New study warns of risk to Great Lakes from invasive Asian carp
Post by Emily Mills on 7/12/2012 1:53pm
All five of the Great Lakes have conditions hospitable to the invasive Asian carp species, and it would take as few as 10 pairs of males and females to establish a successful population, according to study released Thursday by a U.S.-Canadian team of scientists.
The report from Fisheries and Oceans Canada describes the risk posed by Asian carp to the Great Lakes, which were previously thought to be too cold to be hospitable to the fish.
Researchers found that more than 70 river tributaries around the region appear suitable to Asian carp spawning, and conditions in the lakes--especially the relatively shallow and warm Lake Eerie, but also very cold Superior--could support significant populations.
Asian carp were introduced as a way to treat algae-choked aquaculture ponds and sewage treatment lagoons, but the hearty fish have since found their way into rivers and streams after floods washed them out. They’re known to clog up waterways and are easily startled, and initial evidence shows that they tend to crowd out native species of fish.
“The report underscores the severity of the Asian carp threat and the need for leadership so that we can solve the problem once and for all,” commented Andy Buchsbaum, director of the National Wildlife Federation’s Great Lakes office. “The Asian carp are moving toward the Great Lakes far faster than the government response, and this report shows that the cost of inaction will be devastating. President Obama and Gov. Romney need to declare that they will take the necessary action to build an effective physical barrier to keep the Asian carp out of the Great Lakes.”
Five states, including Wisconsin, are currently suing the federal government to block a Chicago-area canal that links Lake Michigan to the Illinois River, which is currently the leading edge of the carp invasion – although DNA from the invasive species has been found just 6 miles from the lake.
The government has already spent some $150 million on repelling the fish, including an electric barrier in that canal.
There are serious concerns that the carp could unravel the entire Great Lakes ecosystem by out-competing with native species, doing serious harm to its $7 billion fishing industry. And the variety of Asian carp that leaps out of the water when startled is already causing at least some harm to local tourism in affected areas.
The Wisconsin Department of Natural Resources notes that while there is evidence of some incursion of bighead and silver carp into the state’s waterways, work is being done to prevent any further spread. “Dams on the Wisconsin River at Prairie du Sac and on the St. Croix National Scenic Riverway at St. Croix Falls would block Asian carp on the Lower Wisconsin River or the Mississippi River from travelling farther inland in Wisconsin,” according to the WDNR website.
“The silver lining is that no young Asian carp nor other signs of successful reproduction have been documented so far in any Wisconsin waters,” says John Lyons, a longtime DNR fisheries researcher and fish identification expert.
Photo by USFWS Headquarters on Flickr, under a Creative Commons license.
Emily Mills is Editor-At-Large for Dane101, as well as Editor of Our Lives Magazine. She is also a freelance writer, photographer, actor, and musician (drummer and singer in local band Little Red Wolf). Originally from several states up and down the Midwest Emily has called Madison home since 2000. Contact her at