Aerial Survey Counts of Harbor Seals in Coastal Alaska (2003-2011)

This dataset supports efforts to estimate the abundance and trends in population size of Alaska harbor seals. Annual surveys of harbor seal populations are fundamental to estimation of seal abundance, distribution, and trends, which in turn are essential for stock assessment, conservation, and management. The most feasible approach to determining harbor seal distribution and abundance is to use aircraft to count seals when they haul out of the water and are visible. Harbor seals in Alaska occupy a geographically extensive range from approximately long. 172ºE to 130ºW (over 3,500 km east to west) and from lat. 51ºN to 61.5ºN (over 1,000 km north to south). Estimation of the abundance of harbor seals statewide requires broad-scale aerial surveys and these surveys have been conducted by NOAA Fisheries, the Alaska Department of Fish and Game, and other collaborators since the early 1980s. This dataset reflects counts of harbor seals from surveys conducted between 2003 and 2011.

This dataset differs from earlier datasets in a few key areas: 1) records generally correspond to a count of the number of harbor seals within a single, geo-referenced digital photo, 2) photographs were not taken when no seals were present so additional analysis of survey effort and flight tracks was required to determine 0 counts.