Cape Town - The red tide currently sweeping the southern and eastern Cape coastline is resulting in the widespread death of marine life.
SANParks spokesman Nandi Mgwadlamba said on Tuesday dead fish, mainly grunters and tiger perch, had been found in the shallow water at Brenton-on-Sea outside Knysna and Robberg at Plettenberg Bay.
Dead heart urchins had also been found at Leisure Isle in Knysna.
In Port Elizabeth last week, some 80kg of dead fish was collected in the Sardinia Bay area alone.
Mgwadlamba said people were also failing to heed warnings not to eat the fish.
“People have been seen collecting the dead fish to braai. We are again cautioning against the collection of fish until further notice,” she said.
While local marine experts were still trying to determine the toxicity of the organism, they cited the rapid fall in dissolved oxygen in the water column as a probable cause for the death of marine life.
Professor Brian Allanson of the Knysna Basin Project said the algal bloom currently being experienced was usually found off California in the US, not southern Africa.
“It is not the same type found along our West Coast. Why it is here now is a mystery, but I am sure with research we could find an answer in the future.”
He said he could not predict when the red tide would subside.
“On Saturday there was a large upswelling of cold water overnight. The algae live on the surface of the water, and with the strong south-easterly winds that blew, we could have expected the distribution to move away from the coast.
“However, with fish already deprived of oxygen, the drop in the water temperature seems to have made grunter and other fish species more uncomfortable. We don’t know the water tolerances of grunter. There are a lot of dynamics to consider.”
Warnings about red tide on the Garden Route were first issued in mid-December, before spreading hundreds of kilometres down the coast to Port Elizabeth and Port Alfred. - GARDEN ROUTE MEDIA