The spiny water flea exhibits a tremendous appetite, which is threatening the ecological stability of the Great Lakes. The invasive species may already be responsible for between $80 million to $163 million in damage, according to a new study.
Ocean-going ships which travel in both the Atlantic Ocean and the Great Lakes have carried at least 180 non-native species into the largest lakes in the United States.
Calculating the full financial cost of damage done to the lakes by non-native species could help biologists, economists, and environmentalists better determine the true cost of invasive forms of life. Currently, only the direct costs of managing non-native species are counted when finding the total costs of non-native species.
The new study adds in the financial impact of damage done to areas away from the initial point of entry. Researchers also calculated costs related to human benefits lost due to the presence of non-native species.
"There are hundreds of billions of dollars' worth of damages we can account for right now. If you add in invasive species' impact on ecosystem services and look at secondary invasions, then that number is likely to be trillions," said Jake Walsh of the University of Wisconsin Madison.
Clean water is essential for the financial benefits of a water body, including swimming, boating and fishing, to local economies.
Lake Mendota in Madison, Wisconsin is one lake which has been damaged by invasive species. In this case, the culprit is the spiny water flea, which has proliferated there since 2009. The tiny creatures traveled from the Soviet Union to the Great Lakes within the ballast water of ocean-going marine vessels.
Once in the lakes, the insects began to feed on a type of zooplankton known to biologists as Daphnia pulicaria. That life form normally feeds on vast quantities of algae, and without the zooplankton, once-pristine waters have started to become cloudy and murky. The problem is compounded by agricultural runoff, sending phosphorus-rich fertilizer into the water, further feeding the growth of algae.
Bringing the Wisconsin lake back to its natural condition would require reducing fertilizer intake into the water body by 71 percent, investigators determined.
Researching quantifying damage done to the Great Lakes by this invasive species was profiled in the Proceedings of the National Academy of Sciences.