Angler ire over sewage in sea water

Fishermen on the False Bay coastline.

Claims that sewage is running into the sea at the Strandfontein side of the False Bay coastline have been refuted by the City of Cape Town.

Retired policeman, community activist and avid shoreline fisherman, Keith Blake, says unhealthy and unhygienic waste is finding its way into the sea.

“I know a lot about the sea and I know that it is not supposed to look like this,” he said.

In a letter to the Plainsman, in which the offices of premier Helen Zille and mayor Dan Plato are copied in, Mr Blake said there is an unhealthy, disgusting smell of sewerage floating almost daily over the Strandfontein area.

“I am no marine expert but I and many shoreline fishermen have noticed a drastic decline in fish catches,” he said.

He said waste flows into the rivers and find its way into the sea.

“I know of sea sewage running into a canal at Zeekoevlei, the fish are not surfacing like they use to nor do they taste the same at Strandfontein. Sewage is running into the sea. The dirt is coming in at an alarming rate. The City hasn’t responded and has not informed us why this is taking place.”

He said Cape Flats people don’t complain about things affecting them. “We can’t allow the sewage problem to be a talk show, they must fix this problem or we will sit with a major plague.”

Sias van Zyl, a fisherman on the False Bay coastline, said it is very sad to see what’s happening to the ocean.

“I have been having this fight for several years. There are water pipes from Macassar, storm pipes coming from Khayelitsha, one on Beespens and Muizenberg and a major sewage plant affecting the sea water as well as dirt coming through those pipes.

“At Strandfontein, just before Baden Powell, there is a little canal in which the dirt makes its way through.”

This is a big problem he said. He said he does not eat the fish that he catches as it has a stench.

“The safety surrounding Blue Flag beaches is not correct”, he said. “Muizenberg allows nets to be pulled within the Blue Flag area, which should not be tolerated on a normal beach where there are bathers, as the sharks follow these nets. From Muizenberg to Strand it is a polluted area and something needs to be done”.

Both Mnandi and Strandfontein beaches in Mitchell’s Plain have been afforded Blue Flag status – an international accreditation which is awarded to beaches that display excellence through meeting 33 criteria covering four categories namely, environmental education and information, water quality, environmental management and safety.

Mr Van Zyl said sewage plants are not functioning when they are clogged up.

“One hundred and fifty condoms were found on the beach, 350 bottles, and sanitary pads were washing up at the coastline beaches. These plants cannot handle this capacity, it clogs and breaks, overflows and pipes open and flow into the ocean,” said Mr Van Zyl.

Xanthea Limberg, mayoral committee member for water and waste services, said the claims about sewage pollution on this part of the False Bay coastline and a resultant decline in fish catches is not true. “It’s not sewage floating above the water. What is visible along that coastline is a natural phenomenon called brown water that is caused by small minute diatoms called Anualus australis.

“People who frequent the False Bay coast for bathing, fishing, surfing or just walking are familiar with the brown discolouration of oceanic water along beaches between Macassar and Muizenberg. Most people confuse the brown colour in the water for sewage pollution. The discolouration is caused by a naturally occurring diatom or micro-algae called Anaulus australis.”

Anualus australis are sometimes called surf-zone diatoms. Surf-zone diatoms favour sandy beaches and are known in most areas of the world such as several Australian sandy beaches. In South Africa, surf-zone diatoms are found in Algoa Bay, False Bay and the Cape South Coast, Ms Limberg said.

The occurrence of Anualus australis is associated, among other things, with an adequate supply of inorganic nutrients. They are known to favour silica-rich environments. Fish thrive on these diatoms as they are a good food supply.

Anaulus australis is a minute single-cell organism. The organism is enveloped in a cell wall which is made up of silicon. The cell wall takes the shape of a pillow and these cells can congregate in long stretches. The surf-zone diatom can double their number from morning to midday due to synchronised cell division.

The cell densities showed an increase from time to time. The trend is not unfamiliar where cell densities can increase and come down to lower levels throughout the year. The highest concentrations occur between Sunrise and Sonwabe beaches.

Ms Limberg said the City’s scientific services branch routinely monitors these areas for the presence of Anaulus australis fortnightly throughout the year.