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<title>UTas ePrints - Seahorse declines in the Derwent estuary, Tasmania in the absence of fishing pressure</title>
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<meta content="Martin-Smith, Keith M." name="eprints.creators_name" />
<meta content="Vincent, Amanda C.J." name="eprints.creators_name" />
<meta content="Keith.MartinSmith@utas.edu.au" name="eprints.creators_id" />
<meta content="a.vincent@fisheries.ubc.ca" name="eprints.creators_id" />
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<meta content="2007-09-27" name="eprints.datestamp" />
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<meta content="Seahorse declines in the Derwent estuary, Tasmania
in the absence of fishing pressure" name="eprints.title" />
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<meta content="270702" name="eprints.subjects" />
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<meta content="Australia; Sex ratio; Size-frequency distribution; Syngnathid; Time series" name="eprints.keywords" />
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<meta content="Seahorses have the potential to be flagship species for estuarine conservation around the world and considerable concern has arisen over their declining abundance in the face of exploitation. All seahorses were recently listed on CITES Appendix II in recognition of threats posed by unsustainable trade. However, the efficacy of this measure and the development of other effective conservation solutions will require an understanding of natural seahorse population dynamics at relevant ecological scales. In this
study, we provide quantitative data on seahorse populations over nested spatial and temporal scales up to 10 km and 3.5 years. Unexploited populations of the big-bellied seahorse (Hippocampus abdominalis) in the Derwent estuary, Tasmania, Australia consisted largely of mature adults with highly female-biased sex ratios at all sites. While big-bellied seahorses had an aggregated distribution at the spatial scale of our transects (200 m2), most individuals were found alone. When they occurred in groups, the distribution of individuals was random with respect to sex in contrast to the pair bonds found in other seahorse species. All three
monitored populations showed significant declines in abundance of 79-98% over the period 2001-2004. Estuarine physicochemical conditions did not change markedly during this period. Possible causes of seahorse declines are interactions with invasive species, disease or reproductive limitation through Allee effects. The magnitude of the declines in the absence of direct exploitation demonstrates
that seahorses face multiple threats. Robust fisheries-independent monitoring will be required to demonstrate that conservation actions such as CITES listing are effective." name="eprints.abstract" />
<meta content="2005-06" name="eprints.date" />
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<meta content="Biological Conservation" name="eprints.publication" />
<meta content="123" name="eprints.volume" />
<meta content="4" name="eprints.number" />
<meta content="533-545" name="eprints.pagerange" />
<meta content="10.1016/j.biocon.2005.01.003" name="eprints.id_number" />
<meta content="UNSPECIFIED" name="eprints.thesis_type" />
<meta content="TRUE" name="eprints.refereed" />
<meta content="0006-3207" name="eprints.issn" />
<meta content="http://dx.doi.org/10.1016/j.biocon.2005.01.003" name="eprints.official_url" />
<meta content="Alcaide, E., Gil-Sanz, C., Sanjuan, E., Esteve, D., Amaro, C., Silveira, L., 2001. Vibrio harveyi causes disease in seahorse, Hippocampus sp. Journal of Fish Diseases 24, 311-313.
Baird, D., Christian, R.R., Peterson, C.H., Johnson, G.A., 2004. Consequences of hypoxia on estuarine ecosystem function: energy diversion from consumers to microbes. Ecological Applications 14,805-822.
Baum, J.K., Meeuwig, J.J., Vincent, A.C.J., 2003. Bycatch of lined seahorses (Hippocampus erectus) in a Gulf of Mexico shrimp trawl fishery. Fishery Bulletin 101, 721-731.
Bell, E.M., Lockyear, J.F., McPherson, J.M., Marsden, A.D., Vincent, A.C.J., 2003. First field studies of an Endangered South African seahorse, Hippocampus capensis. Environmental Biology of Fishes 67, 35-46.
Blaber, S.J.M., Cyrus, D.P., Albaret, J.-J., Ching, C.V., Day, J.W., Elliott, M., Fonseca, M.S., Hoss, D.E., Orensanz, J., Potter, I.C., Silvert, W., 2000. Effects of fishing on the structure and functioning of estuarine and nearshore ecosystems. ICES Journal of Marine Science 57, 590-602.
Curtis, J.M., Vincent, A.C.J., in press. Habitat use of two Red-Listed seahorses, Hippocampus guttulatus (Cuvier 1829) and H. hippocampus (Linnaeus 1758) in a coastal lagoon. Marine Ecology - Progress Series.
deBruyn, A.M.H., Meeuwig, J.J., 2001. Detecting lunar cycles in marine ecology: periodic regression versus categorical ANOVA. Marine Ecology - Progress Series 214, 307-310.
Dias, T.L.P., Rosa, I.L., 2003. Habitat preferences of a seahorse species, Hippocampus reidi (Teleostei: Syngnathidae) in Brazil. Aqua 6, 165-176.
