The lake sturgeon is one of the oldest, largest and longest-living fish in Saskatchewan, but lake sturgeon populations have been dangerously low in the North Saskatchewan River recently.
Owen Watkins, a master's student in the University of Alberta Department of Renewable Resources is conducting research to determine why populations are so low.
The lake sturgeon has been in existence for 200 million years and has been important to Canada's history. Historically, sturgeon were commercially harvested and shipped to Europe as food. Sturgeon populations now, however, are too small to support commercial fisheries. Only about 1,700 fish remain in the North Saskatchewan River and the species is listed as an endangered species in Canada.
Though the number of sturgeon might seem large, very few of the 1,700 sturgeon are old enough to reproduce. Because a sturgeon can live up to 154 years, the fish takes a long time to reach sexual maturity, with a female taking about 25 years. Out of the 1,700 sturgeon in the river, the oldest that the research team has been able to find has been 64 years old, meaning that there are likely to be only eight spawning female fish.
Concerned that the fish might become extinct completely, Watkins has been sewing radio transmitters into lake sturgeons in order to track their movements, create population estimates and to try to determine what has been happening to sturgeon populations over the last 20 years.
Through his research, which has been taking place between Drayton Valley and the Onion Lake bridge on the Saskatchewan Border, Watkins has been testing three theories on the decline of sturgeon populations: that the fish are recovering from low oxygen levels that existed prior to the 1960s before Edmonton began treating its sewage; that the sturgeon use the river only seasonally to spawn and then leave; and thirdly, that the population is being overfished.
The team does not yet have its final findings, but its research will be presented to the Alberta provincial government in order to create a recovery plan and to help manage the North Saskatchewan River for sturgeon and all river fish.
