ST. JOSEPH, Mich. — Cast your reels with a sigh of relief, fishermen.
In a Sept. 6 survey, the US Fish and Wildlife Service detected no evidence of silver carp eDNA in the St. Joseph River, after routine testing this summer turned up a single, positive sample.
The federal agency took 220 new samples from the waterway, reaching as far inland as Berrien Springs—several miles upriver from the positive June 13 result located near Marina Island in St. Joseph.
"It sure is [a relief]," Joanne Foreman, communications director for the Michigan DNR, said. "The danger involved in silver carp is real."
The invasive bottom feeder feeds on plankton and particles in the water column, possessing a hunger and reproductive ability that threatens to bottom out Great Lakes ecosystems and its multi-billion dollar fishery.
"We really don't want to see that," Foreman said. "Our Great Lakes are our playground.
The sampling searches for trace amounts of genetic material from silver and bighead carp—another invasive species. Based off the most recent results, the DNR says it's "highly likely" either species is not present in the St. Joseph River.
VIEW: US Fish and Wildlife Service Invasive Carp eDNA Map
"It is possible for genetic material to be introduced from other sources, " Seth Herbst, DNR Fisheries Research Program manager said in a statement.
In this case, the positive test likely originated from an out-of-state boat or fishing tackle that recently frequented an infested waterway.
"All good so far," Chad Poole said. "Hopefully it stays that way."
The longtime fisherman caught a cooler-full of perch Saturday afternoon. He heard about the silver carp scare from a local radio show.
“From everything I understand, it would be a devastating shot to the whole commercial and recreational fishery in the Great Lakes," Poole said. "I'm sure they're good for something. But I know that the Great Lakes doesn't need or want them."
In October, the DNR—in partnership with the US Fish and Wildlife Service—plans to conduct an electrofishing operation on the St. Joseph River, stunning fish with a non-lethal current that causes them to float to the surface for documentation.
“Everybody out there, you're part of that partnership to do your due diligence," Foremand said. "Be a part of keeping our Great Lakes clean.”
