SLee;
If hot water doesn’t hold as much oxygen as cold water, then why wouldn’t pumping in fresh “hot” water save fish??? Are you not replenishing the oxygen?
IF the water is “fresh”, it doesn’t matter the temp, for the temp factor is eliminated. Why? Because it is fresh, just like the lake water.
If the livewell isn’t operated or set up correctly, it will kill fish, for there is not “fresh” water coming in.
If bass can live in 90 degree water in the lake, then they can live in 90 degree water in a livewell that has the proper setup with recirculation of fresh water.
Make sense???
As for delayed mortality, I hear what you are saying, however there is a difference in releasing healthy fish and lethargic fish.
When you have to chase a fish in a live well and struggle with it in your hands to release it, because it is kicking so hard, that fish isn’t going to die because of being in the livewell.
However,
If the fish is lethargic and has no response to your picking it up and slowly sinks into the depths of the water, sure, that fish “might die”.
I will say “might”, for I took a 40″ pike that was about dead and revived it by keeping her in a large livewell for several, several minutes by pumping fresh water on her. Even when she was ready to go, we still kept her in the livewell for several minutes. I beleive that fish survived, due to being revived with “fresh water” and being confined and calm in a livewell, without stress.
But, I would like to know what your theory is, for the hot weather killing fish in the livewell? What is actually killing them?