest heights of 20m or more) are often observed. This is comparable with the time of rise (5-10 minutes) of the effluent plumes from Sydney’s three deepwater ocean outfalls. Incorporating the effect of these high-frequency internal waves into buoyant jet models, results in dilutions that differ by a factor of two or more and trajectories that may be in the opposite direction, compared with results from buoyant jet models that do not incorporate high-frequency internal waves. This phenomena is not an artefact of the model being used but results because of the time-varying nature of the initial conditions. ______

Taylor, Alan H

OAM FIMarEST MRINA, Chairman Victorian/Tasmanian Branch, Institute of Marine Engineering, Science and Technology, 59 Hillcrest Drive, Templestowe, Victoria 3106, Australia [email protected] The International Maritime Organization (IMO) and the Marine Environment The International Maritime Organization (IMO) is a subsidiary body of the United Nations. One of its main technical committees is the Marine Environment Protection Committee (MEPC) and it ﬁrst met in 1985. This committee meets every 8 months and its next meeting, MEPC 52, is scheduled for 11th to 15th October 2004. The presentation will outline the major Conventions, Protocols and Codes that have been developed by this committee to protect the Marine Environment, it will outline the protection aspects that have been adopted and those subsequently ratiﬁed into International Maritime Law. The Conventions, Protocols and Codes discussed are as follows: • The International Convention for the Prevention of Pollution from Ships - MARPOL 73/78 Annexes I, II, III, IV, V & VI; • Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matters, 1972 as amended (LC 1972) (LC PROT 1996); • International Convention Relating to Intervention on the High Seas in Case of Oil Pollution Casualties, 1969 (Intervention 1969);

Abstracts - Page 123 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

• International Convention Relating to Intervention on the High Seas in Case of Pollution by Substances other than Oil, 1973 (Intervention PROT 1973); • International Convention on Oil Pollution, Preparedness, Response and Co-operation, 1990 (OPRC 1990); • Protocols on Preparedness. Response and Co-operation to Pollution Incidences by Hazardous and Noxious Substances, 2000 (OPRC – HNS 2000); • International Convention for the Control of Harmful Anti-fouling Substances on Ships, 2001 (AFS 2001); • International Convention for the Control and Management of Ships’ Ballast Water and Sediments, 2004 (BWM 2004); • International Management Code for the Safe Operation of Ships and for Pollution Prevention, 1998 (ISM Code); and • Declaration of Particular Sensitive Sea Areas (PSSA) ______

Taylor, Alan1, Geoff Rigby2 & Gustaaf Hallegraeff3 1 Alan H Taylor & Associates, 59 Hillcrest Drive, Templestowe, Victoria 3106, Australia 2 Reninna Pty Limited, 36 Creswell Avenue, Charlestown NSW 2290, Australia. 3 University of Tasmania, Private Bag 55, Hobart Tas. 7001, Australia [email protected] The International Ballast Water Management Convention and its implication for the marine environment and Australian shipping The Marine Environment Protection Committee (MEPC) of the International Maritime Organization (IMO), a subsidiary body of the United Nations signed the Final Act of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments on the 13th February 2004 in London, U.K. The new Convention will enter into force (become ratified)12 months after the date on which no less than thirty States ( the combined merchant fleets of which constitute not less than 35% of the gross tonnage of the world’s merchant shipping) have signed the document. The BWMC was opened for signatures for ratification from 1 June 2004. The presentation will discuss the new Convention, with particular emphasis on the evolution and how the various aspects within the Articles, Regulations and Guidelines will impact on the marine environment and the Australian Shipping Industry. Particular attention is placed on special areas of concern in relation to the Safety of the ship and its crew, Environmental acceptability, Technical effectiveness in achieving the biological and physical standards, Practicality of application and Cost effectiveness. Some of these implications will be highlighted for four specific case examples involving four types of vessels involved in different trades in a variety of commercial operations. ______

