Colourless Red Tide Dishes Up Toxic Shellfish

The Department of Forestry, Fisheries and the Environment (DFFE) has confirmed large numbers of dead white mussel, whelks and other shellfish being washed out at St Helena Bay and Elandsbaai on the West Coast in the past 48 hours.

The dead shellfish indicates that they have died after being paralysed, unable to burrow and then washed up. This is most likely due to the presence of a harmful algal bloom (HAB) or “Red Tide.” Red tides are algal blooms, that is, accumulations of large amounts of phytoplankton (single-cell algae) that are common during summer and autumn along the West Coast.

This particular “Red Tide” is colourless and therefore not visible to the human eye, but paralytic shellfish poisoning neurotoxins are extremely toxic to humans. All shellfish, irrespective of being washed out or collected from shore or subtidal, should not be eaten. Please do not eat the washed out marine animals as they carry significant health risks, rendering them unsuitable for consumption.

The DFFE will continue to monitor the situation with respect to the extent of the “red tide” and resultant mass mortalities on the West Coast.