Trophic Ecology of Atlantic Cod, off Cape Cod, MA, from F/V Riena Marie NEC-FA2001-1 in the Gulf of Maine from 2001-2004 (NEC-CoopRes project)

<p><strong>Trophic Ecology of Atlantic Cod: Insights from Tri-Monthly, localized Scales of Sampling Years 1 &amp; 2</strong><br />
Project Leader: Theodore Ligenza, F/V Riena Marie<br />
Additional Project Participants:<br />
Frank Almeida, Researcher, Northeast Fisheries Science Center<br />
Jason Link, Researcher<br />
Brian Smith, Scientist, Northeast Fisheries Science Center</p>

<p><a href=\"http://northeastconsortium.org/ProjectFileDownload.pm?report_id=323&amp;table=project_report\" target=\"_blank\">Final report</a><br />
<a href=\"http://www.nefsc.nmfs.gov/femad/pbio/fwdp/FWDP.htm\" target=\"_blank\">Project Website</a></p>

<p>The project examined the small scale variation of Atlantic cod feeding based upon tri-monthly stomach sample collections from a nearshore, localized region off Cape Cod, Massachusetts. The first objective was to relate any detectable changes in cod diet and amount of food eaten with changes in temperature, spawning, prey abundance, and major weather events, filling in the information gap between broad scale and in vivo laboratory studies. The second objective was to work cooperatively with the fishing industry to transform anecdotal information into quantitative data. Results suggest that the amount of food eaten by cod is generally stable throughout the year, except when pelagic forage fish migrate through the area. This corresponds to critical periods in the life history of cod. The temporal variation in diet composition remained remarkably consistent each year over the 28-months of the project, suggesting important feeding periods for cod, which correspond to environmental and biological cues. The diet is comprised primarily of several species of forage fish (e.g. Atlantic herring, sand lance, Atlantic mackerel, ophiuroids, Cancer crabs, and other small crustaceans.) Additionally, these results confirm the preference cod exhibit for prey such as herring, sand lance,and crabs. We infer that cod generally eat local forage fish and benthic macro-invertebrates and then supplement their diet by gorge feeding upon migrating pelagic species. (<em>from project abstract</em>)</p>

<p><strong>大西洋鳕鱼营养生态学：基于第1、2年每三月局域尺度采样的研究洞察</strong><br />
项目负责人：西奥多·利真扎（Theodore Ligenza），F/V Riena Marie<br />
项目协作参与者：<br />
弗兰克·阿尔梅达，研究员，东北渔业科学中心（Northeast Fisheries Science Center）<br />
杰森·林克，研究员<br />
布莱恩·史密斯，科学家，东北渔业科学中心（Northeast Fisheries Science Center）</p>

<p><a href="http://northeastconsortium.org/ProjectFileDownload.pm?report_id=323&amp;table=project_report" target="_blank">最终报告</a><br />
<a href="http://www.nefsc.nmfs.gov/femad/pbio/fwdp/FWDP.htm" target="_blank">项目官网</a></p>

<p>本项目基于马萨诸塞州科德角近岸局域海域每三个月一次的胃容物采样，探究大西洋鳕鱼摄食的小尺度变化规律。首要研究目标为：关联鳕鱼食性、摄食量的可检测变化与水温、产卵活动、猎物丰度及极端天气事件的变化，填补大尺度研究与活体实验室研究之间的信息空白。次要研究目标为：与渔业从业者开展合作，将零散的经验传闻转化为定量观测数据。研究结果显示，大西洋鳕鱼的日均摄食量全年整体保持稳定，仅当洄游性上层饵料鱼途经该海域时发生显著变化，这一变化节点与鳕鱼生活史中的关键时期高度吻合。在项目开展的28个月期间，鳕鱼食性组成的年内变化规律每年均保持高度一致，表明鳕鱼存在特定的关键摄食时段，且这些时段与环境及生物信号密切相关。鳕鱼的食物主要由多种饵料鱼类构成，例如大西洋鲱（Atlantic herring）、玉筋鱼（sand lance）、大西洋鲭（Atlantic mackerel）、蛇尾类（ophiuroids）、黄道蟹属（Cancer）螃蟹以及其他小型甲壳类动物。此外，本研究结果证实了大西洋鳕鱼对鲱鱼、玉筋鱼及螃蟹等猎物的摄食偏好性。研究推断，大西洋鳕鱼日常主要摄食局域海域的饵料鱼类及底栖大型无脊椎动物，仅在途经的洄游性上层鱼类大量出现时，会通过暴食行为补充食物来源。（节选自项目摘要）</p>