A new study suggests that Asian carp, which have been spotted in watersheds close to the Great Lakes, would make themselves right at home if they made it to Lake Erie. The study, published recently in the journal Transactions of the American Fisheries Society, used computer modeling to estimate the effect these fish would have on native species.
Bighead and silver carp were first introduced to the United States in the 1970s, when they were imported to control algae growth in aquaculture and sewage treatment ponds. They escaped into the Mississippi River during floods a few years later. Like many invasive species, they’ve been able to out-compete local populations and have spread quickly.
According to the Ohio Environmental Council, there’s reason to believe that individual bighead and silver carp have already made it into Lake Erie (which has the biggest fish population of any of the Great Lakes). But for now, there isn’t an active breeding population that we know of, thanks to over $300 million in efforts from federal agencies.
Conservationists know, however, that it’s simply a matter of time. So they have to ask — when Asian carp start breeding in the lake, just how much damage will they do?
In the new study, which used food-web models, researchers found that the decrease seen in other species might not be as great as one would expect. In fact, some species might even see a population increase should foreign fish move into the neighborhood, because the carp would take care of their more direct competitors for them, and their young would provide an abundant food source for any fish-eating fish. But other species, including prized sport species like walleye and rainbow trout, would see a sharp decline.
The best way to beat an invasive species is to eat it. Asian carp have been fished for commercial sale, but most of the market is in China. While the fish are reportedly delicious, they’re very bony, making for a tough filleting process and a surprisingly low yield of meat for such a large fish. In any case, they’re certainly not easy substitutes for the popular sport fish that currently fill Lake Erie.
Asian carp, which grow quickly and can eat up to 20 percent of their body weight each day, could come to make up 34 percent of the total fish weight in the lake, making them the most abundant fish in terms of biomass.
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SOURCE: The Washington Post, Rachel Feltman
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