Written by Ben Linnell fisheries biologist.

I did some aging of walleye recently. This is a cross section of an otolith taken from a 28Ē walleye that died of natural causes. Each ring that you see is an annuli, or one year of growth. Itís hard to see the outer rings in this picture, but if you count all of the annuli, it makes this fish 16 years old. That means a 30Ē walleye can easily be over 20 years old. Also, you can see that the space in between the first annuli are bigger than the rest. That means that the fish grows rapidly in its first few years of life. As the fish get older, the gap between annuli gets smaller and smaller because their growth rate slows down drastically. Most people think of a walleye as being a a fast growing fish that will top out around 10 years old. Thatís simply just not the case. The day that I was aging these fish, an angler actually brought in a tag from a tagged walleye that he just caught. Everyone in the fisheries department was shocked, because the tag that was brought in hasnít been used since the year 2000. That makes that fish at least 20 years old. Recently, a 27 year old walleye was found in ND. Removing these old fish from the ecosystem can be very detrimental and can take several years for that fish to be replaced in the ecosystem. It also doesnít just apply to walleye. Pike, trout, panfish, bass, and many others can all live to be over 15 years. Selective Harvest keeps these old fish in the water. Harvesting the smaller fish that are young and are much more plentiful is the best way to grow old, trophy fish. Something to think about the next time youíre fishing.

(Of course, different fisheries and regions will have different growth rates, but for the most part, the average trophy fish, no matter where you are, is going to be very old.)


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