Visitors to a Midland beauty spot have been warned about a toxic health threat.
The danger comes from blue-green algae which has formed on the surface of Earlswood Lakes, near Solihull.
The seaweed-like plant – biological name cyanophyta – grows by photosynthesis and spreads extensively on water during hot temperatures.
The health threat – to humans and animals – comes from dipping into, or even just touching, the water surrounding the algae. It produces toxins, called cyanotoxins, which can cause stomach upsets – and, in extreme cases, serious liver damage and a form of motor neurone disease. Dogs have died from being covered in the algal scum.
The Canal & River Trust is worried that children and youths may plunge into the water to cool off at Earlswood Lakes, even though swimming is prohibited.
But there is also concern for off-the-lead dogs who decide to go for a dip.
The Canal & River Trust has posted notices at Earlswood Lakes warning of the ‘health hazard’.
Posters state: “High concentrations of potentially toxic blue-green algae have been found in this water.
“Swallowing the water or algal scum can cause stomach upsets or more serious health effects. Contact with the water or with algal scum can also cause skin or eye problems.
“It is a sensible precaution for you, your children and your animals to avoid contact with the scum or the water close to it.”
Earlswood Lakes consist of three expanses of water – Windmill Pool, Engine Pool and Terry’s Pool – covering 25 acres.
They were built in the 1820s to provide a water supply to the nearby Worcester and Birmingham Canal arm between Birmingham and Stratford-upon-Avon.
Earlswood Lakes are reservoirs which took five years to build and the army of labourers included prisoners-of-war from the Napoleonic Wars.
The beauty spot is open to the public and attracts thousands of visitors, mainly from the nearby Birminghan conurbation.
The lakes offer fishing, sailing, cycling, walking and bird-watching.
Last night, the Canal & River Trust, which took over responsibility for canals, rivers and lakes from British Waterways in 2012, said there were no reports of major problems with the algae at other locations in the Midlands.
A spokeswoman said: “The algae appears every year at Earlswood Lakes but this year has been particularly bad due to the warm weather and prolonged sunshine which promotes its growth.
“Earlswood Lakes is a great place for people to go to see the varied wildlife and heritage it offers. We want people to continue to visit to enjoy the lovely waterside setting but we are asking them to be aware of the current outbreak of the algae in the water.
“It is naturally occurring at this time of year but can be harmful to your skin.
“We are also asking people to be extra careful. If they, or their pets, come into contact with the affected water, they should wash all exposed skin with clean water, particularly before eating or drinking.
“If they are In any doubt about their welfare, after contact with algae, they should seek medical advice.”