<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>UTas ePrints - Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989</title>
<script type="text/javascript" src="http://eprints.utas.edu.au/javascript/auto.js"><!-- padder --></script>
<style type="text/css" media="screen">@import url(http://eprints.utas.edu.au/style/auto.css);</style>
<style type="text/css" media="print">@import url(http://eprints.utas.edu.au/style/print.css);</style>
<link rel="icon" href="/images/eprints/favicon.ico" type="image/x-icon" />
<link rel="shortcut icon" href="/images/eprints/favicon.ico" type="image/x-icon" />
<link rel="Top" href="http://eprints.utas.edu.au/" />
<link rel="Search" href="http://eprints.utas.edu.au/cgi/search" />
<meta content="Edgar, Graham J." name="eprints.creators_name" />
<meta content="gedgar@utas.edu.au" name="eprints.creators_id" />
<meta content="monograph" name="eprints.type" />
<meta content="2007-09-03" name="eprints.datestamp" />
<meta content="2008-01-08 15:30:00" name="eprints.lastmod" />
<meta content="show" name="eprints.metadata_visibility" />
<meta content="Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989" name="eprints.title" />
<meta content="pub" name="eprints.ispublished" />
<meta content="270708" name="eprints.subjects" />
<meta content="270702" name="eprints.subjects" />
<meta content="public" name="eprints.full_text_status" />
<meta content="technical_report" name="eprints.monograph_type" />
<meta content="benthic surveys,
marine reserves
Bathurst harbour
portdavey" name="eprints.keywords" />
<meta content="Five field trips were conducted to the Bathurst Harbour/Port Davey area between October
1988 and July 1989. During each trip the hydrology, benthic fauna, plankton and fish
assemblages in the Bathurst Harbour estuary were surveyed.
During the winter period of peak freshwater outflow, a brackish surface layer (=15 %0)
was present to a depth of =4 m throughout the estuary. The halocline broke down during summer
with surface salinities of =29 %0 prevailing. Bottom waters were close to fully marine
(=33%0) throughout the year.
Surface waters in Bathurst Harbour were found to be extremely depleted in nitrates (<0.1 uM). Oxygen levels were also very low (=35% saturation) during February but were near ?
saturation during the other sampling periods.
Dinoflagellates and copepods were both extremely abundant in Bathurst Harbour. Diatoms
were also abundant during the summer field trips, but were much less common than
dinoflagellates on other occasions. Diatoms did, however, occur in higher densities than
dinoflagellates in the waters of Port Davey. The plankton community (>20 um mesh size) in
Bathurst Harbour was dominated by few taxa, particularly during the winter months. The
dinoflagellate Dinophysis acuminata provided >99% of phytoplankton numbers in October 1988
and July 1989, while the copepods GJadioferens inermis and Oithona austraJis and the
appendicularian OikopJeura sp. provided almost all of the zooplankton numbers.
The diversity of benthic plants and animals decreased rapidly up the Bathurst Harbour
estuary. Discrete communities of benthic organisms, both sessile and motile, were found at the
western entrance to Bathurst Channel and in the rest of the estuary. The overlap zone between the
different communities was a relatively small area between Sarah Island and Schooner Cove.
Mobile invertebrates were most abundant at the Bathurst Channel and Port Davey sites in
February, and at the Bathurst Harbour sites in December. They showed high fidelity to location,
with little indication in this study of a migration up or down the estuary in response to changes in
salinity. Very few mobile invertebrates were found in Bathurst Harbour below 4 m depth.
Fishes in the Bathurst Harbour estuary also showed little response to seasonal changes in
salinity. A number of fishes were, however, possibly prevented from entering the estuary
during February because of low oxygen concentrations then prevailing.
The assemblage of Bathurst Harbour fishes collected by gillnet was unusual in being
dominated by sharks and skates, with all of the common species also being distributed in water
depths >50m along the continentalshelf. The assemblage thus has many characteristics typical
of a deep water assemblage. Included amongst the Bathurst Harbour fishes was a previously
unknown species of skate which may be restricted to the estuary.
By far the most common of the larger fishes was the white-spotted dogfish Squalus
acanthias; this species comprised 86% of the total gillnet catch. Despite these large catches, a
tagging study in which a very high proportion (26 %) of tagged dogfish were recaptured indicated
that the total population in the estuary was not huge, being in the order of only 2,500 animals.
