Fishery Biologists Scott Koproski, Adam Kowalski and Andrea Ania conducted an electro-fishing survey funded through the Service’s Challenge Grant Program this June to collect fishery data surrounding the islands of Thunder Bay in Lake  Huron.  This was a cooperative project between the Michigan Department of Natural Resources (DNR) and the U.S. Fish and Wildlife Service (Service).

The project involved electro-fishing the perimeters of four islands located within Thunder Bay.  The targeted islands included Thunder Bay Island, Scarecrow Island, Sulphur Island and Grass Island.   Effort was measured in ten-minute intervals, and fish were processed after each shocking interval.  Lengths were recorded for all fish encountered, and weights and scale samples were taken for sport fish. 

Two of the four islands where the electro-fishing survey was conducted are owned by the Service as part of the Michigan Islands National Wildlife Refuge (NWR). These are Thunder Bay Island and Scarecrow Island.  However, all four islands provide important feeding, spawning and nursery habitat to the coastal fish species that reside in Thunder Bay. They also provide fishing opportunities for recreational anglers in the community.  Very little is known regarding fish community assemblages and the status of fish populations in Thunder Bay.  The importance of obtaining this fishery data is to provide managers with the necessary information to monitor the possible effects that habitat alteration, exotic species and cormorant predation may be having on these populations.

In addition to the islands, the shoreline of Thunder Bay from Bare Point to the Thunder Bay River mouth was also sampled.  Data collected during the survey is still being analyzed, but this marks the first year that survey crews were able to electro-fish around Thunder Bay Island and Scarecrow Island.  Sampling at both islands in recent years has been problematic due their long distance (> 8 miles) from a suitable launch site.  Data analysis and final reporting for this project will be completed this fall.