I noticed that ice fishing. The bigger the bait, the bigger the fish, every flag. There aren't supposed to be northerns in my tiger lake. The tigers are stocked. Have been every year since 2004. It was on a lake that was wiped out , along with many others, by acid rain. I don't know for sure, but I think they were introduced to control another species when they restored the lakes fish population. I could be wrong, but it's something I'd like to find out.