Tagged animals roamed widely through the estuary.
The major recommendations of the study are that gillnets be banned from the Bathurst
Harbour estuary, that the low nutrient status of the estuary be maintained, and that steps be taken
to ensure that the unique Caulerpa algal beds in Kelly Basin be preserved." name="eprints.abstract" />
<meta content="1992" name="eprints.date" />
<meta content="published" name="eprints.date_type" />
<meta content="Marine Research Laboratories" name="eprints.publisher" />
<meta content="Tasmania" name="eprints.place_of_pub" />
<meta content="111" name="eprints.pages" />
<meta content="116120056" name="eprints.id_number" />
<meta content="University of Tasmania" name="eprints.institution" />
<meta content="Tasmanian Aquaculture & Fisheries Institute" name="eprints.department" />
<meta content="UNSPECIFIED" name="eprints.thesis_type" />
<meta content="Edgar, Graham J. (1992) Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989. Technical Report. Marine Research Laboratories, Tasmania." name="eprints.citation" />
<meta content="http://eprints.utas.edu.au/1739/1/HydrologicalandEcological.pdf" name="eprints.document_url" />
<link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" />
<meta content="Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989" name="DC.title" />
<meta content="Edgar, Graham J." name="DC.creator" />
<meta content="270708 Conservation and Biodiversity" name="DC.subject" />
<meta content="270702 Marine and Estuarine Ecology (incl. Marine Ichthyology)" name="DC.subject" />
<meta content="Five field trips were conducted to the Bathurst Harbour/Port Davey area between October
1988 and July 1989. During each trip the hydrology, benthic fauna, plankton and fish
assemblages in the Bathurst Harbour estuary were surveyed.
During the winter period of peak freshwater outflow, a brackish surface layer (=15 %0)
was present to a depth of =4 m throughout the estuary. The halocline broke down during summer
with surface salinities of =29 %0 prevailing. Bottom waters were close to fully marine
(=33%0) throughout the year.
Surface waters in Bathurst Harbour were found to be extremely depleted in nitrates (<0.1 uM). Oxygen levels were also very low (=35% saturation) during February but were near ?
saturation during the other sampling periods.
Dinoflagellates and copepods were both extremely abundant in Bathurst Harbour. Diatoms
were also abundant during the summer field trips, but were much less common than
dinoflagellates on other occasions. Diatoms did, however, occur in higher densities than
dinoflagellates in the waters of Port Davey. The plankton community (>20 um mesh size) in
Bathurst Harbour was dominated by few taxa, particularly during the winter months. The
dinoflagellate Dinophysis acuminata provided >99% of phytoplankton numbers in October 1988
and July 1989, while the copepods GJadioferens inermis and Oithona austraJis and the
appendicularian OikopJeura sp. provided almost all of the zooplankton numbers.
The diversity of benthic plants and animals decreased rapidly up the Bathurst Harbour
estuary. Discrete communities of benthic organisms, both sessile and motile, were found at the
western entrance to Bathurst Channel and in the rest of the estuary. The overlap zone between the
different communities was a relatively small area between Sarah Island and Schooner Cove.
Mobile invertebrates were most abundant at the Bathurst Channel and Port Davey sites in
February, and at the Bathurst Harbour sites in December. They showed high fidelity to location,
with little indication in this study of a migration up or down the estuary in response to changes in
salinity. Very few mobile invertebrates were found in Bathurst Harbour below 4 m depth.
Fishes in the Bathurst Harbour estuary also showed little response to seasonal changes in
salinity. A number of fishes were, however, possibly prevented from entering the estuary
during February because of low oxygen concentrations then prevailing.
The assemblage of Bathurst Harbour fishes collected by gillnet was unusual in being
dominated by sharks and skates, with all of the common species also being distributed in water
depths >50m along the continentalshelf. The assemblage thus has many characteristics typical
of a deep water assemblage. Included amongst the Bathurst Harbour fishes was a previously
unknown species of skate which may be restricted to the estuary.
