Huge trout probably was feeding on kokanee
Higher populations of kokanee in Okanagan Lake could be in part responsible for huge rainbow trout coming out of the big lake in recent weeks.
Last Friday, Jim Sutherland reeled in a 25.5-pound (11.5 kilograms) rainbow trout in the Gellatly Bay area around West Kelowna.
A couple of weeks earlier a 14-year-old Summerland angler landed a slightly smaller rainbow.
Environment ministry fisheries biologist Paul Askey says when there’s more food, more predators can be supported in a lake and the trend for kokanee populations is up, so it’s not really surprising to see such big trout coming out.
Sutherland’s fish is larger than any other the ministry has recorded from the lake, but that’s only including fish recorded in creel surveys or during fishing derbies. Sutherland says it’s the third largest rainbow that’s been taken from the lake and weighed on a government-certified scale.
Such large fish are few and far between, commented Askey, although acoustic surveys of Okanagan Lake indicate there is, on average, one per hectare.
Trophy fish like Sutherland’s are the result of considerable fishing effort, both in time spent on the water, and decisions like what depth to fish in and where, and what gear to use.
In fact, Askey says there are lots of smaller rainbows as well; fish which target bugs rather than the smaller, stream-spawning kokanee that are now available in abundance in the lake.
This would have been an older fish, perhaps of a different genetic stock, that switches to going after kokanee instead of insects.
Askey said the ministry has records of rainbows in the five to nine kilogram range caught in the ’80s and ’90s in Okanagan Lake. The largest was 9.98 kg.
However, he said fishing pressure on Okanagan Lake has really dropped in the past few decades. The world record rainbow was over 40 pounds (18 kg).