FTV: The Battle Rages On
When the St. Lawrence Seaway was constructed in the 1950s, it opened a whole new era of commerce stretching from the Atlantic coast all the way to Duluth, Minnesota. It also rolled out the red carpet for a host of invasive species. Some (like the sea lamprey) were already here by then while others hitched a ride in the ballast tanks of ocean going freighters (see zebra mussels and round gobies). When the first canal systems opened to by-pass Niagara Falls in the 1920s, the sea lamprey simply swam through the open door into the Great Lakes and began to spread throughout the inland seas all the way in the upper lakes. To give you an idea of how quickly they came to dominate these waters, a July 26 1957 article in The Milwaukee Journal reported there was a, “Blind and desperate hunt [to find a way to combat the lamprey invasion]. The lamprey had practically wiped out the lake trout in Lake Huron and Lake Michigan and threatened to do the same thing in Lake Superior.” The piece was written to announce the first successful use of chemical lampricide to stem the tide and it was front page news.
My first recollections of lamprey go back to the early 1960s when we would cross the Silver River bridge on the Townline Road in Baraga County. We took this route to our camp where the Silver opened into the foot of Huron Bay. Just upstream from the bridge, there was a cable strung across the river with metal rods extending down into the river. Dad explained it was a ‘weir’ designed to keep lamprey from migrating upriver to spawn. On later occasions, we would see the river run yellow for a few days. The postings at the boat landing just downstream from the weir announced the color change was from the lampricide being used to further control the spread of the eel like invaders. Even if it was advertised as ‘non-toxic to humans or pets’, we still avoided swimming in the river for a few days until it cleared up.
The weir was removed at some point but in the 1990s, we were reminded that the lamprey suppression efforts were still ongoing. We were on our usual three week mid-summer stay at The Swamp when a white truck pulled up in front of the porch. I went out and couldn’t help but notice that behind the pickup there was another one with a utility trailer in tow, a third with a boat and trailer attached, and a fourth with a crew cab filled with people. All were sporting the logo of the Great Lakes Fishery Commission Sea Lamprey Control unit. The man in the lead truck hopped out and asked, “Where is the boat landing?” When I pointed up river and said, “About a half mile that-a-way on the other side of the river,” he looked at me like I had grown another head.
The lamprey guy pulled a USGS Topographic Map from the cab and pointed at our location and said, “No, the map said it is right here.” I had used United States Geological Survey maps in my Geography/Earth Science classes for many years. I had also sold them when I was the Geography Department Map Librarian at Northern Michigan University in 1979-80. Their location confusion was immediately apparent. During the Regan administration, the United States Geographic Survey began exploring the conversion of their topographic quadrangles from English units to Metric. They produced some provisional maps (maps that would be ground tested and proofed before being finalized for mass printing) but later abandoned the idea of a wholesale change altogether. The map the lamprey team was using was one of the provisional maps that was never actually released for public use.
“I see the problem,” I told him. “When these provisional maps were circulated for comments, I had written to the USGS that they had erroneously marked our property as a public boat launch. We have been here since 1958 and it never was a public launch site. The public site is up river on the Skanee Road side just past the Townline Road turn off.” As it began to sink in, he asked, “Are you sure?” so I pointed to our dock and asked in return, “Do you think this looks like a public boat launch?” Once we cleared up the confusion, they had to back their vehicles and trailers out to the main road as there wasn’t room to turn around where we stood talking. As a courtesy, I remind him to keep to the outside of the river bends where the deeper channel was located: “There is a big sandbar across the mouth of the river you won’t be able to see at high tide.” That part didn’t sink in and we watched them roar up the middle of the river and get stranded a couple of times before they moved on.
The successful lampricide trial announced by the Milwaukee Journal was done by the Hammond Bay Biological Station (located on Lake Huron about 30 miles southeast of Cheboygan, Michigan). A more recent article marking the events of 80 years ago (from the August 7, 2025 Milwaukee Journal Sentinel – ‘The Fight Continues) puts some historical perspective on the battle for the Great Lakes. Author Andrew Montequin puts it bluntly: “It’s not an exaggeration to say this research station saved the Great Lakes fishery.” According to Montequin, the nature of the beast, so to speak, makes the stakes in the lamprey suppression very high: “Each sea lamprey feeds on about 40 pounds of fish over their lifetime and females typically lay up to 100,000 eggs. It is no surprise sea lampreys pose a threat to the $5 to $7 BILLION Great Lakes fishing industry (the amount varies depending on which source one consults).”
Montequin’s article focused on the Cheybogan area in part because of the historic nature of the area’s involvement in the lamprey suppression effort. The numbers gathered by current lamprey suppression efforts in the same area provide insight to the nature of the ongoing battle. He notes that in just three nearby streams, including the Cheybogan River, traps recently pulled in 14,000 adult sea lamprey over a two week period. Nick Johnson, director of SupCon (The Great Lakes Fishery Commission’s Supplementary Lamprey Control Initiative) did the math comparing his family’s fish consumption to that of the lamprey’s: “This past winter, when the lake froze over, we caught 100 pounds of lake trout in one day. People would tease me that the trout would go extinct if we kept doing that. If we did this every day, it would take 15 years straight to kill as many trout as the lampreys we caught here in just 14 days.”