By far the most common of the larger fishes was the white-spotted dogfish Squalus
acanthias; this species comprised 86% of the total gillnet catch. Despite these large catches, a
tagging study in which a very high proportion (26 %) of tagged dogfish were recaptured indicated
that the total population in the estuary was not huge, being in the order of only 2,500 animals.
Tagged animals roamed widely through the estuary.
The major recommendations of the study are that gillnets be banned from the Bathurst
Harbour estuary, that the low nutrient status of the estuary be maintained, and that steps be taken
to ensure that the unique Caulerpa algal beds in Kelly Basin be preserved." name="DC.description" />
<meta content="Marine Research Laboratories" name="DC.publisher" />
<meta content="1992" name="DC.date" />
<meta content="Report" name="DC.type" />
<meta content="NonPeerReviewed" name="DC.type" />
<meta content="application/pdf" name="DC.format" />
<meta content="http://eprints.utas.edu.au/1739/1/HydrologicalandEcological.pdf" name="DC.identifier" />
<meta content="Edgar, Graham J. (1992) Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989. Technical Report. Marine Research Laboratories, Tasmania." name="DC.identifier" />
<meta content="http://eprints.utas.edu.au/1739/" name="DC.relation" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/BibTeX/epprod-eprint-1739.bib" title="BibTeX" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/ContextObject/epprod-eprint-1739.xml" title="OpenURL ContextObject" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/ContextObject::Dissertation/epprod-eprint-1739.xml" title="OpenURL Dissertation" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/ContextObject::Journal/epprod-eprint-1739.xml" title="OpenURL Journal" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/DC/epprod-eprint-1739.txt" title="Dublin Core" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/DIDL/epprod-eprint-1739.xml" title="DIDL" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/EndNote/epprod-eprint-1739.enw" title="EndNote" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/HTML/epprod-eprint-1739.html" title="HTML Citation" type="text/html; charset=utf-8" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/METS/epprod-eprint-1739.xml" title="METS" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/MODS/epprod-eprint-1739.xml" title="MODS" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/RIS/epprod-eprint-1739.ris" title="Reference Manager" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/Refer/epprod-eprint-1739.refer" title="Refer" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/Simple/epprod-eprint-1739text" title="Simple Metadata" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/Text/epprod-eprint-1739.txt" title="ASCII Citation" type="text/plain; charset=utf-8" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1739/XML/epprod-eprint-1739.xml" title="EP3 XML" type="text/xml" />
</head>
<body bgcolor="#ffffff" text="#000000" onLoad="loadRoutine(); MM_preloadImages('images/eprints/ePrints_banner_r5_c5_f2.gif','images/eprints/ePrints_banner_r5_c7_f2.gif','images/eprints/ePrints_banner_r5_c8_f2.gif','images/eprints/ePrints_banner_r5_c9_f2.gif','images/eprints/ePrints_banner_r5_c10_f2.gif','images/eprints/ePrints_banner_r5_c11_f2.gif','images/eprints/ePrints_banner_r6_c4_f2.gif')">
<div class="ep_noprint"><noscript><style type="text/css">@import url(http://eprints.utas.edu.au/style/nojs.css);</style></noscript></div>
<table width="795" border="0" cellspacing="0" cellpadding="0">
<tr>
<td><script language="JavaScript1.2">mmLoadMenus();</script>
<table border="0" cellpadding="0" cellspacing="0" width="795">
<!-- fwtable fwsrc="eprints_banner_final2.png" fwbase="ePrints_banner.gif" fwstyle="Dreamweaver" fwdocid = "1249563342" fwnested="0" -->
<tr>
<td><img src="/images/eprints/spacer.gif" width="32" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="104" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="44" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="105" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="41" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="16" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="82" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="69" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="98" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="12"><img name="ePrints_banner_r1_c1" src="/images/eprints/ePrints_banner_r1_c1.gif" width="795" height="10" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="10" border="0" alt="" /></td>
