INVASIVE SPECIES: LET'S TALK ABOUT IT
By Mashkodebishikigahbaw, Benji Sam
Lakes, streams, rivers, oceans, and wetlands all provide a sacred connection to life and wellness throughout Indian Country. From nickel mining to pipelines to fertilizer runoff, protecting the quality of water that surrounds the Mille Lacs Reservation and connecting waterways from human impact has been an important staple of our duty as Anishinaabe. Yet, another challenge faces the waterways of the Mille Lacs Band (MLB) that may have a more lasting impact than all the previously mentioned. So why are we not talking about it?
Over the last two decades, a series of invasive species were introduced that have not only survived in Mille Lacs Lake, but are now thriving. These species have developed a cascade as large as any in the history of the lake to current biological knowledge and yet almost nobody wants to acknowledge it. Since the early 2000s several changes have been seen across the unbelievably biodiverse ecosystem that creates Mille Lacs Lake. With such an economic impact to the MLB, the local communities that surround the lake, and an entire region of central Minnesota that rely heavily on the resources at hand, maybe more people should be talking about it.
Biologists from the MLB Department of Natural Resources (DNR), the state of Minnesota DNR, independent study groups from the University of Minnesota-Minneapolis and Duluth campuses, and many other concerned outdoor-folk have noticed a sweeping change across the lake that began in recent memory. Changes include the introductions of the spiny waterflea, Eurasian watermilfoil, Chinese mystery snail, rusty crayfish, and the curly-leafed pondweed. These species have been found in Mille Lacs or existing watershed and have left a tremendous footprint in the ecosystem that has changed the projection of the health of the fishery for the foreseeable future.
Carl Klimah, who is the fisheries manager for the MLB DNR, has been a part of the invasive species conversation during his tenure with the Tribe and has conducted years of research into the depth of the environmental impact of invasives each of the last few years. “Invasive species changed an entire ecosystem from the soil to the water and act like viruses to plants, fish, birds, and the water itself,” said Klimah. “We have seen an entire forage base collapse, and an entirely new food chain has begun to emerge in the lake that we have not seen across all the historical data we have available.”
Large lakes across the state of Minnesota are not entirely unique in the build of their complexity from soil content to their susceptibility to contract such invasives with high levels of travel to and from the Mille Lacs area. Most of the large lakes managed across Minnesota under the MN DNR large lake division also deal with multiple invasives whose affect is still relatively adolescent in their impact. “We aren’t even sure where most of these invasive species came from, but we estimate that their impact might be one that lasts the next few hundred years,” said Klimah.
It has been well documented that invasive species contact new bodies of water through poor transportation practices such as incomplete emptying of live wells, bait bucket dumping across bodies of water, live vegetation on boats and trailers, and by neglect in managing dock systems that may harbor live specimens of invasives looking for new water to invade. These are the factors that we have some control over — manmade or influenced factors such as drying boats out at least 48 hours before traveling to a new body of water, practicing smart bait transfer practices, etc. They should be at the top of the priority list for all outdoorsmen and women.
However, there are also some biological factors that may contribute to ongoing invasive species traveling between bodies of water, including high water flooding that spreads waterways and carries live vegetation and species from one body of water to the next. There has also been speculation that marine-based birds including ducks, geese, and cormorants may also impact natural species in bodies of water in transport from lake to lake. In either case, we now understand that the effects of these invasives outcompete native species for both food and habitat.
Invasive species like the spiny waterflea, Eurasian watermilfoil, and zebra mussels have changed the entire food chain — not simply affecting the fish or lake themselves. Most of these species have had a detrimental impact on the soil conditions and the presence of zooplankton, which is the baseline of the major forage base in Mille Lacs. For example, between 2006 and 2012, zebra mussel adult density expanded their population from 0.0015 per square meter of lake floor in 2006 to 13,651 per square meter in 2012 (Jones & Montz, 2020). In this timeframe, the expansion of the spiny waterflea also impacted the foodchain in the lake and has competed against natural plankton, and their long, sharp tails make them a difficult food for native fish like walleye and perch.
“When we look at all the data we have in front of us, it’s impossible to ignore the impact invasive species have had on the overall biodiversity and biomass in the lake,” said Klimah. “There has been a chain reaction in isolated drop in zooplankton that correlated perfectly with the significant drop in walleye population.” And ti’s true — when the data is observed it is undeniable that when the invasive species boomed and the zooplankton crashed to historically low levels, so did the walleye. Evidence is proving that the survival rate of hatchlings and fingerling walleye is at a historically low level, and one could conclude that when the food that provides nutrients for the majority of all minnows, fry, and fingerlings throughout the lake is disappearing, then so too will the forage base that survives on that food source.
“The chain reaction is incredible, and we are not even yet aware of the impact on other vegetation, birds, water quality down river, and the future of the Ogaa (walleye),” Klimah said. “It’s like playing with multiple wild cards and nature keeps shuffling the deck. We need to do everything we can to reduce the impact of invasives because this might be something that still affects this community generations from now.” This means utilizing the mobile and permanent boat cleaning stations every time we trailer a boat off Mille Lacs, reducing harmful fertilizers and pesticides on lake shores, maintaining shoreline integrity to reduce erosion, and remembering to clean, dry, and transport fish/bait in a responsible manner.
With these invasive species leaving such a lasting impact, we owe future generations our complete focus and attention to maintain our stewardship of the land, the water, and building healthy habits around protecting these resources. The land and water are our greatest resource as Anishinaabe, not only for food but also for the greater economic impact on the Tribe and the community that calls this place home. When the lake does well, so does the Mille Lacs Band. Our duty to the water that provides for us has been and should always be our top priority.
