Last week, a concerning incident occurred along South Australia’s coast between Waitpinga and Parsons beaches, where large amounts of yellow foam and numerous deceased marine creatures, including fish and seahorses, were discovered. This spectacle quickly garnered attention online, but it also had serious implications for public health, as over 100 surfers and beachgoers reported experiencing a range of unexplained symptoms, such as itchy eyes, blurred vision, coughing, and respiratory issues.
Researchers from the University of Technology have identified a type of planktonic algae named Karenia mikimotoi as the source of this problem. This particular species is known to produce harmful toxins that affect both human health and aquatic life. Research involved analysing water samples collected from various locations, including several beaches and a boat ramp, following the alarming reports.
While K. mikimotoi is typically present in Australia’s coastal waters, it generally coexists with other algal species. However, in certain conditions, it can proliferate, leading to an ‘algal bloom’. Such blooms can severely harm marine ecosystems; the toxins produced by K. mikimotoi are not yet fully understood but are suspected to impede fish and shellfish respiration.
The unique health effects on humans remain largely unknown, though the presence of reactive oxygen species from these algae may act as irritants. Researchers have speculated that this could explain the illnesses experienced by beach visitors. Despite the challenges posed by harmful algal blooms, the good news is that the toxins are not long-lasting in the environment once the algae cells die, allowing for rapid recovery of the marine ecosystem.
Current inquiries are focused on whether rising sea temperatures have played a role in triggering this harmful algal bloom and whether such events might become more frequent. The phenomenon is not isolated to Australia, as similar blooms have significantly impacted marine life around the world, including regions in Asia, Europe, and South America.
As scientists continue to study this issue, local communities are urged to be cautious and informed about potential health risks while enjoying their beaches.