DearFriends
of the Lake,
.
During the past week you may have noticed a fish kill in Forest Lake. Small
crappies and sunfish were floating to the windward shoreline. We checked
with the East Metro office of the DNR and described the situation. They indicated
that the fish were dying from a common bacteria called "columnaris".
This occurs when fish are stresssed and vulnerable to bacteria. This was
probably caused by late spawning and a sudden increase in the water temperature
due to the recent hot weather. The DNR advised that this is normal and will not
adversely affect the fish population. Live crappies/sunnies are safe to eat.
See below
the write up from the DNR website for more information.
FLLA Board
of Directors Steve Schmaltz
Dead fish in
your lake?
COLUMNARIS DISEASE
The most common disease occurring in lakes is caused by the bacterium Flavobacterium
columnare. This pathogen causes large kills of sunfish, crappies,
and bullheads in late spring and early summer. Infections in metro area lakes
usually start around Memorial Day weekend and persist until early July.
The bacterium exists naturally in fish populations and expresses itself when
stressful conditions exist. The infection is brought on most commonly when
water temperatures increase rapidly. The increase in water temperature often
brings an increase in spawning activity, which coupled with stress caused by
temperature changes, make the fish more susceptible to the infection.
Fish infected with Chondroccus columnaris are characterized by eroded gill
tissues, with a grey-white to yellowish slime on the skin, gills or fins. These
kills occur on most metro area lakes, and may involve several thousand fish in
some years. In most cases, the numbers lost are small in relation to the total
population, and no change in angler success can be attributed to columnaris
disease.
Live fish infected with this infection are edible. Fish caught with columnaris
should be skinned and prepared as desired. Fish should be cooked to a temperature
of 140 degrees F. for at least five minutes before eating.
Chondroccus columnaris infected fish sometimes suffer a
secondary infection caused by the fungus Saprolegnia. This fungus appears
as a white, cottony growth on the body of the fish. This furry or hairy
appearance disappears when the fish is removed from the water.
This fungus can kill fish by completely covering it. There is no danger to
humans, but a bad taste may develop as a result of the infection. Fish infected
with Saprolegnia should be skinned with the infected
areas cut out, then prepared as usual.
