1 DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use

The long-term goal of this collaborative research effort is to enhance the understanding of how variability in physical, biological, and acoustic signals impact marine mammal habitat use. This is especially critical in areas like the Bering Sea where global climate change can lead to rapid changes of the entire ecosystem. Progressive climate change has the potential to expose areas of the Arctic and sub-Arctic that have been previously unavailable for civilian and military use. Baseline measurements will play an important role in mitigation efforts and environmental assessments as commercial and military activity increases in the region. OBJECTIVES The main objective of this work is to relate synoptic measurements of prey distribution, physical oceanographic process, and sound levels to marine mammal habitat use on the eastern Bering Sea shelf. Integrated data such as these will be vital in understanding the relationship between marine mammals and their environment both in the presence and absence of specific noise sources. Long-term measurements will play an important role in determining the point at which cumulative effects of the environment and human activities impact animal populations, and in identifying the conditions that pose the greatest risk