Residents of the Keweenaw Peninsula may have noticed the presence of a federal government agency in their towns and along the waterways and asked themselves, “what are they doing here?” The US Fish and Wildlife Service is treating several area rivers and streams with a lampracide that ultimately protects the fish population of Lake Superior.
Often times people confuse the US Fish and Wildlife Service with the Department of Natural Resources who regulates fish and game in the state of Michigan, but this group of men and women serve a much different purpose.
‘We’re up here in Hancock, Michigan treating a few streams.’ said, Chris Gagnon, a biologist with the US Fish and Wildlife Service. ‘This one here, the Gratiot River, we’re treating Mud Lake outlet over but the town of Gay, Michigan, and also the Graveraet River over toward Toivola.’ Said, Chris Gagnon, a biologist with the US Fish and Wildlife Service.
Chris and his crew are currently stationed in the Keweenaw Peninsula with mobile labs, and a team of researchers who are making sure that fishing in Lake Superior remains the best that it can be, and they are doing so by battling a predator amongst these waters that nearly wiped out the fishing industry many years ago.
He also said, ‘As adults, sea lamprey will come up streams like the Gratiot river here, and spawn in the gravel much like a salmon or steelhead. After they spawn and lay their eggs, the eggs will hatch and after they hatch the larvae will go downstream and seek out preferred habitat which is generally the sand and the silt in the streams. They’ll live there for about three to four years as non parasitic, harmless larvae.’
This little fellow may seem harmless. But within a few short years, if it weren’t for Chris and his crew, it would develop nearly a hundred teeth and latch on to every fish that it can, sucking the life out of nearly every one of them.
‘They’ll metamorphose into miniature adults. They’ll grow their sucker mouths, they’ll turn color, grow eyes, and they’ll swim out into the Great Lakes where they’ll parasitize on the game fish species that we love, the lake trout and the salmon, for about a year and a half and then they’ll come back upstream as adults, spawn and repeat the whole life cycle over again.’ Gagnon added.
Sea lamprey are not native to the Great Lakes. in the 1800’s the Welland Canal was created in Ontario, Canada. The Canal bypasses Niagara Falls, which created a shipping channel between Lakes Erie and Ontario allowing vessels to and from the upper Great Lakes to reach the Atlantic Ocean. As vessels increased in size, a wider and deeper shipping channel was needed to accomodate, and the retrofitting project of the canal began in 1913.
‘Once we opened up that canal lampreys were able to freely swim up to the Great Lakes.’ Said, Gagnon,
Over the next twenty five years lamprey had made their way into all 5 of the Great Lakes.
He stated, ‘After the sea lamprey invaded the Great Lakes it didn’t take very long for them to really decimate the lake trout population. Extirpating them in Lake Michigan, and in Lake Superior nearly wiping them out so what we do is very important to the fisheries and the economics of the Great Lakes.’
With lake trout were near extinction in the 1950’s, the Great Lakes Fishery Commission was formed as a joint effort between the United Sates and Canada who’s goal was eradicating lamprey and reviving the fish population.
‘By the 1950’s, early 60’s we started treating streams after a lampricide was found that was effective on killing the larval sea lampreys.’ Said, Gagnon.
In the 1960's 85% of large Great Lakes fish exhibited sea lamprey wounds. That number dropped drastically to 2% by 1983, and has remained under control since then through the use of lampricides, and a few other methods of controlling the invasive species.
With over 50 years of data collection the efforts of the US Fish and Wildlife Service have lamprey control down to a science. Biologists monitor Ph levels, stream conditions, and lamprey population estimations. They then use that data to calculate when and how much treatment is needed, to maintain the proper balance that will not harm fish or plants in the water shed. The lampricide is also said to nonharmful to humans.
Generally speaking, once a stream is treated it doesn’t need to be retreated for three to five years, such as the case with the Gratiot River here.
‘In 2015 was the last time we treated this river after they found lamprey in here. Since then lamprey have been found again in this stream so we’re back here to retreat it.’ Gagnon concluded.
Chris and his crew will be working in the area for a few more days, before heading to other parts of the Lake Superior watershed and continuing their mission.