What's the temp range of Brookies vs. Browns vs. Rainbows? What are the lethal upper limits? (providing there is enough DO at those temps)
From all the research I have done, the limits really do vary greatly. Even among the same species. I've tried to pin point a magical number and just can't seem to find it. DO plays as big a role as temperature if not more so. If you have full saturation, trout of all species can handle much warmer temps. Brown trout definitely are more tolerant. Some studies I have seen put them being able to tolerate 78 degrees indefinitely at full saturation and up to 84 degrees for short periods of time. Obviously, this stresses them greatly. Brook trout are by far the least tolerant of the bunch. There are a lot of good studies from Tennessee where they study rainbow trout and brown trout survival in tailwater fisheries from reservoirs. They constantly check temp and DO through out the year and see how survival rates are. Fishing closer to the dam do best, as that is where the water is the coolest... Further down river where the water gets a chance to warm up survival is greatly cut back. A place I fish for trout in a tailwater fishery hold rainbows year round for the first 5 miles or so downstream of the dam and then it switches over to solely browns for another 10 before trout can no longer survive through the summer.
