Funds are provided 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, and allow for the testing of 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.