Nemadji River to be treated for sea lampreyU.S. Fish and Wildlife Service personnel will apply lampricides to the Nemadji and Arrowhead rivers to kill sea lamprey larvae burrowed in the stream bottom.
U.S. Fish and Wildlife Service personnel will apply lampricides to the Nemadji and Arrowhead rivers to kill sea lamprey larvae burrowed in the stream bottom. Applications are conducted between Tuesday and Oct. 17 in accordance with States of Minnesota and Wisconsin permits. Application will be complete in about six days. Application dates are tentative and may change based on local weather or stream conditions near the time of treatment.
Sea lamprey larvae live in certain Great Lakes tributaries and transform to parasitic adults that migrate to the Great Lakes and kill fish. Failure to kill the larvae in streams would result in significant damage to the Great Lakes fishery. Infested tributaries must be treated every three to five years to control sea lamprey populations.
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 they do not pose an unreasonable risk to the general population and the environment when applied at concentrations necessary to control larval sea lampreys. However, as with any pesticide, the public is advised to use discretion and minimize unnecessary exposure. Lampricides are selectively toxic to sea lampreys, but a few fish, insect, 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.
Prior to treatment, personnel collect data on stream water chemistry and discharge. In addition, they may conduct onsite toxicity tests with lampricides and stream flow studies with dyes that cause stream water to appear red or green.
Lampricides are carefully metered into the stream for about 12 hours, and continually analyzed at predetermined sites to assure proper concentrations are maintained as the lampricides are carried downstream.
For more information, call 800-472-9212 or TTY users can call 800-649-3777.