Low-Profile, Low-Bycatch Gillnets, Gulf of Maine, Stellwagon Bank, 2000-2002: catch data from F/V Lady Irene NEC-MP2000-1 in the the Gulf of Maine from 2000-2002 (NEC-CoopRes project)

<h3>Testing of Low-Profile, Low-Bycatch Gillnets</h3>

<p><strong>Project Leader</strong>:<br />
<em>Michael Pol, </em>Massachusetts Division of Marine Fisheries<br />
<strong>Additional Project Participants:</strong><br />
<em>H. Arnold Carr, </em>Massachusetts Division of Marine Fisheries<br />
<em>Robert MacKinnon, </em>Massachusetts Gillnetters' Association</p>

<p>\"Two experimental gillnets were tested that are designed to reduce or eliminate the bycatch of cod while targeting flatfish species. Both experimental designs reduce the vertical profile of the nets in the water. One experimental design modifies a foam-core floatline by adding lead every few feet; the other net replaces the gillnet's floatline with another leadline so that the net lies nearly completely on the bottom. Both are 8 meshes deep (MD) and have different floatation and hanging ratios. The nets were quantitatively compared to standard gillnets (25 MD) to determine their effectiveness in reducing cod bycatch. The nets with lower vertical profiles have been shown to reduce the catch of legal cod, but not discarded cod. Catch rates of flatfish could not be compared, due to low catch numbers. Filming with an underwater camera indicated that the orientation of the nets was different than anticipated. Research has continued on these gillnets with additional funding the Northeast Consortium in FY2001.\" <em>extracted from: Summary of Completed Cooperative Research Projects Funded by the Northeast Consortium, January 2006</em></p>

<p><strong>Parameter names and Descriptions</strong> each with a different form of flotation on the headline.<br />
A: had floats<br />
B: had foamcore and lead<br />
C: had foamcore only<br />
D: second leadline in place of floatline \"NK\" indicates species \"not known\".</p>

<p>Related data objects:<br />
<a href=\"http://nec.whoi.edu/jg/serv/nec/Gear/gillnets_summary.html0%7Bdir=nec.whoi.edu/jg/dir/nec/Gear/,info=nec.whoi.edu/jg/info/nec/Gear/gillnets_summary%7D\">Total weights from all net configurations</a><br />
<a href=\"http://nec.whoi.edu/jg/serv/nec/Gear/gillnets_temp.html0%7Bdir=nec.whoi.edu/jg/dir/nec/Gear/,info=nec.whoi.edu/jg/info/nec/Gear/gillnets_temp%7D\">Gillnet bottom temperatures </a></p>

<h3>低垂度、低兼捕量刺网测试</h3>

<p><strong>项目负责人</strong>:<br />
<em>迈克尔·波尔（Michael Pol）</em>，马萨诸塞州海洋渔业局<br />
<strong>项目其他参与人员</strong>:<br />
<em>H·阿诺德·卡尔（H. Arnold Carr）</em>，马萨诸塞州海洋渔业局<br />
<em>罗伯特·麦金农（Robert MacKinnon）</em>，马萨诸塞州刺网从业者协会</p>

<p>本研究对两款实验刺网（gillnets）开展测试，两款网具均旨在针对比目鱼鱼种的同时，减少乃至消除鳕鱼兼捕。两款实验设计均降低了网具在水中的垂直轮廓高度。其中一款通过每隔数英尺添加铅坠来改造泡沫芯浮子纲；另一款则使用另一根沉子纲替代刺网的浮子纲，使网具几乎完全贴合海底。两款网具均为8目深（MD），且配备不同的浮力配置与挂网比率。研究将上述网具与标准刺网（25 MD）进行定量对比，以评估其减少鳕鱼兼捕的效果。测试结果显示，低垂度网具可降低合法尺寸鳕鱼的捕获量，但对废弃鳕鱼的捕获量无显著影响。由于比目鱼的捕获量较低，无法对其捕捞率进行对比。水下摄影机拍摄结果表明，网具的水下姿态与预期存在差异。2001财年，东北财团（Northeast Consortium）提供额外资助，推动了该类刺网的后续研究。</p>
<em>数据来源：《2006年1月东北财团资助合作研究项目完成总结》</em>

<p><strong>参数名称与描述</strong>（各网具上纲采用不同浮力配置）<br />
A：配备浮子<br />
B：配备泡沫芯与铅坠<br />
C：仅配备泡沫芯<br />
D：使用另一根沉子纲替代浮子纲<br />
注："NK"代表物种信息"未知（not known）"。</p>

<p><strong>相关数据对象</strong>:<br />
<a href="http://nec.whoi.edu/jg/serv/nec/Gear/gillnets_summary.html0%7Bdir=nec.whoi.edu/jg/dir/nec/Gear/,info=nec.whoi.edu/jg/info/nec/Gear/gillnets_summary%7D">各网具配置总重量</a><br />
<a href="http://nec.whoi.edu/jg/serv/nec/Gear/gillnets_temp.html0%7Bdir=nec.whoi.edu/jg/dir/nec/Gear/,info=nec.whoi.edu/jg/info/nec/Gear/gillnets_temp%7D">刺网海底水温</a></p>