The Japanese or Pacific Oyster is an introduced bivalve species in British Columbia waters. Carl and Guiget (1958)
documented its arrival on the Pacific Coast:
"The Japanese or "Pacific" Oyster was first introduced into the Puget Sound area in 1902, and the first shipment of seed oysters to be planted in British Columbia arrived in 1914. By 1926 a considerable industry had developed in Samish Bay near Bellingham, Washington, and success had been attained by plantings in Ladysmith Harbour, Vancouver Island. By 1932 about four million seed oysters had been imported into British Columbia and planted mostly in Ladysmith Harbour. In subsequent years, seed was also planted in Boundary Bay (Crescent Beach), Pender Harbour, Baynes Sound, Cortes Island and other areas."
"Natural spawning [in BC] was first observed in 1926 (Ladysmith Harbour), but it may have taken place earlier than this date, possibly in other areas where fishermen may have planted oysters for their own use. The first major spawnings followed by heavy spatfalls occurred in 1932 and 1936 in Ladysmith Harbour, and in subsequent years scattered individuals were found many miles from this centre. Since then breeding has been irregular. Extensive breeding in Baynes Sound and Pender Harbour in 1942 resulted in the distribution of the Pacific oyster throughout northern Georgia Strait."