As a matter of coincidence, I happened to see a re-run of Mike Rowe’s popular Dirty Jobs from November of 2010. Part of this episode had him in ‘northern Michigan’ learning how to be a ‘lamprey exterminator’. ‘Northern Michigan’ in this case was probably the same area Montequin was writing about. This geographic description isn’t unusual; for some strange reason many people can’t wrap their heads around the Upper Peninsula of Michigan being farther north than northern Lower Michigan. Go figure, but I digress. In this segment, Rowe was attached to a Fish and Wildlife team and got to work on several steps in the process. Using portable backpacks with probes, he was shown how to shock the stream to get the juvenile lamprey to rise out of the mud so they could be scooped up for a census. These numbers are then used to establish which type of eradication method is needed for that stream. Adult lamprey are removed from traps, sorted by sex, and then either sterilized (the males) or packaged for further study and educational purposes (the females). Some of the adults captured were termed ‘beepers’ as the tracking beacons they had received previously set off a detection device.
I wish they had the backpack shockers available back in the 1970s. When my brother was working on his Master of Arts degree in Biology at Northern Michigan University, he did his thesis about fish species in the lakes of the McCormick Track near Michigamme. To get a census on those species he used a combination of traps and electro-shocking so he could tally the species in each lake (before returning them to their home waters). Shocking a lake took a little more equipment so he rigged a flat bottom boat with a platform holding two shocking booms and a portable generator to run them. It worked great, but there was a down side. Not all of the lakes could be reached by road and we ended up hauling all the equipment down foot trails, some as far as a quarter mile from the nearest road. We actually decided the move between two of the lakes was easiest to accomplish by dragging the boat up a small connecting stream.
The lakes in the McCormick track are designated ‘no motors allowed’ so Ron got some unpleasant gestures from hikers. They had no way to know he was there with the proper permission to operate an outboard motor on these lakes. Hauling the shocking boat cross country was an interesting project (not necessarily fun) and helping Ron out over the summer did have some bonuses. It allowed us to get a close up look at the former McCormick lodge and associated buildings. Not many years later, they were dismantled and removed from the area leaving the McCormick track a limited access wilderness area. Watching Mike Rowe accidentally cross his positive and negative booms (thus shutting down his backpack shocker) reminded me of Ron’s sage advice: “Do not let the booms touch – that would be bad.”
Reporter Madeline Heim wrote an article in the same Milwaukee Journal Sentinel all about a more recent invasive species invader. Asian carp have been slowly working their way up the Mississippi River tributaries and the states are doing everything they can to keep them from spreading into the Great Lakes. Asian carp (silver, grass, and bighead varieties) were brought to this country as a way to control plant growth in southern ponds. Flooding allowed a small population to escape into the wild thus producing an explosion in their population. They are fast breeding species that can negatively impact native fish by competing for food and space. Their large numbers can also degrade water quality which in turn affects sensitive species like freshwater mussels. Silver carp pose a different kind of danger: when agitated by the sound of outboard motors, they have been known to jump out of the water. When a flying carp lands in a passing boat, it does more than just startle the boaters. Water skiers and those operating jetskis are also at risk. Imagine being impacted by a flying fish without wings.
An invasive fish consultant from the Minnesota DNR named Grace Loppnow told Heim, “At this point, we don’t have an abundance [of the invasive carp] that’s causing a problem. We’re trying to keep it that way.” The newest method to try and limit the spread of Asian carp sounds a little backward to the lay-person: feed them! Researchers are installing floating feeders at selected locations that will lure bighead and silver carp. By dispensing four or five pounds of a carp’s favorite food consisting of pelletized nutrient rich algae, they are hoping to train them to visit regularly. If the fish can be lured to visit the floating feeders, commercial fishermen will follow to catch them, thus reducing the population.
What will they do with the fish harvested? These will be donated to zoos and raptor centers which would use them as food. Human consumption has been studied and the flesh compares to white fish. It is said to be white, flaky, and mild-tasting but it does have fine bones that some find undesirable. Rebranding them as ‘Copi’ to encourage human consumption has also been tried by some states and research organizations. If large enough numbers can be harvested, they could also be processed for use in the pet food industry.
The ‘feed the pests’ method is only the latest attempt at controlling the Asian carp. According to Heim, “Scientists have worked for decades to find ways to control invasive carp populations – installing barriers that deter the fish with sounds and bubbles, using special nets to snag fish that jump out of the water, and using tags to track them so their movements can be monitored. They have even tried to use remote-controlled kayaks to herd them to specific locations. They have proved to be hard to manage in areas where the Mississippi River is wide with many hiding places as it is near LaCrosse, Wisconsin. In colder months, Loppnow told her that the fish are sluggish and travel in packs, making them easier to round up.”
Will baiting work as a method for controlling the spread of this invasive species? Only time will tell. As with continuing efforts to control sea lamprey, the battle to control invasive species isn’t over by a long shot.
Top Piece Video: I couldn’t find any music by a band called The Lamprey so you will have to settle for The Eels.