A buddy who loves flathead-fishing on the Rock River found this YouTube video about the massive fish kill on the Rock in June of 2009.
That;s biologist Dan Sallee talking straight. Not sure what the setting is, but it looks like a tackle or bait shop.
Considering I have covered a fair number of fish kills over the years, I found some of Sallee's explanations fascinately in the broader sense of kills too, especially when he is talking about the official end of it.

Thanks a lot for putting this up Dale.
It might not be completely obvious, however, that this whole seminar is available on YouTube in ten segments (This is number four).
Mr. Sallee does a terrific job here... and yes, fascinating is the right word to describe this talk.