People are being warned to steer clear of a popular lake following the re-appearance of toxic algae.
Warning signs are being put up at Brooklands Lake in Worthing advising walkers to avoid contact and keep their pets out of the water.
Last year about 50 animals, including swans, ducks and rats, were found dead on the lake after coming into contact with blue green algae.
The Environment Agency says the algae has formed due to the combination of silt formed on the lake bed and the increase in water temperature.
Contact with the water could lead to skin rashes, eye irritation, vomiting, diarrhoea and fever.
Pains in muscles and joints can occur if any users of the water have swallowed or swum through the algae.
Visitors are advised to seek medical help if they experience any of the above symptoms having come into contact with the water.
Worthing Borough Council is working with the agency and also carrying out daily checks on the lake.
A statement on its website said dredging the lake to remove silt is one of the options being considered.
It said: “The council needs to understand what is in the silt as this will influence how the silt can be disposed of.
“As a result, testing of the silt is taking place.
“In addition, a longer-term and sustainable solution needs to be found that helps to prevent the build of the silt in the first place. The council is consulting with key stakeholders such as the Environment Agency on these options.”
In the meantime Brooklands Park is still open for business as usual.
People are asked to report any incidents of pollution or wildlife in distress via the 24-hour emergency hotline on 0800 807 060.