Staff Writer, Capital News
Friday, May 24, 1996
Shore spawning Kokanee fry that emerged earlier this spring on at least one section of Okanagan Lake beach were marooned and died before they could swim out into the lake because of low water levels.
If the scenario was repeated, or is repeated regularly on Okanagan beaches, it could have a huge impact on the population of the little silver fish.
At the beginning of April on that Kelowna beach, Dr. Peter Dill, a biologist at Okanagan University College involved in studying the shore spawning species of Kokanee, was gently digging holes.
Under the rocks and within the top few inches he found hundreds of tiny live fish, the recently-hatched fry from eggs laid at the cost of the adult’s life last fall.
Five days later when he returned to check on his subjects, he found the sand had dried and so had the fish.
Dill was out tagging and studying those red-flushed adult fish last October as they came into shore, laid their eggs and died, and had hoped to be able to begin an egg-to-fry assessment this spring as they emerged.
However, it was a cold winter and the fry emerged late, the lake level was drawn down in order to leave room from the inflow of the spring freshet, or runoff, from creeks in the Okanagan Basin, and not long after those fry emerged, sunny days heated the rocks around them, and the marooned babies were killed.
Dill estimates 25 per cent of the fry on the beach he’s been studying for several years died this spring; hundreds of Kokanee.
Now he’s writing the technical report for the environment ministry on his work this spring, and waiting for confirmation of whether funding has been allotted for him to continue his work, and if so, at what scale he’d be able to continue to conduct his studies.
His work is just part of a long-term study on the differences between stream and shore spawning Kokanee, the conditions the latter need to spawn successfully, and the number of fry that survive.
Those efforts are now a vital part of studies being conducted to try and resolve the current crisis of crashing populations of this little landlocked salmon in Okanagan Lake, a crisis that has resulted in a ban on fishing them being instituted last spring. Dill can’t say yet what effect the marooning of these few hundred fish might have, but believes the reduction in populations of Kokanee in Okanagan Lake is a result of a combination of events, rather than just one.
He hopes next fall to be able to expand his studies to include spawning shorelines in deeper water, perhaps at Carr’s Landing.
The good news this spring is that there’s been an excellent survival rate of fry now migrating from the Mission Creek Spawning Channel, even though there was a record low number of fish spawning in there last fall. On one evening last week Dill says one of his students counted 100,000 of the little inch-long fry leaving the channel for life in the big lake.