</tr>
<tr>
<td rowspan="6"><img name="ePrints_banner_r2_c1" src="/images/eprints/ePrints_banner_r2_c1.gif" width="32" height="118" border="0" alt="" /></td>
<td rowspan="5"><a href="http://www.utas.edu.au/"><img name="ePrints_banner_r2_c2" src="/images/eprints/ePrints_banner_r2_c2.gif" width="104" height="103" border="0" alt="" /></a></td>
<td colspan="10"><img name="ePrints_banner_r2_c3" src="/images/eprints/ePrints_banner_r2_c3.gif" width="659" height="41" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="41" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="3"><a href="http://eprints.utas.edu.au/"><img name="ePrints_banner_r3_c3" src="/images/eprints/ePrints_banner_r3_c3.gif" width="190" height="31" border="0" alt="" /></a></td>
<td rowspan="2" colspan="7"><img name="ePrints_banner_r3_c6" src="/images/eprints/ePrints_banner_r3_c6.gif" width="469" height="37" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="31" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="3"><img name="ePrints_banner_r4_c3" src="/images/eprints/ePrints_banner_r4_c3.gif" width="190" height="6" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="6" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="2"><img name="ePrints_banner_r5_c3" src="/images/eprints/ePrints_banner_r5_c3.gif" width="149" height="1" border="0" alt="" /></td>
<td rowspan="2" colspan="2"><a href="/information.html" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821132634_0,0,25,null,'ePrints_banner_r5_c5');MM_swapImage('ePrints_banner_r5_c5','','/images/eprints/ePrints_banner_r5_c5_f2.gif',1);"><img name="ePrints_banner_r5_c5" src="/images/eprints/ePrints_banner_r5_c5.gif" width="57" height="25" border="0" alt="About" /></a></td>
<td rowspan="2"><a href="/view/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133021_1,0,25,null,'ePrints_banner_r5_c7');MM_swapImage('ePrints_banner_r5_c7','','/images/eprints/ePrints_banner_r5_c7_f2.gif',1);"><img name="ePrints_banner_r5_c7" src="/images/eprints/ePrints_banner_r5_c7.gif" width="68" height="25" border="0" alt="Browse" /></a></td>
<td rowspan="2"><a href="/perl/search/simple" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133201_2,0,25,null,'ePrints_banner_r5_c8');MM_swapImage('ePrints_banner_r5_c8','','/images/eprints/ePrints_banner_r5_c8_f2.gif',1);"><img name="ePrints_banner_r5_c8" src="/images/eprints/ePrints_banner_r5_c8.gif" width="68" height="25" border="0" alt="Search" /></a></td>
<td rowspan="2"><a href="/perl/register" onMouseOut="MM_swapImgRestore();MM_startTimeout();" onMouseOver="MM_showMenu(window.mm_menu_1018171924_3,0,25,null,'ePrints_banner_r5_c9');MM_swapImage('ePrints_banner_r5_c9','','/images/eprints/ePrints_banner_r5_c9_f2.gif',1);"><img name="ePrints_banner_r5_c9" src="/images/eprints/ePrints_banner_r5_c9.gif" width="68" height="25" border="0" alt="register" /></a></td>
<td rowspan="2"><a href="/perl/users/home" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133422_4,0,25,null,'ePrints_banner_r5_c10');MM_swapImage('ePrints_banner_r5_c10','','/images/eprints/ePrints_banner_r5_c10_f2.gif',1);"><img name="ePrints_banner_r5_c10" src="/images/eprints/ePrints_banner_r5_c10.gif" width="82" height="25" border="0" alt="user area" /></a></td>
<td rowspan="2"><a href="/help/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133514_5,0,25,null,'ePrints_banner_r5_c11');MM_swapImage('ePrints_banner_r5_c11','','/images/eprints/ePrints_banner_r5_c11_f2.gif',1);"><img name="ePrints_banner_r5_c11" src="/images/eprints/ePrints_banner_r5_c11.gif" width="69" height="25" border="0" alt="Help" /></a></td>
<td rowspan="3" colspan="4"><img name="ePrints_banner_r5_c12" src="/images/eprints/ePrints_banner_r5_c12.gif" width="98" height="40" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td>
</tr>
<tr>
<td rowspan="2"><img name="ePrints_banner_r6_c3" src="/images/eprints/ePrints_banner_r6_c3.gif" width="44" height="39" border="0" alt="ePrints home" /></td>
<td><a href="/" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('ePrints_banner_r6_c4','','/images/eprints/ePrints_banner_r6_c4_f2.gif',1);"><img name="ePrints_banner_r6_c4" src="/images/eprints/ePrints_banner_r6_c4.gif" width="105" height="24" border="0" alt="ePrints home" /></a></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="24" border="0" alt="" /></td>