Abstracts - Page 124 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Thompson, BAW1,2*, NW Davies3, MJ Riddle1, I Snape1, JS Stark1 1 Australian Antarctic Division, Tasmania 7050 2 University of Tasmania, School of Agricultural Sciences, Tasmania 7004 3 University of Tasmania, Central Science Laboratory, Tasmania 7004 [email protected] Oil degradation, infaunal recruitment and bioturbation in Antarctic sediments In order to investigate the natural attenuation of oil in the Antarctic benthic environment, and its effect on recruiting infauna, a five year in situ experiment was established in an uncontaminated bay near Casey Station, East Antarctica (December 2001). In addition, the influence of sediment reworking (bioturbation) by the heart urchin, Abatus ingens, on oil degradation and infaunal recruitment was investigated. The short-term results are reported in this paper. The oils studied are an unused and a used synthetic lubricant (Mobil); and a ‘biodegradable’ alternative derived from rape seed oil (Fuchs). Sediment was collected, sieved and contaminated with the lubricants (~4000mg.kg-1 dry mass). The contaminated sediment was placed into trays and positioned by divers onto the sea-bed in a randomized block design. Trays were retrieved 5 and 56 weeks after deployment. To investigate the influence of A. ingens bioturbation, two individuals were placed into selected trays and retrieved after 56 weeks. Total Petroleum Hydrocarbons (TPH) in the unused and used lubricants decreased by 17% and the ‘biodegradable’ lubricant by 37% after five weeks; with no further reduction for all lubricants after 56 weeks. Infaunal abundances were significantly greater in the uncontaminated sediments compared to the contaminated sediments after five weeks. Preliminary results suggest that after 56 weeks recruitment more than doubled for all treatments however, the contaminated sediments continued to inhibit recruitment as shown by a higher abundance and species diversity in the control sediments. In the sediments with A. ingens bioturbation, TPH decreased by an additional 15-29% and the total number of individuals were higher than in sediments without bioturbation. The short-term results from our five year study demonstrate that lubricants will persist in the Antarctic benthic environment over long time periods and that such contamination inhibits infaunal recruitment. The lubricant marketed as biodegradable has the potential to be less toxic to Antarctic infauna than the conventional synthetic lubricant. In addition, bioturbation by A. ingens increased rates of biodegradation and recruitment by sediment infauna. ______

Thompson, Peter1, Anya Waite2 & Stéphane Pesant2 1 CSIRO Marine Research, GPO Box 1538, Hobart, Tasmania, 7001 2 Centre for Water Research, University of Western Australia, Nedlands, Western Australia, 6907 [email protected] Pigment differences between a warm core and a cold core eddy off Western Australia The dominant oceanographic feature off the west coast of Australia is the poleward moving Leeuwin current. At latitudes between 25 and 33°S filaments and meanders sometimes “spin up” into a number of eddies rotating clockwise (cold core) or anticlockwise (warm core). During a cruise in October 2003 we investigated two such eddies anticipating the cold core eddy would exhibit sufficient upwelling to develop high near-surface phytoplankton biomass and high productivity while the downwelling, warmcore eddy might develop a climax community of N2 fixing prokaryotes (diazotrophs). In this paper we examine the preliminary HPLC determined pigments from each eddy. They indicate that our preconceptions based upon eddies elsewhere were seriously incorrect. Off WA the entire region was dominated by deep chlorophyll a maxima. The warmcore eddy had greater phytoplankton biomass than the cold core eddy had, or seemed likely to develop. The centre of the warmcore eddy had a deep mixed layer (~275m) that was apparently stable enough to have developed a phytoplankton community composition that varied with depth. The cold core eddy had a deep chlorophyll maximum near the outer edge that was dominated by prokaryotes in the upper 80 meters and chrysophytes below. Based on pigments the phytoplankton community composition was significantly different from that observed in the Leeuwin Current closer to the equator. ______

Abstracts - Page 125 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Thompson, Peter1, Anya Waite2 & Stéphane Pesant2 (Poster) 1 CSIRO Marine Research, GPO Box 1538, Hobart, Tasmania, 7001 2 Centre for Water Research, University of Western Australia, Nedlands, Western Australia, 6907 [email protected] Pulse amplitude modulation (PAM) fluorometry reveals significant variation in photosynthetic parameters in a deep mixed layer within a warm core eddy The dominant oceanographic feature off the west coast of Australia is the poleward moving Leeuwin current. At latitudes between ~25 and 33°S filaments and meanders sometimes “spin up” into a number of eddies rotating clockwise (cold core) or anticlockwise (warm core). During a cruise in October 2003 we investigated two such eddies anticipating the cold core eddy would exhibit sufficient upwelling to develop high near-surface phytoplankton biomass and high productivity while the downwelling, warmcore eddy might develop a climax community of N2 fixing prokaryotes (diazotrophs). In this poster we examine the PAM fluorometric measurements of photosynthetic performance from the centre of the warmcore eddy. The warmcore eddy had a very deep mixed layer that had a near uniform temperature, salinity and fluorescence signal to 275m. In spite of the near uniformity of fluorescence the phytoplankton community was highly variable in pigment concentrations and photosynthesis versus irradiance parameters over the 275m. ______

Thresher, Ronald E & Peter Grewe CSIRO Marine laboratory, GPO Box 1538, Hobart Tas 7001 Development of a species-specific biocide for the control of Caulerpa taxifolia Caulerpa taxifolia is one of the world’s most damaging invasive marine plants, overgrowing large areas of the Mediterranean Sea and forming virtual monocultures since it was accidentally introduced. Outbreaks have recently been reported in NSW and SA, apparently due to translocation of strains native to northern Australia. Success at controlling the invasive plant has been mixed, with eradication in a few areas where it was physically possible, and little impacts in other areas. We examined the potential of using modern genetic techniques to develop a biocide that could be specific to the invasive plant and would be easy to apply in the field. Preliminary results, based on laboratory trials of disrupting photosynthesis, look promising. More extensive trials are required, to optimise the disrupter and to test options for delivery of the toxin in the field. ______

