Cappuccino Coast, Cape Town, South Africa

If the foam forms from the breakdown of a harmful algal bloom (including those caused by some dinoflagellates and cyanobacteria), direct contact with the foam, or inhalation of aerosols derived the foam as it dries, can cause skin irritations or other respiratory discomfort.
Notable occurrences
A large buildup of sea foam occurred on the coast of Yamba, northern New South Wales, 29°26′S 153°21′W on 24 August 2007, and attracted world-wide media attention.