Weird weather stressful for fish
By Phil Cooper, IDFG
May and June are stressful
months for warmwater fish, such as bullheads, perch, bass, crappie and sunfish.
These are the months when
most warmwater fish spawn, taking a lot of a fish's energy. On top of that,
water temperatures typically rise fairly rapidly.
Fish,
being cold-blooded animals, are sensitive to temperature changes, so dramatic
swings in temperature, particularly around the time when fish are stressed from
spawning, can take a toll.
Jim Fredericks, Idaho
Panhandle Regional fishery manager with Idaho Fish and Game, notes that it's
common for people to see a few dozen fish dead or dying around the edges of
northern Idaho lakes this time of year.
"It's very common to see a
die-off of bullhead catfish and sunfish in some of the regional lakes,"
In most cases, early summer
die-offs are the result of a thermal shock on post-spawn fish. There's generally
no risk of swimming in the water or eating healthy fish caught from the lakes.
The unusually cool May and
June this year, with a few warm days mixed in, seems to have been particularly
stressful in a couple of area lakes. Fish and Game received a number of reports
about dead fish in
Biologists with Fish and Game
and the Idaho Department of Environmental Quality have investigated recent fish
kills, and they have observed several dozen fish, representing a variety of
species and sizes.
"In terms of the total number
of dead fish, it's certainly not what I'd call a major die-off,"
Just to be sure, Fish and
Game and a U.S. Fish and Wildlife Service pathologist will be collecting some
fish to conduct tissue samples next week.
In addition, Fish and Game
and the Department of Environmental Quality will continue to watch Spirit and
other lakes around the region where dead fish have been observed.
“My guess is that we've seen
the worst, but we'll definitely keep an eye on it,”