The state Department of Natural Resources and Environment (DNRE) recently received good news in the fight against Asian carp, as new test results were negative for environmental DNA (eDNA) for either Bighead or silver carp in waters located in southwest Michigan.
eDNA is a genetics tool developed by researchers at Notre Dame and the Nature Conservancy which detects the presence or absence of species-specific DNA in an aquatic environment, such as the cells shed by Asian carp through their feces, urine, mucus, and gills.
Between Sept. 15 and Oct. 5 last year, researchers from Notre Dame and the Nature Conservancy collected 74 water samples from the Galien River, in addition to 122 samples from the St. Joseph and Paw Paw rivers.
All samples were negative for Asian carp DNA.
“This is great news for Michigan, but by no means should we relax our stance on Asian carp and the threat they pose to the Great Lakes Basin,” said Office of the Great Lakes Director Patricia Birkholz in a press release. “An ecological separation of the Mississippi River and the Great Lakes remains imperative to our goal of keeping this invasive species out of Michigan waters.”
Concerns over a possible Asian carp invasion of Lake Michigan grew last June when the first live Asian carp, a Bighead carp, was caught beyond electric barriers in Lake Calumet, just six miles from Lake Michigan.
Asian carp, first imported to control algae in fish farms along the Mississippi River, escaped during a flood event in the 1990s. Since then, the carp have moved quickly up the Mississippi River and into the Illinois River, the Des Plaines River, the Chicago Sanitary and Ship Canal, and the Calumet-Sag Channel.
Asian carp can weigh up to 100 pounds, grow to a length of more than 4 feet, and, on average, eat up to 20 percent of their body weight in food a day. They are also extremely prolific. As such, Asian carp pose a major economic concern as they would out-compete other Great Lakes fish species.
Michigan’s fishing industry is estimated to bring in about $7 billion each year.
“Just because we have good news doesn’t mean we should relax our position at all,” said DNRE Spokesperson Mary Dettloff.
In an effort to maintain constant vigilance in the fight against an Asian carp invasion, the team at Notre Dame will continue to collect and analyze over 400 water samples from Michigan waters in 2011. Samples will be taken from the Grand, Raisin, Belle, Black and Pere Marquette rivers to monitor for the presence of Asian carp DNA.