Back in the 80's you could of thrown a bone on a hook and caught fish. I think when the zebra muscles got thick the water cleared. the fish see the boat and spook away. We noticed that we would mark fish everywehre...throw out and WHAM..instantly catch one or 2. Then nothing. Nothing on the graph either. I know people do not like it...but when we trolled...we would make a left or right turn..the far outside bait would always catch one. I just think the clarity of the water gets them out away from the boat....out of reach. But we still catch them in the spring with them. The water is murkey in the western basin then. Just an idea...30 years of fishing it we learned a bit