The GOA study area includes the on-shelf waters of the Gulf of Alaska, extending from approximately Unimak Bight (-163.5°) in the west to Prince of Wales Island (-132.5°) in the east. A grid cell size of 3×3 km² was determined to best support the available data. This corresponds to the nominal resolution of the bathymetric and biological data, and the output of the circulation model used. The resulting study area grid contained 300 rows and 665 columns giving a total of 199,500 cells. The portion of the study area within the U.S. Exclusive Economic Zone (EEZ) contained about 36,000 cells.
Within this study area, we evaluated the utility of circulation model output for species-habitat relationships. We combined the output of a ROMS (Regional Ocean Modeling System) model with local Remote sensing data, and correlated this physical data set with NMFS fishery survey data to predict habitat of Walleye pollock, Pacific cod, rockfish, and flatfish (Gregr et al. in review). The results of this analysis subsequently formed the basis of an economic analysis of the cost to the fishing industry of spatial closures (Berman, et al. in review).
Bering Sea and Gulf of Alaska
The Bering Sea and Gulf of Alaska (BS/GOA) study area encompassed the range of the western stock of Steller sea lions within U.S. waters. It also captured all the recorded NMFS Alaska Region observer data for 2001. We used a 9×9 km² grid because it represents the finest scale supported by the resolution of the environmental indicators available from satellite. The study area contained approximately 45,000 marine cells within the U.S. EEZ.
We used our 9×9 km2 eastern North Pacific/Bering Sea study area to extend our analysis of commerical fish species habitat (Flinn, 2008) and investigate the costs to fishing at a different spatial extent and resolution. These extents also formed the basis of our study of Steller sea lion habitat (Gregr and Trites, 2008).