Alewife Die-Off Prompts DEC Action

• by New York State Department of Environmental Conservation

ALBANY, NY (05/01/2008)(readMedia)-- As a major die-off of alewives, a fish that is an invasive species to inland waters in New York, has continued on the surface and shores of Lake Champlain, the state Department of Environmental Conservation (DEC) has reached out to help provide New York towns and landowners disposal options.

Disposal options for towns and landowners who want to clean the fish from their shore include having the fish hauled to a landfill, or providing the fish to farmers for composting. More information is available from Dan Steenberge, of the DEC’s Region 5 Office, at 518-897-1241 or 897-1242.

While large numbers of dead fish are unsightly and possibly odorous, they do not present a widespread health or environmental problem.

However, the die-off raises the issue of the rapid spread of non-native, or invasive, species in New York.

Alewives are a type of herring, with a gray-green back and silvery, iridescent sides; adults are about 5-6 inches long. They were first found in Lake Champlain in 2005. Their presence and proliferation became more widely known earlier this year when tens of thousands of dead alewives washed up on the Vermont side of the lake. They are now believed to be in great abundance now in the lake – once established in water body, alewives are unlikely to be eradicated. However, effective control of sea lampreys, another invasive species in Lake Champlain, can help by boosting the population of salmon and lake trout, two alewife predators.

Mass die-offs are common for alewives in large lakes. Native to the Atlantic Ocean, they typically enter fresh water only to spawn – and they are not well adapted to freshwater lakes such as Champlain. Experience in the Great Lakes, where they are also introduced, shows that alewives commonly experience population booms and busts. The large scale die-offs may be triggered by cold water temperatures, rapid changes in water temperatures, or stress associated with spawning. This is thought to be responsible for the recent die-off. Nevertheless, DEC will collect some of the fish to test for possible other causes.

It is not certain if alewives entered Lake Champlain by migrating through tributaries or by illegal stocking -- people may have introduced the fish thinking it would provide a good food source for game fish.

Because of the environmental hazards of invasive species, DEC has regulations designed to limit the spread of non-native fish and protect native species. These include:

• Do Not Move Fish From One Water Body to Another.

• Do Not Release Unused Bait Fish – even where using them is allowed.

• Do Not Move Fish Overland Unless They Are Certified As Disease-Free.

Landowners interested in composting fish should go to: www.aqua.wisc.edu/publications/PDFs/CompostSolution.pdf Or contact Cornell University: Jean Bonhotal, 607-255-8444, or Joe Regenstein, 607-255-8041.

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