Okay how does that work, when cold water is denser than warm water. Is the condensed oxygen as usable for the fish in their slowed down condtion, as the expanded oxygen in warmer water?
Turnovers mix surface water and deep water, which provides oxygen to colder deeper waters. Colder water holds more oxygen then warm water.
In deep water there is more oxygen because it is not used up as much, except in very productive lakes where the deep water can go anoxic.
I looked at the temp graph of a few faster flowing rivers on the island, and they temp stays basically the same throughout the year.
Even though the temp is always low in the rivers I fish, coho still have no problem chasing a fly down 20-30 feet in the fall.
I guess with certain species it may be possible, but even with Steelhead this year I have hardly ever had my float more than 2 feet from my weights and have had no problem with them hitting my offering in water up to 5 feet deep.