This layer is intended to represent the geographic extent of NOAA Fisheries’ California Current Cetacean and Ecosystem Assessment Survey. The California Current Cetacean and Ecosystem Assessment Survey started in 1991 and is led by NMFS Southwest Fisheries Science Center. This survey includes ship-, aerial-, and land-based surveys of marine mammals throughout the California Current Large Marine Ecosystem. Survey data have been used to estimate cetacean population size and trends, delineate cetacean population stock structure, describe cetacean and seabird distributions and hotspots, develop species distribution models, and inform marine mammal stock assessment reports pursuant to statutory requirements under the Marine Mammal Protection Act (MMPA). Research vessels conduct line-transect surveys, typically every three years, in summer and fall and span waters out 300 nautical miles offshore, from the US-Canada to US-Mexico border. NOAA research vessels (David Starr Jordan, McArthur, McArthur II, Reuben Lasker, Bell M. Shimada) collect visual sightings data for cetaceans and seabirds, passive acoustic (e.g., towed or drifting array) data for cetaceans, tissue biopsy sampling used for genetics analysis, and oceanographic sampling.