VISITORS to Frensham Great Pond and Common are again being warned not to enter the water at the big pond due to high levels of blue-green algae.

Waverley Borough Council was notified about the high levels of blue-green algae by the Environment Agency, late on Friday afternoon.

Signage instructing visitors to avoid contact with the algae and warning people not to enter the water will be in place “until further notice”.

Blue-green algae are a natural component of a freshwater ecosystem, but their presence is potentially harmful to humans, animals, birds and fish. 

Periods of warm weather followed by heavy rain and then further warm, still conditions cause blue-green algae to appear suddenly.

There is no way of removing the algae from the water once it is established.

Although not all species of blue-green algae are harmful, Waverley recommends that people avoid the algal bloom as it can cause ill health such as dermatitis, eye irritation, rashes, blistering, abdominal pain, diarrhoea and nausea through skin, eye contact or if swallowed.

Should anyone believe that they have been affected by blue-green algae, they should seek medical advice or in the case of their pets, veterinary advice.

A council spokesman said: “Waverley is monitoring the situation closely and will keep the public informed through its website and social media channels.”

It comes less than a year after Frensham Great Pond was closed to bathers for six weeks last September, again after unsafe levels of blue-green algae were discovered.