If you scoop up some water from the ocean in a clear glass and look at it closely, you’ll see that it’s chock full of tiny particles. Seawater contains dissolved salts, proteins, fats, dead algae, detergents and other pollutants, and a bunch of other bits and pieces of organic and artificial matter. If you shake this glass of ocean water vigorously, small bubbles will form on the surface of the liquid.

Sea foam forms in this way – but on a much grander scale – when the ocean is agitated by wind and waves. Each coastal region has differing conditions governing the formation of sea foams.

Algal blooms are one common source of thick sea foams. When large blooms of algae decay offshore, great amounts of decaying algal matter often wash ashore. Foam forms as this organic matter is churned up by the surf.