The Department of Forestry, Fisheries and the Environment (DFFE) has confirmed that large numbers of dead white mussels, whelks and other shellfish have been washing ashore at St Helena Bay and Elandsbaai on the West Coast over the past 48 hours.
According to the department, the shellfish deaths are consistent with paralysis, which prevents the animals from burrowing into the sand before being washed out by the surf. This phenomenon is most likely linked to a harmful algal bloom (HAB), commonly referred to as a “red tide”.
Not visible to the human eye
Red tides are seasonal algal blooms caused by an accumulation of phytoplankton and are common along the West Coast during summer and autumn.
In this case, the department says the bloom is colourless and therefore not visible to the human eye.
Despite its invisibility, the bloom is believed to be producing paralytic shellfish poisoning (PSP) neurotoxins, which are extremely dangerous to humans.
The DFFE has issued a strong warning to the public not to consume any shellfish from affected areas.
“All shellfish, whether washed ashore or collected from the shore or subtidal zones, should not be eaten,” the department said, adding that the marine animals pose significant health risks and are unsafe for consumption.
Assess the extent
The department has assured the public that it will continue monitoring the situation to assess the extent of the harmful algal bloom and the resulting mass mortalities along the West Coast.
Members of the public are urged to heed the warning and avoid collecting or eating shellfish until further notice.
