The New York State Department of Environmental Conservation (DEC) announced today that beginning in June, DEC will treat portions of Seneca Lake to eliminate sea lamprey, a parasitic fish that preys and feeds on other fish species. Seneca Lake tributaries in Chemung, Schuyler, and Yates counties will be treated in early June.

The treatment will help prevent sea lampreys from invading New York waters and protect the fish they target, including lake trout, rainbow trout, brown trout, and landlocked salmon. Eliminating this parasite will help ensure healthier fish species in Seneca Lake and its tributaries and continue to provide anglers with good fishing opportunities.  

Typically, immature sea lamprey live in streams for three to four years before they become parasitic and enter lakes to prey on other fish. As part of DEC’s Sea Lamprey Control Program, fisheries employees apply a lampricide called TFM (3-trifluoromethyl-4-nitrophenol) to streams continuously for approximately 12 hours, killing the young sea lamprey in their larval form. TFM is a pesticide that has been used in Seneca Lake tributaries for decades, and while lethal to sea lampreys, it is harmless to other fish and has no significant impact to the environment.

In addition, the stream treatments pose no significant hazard to human health. Out of an abundance of caution, the New York State Department of Health advises against stream water consumption, fishing, swimming, livestock watering, or irrigation during the treatment period.

DEC will post signage advising of the treatment along the treated streams.