My research interests include the foraging ecology, diving behavior, and physiological ecology of marine mammals. Increases in many formerly depleted pinniped populations coupled with declining fish resources in recent years have intensified competition between humans and pinnipeds. I'm particularly interested in the interaction of a growing California sea lion population, a top-trophic species along the West Coast, and its interaction and impact on commercially important fisheries resources and coastal ecosystems. The lack of data on pinniped foraging behavior makes it impossible to understand how and to what extent this competition may affect both predator and prey populations. Assessing and quantifying top predator impacts on marine resources will allow us to develop sustainable management strategies for marine fisheries.

The goal of my dissertation work is to investigate the foraging and diving behavior, location of foraging, food habits, and at-sea distribution of California sea lions along the California coast and to estimate the impacts of those behaviors on listed stocks of salmonids, other protected fish species, and commercially important fish species. My objectives are to: 1) provide information of the at-sea distribution, movements, and foraging patterns of California sea lions along the west coast of the United States; 2) identify the locations and predominant oceanographic conditions and/or habitats used by foraging California sea lions; 3 ) identify and enumerate prey species to better estimate the role of listed stocks of salmonids, protected species, and commercially important species in the sea lion diet; 4) construct biomass consumption models to compare annual sea lion consumption of prey species with run estimates for listed stocks of salmonids, fish stock assessments, and commercial catches.

Weise, M.J., and J.T. Harvey. 2001. Monitoring pinniped predation of winter-run steelhead in the San Lorenzo River during 2000. Report to: National Marine Fisheries Service, Southwest Regional Office, Contract Number: 40ABBNF901343. 31 pp.

Lance, M.M., A.J. Orr , S.D. Riemer, M.J. Weise , and J.L. Laake. 2001.Pinniped food habits and prey identification techniques protocol. NMFS/AFSC Processed Rpt 2001-04. 36 pp.

Weise, M.J., 2000. Abundance, food habits, and annual fish consumption of California sea lion (Zalophus californianus) and its impact on salmonid fisheries in Monterey Bay , California . M.S. Thesis, San Jose State University , San Jose , California , 103 pp.

Weise, M.J ., and J.T. Harvey. 2000. California Sea Lion ( Zalophus californianus ) Impacts on Salmonid Fisheries in Monterey Bay , California during 1997, 1998, and 1999. Report to: The David and Lucile Packard Foundation, Contract Number: 99-2018.

Weise, M.J., and J.T. Harvey. 1999. Pinniped predation on adult winter-run salmonids in the San Lorenzo River and Scott Creek , CA, 1998 and 1999. In Pinniped predation on salmonids: Preliminary reports on field investigations in Washington , Oregon , and California . National Marine Fisheries Service

Weise, M.J., and J.T. Harvey. 1999. Pinniped predation on adult winter-run salmonids in the San Lorenzo River and Scott Creek , CA, 1998 and 1999. Moss Landing Marine Laboratories Tech. Report. 99-03. 19 p.

Weise, M.J ., and J.T. Harvey. 1999. Food habits of Pacific harbor seals ( Phoca vitulina richardsi ) and their impact on adult winter-run salmonids on the San Lorenzo River. Moss Landing Marine Laboratories Tech. Report. 99-01. 19 p.

Harvey, J.T., and M.J. Weise. 1997. Impacts of California sea lions and Pacific harbor seals on salmonids in Monterey Bay, California. In Pinniped Populations, Eatern North Pacific: Status, Trends and Issues. A symposium of the 127th Annual Meeting of the American Fisheries Society.