Natural resource officials in Minnesota and Iowa are advocating for the construction of two fish barriers on the Mississippi River that they hope willl stop the upstream migration of Asian carp.
These barriers, which would be placed below lock and dam 14 or 15 (just north of Davenport, Iowa) and lock and dam 11 (just north of Dubuque, Iowa), might use bubbles and sounds to stop the fish from entering the open locks. The fish could be directed into pools where commercial fishermen could harvest them. (Similar barriers are already used on a smaller scale to keep fish away from water intake pipes at power plants.) Minnesota Department of Natural Resources employees are looking at a variety of different technologies, trying to find one that's as selective as possible. The idea is to find something that will deter the carp, but not the paddlefish and other species that ecologists want migrating up the river, many of which are threatened or endangered.
How big is the invasive carp problem? That's a little unclear. So far, two species of the fish--bighead and silver carp--have escaped from southern fish farms and moved north along the Mississippi and its tributaries. A third species, black carp, has been caught in several areas, but scientists don't know if it's reproducing. One bighead carp was caught in Lake Pepin (south of the Twin Cities) in the fall of 2003, but no others have since been reported.
But the Upper Mississippi is one of the most pristine of American rivers, and officials are anxious to keep it that way.
Silver and bighead carp can reach more than 50 pounds, and out-compete native species for food such as plankton. Silver carp are also dangerous to recreational boaters and water-skiers, as they jump out of the water when disturbed; they've injured people and damaged equipment.
The University of Minnesota's Bell Museum of Natural History has an invasive carp feature on their "Hot Topic" website.
The Star Tribune has a special feature on invasive species in the Great Lakes.
WHY IS THE ASIAN CARP HERE? IF IT IS NOT NATIVE TO THE MISSISSIPPI RIVER,HOW DID IT GET THERE? WHEN ARE WE GOING TO LEARN TO STOP MESSING WITH NATURE? WE TRY TO CHANGE NATURE TO IMPROVE IT AND THEN 50 TO 100 YEARS LATER WE ARE TRYING TO CORRECT THE PROBLEM WE CREATED.
The invasion of Asian Carp in the Upper Mississippi is primarily the result of a growing demand for highly controlled fish farms, also called aquaculture. Two different species of Asian Carp were introduced to fish farms in Illionois and Arkansas in the 1970s to improve water quality and control aquatic plants. At some point these species escaped from these ponds to our natural river systems.
I believe that you are correct about our forethought when it comes to the environment. However, our society also demands cheap consistent sources of fish for food. As a result there will always be a short-term economic incentive for farmers to increase their yields and make quick decisions without taking into account the larger implications.
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bryan kennedy
Science Buzz Site Admin
THE PEOPLE IN BATH ILL. HAD A REDNECK FISHING TOURNAMENT TO
BRING PUBLIC AWARENESS TO THE ASIAN CARP PROBLEM, THEY ARE ORGANIZING PEOPLE UP AND DOWN THE RIVER TO SHOCK AND SAVE WHATS LEFT OF NATIVE FISH, THEN KILL THE RIVER AND REPLANT
IT THIS IS HEADED UP BY BETTY DEFORD BOAT TAVERN BATH ILL.
309 546 2545 IN THE TOURNAMENT 29 BOATS CAUGHT 1265 CARP
IN 2 HRS WITH NETS 9/10/05 I USED A STICK TO KNOCK THEM OUT OF THE AIR
I believe this is an excellent effort, especially getting the fisherman into it. We need to address the invasive species that are here to stay with a little bit of what we've been able to do to many other fish stocks around the globe. It also helps to keep these carp out, let the cormorants take care of the gobies.
Kingston, Ontario
One Boat, with electic probes, 4 guys, 4 shotguns with non toxic 8 shot, and you have a new skeet shooting sport. Not to mention a new business oppertunity catering to triggerhappy rednecks in the south.
Science Buzz is supported by the National Science Foundation.
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