|Sea foam, Asbury Park, NJ|
Offshore decomposition of phytoplankton blooms dissolves large amounts of organic matter in seawater. Dissolved organic matter acts as a foaming agent or surfactant.
Breaking waves in the near-shore surf zone trap air. The presence of foaming agents generates persistent bubbles that stick to each other by surface tension.
Sea foam can be blown inland by strong on-shore winds.
I am forever walking upon these shores,
Betwixt the sand and the foam,
The high tide will erase my foot prints,
And the wind will blow away the foam,
But the sea and the shore will remain forever.
— Kahlil Gibran (Sand and Foam)