In higher latitudes where lakes freeze over in winter, how do cool fall temperatures fish make it through the winter?
1.) the cooling water slows fish metabolisms down and allows them to go into hibernation in winter.
2.) water from the bottom of the lake raises and provides oxygen to the cooler waters on the surface.
3.) cool water at the surface traps nutrients deep in the lake to provide food during the winter.
4.) the water in contact with the air sinks and mixes with the less oxygenated water in the deeper levels.