Abstracts - Page 126 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Timko, Patrick G, Mark E Baird & Jason H Middleton Centre for Environmental Modelling and Prediction, School of Mathematics, University of New South Wales [email protected] Response of the East Australian Current to wind stress The variability of the East Australian Current along the coast of New South Wales in response to wind stress is examined using the Princeton Ocean Model. Steady wind stress is applied to the ocean surface to determine the along shelf and cross shelf mass and heat transport associated with the wind stress. The upwelling and downwelling of water along the coastline is also investigated to quantify the vertical transport of mass and heat across the shelf break when wind stress favourable to upwelling and downwelling is applied to the model. ______

Tovar-Ávila, Javier1,3, Terence I Walker2, Robert W Day1 (Poster) 1 The University of Melbourne, Victoria, Australia 3052. 2 PIRVic Centre Queenscliff, Victoria, Australia 3225. 3 Instituto Nacional de la Pesca, Mexico. [email protected] Rapid assessment for ecological risk of the Australian angel shark The ecological impact of fisheries on the populations of demersal sharks is not well understood, but it is likely that various species caught as byproduct and bycatch are being markedly impacted. The life history characteristics of most sharks, such as low growth population rate, late sexual maturity, low fecundity and low natural mortality provide for low biological productivity and make their populations susceptible to the effects of fishing. Nevertheless, the potential for most chondrichthyan species to be harvested in a sustainable way has been recognised. The Australian angel shark (Squatina australis) is a relatively important component of the southern Australian fisheries, where they are commonly caught as byproduct. In this investigation, we review the available information of the species and analyse information on its biology using a rapid assessment method for ecological risk. The aim of this investigation is to understand how fisheries impact this species to contribute to aid their management and conservation. The rapid assessment method is based on the evaluation of the biological productivity, catch susceptibility, trends in abundance, and position in the food web of the species. Risk is categorised as low, medium or high. To date biological information from more than 250 Australian angel sharks have been collected from the commercial catches in Southern Australia and have collated to data from various monitoring programs. ______60

Abstracts - Page 127 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Tracey, Sean R1, Jeremy M Lyle1, Guy Duhamel2 (Poster) 1 Marine Research Laboratories, Tasmanian Aquaculture and Fisheries Institute, Hobart, Tasmania, Australia. 2 Museum National d’Histoire Naturelle, Laboratoire d’ichtyologie générale et appliquée, Paris, France. [email protected] Comparing somatic growth and otolith form of striped trumpeter (Latris lineata) from widely separated populations Otoliths were collected from two widely separated populations of striped trumpeter. One from Tasmania, Australia and the other from the French territories of St. Paul and Amsterdam Island. Individuals were aged by counting annuli on transverse sections of sagittal otoliths. Comparative growth of individuals across a range of age classes was assessed. Likelihood ratio tests were employed to identify stock speciﬁc differences in individual length at age, and analyses of otolith morphometrics was used to assess variability in otolith structure between the two stocks. ______

Troy, Sally Chief Scientist, National Oceans Ofﬁce, Hobart Tas. 7000 [email protected] Marine science and Australian oceans management – steps towards an integrated approach What science is needed for improved oceans management? Australia has a vast Marine Jurisdiction and a federated approach to its governance, which means that marine science that is funded by Australian Governments is conducted by a large number of agencies and institutions. In the Commonwealth arena alone there are at least 15 Government agencies that are involved in some type of marine science, posing challenges to do cost-effective science to underpin Australian oceans management. Some recent steps to improve the conduct and use of marine science in this context include: • Development of the “Oceans adaptive management framework” and the “regional marine planning model” - articulation of the processes of regional marine planning and its integration with science to enable forward planning by marine scientists, planners and managers; and • The formation of the Oceans Policy Science Advisory Group (OPSAG) to provide advice to the Oceans Board of Management, an Australian Government cross-departmental body to ensure the implementation of Australia’s Oceans Policy. One of the ﬁrst steps taken by the OPSAG has been to work on a three-year Action Plan for Australian Government marine science. ______

