Michelle Daw, Yorke Peninsula Country Times

An algae toxic to marine life has been detected in water samples collected from Edithburgh and Coobowie.

In a statement released yesterday, Monday, April 14, a Primary Industries and Regions South Australia spokesperson confirmed low levels of Karenia mikimotoi had been found in samples from both locations.

Toxic. Dead marine creatures found near Edithburgh jetty. From left, blue-ringed octopus, garfish, sand octopus and fan worm.
Photos: Paul Macdonald, Edithburgh Diving and Elizabeth Solich 

“There have been no detection of K. mikimotoi from samples collected to date at Point Moorowie, Port Vincent or Stansbury,” the spokesperson said.

“Results of other water samples already collected at Butlers Beach, Marion Bay and Pondalowie this week are still pending.”

PIRSA is continuing to investigate reports of dead fish at several locations on Yorke Peninsula, with the most recent report received on April 8.

As reported in the YP Country Times on April 8, divers at Edithburgh observed large numbers of dead marine life around the town’s jetty on April 6. Similar discoveries have been made at Troubridge Island and Wool Bay.

The toxic algae bloom has also affected beaches on Kangaroo Island and the Fleurieu Peninsula, where mass deaths of pipis (Goolwa cockles) and other marine species have occurred.

Significant levels of the bloom were first detected in early March at Waitpinga and Parsons Beaches, both on Fleurieu Peninsula, both of which have since reopened as algae levels have dropped.

SA Health has issued a warning to beach users about the effects of the algae [see below].

The PIRSA spokesperson said the algae could cause mass deaths of marine life and particularly affect the gills of fish.

“This is a dynamic situation as the bloom travels depending on weather and water conditions, and the impact therefore is unpredictable,” they said.

Water samples collected at Bales Beach, near Seal Bay on southern Kangaroo Island, have indicated high levels of K. mikimotoi.

“The event is thought to have been driven by an ongoing marine heatwave, with water temperatures currently 2.5 degrees Celsius warmer than usual, as well as relatively calm marine conditions with little wind and small swells,” the spokesperson said.

“The bloom is expected to remain present until the state receives strong westerly winds, which historically start around the end of April. Nothing can be done to dilute or dissipate the bloom.

“Similar outbreaks around the world have generally lasted between a week to two months depending on wind, rain and ocean temperature fluctuations.”

The spokesperson confirmed that the commercial harvesting of pipis had not been affected and regular testing continued to ensure their safety for consumption.

PIRSA is working alongside other SA Government agencies, including the Department for Environment and Water.

These agencies met on April 9 to coordinate the sharing of information with the public to help ensure coastal safety during the current school holidays and Easter period.

PIRSA’s role includes investigating any infectious or notifiable animal diseases that may have contributed to the fish deaths.

Underwater ghost town

The water was still brown and murky when veteran diver David Place ventured under and around the Edithburgh jetty yesterday, Monday, April 14.

He said visibility was only about two to three metres, but should have been at least double that.

“There were a few dead fish around but also some species seem unaffected,” Mr Place said.

“I couldn’t find one octopus of any sort — they were prolific just weeks ago.

“There is a white fungus on some rocks and old jetty debris that wasn’t there before this event.

“After diving here for nearly 40 years, I have seen or heard anyone ever mention anything like this here.

“For a jetty that was so full of life, it reminds me of a ghost town.

“It’s so sad — I just hope it can bounce back.”

Health warning

SA Health has issued a warning about coastal waters affected by Karenia mikimotoi.

Exposure to this algae — through sea spray, windborne particles or direct contact — can cause skin and eye irritation, and respiratory symptoms such as coughing and shortness of breath.

Symptoms reported so far have resolved within hours after leaving the water or beach.

This algae does not produce toxins that are harmful to humans or known to cause long-term health effects.

What to do:

• Avoid swimming in obviously affected areas and avoid contact with discoloured water. If you do enter this water, take care to wash in clean water afterwards.
• Do not eat dead fish and cockles because of decomposition and spoilage. Fish caught live are safe to eat.
• Avoid swimming at beaches where there is discoloured water and foam.
• Avoid walking on affected beaches if experiencing symptoms.
• If you live in the area and experience symptoms outside your home, stay indoors with windows closed, until symptoms resolve.
• If you have symptoms that are severe or do not resolve, seek medical advice from your doctor. Call 000 in a medical emergency.

This article appeared in Yorke Peninsula Country Times, 15 April 2025.
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