PaCSEA Bird Survey Summary Data, 2011-2012

This data set was created as a summary layer to more easily represent the original PaCSEA bird transect counts at a consistent scale across the transect for display within MarineCadastre.gov. These map layers display the density of birds (birds/sq km) detected in the Pacific Continental Shelf Environmental Assessment (PaCSEA) 2011 – 2012. PaCSEA involved repeated low-elevation aerial surveys along 32 broad-scale transects to quantify seabirds and marine mammals from shore to the 2000-m isobath. Transects were spaced 15 nautical miles (nmi) apart, between Fort Bragg, California (39° N) and Grays Harbor, Washington (47° N). Surveys were conducted from fixed wing aircraft flying 160 km/h at 60-m above sea level. All birds and marine mammals within a 150 m transect (75 m per side) were counted. Six complete surveys were conducted with 3 surveys each year (winter, summer, and fall). While the actual area sampled varied slightly among surveys, this summary representation uses 6.8 x 6.8 km polygons to display estimates of bird density for all surveys. The actual transect areas are also included in a single file for all 6 surveys. Please consult the metadata file for information and file access for the original study products.