Process structuring coastal marine communities in Alaska:  DOI trust resources

Nearshore marine communities support a wide array of commercially, recreational and culturally valuable resources. Taxa include, but are not limited to, algae, invertebrates, fish, birds and mammals. A broad array of processes are responsible in structuring nearshore marine communities including both physical factors (e.g., temperature, salinity, currents) and biological factors (e.g., reproduction, growth, succession, competition, and predation). Human induced impacts in the coastal regions of Alaska are inevitable and increasing in scale and magnitude. In order to understand, quantify and attribute cause to changes in the nearshore ecosystem it is imperative to understand primary sources of community structuring and of natural or background levels of variation in the system. The sea otter, once nearly extinct, is currently reoccupying previous habitat in much of the North Pacific. The process of recolonization provides a unique opportunity to apply the experimental approach to describing the effects of a large mammalian predator on its prey and subsequent community organization. The role of sea otters in structuring nearshore marine communities in the north Pacific Ocean are recognized as significant, particularly among exposed rocky shorelines. Much less is known of the effects of sea otter reintroduction into soft sediment habitats. It is now possible to examine effects of sea otter foraging as they begin to recolonize Glacier Bay National Park and Preserve in southeast Alaska, a predominately soft sediment marine community. Information on the distribution and abundance of sea otters in and around Glacier Bay will provide the description of the spatial and temporal process of sea otter recolonization and provide the basis for study sites to evaluate changes in community structure before and after the effects of sea otters. Study of sea otter food habits will provide a measure of the direct effects of prey removal. Study of sea otter diving behavior will provide a measure of the bathymetric extent of sea otters in structuring communities. Study of prey populations will allow documentation of changes in abundance and size distributions resulting from sea otter foraging.

APPLICATION OF RESEARCH: Studies of interactions between sea otters and prey species are important to assess the effects that sea otters have on composition and productivity of coastal marine communities, and to better understand how recolonizing sea otter populations may affect commercial, recreational and culturally valuable marine resources. This information is important to resource managers in identifying potential conflicts, identifying mechanisms of change and improve the ability to detect change from human induced sources.

Publications:

Bodkin, J. L., K. A. Kloecker, G. G. Esslinger, D. H. Monson, H. A. Coletti, J. Doherty. 2003. Sea otter studies in Glacier Bay National Park and Preserve. 2002 Annual Report. U.S. Geological Survey, Alaska Science Center, Anchorage, AK. [pdf file - 2.5 MB]

Bodkin, J. L, K. A. Kloecker, G. G. Esslinger, D. H. Monson, DeGroot, J. D., and J. Doherty. 2002. Sea otter studies in Glacier Bay National Park and Preserve. 2001 Annual Report. U.S. Geological Survey, Biological Resources Division, Anchorage, AK. [pdf file - 1.8 MB]

Bodkin, J. L, K. A. Kloecker, G. G. Esslinger, D. H. Monson, and J. D. DeGroot. 2001. Sea otter studies in Glacier Bay National Park and Preserve: Aerial surveys, foraging observations, and intertidal clam sampling. 2000 Annual Report. U.S. Geological Survey, Biological Resources Division, Anchorage, AK. [pdf file - 11.2 MB]

Bodkin, J.L. and Kloecker, K.A.  1999.  Intertidal clam diversity, size, abundance, and biomass in Glacier Bay National Park and Preserve, 1999 Annual Report.  U.S. Geological Survey, Biological Resources Division, Anchorage, AK.  [pdf file - 520 KB]