South Africa 
Toxic red tide in South African waters

afrol News, 6 November - The South African government is urging citizens not to eat the extremely toxic mussels that are washing ashore on the west coast. Even swimming could be dangerous in parts of the attractive coast line. More than 50,000 white mussels today were reported to have been washed ashore by the toxic red tide.

The South African Ministry of Environment and Tourism today issued a warning to residents and tourists in the Elands Bay area, some 300 kilometres north of Cape Town, "to collect and/or eat these mussels as they are highly toxic and could be extremely dangerous." Red tide toxins cause paralysis and have been known to kill humans.

According to the Ministry's spokesperson Phindile Makwakwa, the so-called red tide on the West Coast, between St Helena Bay to Doringbaai - a distance of about 100 km - "has caused more than 50,000 white mussels to wash ashore at Witsand, approximately 10 km north of Elands Bay."

Marine inspectors were "closely monitoring the situation" as scientists from the department took daily water and mussel samples to determine the levels of toxicity. A northerly wind this weekend had been the likely cause of the wash out, which moved the red tide closer inshore.

The good news was that, yesterday's south-easterly wind had pushed the tide offshore again. At the moment "the red tide is approximately 3-4 miles from the coast," Makwakwa informs. It was not informed whether the tide had reached its maximum.

The extraordinary strong toxic tide, caused by blossoming algae, has devastated the coastal ecosystem of the zone for several weeks. Shellfish and other dead marine life forms have washed ashore around Lamberts Bay since 24 October. Scientists at that stage even advised against swimming, calling the phenomenon "one of the most toxic tides we've had in a long time."

Red tides are a returning phenomenon along the African coast, especially in South African waters. In June 2000, a red tide was reported to be responsible for the death of 30 million mussels, also in the Western Cape Province.

Also in February and March this year, Elands Bay was affected by a red tide that beached approximately 1,000 tons of rock lobsters. At this occasion, however, the lobsters were not poisoned, and people came from across South Africa to gather them for food.

The term "red tide" is used to refer to a number of different types of phytoplankton blooms of various hues. This may lead to the development of strong toxins as algae are decaying or directly produced by the algae. In any circumstances, such a heavy phytoplankton concentration will lead to a significant reduction of oxygen in sea water, causing marine life to suffocate.

Sources: SA government and afrol archives

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