Original provider: Minerals Management Service Dataset credits: Minerals Management Service Abstract: This dataset is from the Oregon and Washington marine mammal and seabird surveys studies: Oregon/Washington aerial [birds and mammals] study code: OP, contract number: 14-12-0001-30426, Principal investigators: G. A. Green, Ebasco Environmental, Bellevue, Washington, M. L. Bonnell and K. T. Briggs, Ecological Consulting, Inc., Portland, Oregon. Time period: April 1989 through October 1990 Study area: Pacific Ocean waters of Oregon and Washington from the coast to approximately 60 nautical miles offshore. Methodology: Aerial surveys were conducted along 32 pre-established transects designed to systematically sample marine mammal and seabird abundance in all waters of the study area. Coastal surveys and one shelf break survey were also conducted. Standard transects provided systematic coverage of shelf, slope, and offshore waters in the study area. Sightings of seabirds, pinnipeds, cetaceans, and turtles were recorded. Seabird sightings were recorded only on the shaded side of the aircraft within a strip transect of 50 m width. Marine mammal and turtle sightings were recorded within an unbounded corridor. Declination angle was measured and noted for each marine mammal/turtle sightings and later used to calculate a probability density function of frequency with right-angle sighting distance. Navigation was by Loran and VLF-Omega. One ship survey was also conducted from aboard the NOAA ship Miller Freeman during August 1989. Databases produced: 1) sightings of seabirds and marine mammals on 12 aerial surveys and one ship cruise, and 2) sightings of cetaceans on 12 aerial surveys and one ship cruise.