Most of us learned about invasive species in our elementary and middle school science classes. We learned that these non-native species come into a foreign habitat and begin to compete with native organisms. As they make a home in these new areas, the ecosystem begins to change. In many cases, these invaders will dominate over native species and permanently alter the community of these areas. In order to be considered invasive, a species must completely overtake and alter the previous framework of the ecosystem.
Invasive species are one of the most significant problems facing the Great Lakes right now. The Great Lakes ecosystems have been effected or damaged by over 180 non-native or invasive species. These species are transported into the lakes mainly through human man-made pathways, with organisms stowing away in undrained water from recreation vehicles and on uncleaned or rinsed equipment. Some of the most widespread and urgent threats to the lakes are Zebra Mussels, Sea Lamprey, and Asian Carp.
We care about these invasions because of the significant effects the presence of these organisms cause. These species cause not only ecological damage, but also can negatively effect the economies and quality of life in the cities that surround and rely on these lakes. Industries like fishing, agriculture, and tourism can take serious hits when an area is damaged. Infrastructure can be harmed by buildup of different species. Human health can also be effected when the species produce toxins.
Zebra Mussels are one of the most commonly found invasive species throughout the Great Lakes basins. The mussel can reach a size of approximately 2 inches and are a brown in color with distinctive dark stripes. This species, native to the Black, Caspian, and Asov seas, was introduced to the lakes when one or more ships dumped their ballast tanks into the water. They were first found in 1988, and were present in all five lakes by 1990. Zebra mussels have been extremely damaging to the Great Lakes region. These mussels tend to form collections on surfaces, and have caused problems by clogging and damaging water intake systems in the lakes. This causes a huge economic effect of their presence, with a price of almost $500 million a year dedicated to their removal. These mussels also accumulate toxins in their tissues, which can then be passed up the food chain and into the human food supply.
Sea lamprey is another invasive species causing trouble in the Great Lakes. Lamprey, native to the Atlantic (and possibly Lake Ontario, although this is disputed by experts) were introduced to the Great Lakes via man-made canals and locks, allowing the fish to bypass natural separating barriers (specifically Niagara Falls as an access point to Lake Erie). These eel-like fish can grow to lengths of up to 47 inches. The organisms are parasitic and feed by attaching their sharp, curved teeth to other fish to feed on tissue and fluids, as shown in the picture above. Because of this parasitic behavior, lamprey have a large effect on fish populations, and since their introduction have had a significant effect on the fishing industry in the Great Lakes. Specifically, these fish have had major impacts on lake trout, whitefish, and chub populations. These predators made almost all catch unusable, because up to 85% of fish not killed by lamprey showed evidence of lamprey wounds. This had devastating effects on the Great Lakes economies, especially when first introduced in the the 1950s and 60s.
Most recent debate about invasive species in the lakes has been centered around Asian Carp. This is because the Asian Carp has not yet infiltrated all of the Great Lakes but is growing increasingly closer, with a specimen being caught only nine miles from Lake Michigan in the summer of 2017 and fertile 9 fertile individuals caught in three different lakes between 2013 and 2016. “Asian Carp” is actually a group of four different species of carp, all fo which are highly aggressive predator fish that will likely out compete all other large fish in the lakes and completely change the layout of the Great Lakes ecosystem should they become prevalent.
Management of these invasive species is now one of the largest ecological concerns for Great Lakes Scientists. For Zebra mussels, targeted bacteria are being tested as a control mechanism. For sea lamprey, early containment methods included electrical barriers and dams. A lampricide chemical is currently being used to kill larval lamprey. To fight the carp invasion, work is being done to build an impassable barrier between the Mississippi River and the Lakes to prevent crossover. These control methods are not cheap. The Canadian federal government just committed $20 million towards the fight against Asian carp, in addition to the large sums of money being thrown to the cause from the US and nonprofits.
Invasive species control is one of the most publicized and talked about environmental problems, mostly because improvement of this problem relies heavily on public knowledge and action. While many of the initial introduction previously were due to dumping of commercial ballast tanks, movement of species is just as significant when it occurs through personal recreation vehicles like boats, jet skis, and kayaks. All of this equipment should be drained of all water and flushed to ensure any trapped organisms are released and now transferred to new areas. While the species with widespread effect are no longer possible to eradicate, preventative measures can protect other waterways for the species effecting the Great Lakes and prevent new invasive species from entering the Great Lakes.
(All pictures were sourced from the first linked site in description of species.)
I thoroughly enjoyed reading about these invasive species (although I do not enjoy the unpleasant effects the species have on the environment). Your blog felt professional and well-phrased. While I was reading, I felt the sense that I was scrolling through a professional scientific blog! One thing I would suggest is adding captions to your pictures. When looking at the pictures, I was at times unsure of which part was supposed to be the invasive species (with lamprey picture, I couldn’t tell if the lampreys were part of the fish, and with the Asian carp picture I kept looking for little lampreys.)
It’s very interesting that I was reading through this because I live around the Great Lakes area, and I have never consciously thought about the impact of invasive species. My grandpa would try to fish in the Mississippi River in Minneapolis for the Asian Carp like you mentioned and my parents would always get mad at him because they realized the health detriments that the carp would cause. The reason why I say “consciously” is because I have always been around the lakes region, and there would be conversations about the organisms that live within those lakes, but I brushed it off as if it wouldn’t impact me. I do agree with you that it is about public knowledge and action because if more people know how these species are affecting their own food production it would probably be a bigger deal than it is now. I don’t know how much I agree with the ways to get rid of these species, especially the lampricide chemical that you mentioned. Obviously any proper and healthy mechanism of getting rid of these species will be expensive and long and hard, but in my personal opinion dumping chemicals into the fresh water of the lakes will also cause more problems in the future.
Although I have never been to the great lakes, I can only imagine their beauty and the lengths to which people take in order to protect them. All through out reading your article I was thinking of a local forest near my home town. While the invasive species are much smaller, taking the form of ants and a type of plant, the impacts are extremely clear such as with your three examples. Over the past 3 years I have watched large wooded areas disappear because of these invasive species. Much like your article there are a multitude if groups attempting to combat this problem. These groups give me great hope that the forests of my home town and the the great lakes of yours, will return to their normal activity and successively “evict” the invasive species.
This was a very interesting post on a very interesting topic. I have an interest in animal and ecology so I enjoyed reading your post. I never realized that invasive species can affect so many different parts of the economy. I knew these species had caused harm to other wildlife in the ecosystem, but I didn’t know it could have an industrial effect as well. I can’t help but wonder how big of a hit the economy is taking from these invasive species (I can imagine that it is fairly significant!). Also, are there any invasive species in the areas surrounding the Great Lakes? Over all, great post!
I really enjoyed your post! This is a really interesting topic, one that not many people know about. My family used to go and spend a few weeks every summer on an island in the Straits of Mackinac. My dad fished a lot and one time he came back with a fish that had a lamprey stuck on it. I knew they were weird looking, but I never realized that they were a harmful invasive species. The information was presented in a really interesting and thought out way. There were a few minor spelling errors but overall your blog is really well organized.