The sturgeon has been identified.
http://www.theprogress.com/portals-code/list.cgi?paper=39&cat=23&id=435718&more=The mystery of the dark-tinged sturgeon that turned up unexpectedly in a gillnet at Cultus Lake last month has been solved.
Or at least the part about what type of sturgeon it turned out to be is now known.
Recent DNA lab tests by Fisheries and Oceans Canada have determined it was a white sturgeon and not the much rarer green sturgeon variety. It surfaced in a volunteer’s net at Cultus in April during a pikeminnow removal program.
The precise facts about how it got there are unclear, say officials, but rumours about locals stocking the lake 30 years ago still abound.
“What made us think it was the rarer green variety was the shovel-shaped nose and its darker than normal colouration,” explains fisheries technician Dave Barnes from the Cultus Lake Salmon Lab.
“I suppose we expected all along this was a white sturgeon because they are so much more common than greens.”
The darker tinge of the prehistoric-looking beast is most likely “an adaptive feature” that most fish possess – that is the ability to blend in with their surroundings, Mr. Barnes adds.
It was likely darker than the white sturgeon typically found in the Fraser River because it is living in clear water, as opposed to the turbidity of the Fraser. The darker colour would make it easier to blend in with the bottom of the lake.
“We still suspect this fish was put into Cultus Lake by anglers,” he offers.
Cultus Lake may be the most studied sockeye-bearing lake in Canada, possibly the world, the DFO fish tech suggests.
“And as such, we have nearly continuous data on sockeye in Cultus since 1925,” he says.
The data-collecting initiatives include fish-counting fences and traps on Sweltzer Creek, which is the migration path from the Fraser River to Cultus Lake, and many research programs on the lake itself.
“If sturgeon regularly travelled between these two waterways (Cultus Lake and the Fraser River), I think a few more would have been captured or observed,” Mr. Barnes posits.
The popular lake just south of Chilliwack is full of food sturgeon like to eat, such as crayfish, sculpins, snails and more.
“So however many fish may be present should do well,” he says.
“There should be no cause for alarm from lake users as sturgeon are not dangerous to humans.” (
)
Author
Topic: Sturgeon Caught In Cultus Lake (Read 11965 times)