Snow, Suds or ....?

The fluffy white stuff is foam on Frame Lake, whipped up by the wind. As I walked to work this morning, there were whitecaps on the lake and bits of foam tumbled across the trail. It's the second time I've seen this foam. It isn't pollution, as far as I can tell. Most foaming of lakes is a natural process, created when the surface tension of the water is reduced and the air is mixed in, forming bubbles. Decomposing algae releases cellular products into the water, which lessens the surface tension even more--and voila, sudsy white foam. However, swimming isn't allowed in this lake, for reasons I have yet to learn. Maybe the foam is, indeed, evil.