Basking sharks are found around the world in temperate coastal shelf waters and exist in Canada in both the Pacific and Atlantic Oceans. Along the North American Pacific coast, basking sharks were historically found off California in winter and spring and in particular areas off British Columbia in summer and fall, suggesting a seasonal north-south migration. Basking sharks have rarely been seen in North-American Pacific waters over the last fifteen years. Historically, however, large goupings were observed in nearshore waters along the west coast of Vancouver Island and in one location along the central mainland coast of British Columbia. They spend much of their time near the surface, although there is recent evidence that basking sharks may also use deepwater habitats greater than 1000 m.

The basking shark is the second largest fish in the world, with a maximum recorded size of 12.2 m. This filter-feeder is named after its conspicuous behaviour of 'basking' (more accurately feeding) at the surface. The basking shark is typically blackish to grey-brown. It has an extremely large mouth with minute teeth, elongated gill slits, a pointed snout, and a crescent-shaped caudal fin. Gill openings have prominent gill rakers. Longevity is likely about 50 years, while maximum reported length is 12.2 m. Size at birth probably ranges between 1.5 and 2 m. Males are thought to reach maturity at between 12 and 16 years and females between 16 and 20 years.