DNA of Asian carp detected in Illinois near Lake Michigan

Milwaukee Journal Sentinel

Environmental DNA of six Asian carp was recently detected in Lake Calumet on the far south side of Chicago, a few miles from Lake Michigan, but subsequent testing has not turned up any actual carp.

The discovery of genetic material of silver and bighead carp is the latest found in recent years in Lake Calumet, which is about five miles from Lake Michigan.

Bighead and silver carp have infested the Mississippi and Illinois rivers, and scientists believe that if the fish establish themselves in Lake Michigan and the other lakes, they could edge out native Great Lakes fish and threaten a $7 billion fishing industry.

The U.S. Fish and Wildlife Service reported the findings of the environmental DNA on its website last week. The samples were collected during the week of April 8 and then analyzed at the agency’s genetics lab in La Crosse.

The federal agency followed up with sampling looking for live fish in Lake Calumet with two crews for three days last week but found nothing, according to Amy McGovern, regional coordinator for aquatic invasive species for the service.

McGovern said the sampling for carp was prompted by discoveries of genetic material this year, DNA detections in 2013, 2014 and 2016 in Lake Calumet, and after two Asian carp were caught in 2010 in Lake Calumet and in 2017 in the Illinois Waterway about nine miles from Lake Michigan.

This silver carp was caught in the Illinois Waterway below T.J. O’Brien Lock and Dam, approximately nine miles away from Lake Michigan. The Asian Carp Regional Coordinating Committee says an autopsy shows the 4-year-old male silver carp originated in the Illinois/Middle Mississippi watershed. That would suggest the carp somehow evaded three electric barriers 37 miles from the lake.

The environmental DNA of Asian carp can be found in secretions, feces and urine of the fish, which slowly degrade but can be collected if found in the water soon enough.

The DNA can also come from a boat hull that’s traveled in an area where known populations of the carp inhabit, or from the feces of fish-consuming birds such as cormorants, which are migrating through the region.

McGovern said that DNA is part of a “body of evidence to understand the potential for carp to be there … there are lots of ways genetic material can move through the system.”

The latest findings prompted concerns from one environmental group to push for construction planned by the U.S. Army Corps of Engineers for a new electronic fish barrier near Joliet at the Brandon Road Lock and Dam aimed at deterring the fish from moving farther upstream to the lake.

“The finding of bighead and silver carp eDNA in Lake Calumet, just a few miles from Lake Michigan, is troubling news,” said Molly Flanagan, Alliance for the Great Lakes vice president of policy.

“It’s a stark reminder that we don’t have time to waste. While the agencies continue monitoring and assessing the status of Asian carp, we need to move quickly with the construction of additional Asian carp protections at the Brandon Road Lock and Dam.”