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 (BC) during the non-breeding season with an arrival in August–October and a departure in April–May. The population in coastal BC was assessed in 1985 and again in 2023 from dedicated over-winter aerial surveys. The most recent assessment used counts from 2020–2021surveys that were restricted to southern BC as few animals have been documented further north. Additional observations of California Sea Lions were collected while surveying sites for Steller Sea Lions. These opportunistic counts increased from approximately 1,000 animals in the mid-2000s to several thousand individuals in more recent years. Historically occupied sea lion rookeries and haul-out sites were surveyed with nearby areas monitored for potential shifts in distribution. This dataset contains counts that have been collected from sightings of individuals from 1971 through 2021and replaces a previous dataset limited to the 2016/2017 survey season.

PURPOSE: An aerial survey of the Western Hudson Bay beluga whale (Delphinapterus leucas) population was conducted on August 19th, 2015 to provide a population estimate. Surveys were flown in a DeHavilland Twin Otter (DH-6) fitted with four bubble windows and an optical glass-covered camera hatch at the rear underbelly of the plane. A Global Positioning System (GPS) unit logged the position, altitude, speed, and heading of the aircraft each second. Surveys were initially flown at a target ground speed of 100 knots (185 km/h), and target altitudes of 1,000 ft (305 m) for visual surveys and 2,000 ft (610 m) for photographic surveys. After the second day of flying, the target ground speed was adjusted to 110 knots (204 km/h). Complete coverage of the two photographic strata was achieved using a Nikon D810 camera fitted with a 25 mm lens. The camera was mounted at the rear of the aircraft and directed straight down with the longest side perpendicular to the track line. The camera was connected to a GPS unit to geo-reference photographs, and to a laptop computer to control exposure settings and photo interval. At an altitude of 2,000 ft (610 m), the 25 mm lens captured a ground area of approximately 875 m x 585 m. The photograph interval was set to maintain an overlap of 20 to 40 % between consecutive photos, and with a transect spacing of 600 m, the lateral overlap between photos from adjacent transects was approximately 30 %. DESCRIPTION: Aerial surveys of summering Western Hudson Bay (WHB) beluga (Delphinapterus leucas) were conducted on August 19th, 2015 to update the previous population abundance. The survey area comprised five strata (three visual and two photographic) encompassing high use areas around three river estuaries where recurring aggregations of WHB beluga are found during the summer months. This metadata covers the photographic data related to the survey. The photographic surveys completely covered high density aggregations in the Churchill River and near the mouth of the Seal River.

PURPOSE: An aerial survey of the Western Hudson Bay beluga whale (Delphinapterus leucas) population was conducted on August 12th, 2015 to provide a population estimate. Surveys were flown in a DeHavilland Twin Otter (DH-6) fitted with four bubble windows and an optical glass-covered camera hatch at the rear underbelly of the plane. A Global Positioning System (GPS) unit logged the position, altitude, speed, and heading of the aircraft each second. Surveys were initially flown at a target ground speed of 100 knots (185 km/h), and target altitudes of 1,000 ft (305 m) for visual surveys and 2,000 ft (610 m) for photographic surveys. After the second day of flying, the target ground speed was adjusted to 110 knots (204 km/h). Complete coverage of the two photographic strata was achieved using a Nikon D810 camera fitted with a 25 mm lens. The camera was mounted at the rear of the aircraft and directed straight down with the longest side perpendicular to the track line. The camera was connected to a GPS unit to geo-reference photographs, and to a laptop computer to control exposure settings and photo interval. At an altitude of 2,000 ft (610 m), the 25 mm lens captured a ground area of approximately 875 m x 585 m. The photograph interval was set to maintain an overlap of 20 to 40 % between consecutive photos, and with a transect spacing of 600 m, the lateral overlap between photos from adjacent transects was approximately 30 %. DESCRIPTION: Aerial surveys of summering Western Hudson Bay (WHB) beluga (Delphinapterus leucas) were conducted on August 12th, 2015 to update the previous population abundance. The survey area comprised five strata (three visual and two photographic) encompassing high use areas around three river estuaries where recurring aggregations of WHB beluga are found during the summer months. This metadata covers the photographic data related to the survey. The photographic surveys completely covered high density aggregations in the Churchill River and near the mouth of the Seal River.