For Immediate Release
July 20, 1998
Ellie Koon (USFWS) 616-845-6205
Marc Gaden (GLFC) 734-662-3209
Perry Smeltzer (NRCS) 616-627-2565
Sea Lampreys Finding "Keep Out" Sign at
Renovated Rogers City Dam
Partnership between Presque Isle Conservation District and fishery agencies to bring an end to lampricide treatments in upper Trout River
Rogers City, MIóSummer is here and sea lampreys have been on the move, migrating up Great Lakes streams to spawn. But sea lampreys moving up the Trout River are finding a "Keep Out" sign posted at Sportsmanís Dam in the Herman Vogler Conservation Area near Rogers City, owned by the Presque Isle Soil Conservation District. Recent modifications to the dam are preventing sea lampreys from passing upstream into the upper Trout River and its tributary, Hartwick Creek. The dam was "lamprey- proofed" as part of a cooperative project between the Presque Isle Soil Conservation District, the U.S. Department of Agricultureís Natural Resource Conservation Service (NRCS), the U.S. Fish and Wildlife Service (USFWS), Fisheries and Oceans Canada (DFO), and the Great Lakes Fishery Commission (GLFC).
The Trout River, a tributary to northern Lake Huron, is prime spawning habitat for the exotic sea lamprey. Sea lampreys, fish parasites native to the Atlantic Ocean, spawn in hospitable Great Lakes tributaries then die. Lamprey eggs hatch, live as larvae for several years in silty areas of a river, and then migrate to the open waters of the Great Lakes to prey on fish. Lampreys, when uncontrolled, inflict enormous damage on a fishery; lampreys in the Great Lakes nearly drove the native lake trout, whitefish, and cisco populations to extinction in the 1940s and 1950s. The Great Lake Fishery Commission-sponsored sea lamprey control program has reduced lamprey populations by 90% in most areas of the Great Lakes. Unfortunately, populations in the St. Marys River are again having a severe impact on fish in northern Lake Huron, but efforts underway using lampricides, trapping, and release of sterilized males will promise to improve the situation. Meanwhile, lamprey barrier projects such as those on the Trout River will improve the level of control on smaller streams and free up funds for application in critical areas.
Sportsmanís Dam, built near the turn of the century, consists of an inclined main spillway built of mortared stone and a concrete auxiliary spillway. Adult sea lampreys, snake-like fish about 18 inches in length and 1 Ĺ inches in diameter, can be blocked by a vertical drop, but can climb inclined surfaces by attaching with their suction-cup mouth, swimming in short bursts, and re-attaching. Rogers City residents have observed lampreys passing over the dam in this manner for decades. In addition, the concrete auxiliary spillway had been breached by high water and lampreys found a convenient route around its south end.
Sea lamprey control agents, noting that lampreys easily passed the dam, approached the Presque Isle Soil Conservation District and reported that, with minor changes to the exiting structure, the dam could become an effective sea lamprey barrier. In 1997, work was undertaken to install a vertical step across the face of the main spillway and to rebuild the south portion of the auxiliary spillway. In addition, a built-in sea lamprey trap was included in the design to allow removal of spawning lampreys and to serve as a source of male lampreys for the St. Marys River sterilization program.
The upper Trout River and its tributaries are treated with lampricide every four years, which is expensive and labor-intensive. The cost of a typical treatment of the Trout River is about $90,000. The modifications to the dam cost just $13,000. With establishment of a lamprey barrier at Sportsmanís Dam, treatment of just the lower river, if necessary, will be much less costly and more effective.
The Canadian Sea Lamprey Barrier Engineer with DFO and the U.S. Barrier Coordinator with the USFWS provided guidance on the design. The modifications were financed by the Great Lakes Fishery Commission and overseen by staff of the Natural Resources Conservation Service. Local contractor Fleis Excavation, Inc. did the construction.
"This project will add to improvements in the level of sea lamprey control in Lake Huron," commented Dr. Chris Goddard, the Great Lakes Fishery Commissionís Executive Secretary. "The partnership between the Presque Isle Soil Conservation District and fishery agencies is a prime example of efficient, cooperative fishery management. This collaboration will serve as a model for what we can do with the help of all people who want a healthy, productive Great Lakes."