Integrating Passive Acoustic Monitoring in long-term oceanographic observations of the Bering Strait

This project aims to establish a base program for year-round acoustic monitoring of marine mammals in Bering Strait. Instrumentation will be added onto an existing high resolution physical and biological mooring program (National Science Foundation-Arctic Observing Network (AON) and Russian American Long-term Census of the Arctic), also supported by annual survey data. The combination of these data sets will provide urgently required, base-line information on how species presence varies seasonally with changes in sea ice, currents, ocean water temperatures and freshwater flow. Building on opportunistic proof-of-concept deployments in the strait in the last 2 years, the proposed effort will also provide critical, consistent data on interannual variability. The research project will test cutting edge scientific hypotheses such as: how do oceanographic conditions dictate the residency of different marine mammal species? Are temperate species invading the Arctic? What is the correlation between ice cover and marine mammal sound production? The Bering Strait is the only oceanic connection between the Pacific and the Arctic oceans. It is through this narrow (~85 km) passageway that the entire population of Bering-Chukchi-Beaufort bowhead whales passes twice yearly and that herds of beluga whales access Arctic waters. It is thought to be year-round habitat for ice seals and walrus. The Bering Strait is also the path by which Pacific sub-Arctic marine species are invading the Arctic. As the Northwest Passage becomes a viable Pacific-Atlantic shipping route, every ship along this route will pass through Bering Strait. It is, therefore, the region where climate change and changing anthropogenic utilization may have sizeable impacts on local marine fauna, and where changing fluxes of marine mammals to the Arctic can be well observed. Passive acoustic monitoring is the only method currently available to identify year-round, and in all weather conditions, the presence of marine mammals and other physical (ice movement) or anthropogenic (ships, oil and gas seismic exploration) sounds.本项目旨在构建一套针对白令海峡海域海洋哺乳动物的全年声学监测基础方案。本项目将在现有高分辨率物理与生物锚系观测项目（美国国家科学基金会-北极观测网（National Science Foundation-Arctic Observing Network, AON）与俄美北极长期普查（Russian American Long-term Census of the Arctic））之上加装监测设备，同时辅以年度调查数据作为支撑。多源数据集的融合将提供亟需的基线信息，用以揭示物种出现情况如何随海冰、海流、海水温度与淡水通量的季节变化而改变。依托过去两年在白令海峡开展的机会型概念验证布设工作，本项目还将提供关于年际变异性的关键且一致的观测数据。本研究项目将验证一系列前沿科学假说，例如：海洋环境条件如何决定不同海洋哺乳动物物种的居留模式？温带物种是否正在入侵北极海域？海冰覆盖与海洋哺乳动物发声之间存在何种关联？白令海峡是太平洋与北冰洋之间唯一的海洋通道。白令-楚科奇-博福特海域的弓头鲸种群每年两次经由这条仅约85公里宽的狭窄航道洄游，而白鲸群也通过该航道进入北极水域。该海域被认为是冰海豹与海象的全年栖息场所。白令海峡同时也是太平洋亚北极海洋物种入侵北极海域的通道。随着西北航道成为可行的太平洋-大西洋航运航线，该航线上的所有船舶都将途经白令海峡。因此，白令海峡既是气候变化与人类活动方式改变可能对当地海洋动物群落产生显著影响的区域，也是观测海洋哺乳动物向北极迁徙通量变化的理想场所。被动声学监测（Passive Acoustic Monitoring）是目前唯一可实现全年、全天气况下识别海洋哺乳动物以及其他物理声源（如海冰移动）和人为声源（如船舶、油气地震勘探）的监测手段。