SA harmful algal bloom update
What is happening?
An ongoing bloom of Karenia mikimotoi has caused discoloured water and foam along parts of Fleurieu Peninsula, Kangaroo Island and the southern coast of Yorke Peninsula. This microalgae can cause marine species mortalities, including fish and cockles, by affecting fish gills at certain concentrations.
Why has it appeared now?
Experts believe the bloom is being driven by a marine heatwave – with sea temperatures about 2.5°C warmer than usual – combined with calm conditions, light winds and small swells. The last large event of this type of algae recorded in SA was at Coffin Bay in 2014.
How long might the bloom last?
Similar blooms around the world have lasted from a week to several months, depending on wind, rain and ocean temperatures. This one is expected to persist until strong westerly winds arrive, which historically happens at the end of April. However, persistent high pressure systems have delayed these winds.
Is the bloom harmful to people?
Karenia mikimotoi does not cause long-term harmful effects in humans. However, exposure to discoloured or foamy water can cause short-term skin or eye irritation and respiratory symptoms, including coughing or shortness of breath. These symptoms usually resolve within several hours after leaving the beach area.
What should I do if I experience symptoms?
If you are outdoors and experience irritation, go indoors and close windows until symptoms pass. If symptoms are more severe or do not resolve, seek medical advice from a GP and call 000 if it is a medical emergency.
Can I swim or walk on the beach?
- Avoid swimming or surfing in discoloured water, foam or where marine life is dead or in poor health
- If you experience irritation, go indoors, close windows and rinse exposed skin; seek medical advice if symptoms persist or call 000 in an emergency
- Do not touch or eat dead or dying fish, shellfish or marine wildlife
- Fish caught alive are safe to eat
- Follow beach signage and directions from NPWS rangers
Is it safe to eat seafood from affected areas?
- Do not eat dead or dying fish, cockles or other marine life found on the beach
- Report any marine mortalities to FISHWATCH on 1800 065 522
- Fish caught live are safe to eat
- Commercial pipi harvesting has been closed since 16 April from the Murray Mouth to 10km south of the mouth, to prevent packaging of dead or dying pipis. Ongoing testing in open harvest areas continues to ensure product safety.
What is being done about the bloom?
- Government agencies, including the Department for Environment and Water, the Environment Protection Authority, the Department of Primary Industries and Regions and SA Health are monitoring the situation
- Signs are in place at public entry points to affected beaches, and National Parks beaches remain open
- Nothing can be done to dilute or dissipate the bloom naturally
Are desalination plants contributing to the bloom?
- No health issues are known to be associated with brine discharged from desalination plants and brine is not linked to increased algal growth. All marine desalination plants operated by SA Water are regulated by the Environment Protection Authority, which ensures appropriate management of brine outflow.
Who should I contact about dead wildlife?
- FISHWATCH (fish and general marine wildlife reports): 1800 065 522
- National Parks and Wildlife Service offices (marine wildlife)
Who should I contact with health questions?
- Health advice: SA Health 13 11 26
