My last trip, which is this latest video, was about two weeks ago. Surface water temperature was 61F when we ended that day. I took my boat off the truck already lol, mostly because my focus will shift to the West Coast of VI next week plus this heat would be unbearable in the boat at the lakes. Post-release mortality will definitely go up when surface temperature gets up there, depending on how much handling is involved once the fish get in the net....
the data on water temperature and trout c&r mortality is mostly collected from streams. Unlike lakes, rivers & creeks generally don't stratify, that is form temperature layers. Once river temperatures rise above about 19 degrees Celsius the trout are constantly exposed to that temperature risk. One significant reason trout do so poorly as water temperatures climb above 19 degrees is that water holds less dissolved oxygen the warmer it gets!
I think most stillwater anglers are aware that after completing their spring turnover, lakes stratify in 3 layers. As spring and summer progresses the upper layer gets thicker and warmer. While in most cases it might be no more than 5 or 6 feet thick it can get to temperatures of 30 Celsius that are quickly fatal to trout and be as thick as 30 feet!
Generally the thickness and temperature of that upper layer will be inversely related to the depth and size of the lake. Large deep lakes will have thinner upper layers. If you've ever dived into a lake in summer you may have experienced a sudden change from warm to chilly water just a few feet below the surface. You can also experience this by treading water and dangling your feet into the middle temperature layer.
So what's this all mean for c&r fishing on lakes when surfaces temperatures rise above 65 degrees Fahrenheit? Well not much at first but as the hot summer weather continues, the upper layer of warm water gets warmer and thicker. As the water reaches 70 degrees F or so the trout really won't go into it and anglers need to fish just below the top layer. It's best to reduce the time the fish is exposed to that warm upper layer. Let them stay deep at first and bring them to the surface quickly as they tire & release immediately once landed.
Eventually the top layer gets so thick and the middle layer loses so much oxygen that the fish go into the summer doldrums and you should move to high elevation lakes or go fishing in cold mountain streams.
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Topic: Interior Lake fishing season 2021 (Read 7333 times)