Asian carp threaten Great Lakes

Adam Debrowski

The Great Lakes have already been tested by the likes of resource-devouring mussels and blood-sucking lampreys. The next test: a probable invasion of 100-pound monsters. Their first destination: Lake Michigan.

Asian carp, an inclusive term used for four different species of carp, have been knocking at Lake Michigan’s door for years, rejected only by a withering electric fence in a shipping canal on the Chicago River.

“The way I see it, it’s inevitable,” said Ron Tabiadon, president of the Grand Haven Charter Boat Association and captain of Tab’s Sportfishing charter service. “Nature is going to have to run its course. There’s nothing else you can do.”

The electric fence was an effort by the U.S. Army Corps of Engineers to keep the fish from infiltrating the Great Lakes, but has had to be repaired several times because of harsh underwater conditions.

“They are using constant electric pulses to prevent Asian carp from getting into Lake Michigan,” said Chansheng He, a Western Michigan University geography professor specializing in water resources management. “[If they get past the barrier], Asian carp proliferate, produce and grow very fast. They will overgrow and out-compete native fish species.”

This is why the carp are labeled as “invasive”: because they can eat…and eat…and eat.

According to the U.S. Fish and Wildlife Service, some species of Asian carp can grow up to 60 inches in length and weigh over 110 pounds, all while maintaining the capability to eat up to 40 percent of their weight in food every day. With numbers like these, the amount of food left for native Lake Michigan species plummets quickly.

In addition to blatant danger to the existence of Lake Michigan’s residential fish, silver and bighead carp also pose a direct threat to humans with an ability to jump over 10 feet into the air.

“They instinctively jump out of water when they feel various vibrations. There is potential for these fish to jump into boats and possibly cause injury,” said Jay Wesley, DNR fisheries manager for Southwest Michigan. “I’ve seen shields on boats [in the Mississippi River] to make sure they have something up, especially if they’re going fast.”

Asian carp have been in the United States since the 1970s, when they were imported from China, Taiwan and Russia to clean fish ponds in the Southern United States. During the Great Flood of 1993, some of those ponds overflowed into the Mississippi River, releasing the carp into the single most connective waterway in the country. The carp population eventually stretched out to the Illinois River, where they now reside a short swim away from the electric Chicago barrier.

“The only thing we’re doing in Michigan right now is trying to prevent the fish from coming in,” Wesley said. “We are also participating in the treatment of the Chicago shipping canal by sending supplies, boats and personnel to help in that effort.”

To many in West Michigan, however, the more important point may be the effect the carp could have on local economies.

“It could have a devastating effect on the commercial and recreational fishing industry, and once they enter the Lake Michigan, there’s no way we can keep them from spreading,” said Joy Gaasch, president of the Grand Haven Chamber of Commerce. “It’s very difficult to tell what the total impact would be.”

Grand Haven is home to about 50 charter boat services and over 290 jobs directly connected to its $22 million fishing industry, Gaasch said. Those jobs would be hit the first and probably the hardest, but the reduction of native fish and the addition of the Asian carps’ jumping habits could also greatly reduce the desirability of recreational boating on Lake Michigan, the Grand River and Spring Lake. There are currently over 1,500 boats in the Grand Haven area alone, Gaasch said.

Speculation aside, if the fish get past the barrier, Lake Michigan’s ecosystem may find a way to prevent rampant overpopulation by itself.

“The jury is still out in terms of what their effect on Lake Michigan would be,” DNR officer Jay Wesley said. “The Great Lakes aren’t as productive as they were in the 1960s. There just may not be enough plankton there to support a large population of carp.”

Although DNA was recently discovered upstream from the Chicago barrier, a carp has yet to be seen in the flesh. Until then, those who might be affected by the carp’s possible arrival can only cross their fingers and hope for the best.

“This is something that has been talked about, but hasn’t really been on anybody’s radar until just recently,” Joy Gaasch said. “It’s really an unknown.”