By the time fall has arrived, lakes have become thermally stratified. This means that cold water is found at the bottom, warm water is found at the top and a temperature gradient in between. Dead planktonic organisms, sediments, and other nutrients have become abundant near the surface. As cool winds prevail and the sun is less intense during fall, the surface waters (or epilimnion) begin to cool and become more dense. These cooler, more dense waters begin to sink past the thermocline to the bottom waters or the hypolimnion and the once stratified lake has become a more uniform temperature due to mixing. When the cool water sank during this mixing, it brought with it the nutrients from the epilimnion which provides for benthic organisms.-