The City says the water quality at Strandfontein beach has not shown a major change or decline in the past five years, despite a report of discoloured water and lack of bird and sea life.
Resident Keith Blake said in recent weeks he and other fishermen had noted a darker than usual colour in the water stretching between Strandfontein and Muizenberg beaches.
“We noticed wave after wave of dark coffee, almost oil-like, mixture in the surf on an almost daily basis. The colour of the seawater has also not been clear, almost a pea-soup colouration.”
He said there were also few or no seagulls or seals seen fishing in the surf.
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“There seem to be no black sea birds fishing in the shallows for small fish, no crabs, no octopus - all sea creatures we normally noticed in the past - no fish or extremely few being caught. In the past couple of weeks there seems to be a drastic decrease of local fishermen at Strandfontein.”
Blake called for an investigation into the water quality, and open and transparent feedback on the concerns raised.
Mayco member for spatial planning and environment Marian Nieuwoudt said water quality monitored at Strandfontein has not shown a major change or decline over the past five years, and that the most recent results for April 2021 showed the same pattern.
“What Mr Blake is seeing is brown, coffee-coloured water observed in the False Bay surf-zone due to the surf-zone diatom Anaulus birostratus. These patches are not conventional phytoplankton blooms, but accumulations gathered together by wind-generated surf-zone (circular) currents. They only occur with southerly, onshore winds,” Nieuwoudt said.
Anaulus patches are a completely natural phenomenon that occur on most sandy beaches more than 2km long on the south and east coasts, but not west of Cape Point, Nieuwoudt said.
She added that there had been a ‘red tide’ in the Helderberg area to the east of Strandfontein.
“The dark, reddish-brown colour of the water is from a very dense phytoplankton bloom of mostly the dinoflagellate Ceratium furca. It is non-toxic, but occurs at very high densities, which depletes oxygen levels at night and when it eventually dies and decays.
’’Red tides are a common occurrence on the West and South coasts, especially at this time of year.”
Cape Times