The Alpena FRO conducted Eurasian ruffe (ruffe) surveillance in the Thunder Bay River, Lafarge harbor, and Partridge Point marina areas of Thunder Bay during the month of April. 

The survey was conducted to detect the presence of spawning phase ruffe. 

Small mesh (1.3cm) gill nets (33 x 1.6m) were used during the survey.  Nets were set overnight, biweekly during the month of April.  No ruffe were captured.  

All bycatch were measured and released.  Tissue samples were collected from yellow perch and walleye for a genetic study conducted by The University of Toledo - Great Lakes Genetic Laboratory to determine unique DNA markers for spawning populations of these native species.

The ruffe is an invasive fish species, native to north central Europe that is related to the yellow perch.  It is thought to compete with native species - including yellow perch - for food and habitat resources.  Ruffe were first found in the Thunder Bay area of Lake Huron in 1995.  It is the only area of the lake where the invasive has been captured.  Their population increased and peaked in 1999, then began to decline. 

In 1996 the Alpena FRO initiated fall efforts to remove young-of-the-year ruffe, and in 2002 annual efforts were initiated in the spring to remove adult spawning ruffe. Young of the year were last collected in the fall in 1991 and spawning phase ruffe were last captured in the spring of 2003.  Ruffe have not been captured in the Thunder Bay area since 2003. 

Efforts continue to detect any remnant or resurgence of the population.