Crappie numbers and large/slab gills and red ear are definitely greatly declined on our lake. Too many people taking too many are in my mind a big problem. About 3 years ago heard one ice fisherman state that he and his buddy had taken 1800 gills in a couple weeks. Personally saw a guy shore fishing just across my property line leave to empty his buckets and was back in couple hours fishing again and stated he had 139 in the first batch.
I have read numerous articles the last few years regarding panfish size, reproduction, genetics, etc. linking larger gills with producing larger growing offspring. This translates into the fishery benefiting by releasing slab size fish and only keeping ones of moderate size. The May 2016 In-Fisherman magazine has an article regarding selective blue gill harvest and how it relates to the continuation of large fish in a lake. It also discusses how over taking can ruin a fishery in a very short time and that it may take decades ( if ever ) to recover. I fully believe this has happened to our lake. Our lake is rated average or even below on growth rates, etc. due to habitat, food, structure, etc. Several years of the last 10, we have had an extraordinarily good spring fishing. Large numbers of very large gills & red ears were very easy to catch. One year in particular we were over run with fisherman. Found out some one had posted the info on Internet including the exact spots to fish. There were cars parked along the road for several weeks with people swarming available ( and many private ) shorelines. Something similar happened during ice fishing 6-8 years ago. There has been a decline in size of fish caught ever since. Recent DNR studies have shown large numbers of gills ( reduced red ear & greatly reduced crappie ) but much smaller sizes. I think that thanks to "fish hogs " we have been screwed for years to come.
It is happening all over here in my area. I keep fish to eat and I like it when others do as well, but there are those that are out of control. I'm sorry, but if you are taking over 200 bass, 200 gills, and 200 crappie each year out of a lake less than 50 acres, you are the problem. I had a gentleman tell me the other day how he kept over 1,000 bass last year from one lake that is about 40 acres. He didn't even realize there is a minimum size limit at this DNR controlled lake either Now I know why I can't find a bass in that lake over 14" nowadays...people like that have completely ruined some of the public lakes around me.