Fresh water is fundamental to society. We use it for drinking, manufacturing, energy production, irrigation and fish -- a particularly important protein source in the developing world. Global warming is expected to change what we value in fresh water, as a study co-authored by Hampton last year found lakes warming around the world.
The new study finds that what happens in the winter can have a substantial effect on what happens during the rest of the year. This is especially true for lakes that let in a lot of sunlight, stimulating the growth of algae and zooplankton on the underside of the ice. These in turn serve as food sources for fish at the start of their growing season.