As the ice begins to melt on small ponds in the Adirondacks, don't be alarmed to find hundreds of dead fish floating on the surface.
Rather than being caused by a pesticide spill or disease, the fish were probably killed by a natural phenomenon known as "winterkill," according to the state Department of Environmental Conservation.
Winterkill occurs during long winters when ice and snow block sunlight from entering a pond and prevent aquatic plants from producing oxygen. The ice cover also prevents oxygen in the atmosphere from mixing into the pond. When the ice melts, hundreds of dead fish can be found floating on the surface.
Fish kills have already been reported in a few ponds in the southeastern part of the state. Winterkills are most common in small, shallow, nutrient-rich ponds with lots of decaying aquatic plants.
Winterkills are rare in waters over 20-acres in size and do not occur in larger lakes which have sufficient volumes of oxygen rich water to maintain aquatic life through even the worst of winters.
Winterkills are rarely complete and fisheries usually rebound within a couple of years.
DEC asks that anyone noting a fish kill involving a substantial number of fish that they believe cannot be attributed to winterkill to contact their local DEC regional office.