Foster, S.J., Vincent, A.C.J., 2004. Life history and ecology of seahorses: implications for conservation and management. Journal of Fish Biology 65, 1-61.
Gascoigne, J., Lipcius, R.N., 2004. Allee effects in marine systems. Marine Ecology - Progress Series 269, 49-59.
Gillanders, B.M., Able, K.W., Brown, J.A., Eggleston, D.B., Sheridan, P.P., 2003. Evidence of connectivity between juvenile and adult habitats for mobile marine fauna: an important component of nurseries. Marine Ecology - Progress Series 247, 281-295.
Green, G., Coughanowr, C, 2003. State of the Derwent Estuary 2003: a review of pollution sources, loads and environmental quality data from 1997-2003. Department of Primary Industries, Water and Environment, Hobart, Australia.
IUCN, 2003. 2003 IUCN Red List of Threatened Species. <http://www.redlist.org> (accessed 21.06.04.).
Kiddon, J.A., Paul, J.F., Buffum, H.W., Strobel, C.S., Hale, S.S., Cobb, D., Brown, B.S., 2003. Ecological condition of US Mid-Atlantic estuaries, 1997-1998. Marine Pollution Bulletin 46, 1224-1244.
Krebs, C.J., 1999. Ecological Methodology, second ed. Addison Wesley Longman, Inc., NY, USA.
Kuiter, R.H., 2000. Seahorse, Pipefishes and Their Relatives. A Comprehensive Guide to the Syngnathiformes. TMC Publishing, Chorleywood, UK.
Lourie, S.A., Vincent, A.C.J., Hall, H.J., 1999. Seahorses: An Identification Guide to the Worlds Species and Their Conservation. Project Seahorse, London, UK.
Moreau, M.-A., Vincent, A.C.J., 2004. Social structure and space use in a wild population of the Australian short-headed seahorse Hippocampus breviceps Peters, 1869. Marine and Freshwater Research 55, 231-239.
Perante, N.C., Pajaro, M.G., Meeuwig, J.J., Vincent, A.C.J., 2002. Biology of a seahorse species, Hippocampus comes in the central Philippines. Journal of Fish Biology 60, 821-837.
Pogonoski, J.J., Pollard, D.A., Paxton, J.R., 2002. Conservation Overview and Action Plan for Threatened and Potentially Threatened Marine and Estuarine Fishes. Environment Australia, Department of Environment and Heritage, Canberra, Australia.
Price, A.R.G., 2002. Simultaneous hotspots and coldspots of marine biodiversity and implications for global conservation. Marine Ecology - Progress Series 241, 23-27.
Ross, D.J., Johnson, C.R., Hewitt, C.L., 2003. Variability in the impact of an introduced predator (Asterias amurensis: Asteroidea) on soft-sediment assemblages. Journal of Experimental Marine Biology and Ecology 288, 257-278.
Ross, D.J., Johnson, C.R., Hewitt, C.L., Ruiz, G.M., 2004. Interaction and impacts of two introduced species on a soft-sediment marine assemblage in SE Tasmania. Marine Biology 144, 747-756.
Vincent, A.C.J., 1994. Operational sex ratios in seahorses. Behaviour 128, 153-167.
Vincent, A.C.J., 1996. The International Trade in Seahorses. TRAFFIC International, Cambridge, UK.
Vincent, A.C.J., Marsden, A.D., Evans, K.L., Sadler, L.M., 2004. Temporal and spatial opportunities for polygamy in a monogamous seahorse, Hippocampus whitei. Behaviour 141, 141-156.
Vincent, A.C.J., Sadler, L.M., 1995. Faithful pair bonds in wild seahorses, Hippocampus whitei. Animal Behaviour 50, 1557-1569.
Wijnstekers, W., 2003. The Evolution of CITES, seventh ed. CITES Secretariat, Geneva, Switzerland.
