Outbreaks of red tide along the South African coast are reported periodically in the media, with warnings to the public about the dangers of collecting and consuming shellfish in the affected areas. Most red tides represent useful contributions to plankton production but some periodically produce harmful results. The toxic or harmful algal blooms are normally restricted to the West Coast and it is unusual for red tide in False Bay to be harmful.
Red tides usually occur along the South African Cape west or south coasts in late summer and autumn. The prevailing southerly winds at this time of year cause cold, nutrient-rich water to rise up from the deeper regions of the ocean to the surface, a process known as upwelling.
At night you will see the fluorescence in moving water - looks most spectacular as a wave breaks. Best seen on dark nights with little moon but as the photo below shows, if there is enough it is spectacular with the moon.
Click to go to the Ecology and History page for scientific information on red tides
Rooiels has wonderful rock pools rich with life -- sea urchins, little fish, rocks with a range of limpets and bright coloured seaweed. The photo on the left has Porphyra capensis - purple laver or better known as the Japanese cousin "nori" hanging on the rocks. You can eat this as is - very chewy style biltong - or you can bake it in a hot oven with a little oil and eat it like crisps!
Get a glimpse of what lies below our sea by going on a dive with Nico Kessop by linking to this u-tube video here.
A comprehensive overview of the ecology, fauna and flora of our estuary is given in the Estuaries report which you can download here - or see on the website here.
Seashells on the Rooiels seashore....
The Venus Ear or Siffie (Haliotis spadicea) normally around 40mm is one of the 5 abalone found in South Africa.
The much larger Perlemoen (Haliotis midae) which grows to 230mm can be found usually where poachers have been.
Click to Learn More
Dwaf Fan shells (Chlamys tincta ) These colourful little bivalves have a single fin at its base, where the larger Scallop (Pecten sulcicostatus) has 2 fins