Wildlife is at risk after blanketweed filled a pond in a Brighton park, causing problems for growing tadpoles.

Ruth Gould, founder of the Rotunda Amphibian Preservation Posse group on Facebook, is worried that tadpoles are looking sluggish and fears that blanketweed is out of control in the Preston Park pond.

The pond is a haven for frogs, toads and newts but blanketweed drains the water of oxygen.

It proliferates in ponds with high levels of nutrients which receive a lot of sunlight.

Ms Gould has contacted Brighton and Hove City Council, suggesting that another pond is built near by and that work is carried out on two dried-up ponds in Preston Park to save wildlife.

She said: “I’m so angry. These endangered animals don’t stand a chance. The only way they have to breed is to cross the road to the rock gardens – and they will just get run over or frazzled on a hot day.”

On Monday (17 May), Green councillors Siriol Hugh-Jones and Leo Littman, who represent, Preston Park ward, visited the pond with an ecologist who said that older tadpoles often appeared lethargic but this was normal.

Councillor Hugh-Jones said: “The blanketweed is a problem but solvable through using one of a number of organic fixes.

“The biggest issue is the lack of an easy way for froglets to climb out of the pond.

“Officers did try to address this by putting in boulders earlier in the year to try to provide a way out but these collapsed.”

Councillor Hugh-Jones said that a metal grille could not be used as a ramp for young amphibians as it was a heritage ornamental pond.

She added: “We are also looking at better signage to discourage people from disturbing the tadpoles and newts by pond dipping or letting their dogs enter the pond (modern flea treatments can have an adverse effect on pond life) or putting anything into the pond that shouldn’t be there.

“There have been reports of people putting household soap into the pond, for example, and a number of eels were found when it was drained earlier in the year.

“Those could only have got there as a result of someone deliberately putting them there.”