Woods, C.M.C., 2000. Preliminary observations on breeding and rearing the seahorse Hippocampus abdominalis (Teleostei: Syngnathidae) in captivity. New Zealand Journal of Marine and Freshwater Research 34, 475-485." name="eprints.referencetext" />
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<meta content="Seahorses have the potential to be flagship species for estuarine conservation around the world and considerable concern has arisen over their declining abundance in the face of exploitation. All seahorses were recently listed on CITES Appendix II in recognition of threats posed by unsustainable trade. However, the efficacy of this measure and the development of other effective conservation solutions will require an understanding of natural seahorse population dynamics at relevant ecological scales. In this
study, we provide quantitative data on seahorse populations over nested spatial and temporal scales up to 10 km and 3.5 years. Unexploited populations of the big-bellied seahorse (Hippocampus abdominalis) in the Derwent estuary, Tasmania, Australia consisted largely of mature adults with highly female-biased sex ratios at all sites. While big-bellied seahorses had an aggregated distribution at the spatial scale of our transects (200 m2), most individuals were found alone. When they occurred in groups, the distribution of individuals was random with respect to sex in contrast to the pair bonds found in other seahorse species. All three
monitored populations showed significant declines in abundance of 79-98% over the period 2001-2004. Estuarine physicochemical conditions did not change markedly during this period. Possible causes of seahorse declines are interactions with invasive species, disease or reproductive limitation through Allee effects. The magnitude of the declines in the absence of direct exploitation demonstrates
that seahorses face multiple threats. Robust fisheries-independent monitoring will be required to demonstrate that conservation actions such as CITES listing are effective." name="DC.description" />
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<h1 class="ep_tm_pagetitle">Seahorse declines in the Derwent estuary, Tasmania in the absence of fishing pressure</h1>
<p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Martin-Smith, Keith M.</span> and <span class="person_name">Vincent, Amanda C.J.</span> (2005) <xhtml:em>Seahorse declines in the Derwent estuary, Tasmania in the absence of fishing pressure.</xhtml:em> Biological Conservation, 123 (4). pp. 533-545. ISSN 0006-3207</p><p style="margin-bottom: 1em" class="not_ep_block"></p><table style="margin-bottom: 1em" class="not_ep_block"><tr><td valign="top" style="text-align:center"><a href="http://eprints.utas.edu.au/880/1/Martin-Smith_%26_Vincent2005.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" class="ep_doc_icon" border="0" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/880/1/Martin-Smith_%26_Vincent2005.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />583Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input accept-charset="utf-8" value="884" name="docid" type="hidden" /><div class=""><input value="Request a copy" name="_action_null" class="ep_form_action_button" onclick="return EPJS_button_pushed( '_action_null' )" type="submit" /> </div></form></td></tr></table><p style="margin-bottom: 1em" class="not_ep_block">Official URL: <a href="http://dx.doi.org/10.1016/j.biocon.2005.01.003">http://dx.doi.org/10.1016/j.biocon.2005.01.003</a></p><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">Seahorses have the potential to be flagship species for estuarine conservation around the world and considerable concern has arisen over their declining abundance in the face of exploitation. All seahorses were recently listed on CITES Appendix II in recognition of threats posed by unsustainable trade. However, the efficacy of this measure and the development of other effective conservation solutions will require an understanding of natural seahorse population dynamics at relevant ecological scales. In this
study, we provide quantitative data on seahorse populations over nested spatial and temporal scales up to 10 km and 3.5 years. Unexploited populations of the big-bellied seahorse (Hippocampus abdominalis) in the Derwent estuary, Tasmania, Australia consisted largely of mature adults with highly female-biased sex ratios at all sites. While big-bellied seahorses had an aggregated distribution at the spatial scale of our transects (200 m2), most individuals were found alone. When they occurred in groups, the distribution of individuals was random with respect to sex in contrast to the pair bonds found in other seahorse species. All three
monitored populations showed significant declines in abundance of 79-98% over the period 2001-2004. Estuarine physicochemical conditions did not change markedly during this period. Possible causes of seahorse declines are interactions with invasive species, disease or reproductive limitation through Allee effects. The magnitude of the declines in the absence of direct exploitation demonstrates
that seahorses face multiple threats. Robust fisheries-independent monitoring will be required to demonstrate that conservation actions such as CITES listing are effective.</p></div><table style="margin-bottom: 1em" cellpadding="3" class="not_ep_block" border="0"><tr><th valign="top" class="ep_row">Item Type:</th><td valign="top" class="ep_row">Article</td></tr><tr><th valign="top" class="ep_row">Additional Information:</th><td valign="top" class="ep_row">The definitive version is available online at http://www.sciencedirect.com/science/journal/00063207</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">Australia; Sex ratio; Size-frequency distribution; Syngnathid; Time series</td></tr><tr><th valign="top" class="ep_row">Subjects:</th><td valign="top" class="ep_row"><a href="http://eprints.utas.edu.au/view/subjects/270702.html">270000 Biological Sciences > 270700 Ecology and Evolution > 270702 Marine and Estuarine Ecology (incl. Marine Ichthyology)</a></td></tr><tr><th valign="top" class="ep_row">Collections:</th><td valign="top" class="ep_row">UNSPECIFIED</td></tr><tr><th valign="top" class="ep_row">ID Code:</th><td valign="top" class="ep_row">880</td></tr><tr><th valign="top" class="ep_row">Deposited By:</th><td valign="top" class="ep_row"><span class="ep_name_citation"><span class="person_name">Dr Keith Martin-Smith</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">27 Sep 2007</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">12 Feb 2008 11:23</td></tr><tr><th valign="top" class="ep_row">ePrint Statistics:</th><td valign="top" class="ep_row"><a target="ePrintStats" href="/es/index.php?action=show_detail_eprint;id=880;">View statistics for this ePrint</a></td></tr></table><p align="right">Repository Staff Only: <a href="http://eprints.utas.edu.au/cgi/users/home?screen=EPrint::View&eprintid=880">item control page</a></p>
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