Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use
The long-term goal of this research effort is to enhance the understanding of how variability in physical, biological, and acoustic signals impact marine mammal prey and resulting marine mammal habitat use. This is especially critical in areas like the Bering Sea where global climate change can lead...
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| Format: | Text |
| Language: | English |
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2011
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| Online Access: | http://www.dtic.mil/docs/citations/ADA598694 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA598694 |
| Summary: | The long-term goal of this research effort is to enhance the understanding of how variability in physical, biological, and acoustic signals impact marine mammal prey and resulting 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. The Arctic is projected to experience ice-free summers within 30 years (Wang and Overland, 2009). This will have significant impacts for the natural ecosystem dynamics and human use associated with transportation, fishing, military activity, and energy exploration. Shifts in plankton community structure are a likely response to large-scale changes in ice cover. Zooplankton population dynamics are a dominant component of the ecosystem that provide the crucial trophic link between primary production and Federally-protected species such as marine mammals. Understanding the relationship between ice cover and zooplankton community structure in different regions of the Bering Sea will provide information for predicting upper-level trophic dynamics, including marine mammal distribution and range, as sub-Arctic conditions continue to change. Baseline measurements will play an important role in mitigation efforts and environmental assessments as commercial and military activity increases in the region. The main goal of this year s effort was to relate acoustic backscatter characteristics associated with estimates of zooplankton/neckton abundance, spatial and temporal variability, dominant size class, and taxa to marine mammal detection patterns on the central and southeastern Bering Sea shelf. The first objective examines bio-physical interactions influencing the dynamics of marine mammal zooplankton and fish prey. The second objective relates the prey variability to observed patterns of marine mammal vocal detections indicative of animal presence and habitat use. |
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