Five-minute grid of total marine bird biomass densities surveyed off central California - selected cool water temperature periods, 1980-2001 (CDAS data set AL3_MASS.shp)

AL3_MASS is a polygon shapefile representing 5 minute x 5 minute latitude x longitude cells that house the overall total biomass densities (kg/sq km) of up to 76 species of marine birds during periods of realtively cold or cool sea surface temperatures. Density for each of 76 marine bird species was multiplied by average body mass for that species, and these products summed for all species in a cell, to obtain total biomass density. Cells that were surveyed but in which no birds were observed have total biomass densities of zero.