DEC to launch sea-lamprey treatment on Seneca Lake tributaries

Treatments seek to enhance lake trout and salmon population and size

The New York State Department of Environmental Conservation (DEC) announced that beginning in June, it 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 action 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, per the DEC.

“Eliminating this parasite will help ensure healthier fish species in Seneca Lake and its tributaries and continue to provide anglers with good fishing opportunities,” the department said in a release. 

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,” the agency noted. “In addition, the stream treatments pose no significant hazard to human health.” 

The New York State Department of Health “out of an abundance of caution,” advises against stream-water consumption, fishing, swimming, livestock watering, or irrigation during the treatment period.

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

Treatments are weather dependent. Lampricide applications are scheduled to start June 8 in Catharine Creek in Chemung and Schuyler counties. On June 10, the Keuka Outlet in Yates County will be treated.