Freshwater Fishes of the Columbia Basin Return to Table of Contents Return to Species List

Native Fishes: Family Acipenceridae (Sturgeon)

Acipencer transmontanus (Richardson)	White Sturgeon
Acipenser=sturgeon transmontanus=beyond the mountains

White Sturgeon is the largest freshwater fish in North America, with the largest individuals reaching lengths of up to 6 m and weighing over 800 kg. In the Columbia Basin, White Sturgeon is most commonly found in large, cool, fluvial environments, but some populations have become isolated in the larger lakes. Columbia River and Kootenay River sturgeon were originally isolated by natural barriers at Bonnington Falls since the Pleistocene glaciation, and these populations have become isolated further by a series of impoundment dams along the lower reaches of the Kootenay River. White Sturgeon are currently considered a rare, threatened species in western North America, after populations were reduced to very low numbers by overfishing early this century. As a consequence, harvesting sturgeon in British Columbia has been illegal since 1994. The absence of juvenile fish in life history studies conducted on the Kootenay River suggest that these sturgeon populations have not reproduced since 1974; furthermore, numbers of adult individuals in breeding condition are dangerously low (Cannings and Ptolemy 1998).

Spawning is thought to take place in fast water during June-July during peak freshet flows, and some spawning has been observed in the race tails at the confluence of the Pend D' Orielle and lower Columbia River at the site of Waneta Dam. Some Kootenay River sturgeon make seasonal migrations into Kootenay Lake where they spend the winter at depths of up to 100 m (Cannings and Ptolemy 1998). It seems that females inhabit deeper water than males do during this winter period.

There have been occasional reports of sturgeon in Slocan, upper Arrow and Okanagan lakes, but most Canadian Columbia Basin sturgeon are known from the lower Columbia River, Kootenay River above Bonnington Dam, in Kootenay lake and in the upper Kootenay River.