</tr>
<tr>
<td><img name="ePrints_banner_r7_c2" src="/images/eprints/ePrints_banner_r7_c2.gif" width="104" height="15" border="0" alt="" /></td>
<td colspan="8"><img name="ePrints_banner_r7_c4" src="/images/eprints/ePrints_banner_r7_c4.gif" width="517" height="15" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="15" border="0" alt="" /></td>
</tr>
</table></td>
</tr>
<tr><td><table width="100%" style="font-size: 90%; border: solid 1px #ccc; padding: 3px"><tr>
<td align="left"><a href="http://eprints.utas.edu.au/cgi/users/home">Login</a> | <a href="http://eprints.utas.edu.au/cgi/register">Create Account</a></td>
<td align="right" style="white-space: nowrap">
<form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/search" style="display:inline">
<input class="ep_tm_searchbarbox" size="20" type="text" name="q" />
<input class="ep_tm_searchbarbutton" value="Search" type="submit" name="_action_search" />
<input type="hidden" name="_order" value="bytitle" />
<input type="hidden" name="basic_srchtype" value="ALL" />
<input type="hidden" name="_satisfyall" value="ALL" />
</form>
</td>
</tr></table></td></tr>
<tr>
<td class="toplinks"><!-- InstanceBeginEditable name="content" -->
<div align="center">
<table width="720" class="ep_tm_main"><tr><td align="left">
<h1 class="ep_tm_pagetitle">Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989</h1>
<p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Edgar, Graham J.</span> (1992) <xhtml:em>Hydrological and Ecological Survey of the Port Davey/Bathurst Channel Estuary 1988-1989.</xhtml:em> Technical Report. Marine Research Laboratories, Tasmania.</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 onmouseover="EPJS_ShowPreview( event, 'doc_preview_2232' );" href="http://eprints.utas.edu.au/1739/1/HydrologicalandEcological.pdf" onmouseout="EPJS_HidePreview( event, 'doc_preview_2232' );"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" class="ep_doc_icon" border="0" /></a><div class="ep_preview" id="doc_preview_2232"><table><tr><td><img alt="" src="http://eprints.utas.edu.au/1739/thumbnails/1/preview.png" class="ep_preview_image" border="0" /><div class="ep_preview_title">Preview</div></td></tr></table></div></td><td valign="top"><a href="http://eprints.utas.edu.au/1739/1/HydrologicalandEcological.pdf"><span class="ep_document_citation">PDF</span></a> - Requires a PDF viewer<br />6Mb</td></tr></table><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">Five field trips were conducted to the Bathurst Harbour/Port Davey area between October
1988 and July 1989. During each trip the hydrology, benthic fauna, plankton and fish
assemblages in the Bathurst Harbour estuary were surveyed.
During the winter period of peak freshwater outflow, a brackish surface layer (=15 %0)
was present to a depth of =4 m throughout the estuary. The halocline broke down during summer
with surface salinities of =29 %0 prevailing. Bottom waters were close to fully marine
(=33%0) throughout the year.
Surface waters in Bathurst Harbour were found to be extremely depleted in nitrates (<0.1 uM). Oxygen levels were also very low (=35% saturation) during February but were near ?
saturation during the other sampling periods.
Dinoflagellates and copepods were both extremely abundant in Bathurst Harbour. Diatoms
were also abundant during the summer field trips, but were much less common than
dinoflagellates on other occasions. Diatoms did, however, occur in higher densities than
dinoflagellates in the waters of Port Davey. The plankton community (>20 um mesh size) in
Bathurst Harbour was dominated by few taxa, particularly during the winter months. The
dinoflagellate Dinophysis acuminata provided >99% of phytoplankton numbers in October 1988
and July 1989, while the copepods GJadioferens inermis and Oithona austraJis and the
appendicularian OikopJeura sp. provided almost all of the zooplankton numbers.
The diversity of benthic plants and animals decreased rapidly up the Bathurst Harbour
estuary. Discrete communities of benthic organisms, both sessile and motile, were found at the
western entrance to Bathurst Channel and in the rest of the estuary. The overlap zone between the
different communities was a relatively small area between Sarah Island and Schooner Cove.
