Tagged fish provide DNR with critical information

The Michigan Department of Natural Resources again this year is encouraging Great Lakes anglers who catch marked and tagged fish to report them. The DNR has used the coded-wire tag program to mass mark various fish species in Michigan since the 1980s. Mass marking provides critical data as fisheries biologists look to determine the value of naturally reproduced fish versus stocked fish, and lakewide movement of fish.

The coded-wire tag program involves implanting a small, coded-wire tag, which is invisible to the naked eye, into the snout of a fish. A fish containing a coded-wire tag can be identified because its adipose fin (the small, fleshy fin between the dorsal and tail fins) has been removed. An angler who catch a tagged fish then can record needed information about the fish, remove and freeze the fish’s snout, and drop it off at a designated location. A statewide list of dropoff locations can be found on the DNR website.

For years the DNR primarily tagged Chinook salmon and lake trout as part of its mass marking effort in Lake Huron. Tagging these fish has helped biologists understand more about lakewide natural reproduction and how many wild fish are available in the Great Lakes. It also has helped determine if the percentage of wild fish varies from year to year and how fish stocking locations contribute to lake and river fisheries. Additionally, it provides insight into fish movement and where fish are stocked compared to where they are caught.

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