A foamy substance found on Durban beaches is not sewage; it’s known as ocean foam or spume and is a nutritious broth or soup of organic matter.
The foam that has surfaced on the shoreline of uShaka Beach is not sewage as reported on social media sites - and the eThekwini Municipality said they are not pumping sewage into the beach.
eThekwini Municipality is currently busy with a sand-pumping operation on the beachfront close to the harbour mouth. This is done on annually to ensure that beaches remain in pristine condition, the municipality said.
Communications head, Lindiwe Khuzwayo said eThekwini Municipality would like to clarify that social media reports, claiming that the city was pumping sewage into uShaka Beach were “false, malicious and based on ignorance”.
“The city is busy with a sand pumping operation on the beachfront, close to the harbour mouth,” she said.
“It is done on an annual basis to ensure that beaches remain in pristine condition for all beach goers. If the city did not pump the sand, the beaches would erode with the action of the waves. The darker colour of the sand is a result of naturally occurring minerals such as quartz, feldspar, titanium and ilmenite - which is black in colour. This should not be confused with oil or a sewage spill,” said Ms Khuzwayo.
People are cautioned to avoid the area where the sand is being pumped - especially towards the water’s edge as the sand is soft and liquefied and could act like quicksand, she added. The sand-pumping scheme creates a recreational beach and pumps approximately 280 000 cubic metres of sand onto the beaches every year. This also acts as a buffer between the beach and infrastructure, Ms Khuzwayo explained.
“The harbour breakwaters prevent the natural migration of sand from south to north on our beachfront, necessitating the sand pumping operation. Continuous beach monitoring programmes are in place to provide sediment data on the beaches which guide the sand pumping scheme,” said Ms Khuzwayo.
“The foamy substance in the water is a natural occurrence due to turbulence in the water and is not harmful.”
According to the South African Association of Marine Biological Reseach (SAAMBR), ocean foam or spume, is a “nutritious broth or soup of organic matter”. Sea water comprises lots of different things including water, salts, and organic matter such as bacteria, plankton (tiny plants and animals), broken down bits of bigger plants and animals, animal faeces and much more. Under turbulent conditions created by strong winds and waves – the soup can get whipped up into a protein-rich foam of air bubbles on the surface.
This is nature’s way of filtering out organic matter from the water column onto the sea surface and from there it can wash up onto the beach. Sea foam is not harmful to humans - it is a sign that the ocean is filled with life. Sometimes, however, sea foam can have harmful effects on both humans and the environment. This is when harmful algal blooms (such as red tide) occur and decay near shore, or when the sea foam concentrates man-made pollutants. To be cautious it is best to stay away from the foam, especially close to industrial outfalls and pipelines.