I was thinking it was further down lake where the kill was taking place, maybe between big m and shell knob? Am I right about that? If beaver will keep water coming in you'd think the lake would be good up to the owl creek or rock creek area. That's just guessing though. If beaver doesn't let water in then I could see it getting bad up river in a hurry. When I become president we are getting rid of the stripers and tearing down beaver dam.
The best thing for fish care is good batteries and pumps. Run them suckers constantly. I like the idea of ice but I don't trust what they put in it some I'm iffy on using it. If I knew it was pure clean water I'd be good. I do use frozen water bottles and ice packs to chill the water sometimes and throwing a life jacket over the live well lids never hurts.