Health experts are warning people to avoid body contact with, and drinking from, Lake Alexandrina until further notice.

People living in the area or visiting parts of the lake can still enjoy boating and fishing but are strongly advised to take extra care not to ingest the water.

Water samples collected on Thursday 21 March from Lake Alexandrina showed elevated levels of potentially harmful blue green algae across the lake. Unlike other blue green algae, the species detected at Lake Alexandrina generally does not form scums and is not easily visible to the naked eye.

Consumption of water containing blue green algae can cause gastro-intestinal symptoms including vomiting, bloody diarrhoea as well as fever and headaches. Direct contact with the water may also cause local irritation to the skin, eyes, ears, nose and mouth.

If you have been in the water at Lake Alexandrina and you start feeling unwell, seek help. Consult with your GP and say you may have been exposed to blue green algae.

Pets are particularly vulnerable and should be kept out of the water. Algae may also stick to their fur, giving them a higher exposure.

Fish caught in the lake should be cleaned and gutted thoroughly before being eaten.

The type of blue green algae in the lake has not previously been detected in such high numbers in South Australia. While the cause is unknown, health experts believe climate variability may be a factor.

SA Water does not source water from the lake and has confirmed that water it supplies from other sources to the area remains safe to drink.

Regular testing of blue green algae levels is being carried out and results are published on the SA Health website. Check back regularly for updates as the situation is variable and subject to change.

Unlike other blue green algae, the species detected at Lake Alexandrina generally does not form scum and is not easily visible to the naked eye. This species has not previously been detected in such high numbers in South Australia.

Wellington East Water Quality Testing

Following SA Health's advice regarding blue-green algae present in Lake Alexandrina, Coorong District Council has facilitated regular water quality testing at the Wellington East Marina. As at 24 April 2024, results regarding blue-green algae levels are within an acceptable range and do not currently pose a risk to public health - these results have also been verified by SA Health.

Further SA Health Advice

Preventing illness
If you suspect contamination of water with blue green algae:

• do not use the water for any purpose including drinking, cooking, washing or showering (boiling the water will NOT make it safe to drink)
• do not consume shellfish sourced from the water
• do not let pets and livestock bathe in or drink contaminated water (particular care should be taken with dogs as they can ingest very high concentrations of organisms from grooming their coat after contact)
• if irrigation with water contaminated with blue green algae is unavoidable, do not use contaminated water directly on edible parts of plants being grown for human consumption.

Health effects of blue green algae
If you have swallowed large amounts of algae affected water, you may develop symptoms including:

• nausea
• bloody diarrhoea
• vomiting
• fever
• headaches.

Contact your GP if symptoms develop and let them know you may have been exposed to blue green algae.