SA Health has issued a blue-green algae warning for Lake Alexandrina and the Murray River from Clayton Bay to Goolwa and Hindmarsh Island. 

It says water samples taken yesterday, Thursday 21 March, showed elevated levels of potentially harmful blue green algae.

The department has warned the public not  to ingest water from Lake Alexandrina and not to swim or dive until further notice.

SA Health says the species of algae detected is different from other kinds in that it does not form a scum on the surface and so is not easily visible.

It is unusual to find such a wide spread of it in South Australia.

The department warns that pets are particularly vulnerable and should be kept out of the water.

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

Direct contact with algae affected water may cause irritation to the skin, eyes, ears, nose and mouth. If you experience irritation, wash the area with clean water.

Swallowed the affected water may lead to illness, with symptoms including nausea, bloody diarrhoea, vomiting, fever, or headaches.

Anyone experiencing these symptoms should contact their GP and let them know you may have been exposed to blue green algae.

SA Health will conduct regular testing of blue green algae levels in the lake.

For more information, visit the SA Health website.