Saturday, September 11, 2010

Local Rivers: Pesticide Will Kill Lamprey Larvae

The Lake Champlain Fish and Wildlife Management Cooperative (Cooperative) will be applying lampricide to portions of five tributaries to Lake Champlain during the month of September. Vermont Department of Fish and Wildlife, New York State Department of Environmental Conservation, and U.S. Fish and Wildlife Service will be treating the Salmon River, Little Ausable River, Ausable River, and Putnam Creek in New York, and Lewis Creek in Vermont.

Treatments are scheduled to begin in New York on September 14th and finish in Vermont by the end of the month. These treatments are part of the Cooperative’s long-term sea lamprey control program for Lake Champlain. The trout and salmon populations of the lake are the primary beneficiaries of these efforts, yet lake sturgeon, walleye, and many other species are affected too.
Larval sea lamprey live in rivers for four years before transforming to their parasitic phase and emigrating to Lake Champlain where their effect on the fishery becomes apparent. One of the Cooperative’s Integrated Pest Management approaches is to apply a selective pesticide, TFM (3-trifluoromethyl-4-nitrophenol), to rivers in prescribed and precise concentrations while continuously monitoring those levels to inform adjustment decisions. The concentrations used are carefully balanced to ensure effective elimination of sea lamprey larvae and protection of non-target species. The application of TFM lasts 12-14 hours depending on conditions, yet it can take days for all of the TFM to clear the rivers depending on distance and flow rates.

Toll free numbers for New York (800-638-5432) and Vermont (800-640-3714: excludes calls made from outside Vermont) provide information on the treatment schedule for each of the five rivers, progress reports, updates on treatments, and water use advisories.

Temporary water use advisories will be in effect for each of the five treated rivers to minimize human exposure to affected waters. Each state’s Department of Health recommends that the treated river and lake water not be used for drinking, swimming, fishing, irrigation, or livestock watering while the advisories are in effect.

The treatments and water use advisories will have no effect on most residents in the Champlain Basin and no municipal water supply systems will be affected. Cooperative staff have identified all landowners with property in the affected areas. A letter was sent to residents informing them of the planned treatment and asking them if they or their livestock use water from a surface supply that will be affected by the treatment. Days before the treatments begin, another letter will be sent to inform residents of the impending treatment and to arrange any water usage accommodations.

Local television and radio stations will broadcast the dates when advisories begin and expire. The treatment schedule is subject to change as weather conditions, stream flows, or logistical issues may arise during the treatments. Residents will be kept apprised of any such changes through these media.

Annual assessments show that sea lamprey populations have been reduced by over 50 percent since 2006, but remain above our goal. Several initiatives are underway to further reduce the population and attain our fishery goal.

Sea lamprey control generates a favorable economic benefit/cost ratio as angling opportunities increase. In 1999, after the Eight-Year Experimental Sea Lamprey Control Program on Lake Champlain, Alphonse H. Gilbert, Ph.D., a University of Vermont economist, determined sea lamprey control produced benefits of approximately $29.4 million with costs of about $8.4 million. These benefits were attributed to the increased number of boaters and anglers spending longer periods of time in the Lake Champlain area.

Photo: Sea lampreys on a lake trout. Courtesy Wikipedia.

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One Response

  1. Larry Master says: