Owners of shallow
ponds and lakes, especially in Northern Indiana, should watch for fish kills
this spring, the Indiana Department of Natural Resources is warning.
record or near-record snowfall and ice up to 20 inches thick on lakes and
ponds, Indiana fisheries biologists anticipate numerous reports of fish
kills once the bodies of water thaw.
The most common
cause of fish kills in Indiana ponds is lack of oxygen.
Aquatic plants can
produce oxygen only when sunlight is available. While some sunlight can
penetrate clear ice, snow can block sunlight, resulting in dangerously low
ponds are more susceptible to winter kills. As aquatic plants naturally die
during winter, plant decomposition consumes oxygen which fish and other
aquatic life need. Once a winter kill begins, little can be done to stop it.
Drilling holes in the ice will not help.
Pond owners who
experience a fish kill or need advice on other pond-related issues can refer
to Indiana’s Pond Management Booklet at wildlife.IN.gov/3356.htm
Biologists do not
expect significant fish kills at deep natural lakes and reservoirs. The
exception could be winter kills of gizzard shad, a species which is
vulnerable to prolonged cold weather. Because the species is prolific and
fast growing, shad losses do not have a lasting impact on shad populations.
Lake residents and
anglers who observe significant fish kills on public waters should contact
their district fisheries biologist. Contact information is in the 2014
Fishing Regulation Guide or at wildlife.IN.gov/3590.htm