Abstracts - Page 128 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Tsotsobe, Sakhile1*, Hans Verheye1 & Mark Gibbons2 1 Marine & Coastal Management, Private Bag X2, Rogge Bay 8012, Cape Town, South Africa 2 Zoology Department, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa [email protected] Spatio-temporal variation in the abundance and community structure of the major copepod species in northern Benguela This paper forms part of a broader study, which examines long-term variability in zooplankton biomass, abundance and community structure in the northern Benguela – the Benguela Current ecosystem is one of the world’s largest upwelling systems – over the past four decades, and focuses particularly on the period 1979-1981. Previous works on zooplankton have provided only ‘snapshot’ impressions of zooplankton abundance and distribution in this region. Therefore, this study is important in that it presents data which cover, at best, three full annual cycles. Samples were collected monthly during SWAPELS (South West African Pelagic Egg and Larval Surveys) cruises which took place from the early 1970s to the late 1980s. During these cruises a maximum of 28 transects – each comprising a maximum of nine stations – was sampled, spanning the shelf region along the entire Namibian coast. The study focuses on samples collected on a transect off Walvis Bay, in a region historically known to be important for ﬁsheries. The aim of this paper is to describe temporal and spatial variations in the abundance and biomass of mesozooplankton, with emphasis on the major copepod species. In addition, these data will allow to perform an initial comparison of zooplankton with published data of the 1950s/60s, as well as recent data collected during Namibia’s current environmental monitoring programme, in order to examine possible long-term changes in this region. Long-term zooplankton time-series in other upwelling systems indicate signiﬁcant declines in abundance and/or biomass over the past 4-5 decades. In contrast, zooplankton abundance has increased 100-fold in the southern Benguela, off the west coast of South Africa. However, there are no published long-term studies on zooplankton of the northern Benguela. Analysis of all the data is currently underway, and will be presented at the meeting. ______

Twomey, Luke1, V Pez1, F Verspect1, A Waite1, C Pattiaratchi1 & P Thompson2 1 Centre for Water Research, University of Western Australia, Crawley WA 6009 2 CSIRO Marine Research, Hobart Tas. 7000 Nutrient limitation off Western Australia Biomass and distribution of the phytoplankton community were investigated relative to the availability of dissolved inorganic nutrients during the Southern Surveyor cruise SS0903 between the Abrolhos Islands and Cape Leeuwin, WA. A consistent subsurface chlorophyll maximum was identiﬁed on the continental shelf and below the Leeuwin current at depths of 70-110 m. Phytoplankton biomass was typically 3-4 times greater at the subsurface chlorophyll maximum than at the surface. These ﬁndings were consistent with higher dissolved inorganic nutrient concentrations with increasing depth. Uptake rates for 15N labeled ammonium, nitrate and N2 were calculated at the surface and subsurface chlorophyll maximum at the shoreline, 300 m contour and 1000 m contour on 15 transects. These results are presented to discuss spatial variability of nitrogen uptake in the study area and the preference for different forms of nitrogen. ______

Abstracts - Page 129 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Valentine, Joe*1 & Craig Johnson1 1 Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, GPO Box 252-05, Hobart, Tasmania 7005 [email protected] Establishment of dense stands of the introduced kelp Undaria pinnatifida in Tasmania depends on disturbance to native algal assemblages Despite high rates of occurrence of non-indigenous organisms in the marine environment, few studies have critically examined mechanisms underpinning the invasion process. We used manipulative experiments to examine the invasion dynamics of the Asian kelp Undaria pinnatifida at two sites on the east coast of Tasmania. Disturbance to reduce cover of the native algal canopy was found to be a critical stage in the establishment of U. pinnatifida, while the presence of a stable canopy of native algae inhibited sporophyte development. In the first season of sporophyte growth following canopy disturbance, U. pinnatifida recruited at high densities (up to 19 plants per m2) while remaining rare or absent in unmanipulated plots. This result suggests that U. pinnatifida gametophytes occur throughout these native algal beds, but do not develop into visible sporophytes while the canopy is intact. The timing of disturbance was also an important factor. U. pinnatifida recruited in higher densities in plots where the native canopy was removed just prior to the sporophyte growth season (winter 2000), compared to plots where the canopy was removed 6 months earlier during the period of spore release (spring 1999). In the second year following canopy removal, U. pinnatifida abundance declined significantly, associated with a substantial recovery of native canopy-forming species. We recorded similar responses of U. pinnatifida in areas where native algae were removed by natural phenomena. From a management perspective, where disturbance is linked to human activity, managing the disturbance is likely to prove a more practical and cost-effective option than targeting the plant directly. ______van Polanen Petel, Tamara1, Melissa Giese2, Mark Hindell*1 1 Antarctic Wildlife Research Unit, University of Tasmania, School of Zoology, Tas 7005 2 Australian Antarctic Division, current postal address: Marine Species Section, Marine and Water Division, ACT 2601 [email protected] Behavioural responses of lactating Weddell seals (Leptonychotes weddellii) to human activity From late October until early December, Weddell seals haul out onto the fast ice to pup. This period corresponds with the time in which human activity dramatically increases on the continent. This increase in visitation, during an important period of the seal’s annual life cycle, has the potential to negatively affect the seals. Weddell seals are frequently subject to approaches by pedestrians and vehicles but as yet there is little empirical information on the effect that this activity may be having on the seals. Our study investigates the behavioural response of lactating Weddell seals to pedestrian approaches and vehicles drive-bys. The study is management-orientated with the general aim of providing objective information for the development of guidelines for managing interactions between people and Weddell seals. The research adopts an experimental approach, which involves exposing the seals to controlled approaches while their responses are quantified. Here, we present the data on the behaviour, looking at approacher, during an approach by a single person, and by a group of people (5). Preliminary results indicate that 66% (n=29) of lactating females approached by a single pedestrian looked up at the approacher, of these, 21.3% of seals did so when the approacher was standing at the furthest distance from the seals at 20 m. During approaches by the group, 76% of seals looked at the approacher, of which 11.4 % looked up before the approachers were at the furthest distance of 20 m. The co-variates, pup exposure, distance to water and distance to nearest conspecific were found to be influential for the group approach, while pup exposure and distance to water were found to be influential for the single approach. Recommendations are made for approaching lactating Weddell seals and their pups. ______

