The fish have been hard to pattern for this time of year. For the most part, they just aren't doing what they should be doing where they should be doing it. I'm no biologist so I don't know whether that has more to do with the cooler temperatures or the die-off. But I'm leaning more to the lower temps keeping the fish scattered and not schooled up like they should be.
There's areas of the St. Clair River that should be fishing real strong right now but they're just not. Water surface temps are still running below 70, compared to last year when they hit 70 by late July. I'm a firm beleiver that these fish, especially in the upper stretches are either resident river fish, or Lake Huron fish - therefore not effected by what we saw happen in St. Clair with all the dead fish.
The tournament weights are way off what they were last year at this time. For example, in yesterday's BFL there were only 2 bags over 20lbs, and 20th place was 13-10. In last year's tournament on the same weekend there 7 bags over 20lbs, and 20th place was 17-7. Again, I think this is because the lake is just hard to pattern with them still being scattered and not where they "should be" in strong numbers. For example: The guy that won the Stren tournament two weeks ago had a three day combined weight of 61-05 (22-11, 18-06, 20-04). In yesterday's BFL he had 11-12, in weather conditions very similar to the last day of the Stren when he caught 20-04.