NMML 2002-2010 Bering Sea Shelf Cetacean Survey

Original provider:
National Marine Mammal Laboratory

Dataset credits:
National Marine Mammal Laboratory

Abstract:
Visual line-transect surveys for cetaceans were conducted in the southeastern Bering Sea (SEBS) in association with a NOAA/Alaska Fisheries Science Center’s pollock stock assessment survey aboard the NOAA ship Miller Freeman (2002 and 2004) and the NOAA ship Oscar Dyson (2008 and 2010). In 2002 and 2004, the surveys were a continuation of those done in 1999 and 2000, taking advantage of the survey platform as it ran transects through SEBS. In 2008 and 2010, the cetacean survey was included as part of the Bering Sea Integrated Ecosystem Research Program, a NPRB funded project to test and improve our understanding of effects of climate change and management actions on the Bering Sea ecosystem. Methods in all years were the same with three observers rotating through two 25x (Big Eye) binocular positions and one recorder on the flying bridge. Survey effort was conducted along the pollock survey transect lines, weather permitting. Additional effort was conducted while in transit to and from pollock survey waypoints. Transect survey effort was 3,761 km in 2002, 1,692 km in 2004 (observers were present for only half of the survey), 3,255 km in 2008 and 1,681 km in 2010. The following cetacean species were recorded: fin whale (<i>Balaenoptera physalus</i>), sei whale (<i>Balaenoptera borealis</i>), minke whale (<i>Balaenoptera acutorostrata</i>), humpback whale (<i>Megaptera novaeangliae</i>), gray whale (<i>Eschrichtius robustus</i>), sperm whale (<i>Physeter macrocephalus</i>), Baird’s beaked whale (<i>Berardius bairdii</i>), Stejneger’s beaked whale (<i>Mesoplodon stejnegeri</i>), killer whale (<i>Orcinus orca</i>), Pacific white-sided dolphin (<i>Lagenorhynchus obliquidens</i>), Dall’s porpoise (<i>Phocoenoides dalli</i>), and harbor porpoise (<i>Phocoena phocoena</i>). Pinniped species were also recorded to include the Steller sea lion (<i>Eumetopias jubatus</i>) and the northern fur seal (<i>Callorhinus ursinus</i>), as well as the sea otter (<i>Enhydra lutris</i>). Fin whales were the most common large whale, and Dall's porpoises were the most common small cetacean. Distribution, abundance estimates and population trends for fin, humpback, and minke whales, and Dall’s and harbor porpoise are currently being analyzed.

原始提供方：
美国国家海洋哺乳动物实验室

数据集贡献方：
美国国家海洋哺乳动物实验室

摘要：
在白令海东南部（SEBS）开展了鲸类目视样线调查，该调查结合了美国国家海洋和大气管理局（NOAA）阿拉斯加渔业科学中心分别于2002、2004年在NOAA米勒·弗里曼号及2008、2010年在NOAA奥斯卡·戴森号上进行的狭鳕资源评估调查。2002和2004年的调查是1999和2000年调查的延续，利用调查平台在SEBS内的样线航行开展工作。2008和2010年，鲸类调查被纳入白令海综合生态系统研究计划——一项由NPRB资助的项目，旨在检验并增进对气候变化及管理措施对白令海生态系统影响的理解。

所有年份的调查方法一致：三名观察员轮流在两个25倍（大眼）双筒望远镜观测位开展观测，另有一名记录员在飞桥上工作。天气允许时沿狭鳕调查样线进行调查，往返狭鳕调查点位途中也开展额外调查。2002年样线调查里程为3761公里，2004年为1692公里（观察员仅参与一半调查），2008年为3255公里，2010年为1681公里。

记录到的鲸类物种包括：长须鲸（Balaenoptera physalus）、塞鲸（Balaenoptera borealis）、小须鲸（Balaenoptera acutorostrata）、座头鲸（Megaptera novaeangliae）、灰鲸（Eschrichtius robustus）、抹香鲸（Physeter macrocephalus）、贝氏喙鲸（Berardius bairdii）、史氏喙鲸（Mesoplodon stejnegeri）、虎鲸（Orcinus orca）、太平洋白边海豚（Lagenorhynchus obliquidens）、多尔鼠海豚（Phocoenoides dalli）及港湾鼠海豚（Phocoena phocoena）。还记录到鳍足类物种：北海狮（Eumetopias jubatus）、北海狗（Callorhinus ursinus），以及海獭（Enhydra lutris）。

长须鲸是最常见的大型鲸类，多尔鼠海豚是最常见的小型鲸类。目前正在分析长须鲸、座头鲸、小须鲸以及多尔鼠海豚和港湾鼠海豚的分布、丰度估计及种群趋势。