Abstracts - Page 130 AMSA2004 - Authors and Abstracts (alphabetically by presenter) van Senden, David Principal Engineer, Manly Hydraulics Laboratory, NSW Department of Commerce [email protected] Mixing in estuarine wetlands: The role of long waves Estuarine wetlands form an important component of estuarine systems along Australias eastern seaboard. Expansion of agricultural activities in the 1900s led to the construction of drainage channels and levee banks designed to convert the low-lying wetland areas to pasture for grazing. Typically, one-way floodgates were installed to prevent tidal flow into the wetland but allow flood waters to drain from the wetland. Over the past 20 years recognition of the importance of these wetlands as ecosystems supporting a wide variety of flora and fauna such as migrating birds, fish and their nutrient filtering qualities has led to a desire to reinstate the areas or at least arrest their decline. This has resulted in a number of wetland areas being reopened to the adjacent estuary waterways with the reintroduction of tidal flows. Salinity and water level monitoring in the Yarrahappini wetland system near Kempsey over a three year period indicates the complex interaction between inflows due to surface and groundwater runoff and oceanic influences of tides and long waves. Flushing of the backwater areas and is dominated by long wave motions associated with coastal trapped waves and spring-neap pumping of the water level rather than tidal variations.

Davidson, Andrew T1, Tessa Vance1,2*, Paul G Thomson1, Nina Cadman1, Graham Jones2 (Poster)

1 Department of the Environment and Heritage, Australian Antarctic Division, and Antarctic Climate and Ecosystems Cooperative Research Centre. Channel Highway, Kingston, Tasmania 7050 2 Department of Environmental Science and Management, Southern Cross University, PO Box 157, Lismore, NSW 2480 [email protected] The effects of solar UV radiation on an Antarctic marine microbial community Ozone depletion and global warming will enhance the levels of damaging ultraviolet-B radiation (UVBR, 280-320 nm) received by Antarctic phytoplankton for the foreseeable future. Despite intensive research, the ramifications on Antarctic marine biota remain unclear. We examined the effect of solar UVR on an Antarctic marine microbial community at Davis Station in terms of biomass, productivity, sulphur chemistry and species composition/succession. Three minicosms were simultaneously filled with 200 µm filtered seawater from beneath melting sea ice, gently mixed to maintain cell suspension and exposed to photosynthetically active radiation (PAR, control); PAR + ultraviolet-A radiation (UVAR, 320-400 nm); or PAR + UVAR + UVBR. Concentrations of phytoplankton, chl a and rates of primary production were higher in treatments exposed to PAR+UVAR than the controls, indicating these wavelengths can benefit some cellular functions including photosynthesis. In contrast, exposure to PAR+UVAR+UVBR caused changes in the composition and abundance of protist species and reduced rates of primary production. However, chl a concentrations were unaffected by UVB-induced inhibition of phytoplankton, suggesting re-allocation of metabolism to maintain photosynthetic capacity under UVBR stress. Overall, intracellular DMSP (dimethy lsulfoniopropionate, the biochemical precursor of dimethylsulphide, DMS) concentrations appeared to be enhanced by exposure to both UVAR and UVBR. In contrast, UVBR resulted in lower concentrations of DMS and dissolved DMSP during the first 2 days exposure. This decline may be due to photo-oxidation of DMS to DMSO or consumption of DMS and dissolved DMSP by the increased concentrations of metabolically active bacteria at this time. Though UVBR effects on Antarctic marine microbial communities are subtle, UV- induced changes may affect the nature and availability of carbon to higher trophic levels and the draw- down, metabolism or release to the atmosphere of gases that significantly influence global climate. ______

