Preliminary estimates of cetacean abundance off California, Oregon, and Washington based on a 1996 ship survey and comparisons of passing and closing modes

Visual sighting surveys on two ships in summer/fall 1996 were used to estimate the abundance of most cetaceans found within 555 km (300 nmi) of the coasts of California, Oregon, and Washington. Surveys systematically covered 14,400 km of pre-determined transect lines within this study area... The 1996 survey was conducted using two National Oceanographic and Atmospheric Administration (NOAA) research vessels... Teams of three observers searched from the flying bridge deck of both vessels using line-transect methods... Two observers searched through 25x pedestal-mounted binoculars while the third observer searched with unaided eyes and a 7x hand-held binocular. 1997 NMFS (National Marine Fisheries Service) SWFSC (Southwest Fisheries Science Center) Library Public Domain 1863