Pond owners should be wary of possible winterkill

LINCOLN, Neb. – Private pond owners should be wary of fish possibly succumbing to winterkill.

Excessive snow, especially in southeastern Nebraska, and thick ice from recent frigid weather have created conditions for potential winterkill, according to Jeff Blaser, private waters specialist with the Nebraska Game and Parks Commission.

Winterkills typically occur in small, shallow ponds with abundant aquatic vegetation. Snow and ice covering a pond prevent the water from exchanging oxygen with the air. Excessive snow and thick ice allow little sunlight penetration, so plants are unable to produce enough oxygen. If excessive snow cover and thick ice persists, the plants die and subsequent decomposition, along with respiration by various aquatic organisms, can deplete the oxygen, resulting in a fish kill.

Blaser recommends pond owners take stock of their waters at ice-out.

“Depending on the size of the pond, the presence of 40 or 50 dead fish would not indicate a large winterkill,” he said. “Thousands of dead fish of various species and sizes would be evidence of a major die-off event.”

Blaser suggests owners check for fish, visually and angling, following ice-out to help determine the status of the fish populations. The findings from these actions could indicate a pond is a candidate for restocking.

Pond owners can contact Blaser at 402-499-4041 for management suggestions if they had a major fish kill.