We have all seen this foam around our docks and shores on windy days.   Several people have asked about it ..here is a good explanation from Cottage Life.

Don’t worry, this froth is very likely natural. (The other explanations—the bubbles came from pollution; the bubbles came from your fish, because they threw a foam party—are improbable.) Lake and river water contains organic matter, and when that matter breaks down, it releases compounds like the fatty acids in soap. These compounds lower the surface tension of the water, and make it susceptible to foaming when wind, waves, or currents stir it up. Sometimes the foam piles up against docks, logs, or other floating objects. It’s not harmful, but it may look brown or green, and it probably smells earthy or fishy.

Here is a small amount,,but it usually clumps together