|Eurasian Ruffe - USGS|
Eurasian ruffe (also known as ruffe or river ruffe), an eastern European species, has been found in western Lake Superior since 1986, and has been one of the most dominant fish in bottom trawls in channels within the Duluth-Superior Harbor. The U.S. Fish and Wildlife Service’s (USFWS) Ashland Fish and Wildlife Conservation Office monitored the expansion of ruffe populations and the species’ range across Lake Superior.
“To date, fishery management agencies have not witnessed any significant impact on native fish species like yellow perch and walleye in the areas where ruffe populations have become established and are quite abundant in our bottom-trawl surveys,” says Mark Brouder, Ashland Fish and Wildlife Conservation Office Field Supervisor.
A recent basin-wide survey by the University of Notre Dame, Central Michigan University, and The Nature Conservancy has found Eurasian ruffe DNA in water samples taken over the past year from Calumet Harbor in northeast Illinois. This sampling is designed to use an analytical technique to detect species by filtering the water and detecting DNA that organisms leave behind. In fish, the DNA may be in slime, urine, or fecal material. The initial conclusion from the Calumet Harbor water samples did not detect ruffe, but follow up analyses suggest that ruffe environmental DNA (or eDNA) may be present in a small portion of the samples.
“Calumet Harbor is a vibrant harbor with international and intra-lake shipping present,” said Kevin Irons, Aquatic Nuisance Species Program Manager for the Illinois DNR. “The detection of Eurasian ruffe DNA is not all that surprising, given that ruffe has been in the Great Lakes for decades. Illinois DNR monitors Calumet Harbor annually, and we have certainly been aware of ruffe in the basin. To date, we have not captured any ruffe, and in fact we don’t believe Eurasian ruffe are established anywhere in southern Lake Michigan”.
Environmental DNA surveillance has been used to heighten efforts regarding Asian carp detection; however, the relationship between eDNA and live fish presence has not been fully understood.
“Certainly, eDNA can come from swimming fish, but alternatively eDNA can be transported by birds, boat hulls, fishing nets, and other mechanisms,” said Kelly Baerwaldt, joint U.S. Army Corps of Engineers/USFWS eDNA Program Manager. “Because Lake Calumet is such a busy port, lake freighters from infested regions could simply discharge water and enable detections. Although 85% of eDNA breaks down in the environment quickly, within a few days, the remaining small portion can remain detectable for up to a month.”
The Illinois DNR will continue to work with USFWS biologists who monitor the Great Lakes to continue sampling in the Calumet Harbor area to heighten sampling efforts for fish across the Great Lakes to look for Aquatic Nuisance Species. Illinois DNR monitors Calumet Harbor throughout the summer with electrofishing. The Illinois Natural History Survey monitors near-shore waters of Lake Michigan with micro-mesh gillnets, noted as a preferred gear for catching ruffe. To date, Illinois officials report NO Eurasian ruffe have been seen or reported from Illinois waters.
“The Illinois DNR urges anglers to report fish that may be ruffe, as they may be taken while fishing for yellow perch or other fish in the Calumet Harbor area, or anywhere in waters surrounding Chicago,” IDNR’s Kevin Irons said. “A clear cell phone picture of the fish from several angles can help in identification, or you may simply put fish in a ziplock/plastic bag and freeze it. This species is listed as injurious, so these fish cannot be transported alive in Illinois. If found, please note specifically where the fish was caught and include time and date information.”
To stop the movement of all aquatic nuisance species, sportsmen and women are reminded to ‘Stop Aquatic Hitchhikers’ and ‘Be a Hero – Transport Zero’ by following three simple steps: 1) Remove plants animals and mud from equipment; 2) Drain all water from your boat and gear; and 3) Dry everything thoroughly with a towel.
To find out more about the Eurasian ruffe, check the USGS Non-indigenous Aquatic Species website at
Be A Hero – Transport Zero campaign video can be found at http://www.youtube.com/watch?feature=player_embedded&v=z83g72eZ1RM.
To report Eurasian ruffe locations or other Aquatic Nuisance Species, please call the Illinois ANS Program office at 217-785-8772.