Swimmers are being warned not to enter Lake Ainsworth at Lennox Head following an outbreak of toxic blue-green algae.
The Ballina Shire Council has issued a ‘Red Alert’, which is a warning that people should not undertake recreational activities where they may be coming into direct contact with the water such as swimming.
Warning signs around the lake will remain in place while the high levels of blue-green algae are present.
The council said the species of blue-green algae identified are potentially toxic and may cause gastroenteritis in humans if consumed and skin and eye irritations after contact.
People are advised not to enter the water while this Red Alert level warning is in place.
Blue-green algae usually appear as green paint-like scums on the water, near the edges, or as greenish clumps throughout the water. It makes the water appear dirty, green or discoloured and generally has a strong musty or earthy odour.
Blue-green algae scums have been observed in the lake and have the potential to move around in wind and currents.
Blue-green algae occur naturally and can reproduce quickly in favourable conditions where there is still or slow-flowing water, abundant sunlight and sufficient levels of nutrients.
It is not possible to predict how long the algae will remain at high levels. Regular monitoring will continue by Ballina Shire Council and the alert will be lifted as soon as the high levels of algae dissipate.
People who believe they may have been affected by blue-green algae are advised to seek medical advice.
The algae status of Lake Ainsworth is updated weekly on Council’s website ballina.nsw.gov.au