Local residents of New South Wales and Queensland, Australia have reported that recent storms have brought in large amounts of sea foam on the beaches and nearby towns.
However, experts are warning against exploring or playing in the foam because there are sea snakes and other creatures lurking around in there.
There are 32 species of poisonous sea snakes around Australia, and their bites require antivenom.
There also could possibly be dangerous trash strewn around in the foam. The water can also contain pollutants that could be toxic to humans and animals.
Nathan Fife, the Gold Coast lifesaving services supervisor at Surf Lifesaving Australia, told Guardian Australia, “There’s been trees and things like that have washed up. I think there was half a cow that washed up at the beach yesterday, so make sure what’s in front of you — there are trees and logs floating around, so please be careful.”
Hazel the dog rescued from sea foam in Byron Bay, Australia. Sea foam often forms when strong winds and large waves whip up the cresting waves. pic.twitter.com/KSmREu2ADs
— BBC Weather (@bbcweather) December 14, 2020
Sea foam is created by the agitation of seawater, especially when it contains higher concentrations of dissolved organic matter (including proteins, lignins, and lipids) derived from sources such as the offshore breakdown of algal blooms.
These compounds can act as surfactants or foaming agents. As the seawater is churned by breaking waves in the surf zone adjacent to the shore, the surfactants under these turbulent conditions trap air, forming persistent bubbles that stick to each other through surface tension.
Sea foam is a global phenomenon and it varies depending on location and the potential influence of the surrounding marine, freshwater, and/or terrestrial environments. Due to its low density and persistence, foam can be blown by strong on-shore winds from the beach face inland.
The physical processes that contribute to sea foam formation are breaking surface waves, bubble entrainment, and whitecap formation. Breaking of surface waves injects air from the atmosphere into the water column, leading to bubble creation. These bubbles get transported around the top few meters of the surface ocean due to their buoyancy.
The smallest bubbles entrained in the water column dissolve entirely, leading to higher ratios of dissolved gases in the surface ocean. The bubbles that do not dissolve eventually make it back to the surface. As they rise, these bubbles accumulate hydrophobic substances. The presence of dissolved organic matter stabilizes the bubbles, aggregating together as sea foam.
Some studies on sea foam report that breaking of algal cells in times of heavy swells makes sea foam production more likely.
sea foam is generally a mixture of decomposed organic materials, including zooplankton, phytoplankton, algae (including diatoms), bacteria, fungi, protozoans, and vascular plant detritus, though each occurrence of sea foam varies in its specific contents.
In some areas, sea foam is found to be made up of primarily protein, dominant in both fresh and old foam, as well as lipids and carbohydrates. The high protein and low carbohydrate concentration suggest that sugars originally present in the surrounding mucilage created by algae or plant matter has been quickly consumed by bacteria.