The United States population of California Sea Lions (Zalophus californianus) range from southeast Alaska to the Pacific coast of central Mexico. While this population does not breed in Canada, some sub-adult and adult males migrate northwards to British Columbia during the non-breeding season with an arrival in August-October and a departure in April-May. The population in coastal BC has not been fully assessed since 1985. However, opportunistic counts suggest that California Sea Lions overwintering in BC increased in abundance from approximately 1,000 animals in the mid-2000s to several thousand individuals in more recent years.

The survey targeted Steller sea lions and sites were chosen based on knowledge of historically occupied rookeries and haul-out sites with nearby areas monitored for potential shifts in distribution. The presence of California Sea Lions are based on incidental observations while surveying sites for Steller sea lion counts. This dataset contains counts that have been collected from sightings of individuals in the 2016/2017 survey season.