The Michigan DNR and the Great Lakes Indian Fish and Wildlife Commission stock lake trout and Salmon in Lake Superior (among other great lakes). They also track and monitor the habits of the fish by several different methods. One of the ways they do this is by clipping the adipose fin. (See Fin Clips on the DNR website.)
Every angler should be on the lookout for these fin-clips on the fish they land in order to help gather information. You also can be rewarded for reporting tagged fish since they will mail you a check if you provide your mailing address when reporting them. Besides, it helps us fishermen in many ways:
1. It helps to determine the effectiveness of stocking programs.
2. We can learn the habits of the fish that we target.
3. They can determine the growth rates.
4. They get a better idea of mortality rates.
These are just a few reasons to be aware of, and watch for fin-clips and/or tags on the fish we catch. The DNR website has more information about these markings here:
Adipose-Clipped Chinook Salmon in Lake Superior.