coastal british columbia  

What is that foam in the surf? by James G. Acker  

Sea Foam

by James G. Acker

I think that the most I ever learned about foam was in an article about beer (seriously).

The article about beer basically said this: _any_ aqueous solution can form a foam, but (obviously) the identity of what is dissolved in solution affects both the consistency and quality of the foam. In general, the higher concentrations of dissolved organic matter [proteins, lignins, and lipids] will cause a foam to be thicker and longer-lasting. If a foam is thick and persistent, that will give it a greater ability to entrain particulates, which are likely to affect the color of the foam.

Foams seen on sandy beaches are likely not generated in situ. More commonly, a phytoplankton (algal) bloom offshore will dissolve a large amount of organic matter in seawater, and as this water is transported onshore by winds and then agitated in the surf zone, foams will form. Speaking of contaminants, if the bloom was a "red tide", the foam could contain toxins that could become aerosols. These toxins might cause irritation and other respiratory discomfort if inhaled. This phenomenon occasionally happens along the west coast of Florida.

---- James Acker