There's been a steep drop in natural walleye reproduction on some northern Wisconsin lakes and the DNR fisheries scientists are trying to figure out why. During the Natural Resources Board meeting this week, DNR fisheries spokesperson Joe Hennessy said there's been a walleye population rebound on the Minocqua Chain. There's been an agreement for no walleye harvest on the Chain for six seasons. He said an overriding issue is fish replacing themselves... "Both Minocqua and Kawaguesaga have gotten above three fish per acre. Minocqua a little bit over four. But for whatever reason they're not producing natural year classes..." Hennessey says they can build much larger populations through natural reproduction than through stocking. The state has invested more money to raise larger fingerlings to try to improve survival rates. Hennessey cited the need to look at each lake individually and analyze what type of limits needed to be in place to continue natural reproduction. He said in Vilas county is Little John Lake that has good reproduction and four lakes nearby including large Trout Lake. Each lake requires a different approach... "Around(Little John lake) are four other walleye lakes and none of them are more than five miles away from the boat landing at Little John. We have three different walleye regulations across these five lakes..." Biologist Max Wolter said they went to a standard size and bag limit approach in 2015 after complaints about the sliding scale bag limits that were in place before. He said there were times when sliding limits on lakes changed while anglers were out on the water.