Abstracts - Page 131 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Waite, Anya M Group Leader, Biological Oceanography, Centre for Water Research, University of Western Australia, Crawley 6009 WA Leeuwin Current meso-scale eddies: Death traps or nurseries? (A preliminary overview of the 2003 Eddy Voyage) In the ultra-oligotrophic waters off Western Australia (WA), production hinges on the import of nutrients into surface waters through upwelling and meso-scale cyclonic eddies. Upwelling is largely suppressed by the Leeuwin Current on this coast, so mesoscale eddies are possibly of major importance for the overall productivity of the region. They are considered possible sites of enhanced growth rates (“Nurseries”) for fish larvae and rock lobster phyllosoma, whose dispersal, retention and nutrition are poorly understood. However, some eddies are areas of convergence which are possible “Death-Traps” for larvae whose recruitment success depends on their nutrition. In addition, nitrogen gas from the atmosphere may play a key role in driving production through nitrogen fixation, but its importance has never been quantified here. In October 2003 we studied a pair of counter-rotating eddies off the coast of WA. We quantified nutrients, primary and secondary production inside and outside the two eddies. We mapped the eddies in 3-D, using underway measurements of currents (ADCP), T-S signature (SeaSoar mapper, CTD), and measured nutrients (autoanalysis), primary production, and the abundance of zooplankton and fish larvae. This was punctuated by stations where primary and secondary production are determined using water samples and plankton nets. We deployed a drogue with sediment traps to estimate the flux of organic matter inside each eddy. This seminar will give an overview of the voyage and the results generated to date, showing overall patterns, snapshots of physical Eddy features using the SeaSoar, and evidence of a curious and possibly a singular physical structure of cyclonic Leeuwin Current eddies which could strongly impact production patterns in the region. ______

Waite, Anya M1, Carrie Holl2 & Joseph Montoya2 1 Group Leader, Biological Oceanography, Centre for Water Research, University of Western Australia, Crawley 6009 WA 2 School of Biology, Georgia Institute of Technology, 310 Ferst Drive, Atlanta GA 30332 USA Contrasting food webs in cold-core and warm-core eddies: evidence from δ15N and δ13C stable isotopes Because mesoscale eddies can impact vertical fluxes of nutrients to surface waters via the enhancement of either upwelling or downwelling, their dynamics have a possibly significant impact on the nutrition of the marine food web. Here we investigate contrasts in food web structure between the cold and warm-core eddies studied during the 2003 Eddies Cruise as elucidated by natural abundance δ15N and δ13C isotopic measurements of various size fractions and organisms within the eddies. The natural abundance of stable isotopes of nitrogen and carbon in oceanic waters can provide important clues as to the nitrogen sources and primary feeding pathways of the ecosystems trapped within the eddies. Preliminary evidence suggests that the fish populations may be typical broad open ocean assemblages, while planktonic organisms trapped within the eddies show distinct local eddy signatures more typical of the source waters of the eddies. ______

Abstracts - Page 132 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Wang, XH School of Physical, Environmental and Mathematical Sciences, University of New South Wales at Australian Defence Force Academy, Canberra, ACT 2600, Australia Circulation and heat budget of the northern Adriatic Sea (Italy) due to a Bora event in January 2001: A numerical model study The Princeton Ocean Model was implemented to investigate the response of northern Adriatic Sea during the Bora event in January 2001 when strong wind and surface cooling was reported. The model has been run with realistic wind stress, surface heat flux and river runoffs forcings continuously from January 1999 to 31 January 2001. The wind stress and surface heat flux was computed by the bulk parameterization, using the ECMWF analysis fields and the COADS (Comprehensive Ocean Atmosphere Data Set) cloud data. All the freshwater sources along the Adriatic coastlines were represented by point or line source functions. Open boundary conditions in the Ionian Sea along a latitudinal boundary were nested within a large scale model of the Mediterranean Sea. The numerical study found that, before the Bora event of 13-17 January 2001, the water column of the northern Adriatic Sea (NAS) was stratified by salinity and the temperature was already cooler at the surface and over the shallower shelf region. The pre-Bora circulation of the NAS was relatively weak and baroclinic with maximum surface currents occurred near the Italian coast. During the Bora event, the water column was well mixed in the most of coastal region of the NAS. The atmospheric cooling produced colder water over the northern and western Adriatic Coast. The circulation of the NAS was barotropic and dominantly wind driven, with maximum current speed of about 1 m s-1. The numerical study also demonstrated that the Bora event decreased the heat content of the water column with an area averaged value of 205 W m-2 over the shallow northern shelf. It was concluded that the heat budget of the NAS during the Bora event was a balance between the surface heat loss, horizontal advection and heat content change. The horizontal advection played a particularly important role in controlling the water temperature change over the shallower northern shelf. ______

Webster, Ian CSIRO Land & Water, GPO Box 1666, Canberra, ACT 2601 [email protected] The Coorong – hydrodynamic features of a unique system The Coorong is a coastal lagoon system that stretches for 120km along the South Australian coast to the east of Adelaide. It is only several kilometres wide and less than two meters deep on average and has a single connection to the sea via narrow channel near one end. Although the water within the estuary is freshened by controlled discharges through barrages also near this end, salinities exceed 4 times those of sea water in the towards its other end. The salinity along the Coorong is controlled by evaporation and longitudinal mixing and exchange. In this talk I will describe how mixing and exchange in this unique water body are driven by the interplay water level changes associated with seasonal sea level variations, the tides, by barrage operation, and by the winds. The Coorong has a special signiﬁcance for Peter Holloway. He undertook his PhD study there on the dynamics of temperature and salinity stratiﬁcation. ______

