DEC Reports Alewife Die-Off on Lake Champlain

Thousands of dead fish are appearing on the surface and shores of Lake Champlain the New York State Department of Environmental Conservation reported today. The dead fish are being sighted on both the New York and Vermont sides of the lake.

The fish are alewives, a type of herring with a gray-green back and silvery iridescent sides. Both 2-3 inch immature fish and 5-6 inch adult fish may be found. Alewives are an invasive species, first found in the Lake Champlain in 2005. Their presence became more widely known earlier this year when tens of thousands of dead alewives turned up on the Vermont side of the Lake.

Alewives are susceptible to rapid drops in water temperature that can occur at the onset of winter and when cold waters from melting ice mix with the somewhat warmer waters below. This is what caused the die off in Vermont earlier this year and is thought to be responsible for the recent die-off.

The fish might have died over the winter, but were preserved in the cold waters under the ice. Now that the ice is thawing, these dead fish are surfacing. Vermont officials had tested alewives from the January die-off and found them negative for viral hemorrhagic septicemia (VHS).

While large number of dead fish are unsightly, and possibly odorous, they do not present a wide spread health or environmental problem. Gulls, raccoons and other scavengers will consume many of the fish, the rest will decompose, following the cycle of the natural environment.

It is not certain if the alewives was entered the lake as a result of illegal stocking of the fish into waters in the Lake Champlain watershed or by migrating through connecting canal systems. Misguided anglers may have introduced the fish thinking they would provide a good food source for gamefish. Unfortunately, alewives in the Great Lakes, where they are also an invasive species, have a history of large crash and boom population cycles.

DEC has regulations that anglers must follow to prevent the spread of non-native fish and ensure healthy populations of native and managed fish: