Humans at War with Alien Invasion: But Who Is the Real Fish Killer?
Humans are destroying our planet. One of the most devastating and unknown ways is through invasive species. I chose an example to demonstrate this close to home, in our very own Lake Ontario.
We still don’t know where they came from. If they were introduced through the Erie Canal in 1825 or from the Welland Canal in 1919. What we do know is it wasn’t a problem before we started to build canals connecting bodies of water all around Canada and the U.S. Before we knew it though, it had spread like a virus through Lake Ontario to Lake Erie, Michigan, Huron and Superior. Killing our local fish populations and creating a very large unbalance in our ecosystem that has impacted our natural ecosystem and Canadians for many years to come. I am talking about one of the most famous invasive species in Canada, the Sea Lamprey.
How did they get here? They were first discovered in the 1830s, where they were native to the inland Finger Lakes and Lake Champlain in New York and Vermont. It was through the expansion of human cities and the need to transport goods across the border that compelled us to connect bodies of water that nature never intended to. This is what led to the spread of this species that was previosly unfamiliar to the waters of Canada. The sea lamprey is not evil, no plant or animal is evil, it was merely trying to survive and grow and we presented it with a whole new habitat that it was not natrtually supposed to thrive in. So, it isn’t the lampreys fault, it’s ours, we are the most invasive species on this planet.
So what so bad about it? So what, theres a new fish in our waters, how can it hurt other fish? It has killed more fish than any other invasive species in Canada, actually. Sea lampreys don’t eat other fish whole like most predatory fish, they eat only the blood and flesh. Whether the fish is big or small, as long as is can get its mouth on it it will latch on for days, even weeks, eating away at the fish, resulting in a slow death. The lamprey uses its suction-cup like mouth to attach itself to the skin of a fish and rasps away tissue with its sharp probing tongue and teeth. Secretions in the lampr
ey's mouth prevent the victim's blood from clotting. Victims typically die from excessive blood loss and/or infection. They can be up to a metere in length and they are very persistant and vicious fish.
How has this impacted our ecosystem? It has decimated our natrual fish population in the 1930s and 1940s. They have created a problem with their aggressive parasitism on other predator species and game fish, such as lake trout, lake whitefish, chub, salmon and lake herring. Elimination of these predators allowed the alewife, another type of invasive species, a kind of herring introduced by us as a cheap fishing bait, to explode in population, having adverse effects on many native fish species. Also in this time there was also a major over fishing problem and we almost made the lake trout an extinct species. The life cycle of sea lampreys is anadromous, like that of salmon.The young are born in inland rivers, live in the ocean as adults, and return to the rivers to breed. This also caused a problem with the salmon, the salmon that survied the sea lampreys in the lakes also had to compete with them for breeding space. Reports have said that sometimes the rivers were so full of lampreys the salmon coudn’t get through to breed.
What have we done to help? There has been a lot of control attempts for this problem. Some of the more effective ones are electrical barriers and the dumping chemicals in the rivers to kill them. They may work in killing the lampreys, but imagine how many other species they kill, and when they die of chemical poisoning, many other fish are living with the effects such as birth defects, sickness and weak immune system. However, we are however working on a more enviromentaly friendly way of ridding our waters of this invasion. Genetic researchers have begun mapping the sea lamprey's genetics in the hope of finding out more about its evolution; scientists and conservationalists trying to eliminate the Great Lakes problem are working with these genetic scientists, hoping to find out more about its immune system. It is a massive research effort into developing synthesized pheromones. These are believed to have big influences on the sea lamprey behavior. One pheromone can be a migratory function in that odor emitted from larva are thought to lure maturing adults into streams with suitable spawning habitat; the other, a sex pheromone, is emitted from males and is capable of luring females long distances to very specific. Effort is being made to determine the function of each pheromone, each part of each pheromone, and if they can be used in a targeted effort at environmentally friendly lamprey control.
Humans are destroying our planet. One of the most devastating and unknown ways is through invasive species. I chose an example to demonstrate this close to home, in our very own Lake Ontario.
We still don’t know where they came from. If they were introduced through the Erie Canal in 1825 or from the Welland Canal in 1919. What we do know is it wasn’t a problem before we started to build canals connecting bodies of water all around Canada and the U.S. Before we knew it though, it had spread like a virus through Lake Ontario to Lake Erie, Michigan, Huron and Superior. Killing our local fish populations and creating a very large unbalance in our ecosystem that has impacted our natural ecosystem and Canadians for many years to come. I am talking about one of the most famous invasive species in Canada, the Sea Lamprey.