Mobile invertebrates were most abundant at the Bathurst Channel and Port Davey sites in
February, and at the Bathurst Harbour sites in December. They showed high fidelity to location,
with little indication in this study of a migration up or down the estuary in response to changes in
salinity. Very few mobile invertebrates were found in Bathurst Harbour below 4 m depth.
Fishes in the Bathurst Harbour estuary also showed little response to seasonal changes in
salinity. A number of fishes were, however, possibly prevented from entering the estuary
during February because of low oxygen concentrations then prevailing.
The assemblage of Bathurst Harbour fishes collected by gillnet was unusual in being
dominated by sharks and skates, with all of the common species also being distributed in water
depths >50m along the continentalshelf. The assemblage thus has many characteristics typical
of a deep water assemblage. Included amongst the Bathurst Harbour fishes was a previously
unknown species of skate which may be restricted to the estuary.
By far the most common of the larger fishes was the white-spotted dogfish Squalus
acanthias; this species comprised 86% of the total gillnet catch. Despite these large catches, a
tagging study in which a very high proportion (26 %) of tagged dogfish were recaptured indicated
that the total population in the estuary was not huge, being in the order of only 2,500 animals.
Tagged animals roamed widely through the estuary.
The major recommendations of the study are that gillnets be banned from the Bathurst
Harbour estuary, that the low nutrient status of the estuary be maintained, and that steps be taken
to ensure that the unique Caulerpa algal beds in Kelly Basin be preserved.</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">Report (Technical Report)</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">benthic surveys,
marine reserves
Bathurst harbour
portdavey</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/270708.html">270000 Biological Sciences > 270700 Ecology and Evolution > 270708 Conservation and Biodiversity</a><br /><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">ID Code:</th><td valign="top" class="ep_row">1739</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">Mr David Lenel</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">03 Sep 2007</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">09 Jan 2008 02:30</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=1739;">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=1739">item control page</a></p>
</td></tr></table>
</div>
<!-- InstanceEndEditable --></td>
</tr>
<tr>
<td><!-- #BeginLibraryItem "/Library/footer_eprints.lbi" -->
<table width="795" border="0" align="left" cellpadding="0" class="footer">
<tr valign="top">
<td colspan="2"><div align="center"><a href="http://www.utas.edu.au">UTAS home</a> | <a href="http://www.utas.edu.au/library/">Library home</a> | <a href="/">ePrints home</a> | <a href="/contact.html">contact</a> | <a href="/information.html">about</a> | <a href="/view/">browse</a> | <a href="/perl/search/simple">search</a> | <a href="/perl/register">register</a> | <a href="/perl/users/home">user area</a> | <a href="/help/">help</a></div><br /></td>
</tr>
<tr><td colspan="2"><p><img src="/images/eprints/footerline.gif" width="100%" height="4" /></p></td></tr>
<tr valign="top">
<td width="68%" class="footer">Authorised by the University Librarian<br />
© University of Tasmania ABN 30 764 374 782<br />
<a href="http://www.utas.edu.au/cricos/">CRICOS Provider Code 00586B</a> | <a href="http://www.utas.edu.au/copyright/copyright_disclaimers.html">Copyright & Disclaimers</a> | <a href="http://www.utas.edu.au/accessibility/index.html">Accessibility</a> | <a href="http://eprints.utas.edu.au/feedback/">Site Feedback</a> </td>
<td width="32%"><div align="right">
<p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><img src="http://www.utas.edu.au/shared/logos/unioftasstrip.gif" alt="University of Tasmania Home Page" width="260" height="16" border="0" align="right" /></a></p>
<p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><br />
</a></p>
</div></td>
</tr>
<tr valign="top">
<td><p> </p></td>
<td><div align="right"><span class="NoPrint"><a href="http://www.eprints.org/software/"><img src="/images/eprintslogo.gif" alt="ePrints logo" width="77" height="29" border="0" align="bottom" /></a></span></div></td>
</tr>
</table>
<!-- #EndLibraryItem -->
<div align="center"></div></td>
</tr>
</table>
</body>
</html>
