Stateside: Asian Carp and the Great Lakes

Sep 13, 2012

They've become YouTube stars: big fat Asian carp leaping into boats and sometimes breaking bones as they come flailing into the boat of some poor person who just wanted to enjoy some time on the water.

The headlines about Asian carp seem to be getting more and more ominous as they make their way up the Mississippi and get closer to the Great Lakes.

All week long, Michigan Radio's Rebecca Williams has been taking a closer look at Asian Carp and the potential threat to the Great Lakes on The Environment Report.

Asian carp is a general term used for four species of fish officials are worried about: bighead carp, black carp, grass carp, and silver carp (the jumping, YouTube carp).

Williams explained that scientists are most worried about silver carp and bighead carp because they eat food at the bottom of the food chain - plankton.

She explained that Asian carp were brought to the U.S. in the 1970s, and at some point they escaped the fish farms and research ponds in the south.

Cyndy wanted to know how worried people should be about carp.

"We're hearing a big spectrum of opinions. There are bureaucrats and some people in some environmental groups that are talking about a devastating effect on a $7 billion fishery, and then billions of dollars in tourism - and they're worried about silver carp jumping into boats when they're talking about tourism. But in the scientific community, there is a more moderate view generally. There is the consensus that Lake Erie is probably the most hospitable for Asian carp. It's warm, and carp like warm water, and they need a lot of food. Generally the consensus is that they'll do well in Lake Erie, also probably well in certain bays: Green Bay, Saginaw Bay, places where it's warmer."

Williams explained how researchers use something called "environmental DNA" to track where Asian carp are. Researchers take water samples and look for traces of carp DNA.

"...it's not certain if they have positive DNA hits if that's a live carp or if the DNA somehow got carried by birds and brought from one water body to another."

"The tricky thing here is that it's not certain if they have positive DNA hits if that's a live carp or if the DNA somehow got carried by birds and brought from one water body to another. Or if maybe a silver carp jumps onto a boat, and then the water comes off the deck of that boat and gets carried into another water body."

Williams says there have been continuous positive hits in the Chicago area. Some of these have been above a system of electric barriers designed to keep adult Asian carp out of Lake Michigan. She says positive hits for silver carp have also been found in Lake Erie, which surprised some researchers. They still don't know whether the positive DNA hits mean live carp are in Lake Erie or not.

Williams explained that the Army Corps of Engineers says the system of electric barriers near Chicago is effective, but some researchers say juvenile fish, fish smaller than 2 inches, could swim through those barriers.

Cyndy asked Williams whether it's true that the entire Great Lakes ecosystem could be ruined if these invasive fish get in.

The majority of scientists don't think the entire system would be affected, said Williams. She reiterated that scientists think there could be negative impacts in Lake Erie in particular, and in warmer bays around the Great Lakes.

The majority of scientists don't think the entire system would be affected, said Williams. She reiterated that scientists think there could be negative impacts in Lake Erie in particular, and in warmer bays around the Great Lakes. Yellow perch and walleye could be affected, said Williams, but "it's less clear whether the salmon populations would be affected, and that's, of course, one of the more popular sport fish in the lakes."

Williams says the experts make a point of saying that we should keep Asian carp out of the Lakes.

The other major concern is someone intentionally putting Asian carp into the lakes.

Williams says it's illegal to move live carp in the Great Lakes region, but for many years, it was legal to move them around.

There's a market for Asian carp and some businesses in Illinois are shipping the fish to China and Europe and some Los Angeles markets.

Williams has eaten Asian carp herself. The verdict:

"It was pretty mild. It was not fishy. The way I had it prepared it was sort of like a crab cake. There was some butter. There was some cream. You mix those things in, it's kind of hard to tell, but it was pretty good!"

There are two ways you can podcast "Stateside with Cynthia Canty"

You can join The Environment Report's Rebecca Williams for Michigan Radio's next Issues and Ale - all about Asian Carp. It'll be at the Kirby House in Grand Haven on Tuesday, September 18th from 6-7:30pm. You can find out more information here.