Asian carp eDNA found in Kalamazoo
Kalamazoo, Mich. — State and federal officials are resampling a stretch of the Kalamazoo River – from Lake Michigan to the Caulkins Dam – after a sample collected in July tested positive for Asian carp eDNA, the first in Michigan waters outside of Lake Erie’s Maumee Bay.
“It means there could be a fish there or genetic materials of fish there,” Jay Wesley, Lake Michigan basin coordinator for the Michigan DNR, told Michigan Outdoor News.
“We’re taking it seriously. This is the first sign any genetic material has been in Michigan waters.”
On Oct. 2, DNR officials discovered a single positive eDNA sample for silver carp – one of two species of Asian carp officials are working to keep from invading the Great Lakes through the Chicago shipping canal – among 200 samples collected from the lower Kalamazoo River in July.
The silver carp eDNA indicates the presence of the fish’s genetic material, such as scales, excrement, or mucous, but does not necessarily mean a live fish is present. The eDNA can transfer to water bodies on boats, fishing gear, birds, and through other means, officials said.
The lone positive sample was collected about a mile downstream from Caulkins Dam, but upstream from M-89, near the Swan Creek tributary. Two hundred samples collected on the same stretch a month earlier did not net any positive results, Wesley said.
DNR officials immediately collaborated with the U.S. Fish and Wildlife Service to take 200 new samples from areas downstream of the dam during the second week of October, and currently are rushing to process the results in the lab, Wesley said.
Aside from resampling the river, DNR officials also are increasing their presence on the Kalamazoo to solicit feedback from anglers and to increase public awareness about the invasive fish, which are known to leap out of the water, grow large, and outcompete native fish for food.
“I think they are going to process those quicker for us, so I’m hoping to have more information within a month, in November,” Wesley said of the additional water samples. “Based on the results of that, we will determine what actions we need to take.”
If officials discover another positive sample, they most likely will increase their efforts with gill nets and electrofishing to look for live silver carp. If the samples are all negative, they’ll likely resume their current eDNA sampling, Wesley said.
Wesley believes “the most probable cause” of the recent positive sample is livewell water.
“When we were there we noticed boats from Illinois and Missouri and those both have Asian carp,” he said.
The only prior positive eDNA sample discovered in Michigan waters was found in Maumee Bay, which borders both Ohio and Michigan along Lake Erie’s southwest coast, in 2013. Another Asian carp eDNA sample was discovered last year on the Wisconsin side of Lake Michigan, in Green Bay.
The news of the positive eDNA sample prompted renewed calls from Michigan U.S. Rep. Candice Miller to hydrologically split the Great Lakes from the Mississippi River system, where Asian carp have become established. Miller introduced the Defending Against Aquatic Invasive Species Act of 2014 in February to do exactly that.
“This test only reconfirms that, unless drastic action is taken, Asian carp will invade the Great Lakes and wreak havoc on the economic and recreational resources they provide,” Miller said in a statement.
DNR Director Keith Creagh also called for closing the Chicago shipping canal in an Oct. 7 statement announcing the positive eDNA finding.
“Michigan continues to advocate for hydrological separation between the Mississippi River basin and the Great Lakes basin as the best long-term solution to the threat of Asian carp,” Creagh said.
Wesley said that while the positive test is “kind of the first line of evidence that (Asian carp) could be here,” DNR officials are not jumping to conclusions.
“We’ve learned our lesson from other states that had eDNA positive samples where no fish were found,” he said.
DNR officials have received no reports of live Asian carp in the Kalamazoo River, but are encouraging anglers to report any Asian carp sightings at Michigan.gov/Asiancarp