It was a blustery and wet weekend on the coast. The “old timers” say they have never seen such foam on the beach.
What is sea foam (also called spume)? Dissolved organic matter, like protein, fats and a grab bag of other stuff is constantly being released by sources such as dead fish, seaweed and algal blooms, and it’s floating around in the ocean. Tides pull some of this stuff in closer to shoreline and as waves break, they agitate seawater, air and all this organic matter together. likes the world’s grossest milkshake. The organic compounds can act as surfactants or foaming agents. As the seawater is churned by breaking waves in the surf zone, the presence of those surfactants under turbulent conditions traps air, forming persistent bubbles that stick to each other.
While sea foam is pretty gross even under normal conditions, it’s an important part of the coastal food web and acts a reservoir of recycled nutrients for some beach-dwelling animals. The menu even changes depending on the season. Researchers studying sea foam in South Carolina in the late 1980s discovered that the foam is composed mostly of macroalgae (seaweeds) in the fall, winter and early spring, and mostly phytoplankton (microscopic plant-like organisms) in the late spring and summer.
We were playing ball and frisbee with the dogs, almost lost the frisbee one time in a pile of foam. Because of rogue waves we stayed well away from the water.
Sea foam information from: