Cappuccino Coast, Cape Town, South Africa

If crude oil discharged from tankers at sea, or motor oil, sewage and detergents from polluted stormwater are present, the resulting sea foam is even more persistent, and can have a chocolate mousse texture.
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.