The DNR communications team works with agency experts to develop the weekly questions and provide the answers. This feature addresses current DNR issues, interesting topics, or the most frequently asked questions from around Minnesota.
Q: How many watercraft inspectors does the DNR hire to check for invasive species?
A: Our goal is to hire 100 Level 1 watercraft inspectors and 46 Level 2 watercraft inspectors each season. Level 2 inspectors not only inspect boats and equipment for aquatic invasive species, but can decontaminate watercraft using hot high-pressure washers. DNR watercraft inspectors will work at more than 250 public water access sites this season.
The DNR also partners with local units of government so that they can hire their own watercraft inspectors. So far this season, we have trained more than 300 of these local inspectors.
--Heidi Wolf, watercraft inspection program coordinator
Q: How old do muskie get, and how long does it take to grow a 50 incher?
A: The oldest muskellunge I have aged was 22 years, and muskellunge in Canadian waters have been aged up to 30 years old.
In both cases, ages were assessed using the cleithrum, a calcified structure that requires lethal sampling and is collected from harvested fish anglers bring into taxidermy shops.
Traditional aging methods used scales because they were easy to sample and fish didn’t have to be sacrificed. Various studies have since found the scale aging method underestimates age, particularly for larger fish.
Growth and ultimate size can vary among bodies of water, depending on factors such as lake productivity, forage and genetics. Depending on the body of water, muskellunge in Minnesota could take 13 to 21 years to reach 50 inches.
Jerry Younk, DNR fisheries research biologist