Lamprey control planned for Crockery Creek

Alex Doty • Jun 3, 2017 at 11:00 AM

The U.S. Fish & Wildlife Service has announced plans to apply lampricide to Crockery and Norris creeks in Ottawa and Muskegon counties to kill sea lamprey larvae burrowed in the stream bottom.

The applications will be conducted June 13-22 in accordance with state permits. It will only take about three days to complete the applications; however, the actual date depends on weather and stream conditions.

Dan O’Keefe, Michigan Sea Grant educator, said treatment of Great Lakes tributaries is done on a rotating basis, typically every 3-5 years, in order to control the invasive species.

“The sea lamprey is the invasive lamprey that came into the Great Lakes in the 1930s and spread throughout the 1940s,” O’Keefe said. 

Sea lamprey larvae live in certain Great Lakes tributaries and transform to parasitic adults that migrate to the Great Lakes and kill fish, which could in turn result in significant damage to the region’s fishery.

“When they are growing, they live in the sediment of the rivers,” O’Keefe said.

He noted that each lamprey that matures and reaches the Great Lakes has the ability to kill about 40 pounds of trout and salmon.

“Each one takes quite a toll on the fishery,” O’Keefe said.

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

The public is still advised to use discretion and minimize unnecessary exposure. Lampricide is 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 lampricide may cause mortality among aquatic organisms stressed by crowding and handling.

Agricultural irrigation must be suspended for 24 hours during and following a treatment.

Extensive preparations are required for a safe and effective stream treatment. Prior to treatment, personnel collect data on stream water chemistry and discharge. In addition, they may conduct on-site toxicity tests with lampricide and stream flow studies with dyes that cause stream water to appear red or green.

The lampricide is metered into the stream for approximately 12 hours and continually analyzed at predetermined sites to assure that proper concentrations are maintained as it carried downstream.

O’Keefe said it’s estimated that between chemical and physical controls, 90 percent of the sea lamprey population can be controlled.

“It really is impossible to get to the very last one in a large system,” he said.

Added O’Keefe: “It’s a great lesson for all invasive species. We know (what happens) when an invasive species gets a foothold in the Great Lakes.”

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