More than 1,000 kokanee have washed up on the shores of Okanagan Lake in the past four days, and biologists are trying to figure out what's hurting the popular game fish.
Strong winds and a virus outbreak are two possible reasons, according to the B.C. government.
Previous die-offs have been associated with strong winds, which can send warm surface water deep into the lake, causing the kind of abrupt temperature change that can shock and kill fish, according to a B.C. government release.
A fish health lab in Duncan, B.C. is also testing kokanee tissue samples for infectious hematopoietic necrosis virus, which has been linked to previous die-offs.
The recent die-off is not severe enough to impact the lake's overall kokanee population, which hit a record level of more than 336,500 last year, according to the government.
kokanee are landlocked salmon, and the second-most popular game fish in the province after rainbow trout.