U.S., Canadian scientists fighting sea lamprey along Manistee River

Jamie Storozuk of Fisheries and Ocean Canada checks to be sure the correct amount of lamrpricide is being pumped into Bear Creek. The Canadian organization is helping the U.S. Fish & Wildlife Service in the fight limit the number of sea lamprey in the Great Lakes. (Dave Yarnell/News Advocate)

MANISTEE COUNTY — There’s a battle going on in Manistee County for which U.S. forces have brought in reinforcements from Canada.

It’s the fight against sea lamprey, the snake-like creature that can grow up to 35 inches long. It lives by attaching to fish, generally killing its prey.

Clint Wilson of Fisheries and Oceans Canada was checking the flow rate and stream chemistry on a tributary of Bear Creek on Thursday in Manistee County. The crew of 14 Canadian scientists along with staff from the U.S. Fish & Wildlife Service are treating the Manistee River and its tributaries to kill sea lamprey larva. (Dave Yarnell/News Advocate)

Through the next several weeks personnel from the U.S. Fish & Wildlife Service and Fisheries and Oceans Canada are applying lampricide chemicals in the Manistee River system to kill sea lamprey larvae burrowed in stream bottoms.

Last week the Canadian crew treated Cedar Creek, on Saturday they were treating Manistee River tributaries in the Copemish area, and on Sunday they treated Bear Creek near Kaleva.

Sea lamprey larvae transform to parasitic adults that migrate to the Great Lakes and kill fish. Infested tributaries must be treated every three to five years with lampricides to control sea lamprey populations.

“The life cycle of the sea lamprey dictates the treatment cycle,” said Jeff Slade, supervisor of The U.S. Fish & Wildlife Service Ludington Biological Station. “We treat the streams to remove most of the larvae. Through recruitment, they re-establish and after three or four years those larvae are of a length where we want to treat the stream before they metamorphose and go out into the Great Lakes and start feeding.”

Slade said sometimes the treatment program isn’t as effective as it should be.

“When that happens, it leaves a large portion of the larval population and if we don’t treat if for another three or four years, a good portion of those larvae are going to grow and go out into the lake before we treat it again,” Slade said. “We had a rain event right after we treated the Big Manistee last year, so we weren’t able to maintain our minimal lethal concentrations of lampricide throughout the system. That made it important for us to come back and re-treat this year.”

He said once the treatment starts, crews work around the clock to be sure there are lethal concentrations of the chemicals for at least nine hours all along the streams. Crews do a lot of research before applying the chemicals.

“The first couple of days they’ll collect preliminary information on flow rates and water pH and alkalinity because that also effect the tocicity of the lampricide,” Slade said.

From that information they develop a treatment plan.

“The Department of Fisheries and Oceans staff are the lead treatment supervisors on the Manistee County project and we have staff assisting them,” Slade said.

The Ludington Biological Station is responsible for a large portion of the Great Lakes — lampricide control and larval assessment for the lower peninsula, Indiana waters of Lake Michigan and the south shore of Lake Erie. Slade said his office works closely with the U.S. Fish & Wildlife Station in Marquette, which is responsible for Lake Superior, Western Lake Michigan and the St. Mary’s River. That office also operates the sea lamprey adult assessment program, risk management program and barrier program for all of the Great Lakes.

According to Slade, sea lamprey invaded the Great Lakes through the Welland Canal in 1920. By 1938 they had established in all of the Great Lakes. By the late 1940s fish stocks were dropping rapidly as sea lamprey adapted to the Great Lakes. The Great Lakes Fishery Commission was established by the U.S. and Canadian governments to develop and operate a sea lamprey control program.

Scientists check water samples in the Fisheries and Ocean Canada research truck at Bear Creek where it crosses Nine Mile Road near Kaleva. At work (from left to right) are Marian Seed, Richard Middaugh and Chris Best. On Saturday and Sunday the crew was applying Lampricide to Bear Creek to kill as many sea lamprey larvae as possible. (Dave Yarnell/News Advocate)

“The U.S. Fish & Wildlife Service and Fisheries and Oceans Canada are the contracted parties to do that,” Slade said. “Today there are only 10 percent of the number of sea lamprey that there were in the 1950s. We work with state, tribal and federal fisheries managers in each of the Great Lakes to establish target levels Right now we’re at levels slightly above our target, so we’re working to reduce the populations.”

Slade said it is unlikely sea lamprey will ever be totally eradicated.

“The female adult sea lamprey can produce up to 90,000 eggs, so they have a real high reproductive potential,” he said. “It doesn’t take many adult sea lamprey to create a large larvae population. None of our control methods right now will kill all of them. Most of our stream treatments are 95 to 98 percent effective, but if there are 4 million larvae and you leave 5 percent, you’re leaving a lot.”

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The U. S. Environmental Protection Agency and Health Canada Pest Management Regulatory Agency have reviewed human health and environmental safety data for lampricides, and in 2003 concluded that the lampricides (Lampricid and Bayluscide) pose no unreasonable risk to the general population and the environment when applied at concentrations necessary to control larval sea lampreys.

As with any pesticide, however, the public is advised to use discretion and minimize unnecessary exposure. Lampricides are selectively toxic to sea lampreys, but a few fish, insects and broadleaf plants are sensitive. Persons confining bait fish or other organisms in stream water are advised to use an alternate water source because lampricides may cause mortality among aquatic organisms stressed by crowding and handling. Agricultural irrigation must be suspended for 24 hours, during and following treatment.

Additional information is available by calling (800) 472-9212 or contacting the Marquette or Ludington Biological Stations through the Michigan state relay service at (800) 649-3777.

Further information on the U.S. Fish & Wildlife Service is available at www.fws/gov. Information on Great Lakes Fishery Commission is available at at www.glfc.org.

Source: U.S. Fish & Wildlife Service

 

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Posted by Dave Yarnell

Dave was formerly the News Advocate features writer and retired in November 2013.

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