The Environment Protection Authority has received results identifying the species Karenia mikimotoi (Kar-een-ia mickey-mow-toy) as the cause of the microalgae bloom on the Fleurieu Peninsula.
Karenia mikimotoi is toxic to fish and invertebrates and can cause general allergic-type responses in humans.
Human exposure, including through breathing in algae particles, can cause respiratory and eye irritation or skin rashes in some people, while ingestion could cause stomach upsets or flu-like symptoms.
Karenia mikimotoi can also cause mass mortalities of marine species at varying concentrations. This species can have a range of health impacts on marine life but is known for impacting on the gills of fish, typically causing mortality.
The EPA expects the microalgae will dissipate naturally over time depending on wind, swell and tidal conditions and they will continue to monitor the bloom.
Over the past week, reports from the public have conveyed sightings of the bloom, and its effects on marine life and humans, from Cape Jervis to Encounter Bay.
Waitpinga Beach and Parsons Beach will remain closed until further notice and people should adhere to the warning signs located at other council-run beaches.
Blooms of this type of algae have been observed in marine waters across the world, being first recorded in the 1930s.
They have caused mass mortalities of fish, shellfish, and other invertebrates in the coastal waters of many other countries, including Japan and New Zealand. The last time a large event of this type of algae was recorded in SA was in 2014 in Coffin Bay.
The event has been driven by an ongoing marine heatwave, with marine water temperatures currently 2.5C warmer than usual, as well as relatively calm marine conditions with little wind and small swell.
To report conditions please contact Fishwatch on 1800 065 522 or report to the EPA on 1800 623 445 or via [email protected]
As put by Susan Close
Now we know exactly what we are dealing with, I would encourage people to avoid the water and shoreline along the affected beaches.
The EPA will continue to monitor the microalgae bloom and beaches will reopen as soon as it dissipates.
If people do come into contact with the microalgae, please follow the health advice and wash it off with fresh water.
With temperatures, including water temperatures, continuing to rise as part of climate change, we need to remain vigilant for these type of events and I thank everyone who took to the time to report the bloom to authorities.
As put by David Cunliffe, SA Health Principal Water Quality Adviser
Karenia mikimotoi is toxic to fish but not humans.
In humans, exposure (including through breathing in algae particles broken up by the surf and wind) can cause general allergic-type responses, including respiratory and eye irritation or skin rashes in some people, while ingestion could cause stomach upsets or flu-like symptoms.
These symptoms disappear when the exposure stops or following washing in clean water. There are no long-term effects.
In general, people should avoid contact with discoloured fresh or marine water. If they do enter this water they should take care to wash in clean water afterwards.
