Dog owners have been warned about the dangers of a potentially deadly algae at Anglers Country Park.
Signs have been installed at the popular tourist destination alerting visitors to the threat of blue-green algae.
A Wakefield Council spokeswoman said: “Countryside rangers spotted an algal bloom on small areas of the main lake at Anglers Country Park in early August.
“While it was more green-brown than blue-green, and therefore less likely to be harmful than bluer variants seen elsewhere, we decided to adopt a precautionary approach and erected temporary signs asking people to keep their dogs out of the water.
“We are not aware of any reports of dogs or any other animals being affected.
“These algal blooms are seasonal and cooler temperatures and strong winds will disperse them.”
The Environment Agency said blue-green algae was a bacteria which spreads rapidly over the surface of still and slow-moving waters and it can suffocate fish.
It can cause humans to get skin rashes, eye irritation, vomiting, diarrhoea, fever and muscle and joint pain.
Anyone who spots blue-green algae on public or private waters can contact an incident hotline on 0800 807060.