The Indiana Department of Natural Resources announced final preparations are underway for construction of a low-head, fixed-crest dam to block passage of sea lampreys in Trail Creek, a stream in Michigan City that supports spring spawning runs of native fish.
Sea lampreys are a pest in the Great Lakes region. They are native to the Atlantic Ocean and made their way into the Great Lakes in the early 1900s via the St. Lawrence Seaway when the Welland Canal connected Lake Ontario to the upper lakes.
Sea lampreys attach to fish with a sucking disk and sharp teeth as they feed on body fluids, often scarring and killing host fish. An adult sea lamprey can kill 40 or more pounds of fish. Sea lampreys have been a major cause of the decline in lake trout populations. Lake trout are a long-lived species that don’t reach maturity until at least age 6 and live in excess of 20 years, making them a prime host for sea lamprey.
Barriers are one of the integrated approaches used to reduce the number of sea lamprey in the Great Lakes and have reduced or eliminated the need for chemical treatment on many streams. Barriers are constructed to block the upstream migration of spawning sea lampreys while allowing other fish to pass with minimal disruption.
Historically, Trail Creek was treated with a chemical lampricide about every six years to reduce the number of young lamprey entering the lake. Placement of the barrier should eliminate the need for these treatments and reduce the number of lamprey in the lake.
The 52-inch-high, 45-feet-wide barrier will be placed in Trail Creek near Springfield Avenue. It will include a lamprey trap and a fish ladder that will allow non-jumping fish to move freely through the system.
The trapping facility will be operated from the middle March until June 15. All adult sea lampreys will be collected and removed while other fish species will be passed above the barrier. A jumping pool immediately downstream will allow adult steelhead and salmon the ability to move above the barrier during their upstream spawning migrations. Fishing opportunities will be restricted within 100 feet on either side of the barrier.
The DNR is a partner in construction of the barrier along with the U.S. Fish and Wildlife Service, Great Lakes Fishery Commission, and the U.S. Army Corps of Engineers. Additional support for the project was provided by Michigan City and the local school corporation.
The Great Lakes Fishery Commission was formed in 1955, in part to control sea lampreys.
Additional information on sea lamprey control in the Great Lakes can be found at the Great Lakes Fishery Commission website: http://www.glfc.org/sealamp/