How old is that fish

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!

If you're ready to learn more about the ways we interpret traditional 2D sonar, be sure to check out our latest instructional DVD, Angler's Guide to Sonar Interpretation. Here, you'll learn to make critical visual connections between sonar images and the actual underwater objects using an Aqua-Vu underwater camera system. Includes a detailed analysis of many different types of natural and artificial structure, lessons on fish identification, opportunities to practice your skills and even sonar puzzlers. Also included are hardware setup tips and sonar settings for peak sonar and imaging performance. Optimized for Humminbird HELIX, but the sonar interpretation skills apply to any fish finder! Approx. 60 minutes on DVD video.
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