Central Coast Council is warning beach goers against swimming and recreational fishing at Terrigal, Avoca and Copacabana beaches following the discovery of marine algal blooms.

The red coloured algae that has appeared on some of  Central Coast’s beaches has been identified as Trichodesmium erythraeum, commonly referred to as ‘red tide’ or ‘sea sawdust’. A similar algal bloom was detected on Sydney beaches over the weekend.

Contact with the red coloured algae in the affected water in some cases can cause skin rashes, asthma and eye and ear irritations. Anyone who comes into contact and experiences health effects should seek medical attention.

People should avoid eating recreationally collected shellfish in affected waters. There is some evidence that small quantities of algal toxins may enter seafood flesh if a bloom produces toxins. Finfish caught in the area should be well cleaned, washed with uncontaminated water and any internal organs disposed of before consumption. Seafood must be properly cooked.

Trichodesmium or Red Tide as it’s known, is a common occurrence on the east coast of NSW and is caused by upwelling of nutrient rich deep ocean waters that comes down the coast in the warm waters of the Eastern Australian Current. It can be observed as red brown slick of saw-dust like particles at the water surface. Generally these blooms dissipate with changing tides and or wind conditions and might be observable as slicks for hours to days at a time.

The bloom appears as a yellow- brown surface scum with an oil slick type of appearance. When it decomposes it may release a pinkish colour into the surrounding water and take on a pale green colour.

The bloom is likely to dissipate naturally in the next few days and beach goers are advised to look out for signs of the algal bloom before entering the water.