Invasive Ruffe - courtesy graphic

The fishery resource offices of Ashland, Alpena, Lower Great Lakes, and the Ontario Ministry of Natural Resources (OMNR) collaborated in drafting the report,  “Surveillance For Ruffe in the Great Lakes 2006”. 

The invasive, perch-like ruffe received the stigma of “nuisance species” in 1992, following suspected implication with declines of native forage fish in the Twin Ports harbor of Duluth, Minnesota and Superior, Wisconsin.

 The report summarizes fish sampling activity in each of the Great Lakes that targets invasive ruffe, as well as other reported fish sampling that does not target ruffe, but is capable of capturing ruffe incidentally. 

From this sampling data, new locations containing ruffe are identified, the range of ruffe is updated, and control strategy is evaluated based on location of new discoveries and the suspected pathway of introduction. 

Sampling that targets ruffe (dedicated ruffe surveillance) also collects baseline data on native fish communities.  Since 1992, the USFWS and OMNR have been tracking the ruffe to document its range, evaluating opportunities to delay ruffe range expansion in the Great Lakes, and working to prevent range expansion into inland lakes and streams. 

Assisting with this task are numerous cooperators including the U.S. Geological Survey, the state departments of natural resources bordering the Great Lakes, Fisheries and Oceans Canada, Environment Canada, Native American communities, the Ontario Federation of Anglers and Hunters, Sea Grant, universities, and recreational anglers. 

The ruffe was confined to western Lake Superior until 1995, when it was detected in Lake Huron, near Alpena, Michigan.  Catch per unit effort in Lake Huron surveillance trawls reached a climax of 660 per hour in 1999, but declined to zero in 2001.  Capitalizing on a distressed, self-confined ruffe population, the Alpena FRO enhanced the ruffe decline by initiating an intense gill netting effort in 2002 to remove adult spawning ruffe. 

Paralleling the ruffe decline in Lake Huron was increasing round goby abundance there, suggesting that the goby may have also been a contributing factor in that ruffe decline.  No ruffe have been captured from Lake Huron since 2003.  In Lake Superior during 2006, the ruffe made a major range advance of 226 km eastward along the south shore from Marquette Harbor, Michigan. 

Along the Lake Superior north shore, minor expansion was verified within the ruffe range in Thunder Bay, Ontario.  The Bays de Noc have comprised the ruffe range in Lake Michigan, since 2002 and 2004.  No ruffe range expansion was detected in Lake Michigan during 2006.  In the Lower Great Lakes, ruffe remain undetected, as well as in all inland lakes and streams within the Great Lakes Basin.  The complete ruffe surveillance report is distributed to the Great Lakes Panel on Aquatic Nuisance Species (ANS) and the National ANS Task Force; and will be available on the Ashland FRO website, http://www.fws.gov/midwest/ashland