What causes sea foam drifts?

During storms some coastal towns are flooded with foam.

In 2015 British coastal town Cleveleys was inundated with foam during a storm that whipped up the sea with strong winds. The roads were covered with foam with drifts several feet high in places.

What causes sea foam?

Sea foam is formed when the ocean churns up high concentrations of organic matter. Although a natural phenomena, pollution from contaminants can make it worse. It is not normally harmful to health but can sometimes irritate the eyes and airways.