An outbreak of harmful algal bloom, also known as a red tide, has been confirmed along some parts of the Garden Route coast.
People should not fish, bathe or swim in affected areas such as Plettenberg Bay, Knysna and Wilderness, warned environmental affairs department spokesperson Xolile Nqayi.
The algal bloom was normally caused by large concentrations of red or brown-coloured microorganisms. These can become concentrated in filter feeders such as mussels and oysters, making them poisonous to humans.
Nqayi said the discolouration was first seen last Monday. It was expected to last for up to a few weeks.
“Unfortunately, nothing can be done about it as it is a part of a natural process; however the expectation is that nature will take its course and the harmful algal bloom will subside with time.”
South African National Parks (SANParks) officials seemed to think the same organisms found in last year’s algal bloom had returned to the coastline.
“We are conducting further water samples to determine its toxicity as it was not certain last year whether the red tide was in fact toxic or not,” said Professor Brian Allanson of the Knysna Basin Project.
Members of the public were advised not to collect shellfish or eat any fish that washed up on the shore.
SANParks had put up the relevant warning signs in the affected areas.