DECATUR — The state Department of Natural Resources is looking at options to deal with thousands of invasive Asian carp that are spawning at the base of the Lake Decatur dam.
Jacques Nuzzo, program director for the Illinois Raptor Center and an avid outdoorsman, contacted the state department after taking drone footage of the fish that showed them clustered in the area, looking from above like large black clouds in the water. Nuzzo had been birdwatching at the dam and noticed a larger amount of the fish than usual.
"I realized they were Asian carp and I thought, well, this isn't good," Nuzzo said. "I've seen Asian carp here, but I've never seen this many at once."
Asian carp are an invasive species, meaning they can cause serious damage in lakes and rivers by out-competing native fish populations for food and space. Steps have already been taken to keep the fish out of Lake Decatur, and officials say despite the dramatic appearance, the situation isn’t dire.
“We have taken measures in the past to prevent the fish from getting over the dam,” City Manager Scot Wrighton said. “DNR has been contacted, but in the meantime, they can’t get over the dam because of what we already have in place.”
Kevin Irons, the department’s aquaculture and aquatic nuisance species program manager, said the fish are not currently posing a threat to Lake Decatur, as there is no evidence they can get over the dam. "While it may seem like mass amounts of fish, it's really not that much compared to the rest of the state," Irons said.
He said the department and Lake Decatur staff are in the process of deciding what to do about the carp.
"We are weighing our options like having commercial fishermen come in or potentially go a different route, but we are looking to make a decision soon," Irons said.
Nuzzo said it’s not easy to get the fish out of an area. "You can't just go out and net them,” he said. “It takes some math and planning."
There are four species of carp that, together, are commonly called “Asian carp,” according to the National Park Service. They are bighead carp, black carp, grass carp and silver carp, all brought to the U.S. in the 1960s and 1970s to control algae, weed and parasite growth in aquatic farms. The captive fish escaped into the Mississippi River and have been spreading ever since, changing the ecological makeup of areas and overrunning native species of fish.
The city of Decatur five years ago installed barriers specifically designed to keep the non-native fish out. The barrier installment came after years of Asian carp sightings in the Sangamon River. The 4-foot screen barriers represented about $120,000 of a $4 million dam repair project.
Efforts to control the fish are widespread. Earlier this month, leaders of states and Canadian provinces in the Great Lakes region agreed on a plan to protect the lakes from the species; in a joint resolution, they urged Congress to allocate money for the plan, which would cost $778 million.