Abstracts - Page 133 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Welch, David1 & Jayson Semmens2 1 Chief Scientist, Census of Marine Life Project “POST”, Kintama Research Corp., 4737 Vista View Crescent, Nanaimo, B.C. Canada V9V 1N8 & Fisheries and Oceans, Pacific Biological Station, Nanaimo, B.C. Canada V9T 6N7 2 Research Fellow, Census of Marine Life Project POST, University of Tasmania, Tasmanian Aquaculture and Fisheries Institute, Private Bag 49, Hobart Tas. 7001 [email protected] Developing a permanent continental-scale acoustic tracking array for marine fisheries research: The goal and the strategy The Census of Marine Life is helping to develop “POST”, the Pacific Ocean Shelf Tracking array, a permanent seabed acoustic array for tracking marine animals. Potential fisheries capabilities include measuring direction, speed of movement, depth, and survival for up to 256,000 individual animals as small as 11 cm in length. Current plans involve the development of 30 or more cross-shelf monitoring lines spaced along the West Coast of North America. Each monitoring line would consist of autonomous seabed nodes spaced at roughly 1 km intervals across the shelf and down the slope. Nodes would be modular and use an acoustic modem to communicate with a ship overhead, upload data, and receive new programming. We are currently starting a two year demonstration phase for POST, which involves tagging and tracking thousands of salmon smolts over a large-scale demonstration array. If we are successful, by the end of 2005 we should have demonstrated the potential value of the information obtained from such a tracking network and developed the major remaining technical components. The establishment of an acoustic array for fish tracking can also provide the data transmission and power supply backbone needed to host other ocean sensors at low additional cost. For example, temperature and salinity sensors could be placed on the seabed nodes, providing detailed fields of the changes in bottom temperature and salinity over time, while upward looking ADCPs and seabed current meters could provide detailed data on changes in current structure. These data could be meshed with the fish movement data to describe how animals move relative to changes in the three dimensional structure of the ocean. The ability to develop such a coastal-GOOS (“Global Ocean Observing System”) capability is second only to the fisheries capabilities and is an important aspect of the development that we must plan for. ______

West, Elizabeth J Department of Biological Sciences, University of Wollongong, NSW 2522 [email protected] The role of anthropogenic activity in the fragmentation and dispersal of the invasive alga, Caulerpa taxifolia The establishment of the invasive alga, Caulerpa taxifolia, in several estuaries of New South Wales has caused great concern and raises the question of the possible role of anthropogenic activity in promoting its spread. Studies from the Mediterranean invasion have suggested that some anthropogenic activities may increase the degree of fragmentation and assist in dispersal of C. taxifolia, however, to date, there is little supporting experimental evidence. This study examined the potential role of anchoring by small boats in the dispersal of C. taxifolia within and between estuaries. First, experiments were done to quantify the biomass of fragments removed from an estuary by different types of anchors (sand vs rock) and anchor attachments (rope vs chain). Second, experiments were done to examine whether fragments removed from an estuary can survive exposure during transportation under conditions present in small boats. The viability of C. taxifolia fragments removed from the water was examined under different conditions of shading, moisture and length of exposure. Both sand and rock anchors removed similar amounts of C. taxifolia. In contrast, chains collected more C. taxifolia than ropes. Fragments removed from the estuary were viable under some conditions after periods of desiccation (1 hour to 1 day). Provision of shade and moisture as would be provided by anchor boxes, ﬁshing gear and wet ropes increased the survivorship of C. taxifolia. This study demonstrated that fragments can be removed from an estuary by anchors and can survive periods of desiccation for periods, which would allow transport within and between estuaries. These results have important consequences for management of C. taxifolia in NSW estuaries and worldwide.

Abstracts - Page 134 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

White, Camille A, John AE Gibson & Kerrie M Swadling School of Zoology, University of Tasmania, Private Bag 5, Hobart Tas. 7001 camillew@postofﬁce.utas.edu.au Pathways of community development following isolation from the marine environment: A case study in two Antarctic saline lakes The process of lake evolution occurs on many coastlines around to globe, particularly those affected by isostatic rebound following glacial retreat. The faunal communities that develop in these lakes are in part derived from the trapped seawater. Differences in local geology and bathymetry, climate and weather, timing of isolation, and stochastic events can all inﬂuence the development of these communities. Numerous marine-derived lakes occur in areas such as the Vestfold Hills, East Antarctica, where a full range of developmental stages can be seen and isolation events are still occurring. In this study, palaeozoology was used as a tool to trace community development following isolation from the marine environment in two lakes of the Vestfold Hills. Observations were also made from several marine fjords and semi-isolated marine basins (SIMBs) in this area. There appear to be several characteristics that allow marine organisms to survive, and in some cases thrive in these lakes. Following an isolation event, the nutrient content of these small pockets of water tend to increase. Hence, organisms with short generation times and rapid feeding rates dominate. For example, a diverse assemblage of tintinnids was observed in the sediments soon after isolation. Conversely, larger taxa that are dependent upon stable pelagic environments for reproduction will disappear, as will those with narrow environmental tolerances. Accordingly, lower diversity is frequently observed in SIMBs when compared to fjords and the open ocean. As lakes age further, nutrient levels decrease, and remains of taxa with wide environmental tolerances, such as the calanoid copepod Paralabidocera antarctica and the ciliate Magnifolliculina, become dominant in the lake sediments. ______

