How old is that fish?

Modern fish management, with tags, chemical markers and acoustic tracking, provides valuable insights into the fisheries that we all enjoy. Earlier this year, we encountered a walleye that was AT LEAST 25 years old. Here's the fish; you can see its MN DNR tag alongside its soft dorsal fin.

We recorded the tag number and submitted it to the MN DNR, which provided an informative report about the fish's history:

This fish was caught on Mille Lacs, and was initially tagged in 2004 (!) at a length of 20 inches. The best info I could find on average age/length relationships puts this walleye at 10-12 years old at the time of tagging. That makes this fish, at the time of its most recent recapture, somewhere in the neighborhood of 23-25 years old. A tired, worn out male walleye indeed!

Interestingly, the fish was also recaptured 5 years before we caught him, almost to the day, and hadn't grown a bit between those two dates. Notice also that this fish was a total home-body, having been caught and recaptured three times in the same region of the lake, on the west side near Shah-bush-kung Bay.

Science at work!