Great Lakes Aquatic Habitat News
The Newsletter of the Great Lakes
Aquatic Habitat Network and Fund
Volume 8, Number 5 • September-October 2000
Great Lakes Aquatic Habitat NewsThe Newsletter of the Great Lakes
|
|
When most people think about brook trout they conjure images of beautiful and delicate fish, which are often the rare prizes found in headwater streams. Few think of large trophy sized fish. Yet, in Lake Superior in the late 1800s, large brook trout were abundant. These trout, called “coasters” because they tended to dwell near the coast of Lake Superior, exhibited a life history more like a sea-run salmon than their headwater-dwelling sisters. Juvenile coaster brook trout spent their early life in tributary streams or in sheltered shoal areas and then migrated to the large lake waters for much of their adult life. They then returned again to those same rearing grounds to spawn over cool groundwater upwellings. Consistent and reliable information about the stocks are lacking but current populations have breeding age fish that can average 15 inches, with a few topping 20 inches. They were highly prized for fishing because they were easy to catch, large, and tasty.
As is true in many cases, the very qualities that make a species attractive to humans also become its undoing. Some have reported that coaster stocks were depleted by the mid-1800s because of overfishing. Coasters were extremely vulnerable to angling pressure. Compounding the problems they had because they were a desirable sport and commercial fish, habitat degradation from logging, mining, road development, poor land use practice, and the introduction of pacific salmon and other species of trout all contributed to further declines in their populations. By the mid-1900s, viable populations of coaster brook trout were found in very few locations. The Nipigon River in Ontario is probably the most well known site. The coasters found in and around the Nipigon River and Bay are particularly large. Other noteworthy remnant populations can be found on Isle Royale and in the Salmon Trout River in Michigan.
Over the years agencies within the Lake Superior basin have made repeated attempts to restore coaster brook trout. They have done this mostly by stocking various strains of brook trout. For a number of reasons these efforts met with limited success. Fortunately, since the mid-1990s there have been renewed efforts to reestablish coaster brook trout, which is an important part of the natural legacy of Lake Superior. Recent projects have included research on the life history of coasters, development of wild brood stocks, habitat protection and restoration, and controlled stocking to reestablish viable populations. Trout Unlimited activists have played an important role in these efforts. TU, in fact, was the only private organization appointed as a member of the plan development team, which led to the publication of “A Brook Trout Rehabilitation Plan for Lake Superior” in 1999. Initial results have been promising and there is renewed optimism about the future of these unique fish. Some highlights of TU’s involvement and their contributions to coaster brook trout restoration are listed below.
Genetic Studies – In cooperation with a number of partners, TU has helped support a series of genetic studies. The studies are meant to find out if there is a genetic basis for brook trout exhibiting this particular life history pattern. No specific genetic marker has yet been detected, but more sensitive genetic studies are currently in progress. These studies did reveal that coasters may spawn on groundwater upwellings along the lake shore as well as in the tributary streams.
Population Studies – The US Fish and Wildlife Service has conducted population studies on the known remnant populations of coaster brook trout on Isle Royale. Although ongoing, this study has already provided important insights into the life history patterns of coasters. As with the genetic studies, this was supported in part by TU’s Coldwater Conservation Fund and funds from TU Illinois Council. The Minnesota Council of TU has also provided scholarships to two graduate students who are studying the life history of coasters and their habitat requirements.
Stream Habitat and Fishery Surveys – The Gitche Gumee Chapter of TU was successful in obtaining two Embrace-a-Stream grants to work with the Minnesota DNR to survey Lake Superior tributary streams. They looked for evidence of any existing remnant coaster populations as well as potential efforts for reintroduction. They have found some brook trout in the lower portions of streams with some evidence that there is migration to the lake.
Protection from Overharvest – Since coaster brook trout are so vulnerable to overexploitation, protective regulations are critical to the success of coaster restoration efforts. Both the Michigan and Minnesota TU Councils have been successful in lobbying their respective states for better regulations.
Brood Stock Development – When the population of species has been so decimated often the only chance for recovery requires reintroduction from conservation brood stocks. TU councils and the national office have supported the US Fish and Wildlife Service in the development of wild brook stocks from the Isle Royale populations, and contributed to efforts by the Red Cliff Tribal hatchery which is home to the only disease-free Nipigon River broodstock.
Reintroduction Efforts – The US Fish and Wildlife Service and the Grand Portage Tribe in Minnesota have cooperated on an experimental reintroduction of coasters into Grand Portage Creek. The reintroduced populations are small, but there are promising signs of natural reproduction. The Minnesota Council of TU assisted with public outreach and education, including a special feature story in tribal and other local news media and presentation of youth education awards to tribal members for their efforts on Grand Portage Creek. There are also new attempts to reintroduce coaster brook trout into the Gratiot River in Michigan.
Habitat Protection and Restoration – TU and its partners have embarked on a multi-year effort to develop a watershed restoration plan to restore habitat on the Salmon Trout River in Michigan and protect the resident remnant population of coaster brook trout. Michigan’s Copper Country TU Chapter, the Illinois Council of TU, the Coldwater Conservation Fund, and TU’s Shared Streams program have all contributed to this effort. Across the border in Wisconsin, TU’s Wild River Chapter, the Wisconsin State Council, and TU national staff helped their partners obtain federal funding to establish the Whittlesey Creek National Wildlife Refuge. The US Fish and Wildlife Service believe that the Whittlesey will be a potential candidate for coaster brook trout reintroduction efforts in coming years. TU has also been participating on a task force in Wisconsin to help the WDNR develop their own rehabilitation plan for coaster brook trout.
Public Education and Outreach – Trout Unlimited has developed a restoration brochure and commissioned a coaster brook trout painting as part of a public education effort. TU is planning a much larger public education and media outreach strategy for the coming years.
The efforts listed above are just the beginning of a long journey. We still need to know much more about the life history of coasters and which brood stock strains are most appropriate for reintroduction. We also need to continue to protect and improve habitat, and protect populations from overharvest. And finally we need to keep raising public awareness and support for coaster brook trout reintroduction.