Abstracts - Page 135 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Wolkenhauer, Svea-Mara1,2, Sven Uthicke3 , Timothy Skewes2 & Roland Pitcher2

1 Institute for Biodiversity Research, University of Rostock, Universitätsplatz 2, 18055 Rostock, Germany 2 CSIRO Division of Marine Research, PO Box 120, Cleveland Qld 4163 3 Australian Institute of Marine Science, Townsville MC Qld 4810 [email protected] Sea cucumber removal and its consequences for seagrass growth: a case study on commercially important sandfish Holothuria scabra in shallow seagrass beds of Moreton Bay, Queensland Holothuria scabra is one of the most important Bêche-de-mer (dried sea cucumber product for the food industry) species and can now be considered overfished in most countries of the Indo-Pacific region. An artisanal fishery for Bêche-de-mer by the Aboriginal community in Moreton Bay (Queensland) commenced in early 2003. To assess the ecological role of holothurians and monitor potential impacts of the fishery on their habitat, we have conducted a series of exclusion experiments in an unfished high density area (0.8-1.25 m-2) of sea cucumber Holothuria scabra. In situ underwater exclusion cages were deployed for approximately 2 months (4 m depth) in winter 2003 and summer 2004. To simulate the removal of H. scabra we manipulated densities in 3 treatments in replicate cages, namely Caged-Controls (with natural densities), Caged-Exclusions and Natural-Controls (without cages). Several biological and chemical parameters were measured from the sediment about once a week. These included organic matter, chlorophyll a and depth of the anoxic layer. None of these parameters showed significant changes due to sea cucumber exclusion. In addition, seagrass (Cymodocea serrulata) biomass, growth and morphology were determined. In contrast to the sediment parameters, seagrass growth, measured as biomass increase and leaf length growth per day, significantly decreased by at least 10% in treatments where H. scabra were excluded. If these results can be confirmed in ongoing repeated experimental runs during different seasons, it can be hypothesised that seagrass benefits from the presence of holothurians in a similar fashion as has already been documented for microphytobenthos. Seagrass might be able to use higher levels of nutrients originating through bioturbation of existing nutrients from the sediment or by additional excretion of nutrients through the animal itself. An overfishing of these holothurians could thus have significant consequences for the ecology of seagrass bed ecosystems. ______

Abstracts - Page 136 AMSA2004 - Authors and Abstracts (alphabetically by presenter)

Wright, SW, HJ Marchant, AT Davidson, FJ Scott, R van den Enden, P Thomson, K Westwood (Poster) Australian Antarctic Division, 203 Channel Highway Kingston Tas. 7000 [email protected] Microorganisms rule the Southern Ocean The Southern Ocean is often described as a krill-based ecosystem. However current estimates suggest krill represent only about 1% of the biomass, and other zooplankton nearly 5%. The bulk of the biomass is microbial, 67% phytoplankton, 17% protozoa and 9% bacteria. The enormous biomass of phytoplankton (around 6000 million tonnes) affects regional climate through uptake of carbon dioxide and release of compounds such as dimethyl sulphide. ______

Zacharek, Andrew National Oceans Office, GPO Box 2139, Hobart Tas. 7001 [email protected] Assessment of risks from multiple uses of oceans Risk assessment is the systematic, logical and repeatable process of considering available information to predict the relative effects of various scenarios. Assessing and managing risks to the marine environment, industries and communities is an integral part of ecosystem-based management. While methods to asses risk in many marine sectors such as fisheries, tourism and the petroleum industries are well developed, there is a need for an integrated approach to risk assessment for ecosystem-based ocean management. The challenge is to build on national standards for risk assessment to investigate possible cumulative impacts arising from multiple human activities. Applying the process to examine risks to social and economic objectives as well as ecosystem impacts will also be challenging. The National Oceans Office is developing a risk assessment approach that uses available information and consists of an overview phase and subsequent more focussed risk assessments. This risk assessment approach will identify current and emerging threats to marine ecosystem health, and marine-dependent industries and human communities. It will also assist in determining appropriate planning and management responses to those threats. This approach is being trialled within the South-east Marine Region in 2004 and will be refined with that experience. ______

Abstracts - Page 137