I see the comments about the ministry adding in chemicals to kill the weeds. I have had a cottage on the lake for 11 years and every year the fishing seems to get worse. As far as the ministry I am not aware of them adding anything to the lake. The cottage association meet with the ministry last year after we had 2 bad years of flooding and there was talk about the weeds but they have never said anything about adding anything to the water. People even suggested to them ways of trying to help with the weeds and they said they were not prepared to do anything at this time. They said the fish population is very good but, I find it harder to catch the fish. Could be that they are not hungry. Also if you read the ministry guide to eating sport fish you will see that it shows the lake being very healthy. The algae bloom happens every year and depending on how hot it is, how much rain and wind there is we dictate how long it lasts.
Not sure if this helps anyone.