LIBBY — An algae bloom and a fast-moving storm combined to kill at least 10,000 kokanee salmon in Lake Koocanusa in northwestern Montana.
State fisheries biologist Mike Hensler tells the Missoulian recent hot, calm weather caused the water on the top of the lake to warm, allowing algae to bloom.
The Department of Fish, Wildlife and Parks says a storm on Sunday brought strong winds that moved the algae deeper into the water, where it was ingested by salmon.
FWP spokesman John Fraley says the fish became disoriented after ingesting toxic blue-green algae and came to the surface. They were unable to dive back into cooler water and were killed by the warm surface water.
Fraley says the die-off of the 8- to 10-inch salmon affected a small portion of what will be next year’s adults.
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