A harmful species of algae has been found in Radipole Lake.

The Environment Agency confirmed yesterday that they discovered blue-green algae in a number of samples taken from the lake in Weymouth.

The tests come after dead birds were found in the lake’s algae which has developed on the water surface as a result of the recent heat.

Blue-green algae is a type of bacteria which is found naturally in waters around the world, and it increases when water temperatures rise. When blue-green algae develop they can turn waters green and produce toxins which can cause wildlife harm depending on the size of the animal and severity and type of algal bloom.

A spokesman for the Environment Agency said: “We have looked at two samples taken from Radipole Lake, the first taken last Friday and a further sample taken on Wednesday.

“The sample taken on Friday contained a blue-green algal species called oscillatoria which produces toxins, and when present above a threshold can cause short term adverse health outcomes, such as skin irritations.”

He added: “These effects are likely to occur at a low frequency if there is no visible algal scum present in the water. The second sample showed the number of cells had reduced significantly. This was probably due to the rainfall over the weekend dissipating the bloom. We will take a further sample next week to determine if the bloom is still present.”

Waters are susceptible to problems with blue-green algae, typically between June and November. However, it isn’t normally found in saline waters like Radipole Lake where fresh water mixes with sea water.

The lake’s algae is expected to reduce naturally as the temperature begins to drop.

Weymouth and Portland Borough Council has been informed about the lake’s blue-green algae presence and is working with the Environment Agency and the RSPB to solve the problem.

The council plans to undertake a lake clean-up and is looking into a longer-term solution including reed planting, raising the lake’s water levels, dredging the lake and using booms to block off areas.

A council spokesman has advised children and dogs away from the lake’s water because of the potentially harmful algae blooms, and has told anyone who comes into contact with the algae to wash the affected areas thoroughly.

The spokesman added: “We advise people against swimming in the lake. If you believe your dog has been exposed to algae, contact your vet.”