The population density of muskies in Minnesota’s Lake Bemidji is decreasing.

In fact, the state’s department of natural resources recently estimated that there are 500 to 600 adult muskies in Lake Bemidji. The good thing is the muskies in 6,581-acre Bemidji are huge.

During recent sampling, the DNR caught 80 muskies in the lake, with one in every four females turning out to be 50 inches or longer. The largest weighed 46 pounds.

“We started seeing this last year on Bemidji, and we were surprised by the size distribution,” said Gary Barnard, the DNR’s Bemidji area fisheries supervisor in an interview with the St. Paul Pioneer Press. “So this year we spanned the entire spawning period to make sure we weren’t doing something that was biased toward capturing bigger fish. We found the same thing this year: A lot of these fish are big.”

The reason behind this trend is uncertain. One answer seems simple enough — it could be a case of musky cannibalism. The DNR has not found signs of signs of disease or a lack of food, leaving the cannibal theory as a strong option.

Another possibility, according to Barnard, is that the fish are delaying their sexual maturity in order to grow bigger, and smaller fish are not coming into the shallow water to spawn, a behavior that male bluegills have shown.

“There’s a lot of consternation in the musky world right now,” Branard said. “We’re seeing a lot of these lakes crash, and then we see the DNR pull stocking back to see if there’s natural reproduction. The DNR did a great job creating a world-class musky fishery, but now we need to maintain it.”