Sources of dietary variability and prey size utilization of two deep-water skate species from the Gulf of Alaska: Bathyraja aleutica (Gilbert, 1895) and Bathyraja interrupta (Gill and Townsend, 1897)

Simon C. Brown

sbrown@mlml.calstate.edu

831-771-4419

Graduated – Fall 2010

Abstract:

Skates appear to play an important ecological role in continental shelf and slope ecosystems, often occupying upper trophic levels and consuming a diverse assortment of prey species consisting of polychaetes, crustaceans, cephalopods, and fishes.  The potential ecological interactions of skates with their prey, with commercially important groundfish species, and with fisheries emphasizes the need to better understand their trophic ecology and to incorporate this information into multispecies and ecosystem-based management considerations.  However, due to the limited commercial status of skates, basic trophic information for common skate species in many ecosystems, such as the Gulf of Alaska, is inadequate for such purposes.  Therefore, the purpose of this study is to quantify the diet composition and examine sources of variability in the diets of two common skates species: the Aleutian skate (Bathyraja aleutica) and Bering skate (Bathyraja interrupta) from the western Gulf of Alaska continental shelf ecosystem.

Funding:

Funding for this project was provided by:

NOAA through the National Shark Research Center and Pacific Shark Research Center

and the North Pacific Research Board (Project number 612)

Presentations:

Brown S., Bizzarro J.J., Boyle M.D., Ebert D.A., and Cailliet G.M. (2008) The diet composition of four abundant skate species of the Gulf of Alaska (Poster). Western Groundfish Conference. Santa Cruz, CA. February 2008.

Brown S., Bizzarro J.J., Boyle M.D., Ebert D.A., and Cailliet G.M. (2008) The diet composition of four abundant skate species of the Gulf of Alaska (Poster). American Elasmobranch Society Meeting, July, 2008.

Publications:

(Co-author)

Ebert, D.A., J.J. Bizzarro, S.B. Brown, M.D. Boyle, and G.M. Cailliet. 2008. Diet and trophic ecology of skates in the Gulf of Alaska (Raja and Bathyraja spp.): ecological information for ecosystem-based management of demersal resources. North Pacific Research Board Final Report 621, 57 p.