I've been watching closely during this period. I walk the outside of the pond a couple times a day (with my net to scoop out dead fish).

I have not noticed any odd behavior. I've watched for air-gulping or hanging out near the surface and have not noticed this.

As for the rains, those came in recent days, after most of the damage seems to have been done. I've seen far fewer dead fish in the last few days than I was seeing before.

The reason I was concerned about the bluegills is that I figured that perhaps a small bit of fish-kill was to be expected if I had perch in water that reached 85-90 degrees. I just heard that water temperatures in Michigan (in general) are the highest they've been in several decades. My worry with the bluegills is that I'd expect them to handle the warm water much better than the perch, and if they are kicking the bucket also, then perhaps there is something more serious going on.

Though I lost power for a couple days, it is back on now, and the pond is being aerated 24/7 like usual. Interestingly, I seemed to notice fewer dead fish during the recent days w/o power (and w/o aeration) than I did before when it was going full time.

Thanks for the response.