Numerical abundance, catch-per-unit-effort, percent composition from F/V Stormy Weather NEC-HH2006-1 in the Gulf of Maine off New Hampshire coast from June 2008 (NEC_ProjDev project)

<p><strong>\"Development of a Multi-Beam Sonar as a Fisheries Tool for Stock Assessment and Essential Fish Habitat Identification of Groundfish in the Western Gulf of Maine\"</strong></p>

<p>This data set:<br />
Mean and standard error (S.E.) for numerical abundance, catch-per-unit-effort (CPUE, fish per 30-minute tow), and percent composition (%) of fish enumerated in 10 tows of a 6.5-inch mesh otter trawl by F/V Stormy Weather in Area Closure 133 on 21, 22, and 25 June 2008.</p>

<p><u>Abstract</u><br />
Stock assessments based on accurate abundance and distribution data are essential to developing effective management strategies for the Gulf of Maine stock of Atlantic cod, <em>Gadus morhua</em>. The purpose of this study was to prove the concept of using multi-beam sonar as a fisheries tool for studying the behavior and quantifying the abundance of groundfish. The focus of this research was was to develop multi-beam sonar (MBS) as a fisheries survey tool. MBS can complement traditional narrow-beam echosounder and trawl surveys because MBS has a large sampling volume, three-dimensional spatial description, and potentially fewer behavior-related sampling biases than traditional trawl surveys. Relationships between acoustic backscatter and fish biology need to be understood before reliable acoustic surveys using MBS can provide sciencebased information for stock assessments. A series of acoustic and optical measurements were made using 38- and 120-kHz EK60 split-beam echosounders and a 300 kHz EM3002 MBS. These were fixed to a surface platform over a 98 cubic meter submersible cage of 5-cm stretched mesh twine. After standard sphere calibration, the cage was stocked with 195 live Atlantic cod with a mean total length of 80.7 ± 0.8 cm (± standard error; range 51.5-105.0 cm) from nearby spawning grounds 10-15 km off the New Hampshire coast, USA. The sonars were synchronized to collect acoustic data on a captive population of mature cod of known size and number under video surveillance by two underwater cameras. Cod were incrementally removed from the cage to provide a time-series of acoustic backscatter at four densities (n=195, 116, 66, and 23). Preliminary results demonstrate the feasibility of the EM3002 MBS to detect cod and show that quantification of the acoustic backscatter is possible.</p>

<p>See <a href=\"http://northeastconsortium.org/ProjectFileDownload.pm?report_id=865&amp;table=project_report\">final report</a></p>

<p><strong>“多波束声呐作为渔业工具的开发：用于缅因湾西部底层鱼类的资源评估与关键鱼类栖息地识别”</strong></p><p>本数据集包含：<br />2008年6月21日、22日及25日，由F/V Stormy Weather号渔船在133号封闭海域开展的10次6.5英寸网目底拖网作业中，所统计鱼类的数量丰度、单位捕捞努力量渔获量（CPUE，单位为每30分钟拖网渔获尾数）以及鱼类组成百分比的平均值与标准误（S.E.）。</p><p><u>摘要</u><br />基于准确的丰度与分布数据开展的资源评估，对于制定大西洋鳕鱼（<em>Gadus morhua</em>）缅因湾种群的有效管理策略至关重要。本研究旨在验证将多波束声呐（Multi-Beam Sonar）作为渔业工具，用以研究底层鱼类行为并量化其丰度的可行性。本研究的核心目标是开发多波束声呐（MBS）作为渔业调查工具。多波束声呐可作为传统窄波束回声测深仪与拖网调查的补充手段，因其具备更大的采样容积、三维空间描述能力，且相较于传统拖网调查，由鱼类行为导致的采样偏差潜在更低。在使用多波束声呐开展可靠的声学调查并为资源评估提供科学依据的参考信息之前，需明确声学背散射与鱼类生物学特性之间的关联。本研究使用38kHz与120kHz的EK60分裂波束回声测深仪，以及300kHz的EM3002多波束声呐开展了一系列声学与光学测量。上述设备被固定于水面平台，该平台架设在上覆98立方米、5cm拉伸网目绳线制成的可潜笼之上。经标准球体校准后，该潜笼被投放至美国新罕布什尔州海岸外10-15公里的邻近产卵场，放养195尾活大西洋鳕鱼，其平均总长度为80.7±0.8厘米（±标准误；体长范围51.5-105.0厘米）。声呐设备同步采集由两台水下摄像机进行视频监控的、已知体型与数量的圈养成熟鳕鱼种群的声学数据。研究人员逐步从潜笼中移除鳕鱼，以获取四种不同种群密度下的声学背散射时间序列数据（种群数量分别为n=195、116、66与23）。初步结果证实了EM3002多波束声呐检测鳕鱼的可行性，并表明对声学背散射进行量化具备可行性。</p><p>详见<a href="http://northeastconsortium.org/ProjectFileDownload.pm?report_id=865&amp;table=project_report">最终报告</a></p>