How did they get here? They were first discovered in the 1830s, where they were native to the inland Finger Lakes and Lake Champlain in New York and Vermont. It was through the expansion of human cities and the need to transport goods across the border that compelled us to connect bodies of water that nature never intended to. This is what led to the spread of this species that was previosly unfamiliar to the waters of Canada. The sea lamprey is not evil, no plant or animal is evil, it was merely trying to survive and grow and we presented it with a whole new habitat that it was not natrtually supposed to thrive in. So, it isn’t the lampreys fault, it’s ours, we are the most invasive species on this planet.
So what so bad about it? So what, theres a new fish in our waters, how can it hurt other fish? It has killed more fish than any other invasive species in Canada, actually. Sea lampreys don’t eat other fish whole like most predatory fish, they eat only the blood and flesh. Whether the fish is big or small, as long as is can get its mouth on it it will latch on for days, even weeks, eating away at the fish, resulting in a slow death. The lamprey uses its suction-cup like mouth to attach itself to the skin of a fish and rasps away tissue with its sharp probing tongue and teeth. Secretions in the lampr
ey's mouth prevent the victim's blood from clotting. Victims typically die from excessive blood loss and/or infection. They can be up to a metere in length and they are very persistant and vicious fish.
How has this impacted our ecosystem? It has decimated our natrual fish population in the 1930s and 1940s. They have created a problem with their aggressive parasitism on other predator species and game fish, such as lake trout, lake whitefish, chub, salmon and lake herring. Elimination of these predators allowed the alewife, another type of invasive species, a kind of herring introduced by us as a cheap fishing bait, to explode in population, having adverse effects on many native fish species. Also in this time there was also a major over fishing problem and we almost made the lake trout an extinct species. The life cycle of sea lampreys is anadromous, like that of salmon.The young are born in inland rivers, live in the ocean as adults, and return to the rivers to breed. This also caused a problem with the salmon, the salmon that survied the sea lampreys in the lakes also had to compete with them for breeding space. Reports have said that sometimes the rivers were so full of lampreys the salmon coudn’t get through to breed.
What have we done to help? There has been a lot of control attempts for this problem. Some of the more effective ones are electrical barriers and the dumping chemicals in the rivers to kill them. They may work in killing the lampreys, but imagine how many other species they kill, and when they die of chemical poisoning, many other fish are living with the effects such as birth defects, sickness and weak immune system. However, we are however working on a more enviromentaly friendly way of ridding our waters of this invasion. Genetic researchers have begun mapping the sea lamprey's genetics in the hope of finding out more about its evolution; scientists and conservationalists trying to eliminate the Great Lakes problem are working with these genetic scientists, hoping to find out more about its immune system. It is a massive research effort into developing synthesized pheromones. These are believed to have big influences on the sea lamprey behavior. One pheromone can be a migratory function in that odor emitted from larva are thought to lure maturing adults into streams with suitable spawning habitat; the other, a sex pheromone, is emitted from males and is capable of luring females long distances to very specific. Effort is being made to determine the function of each pheromone, each part of each pheromone, and if they can be used in a targeted effort at environmentally friendly lamprey control.
Hey Stefano!
ReplyDeleteSo what are you saying? Do you think humans are stewards of the world or not? Because I think that we are now stewards that are trying to fix all of our mistakes we have done in the past. Also, has there been any decrease in the population in sea lampreys since the idea of introducing the synthesized pheromones? I would hope so because this sounds like a huge problem that is wiping out a lot of different species of fish! Anyways, great blog, really informative, and i hope we're doing something about it! Keep it up!
Stefano, nice job on the post.
ReplyDeleteFirstly, I liked how you picked a Canadian issue; its always easier to relate a problem that we're actually experiencing here in our own country.
The topic of invavsive sea lampreys was really interesting. I knew about invavsive zebra mussels in the Great Lakes, but I'd never even heard of sea lampreys before now.
I strongly agree with what you wrote here:
"The sea lamprey is not evil, no plant or
animal is evil, it was merely trying to survive and grow and we presented it with a whole new habitat that it was not natrtually supposed to thrive in."
I think it's true how it's entirely our fault that this whole thing happened. We built canals that would have never naturally occured, allowing the sea lampreys to invade the Great Lakes and have a strong impact on the fish population.
But is it really fair to say these things:
"Humans are destroying our planet."
and:
"we are the most invasive species on this planet."
We built those canals for a reason, to facilitate trade between Canada and the U.S. Trade with the U.S. was (and still is) a vital part of Canada's economy, and the Welland and Erie Canals was instrumental in helping our countries to develop that trade partnership.
Sure, the sea lampreys invading the Great Lakes was a negative side-effect, but back then we couldn't possibly have forseen that happening. Now that we know about it, we're trying hard to fix the problem. And nowadays, we would never make allow such an environmental blunder to occur.
So basically what I'm saying is, humans make mistakes, and this is a prime example. But we almost always identify our mistakes and try to fix them, so we're really not as damaging as we're made out to be.
Anyways, great post, it's clear you did a lot of research.