The combination of calm conditions, northerly currents and warm water has created the perfect conditions for marine algal blooms to grow.
A marine algae warning has been issued for the Evans River.
Trichodesmium (marine algae) occurs naturally in tropical and subtropical ocean waters and is commonly known as sea sawdust, red tide and sea scum.
Residents and visitors are advised to avoid affected areas. In most cases, the blooms are harmless and can be easily washed off the skin by rinsing with water.
However, if they deplete the oxygen content of the water, they can cause death to aquatic animals and may irritate the skin of some people.
Under certain conditions these blooms or slicks may become beached which can result in a putrid, almost fishy smell along the beach.
Its may be brown, green and pink as it dies off.
For more information on current algal alerts call the information line on 1800 999 457 or visit the Water NSW website.
To report algal blooms email RACC@waternsw.com.au