'Real harm to wildlife': Invasive crayfish in Hampstead Heath Ponds


A wildlife expert has warned invasive crayfish species could have a 'devastating effect'on Hampstead Heath's Ponds. - Credit: Nick Kaufmann

A wildlife expert has warned that the growing number of invasive crayfish in Hampstead Heath Ponds could cause "real harm" to native wildlife.

Last week, a large 'lobster-like creature' was found at Kenwood Ladies' Pond, leaving swimmers stunned.

Two different species of the crustacean were found by Heath walker Nick Kaufmann earlier this year, neither of which are native to the UK.

Andrew Whitehouse of invertebrate conservation trust Buglife identified one as a red swamp crayfish, and the other may be a Turkish crayfish, though the creature had been dead for some time so it was difficult to be sure, according to the expert.

He said the increased presence of these species in the Heath's ponds is "not desirable".

Andrew told the Ham&High: "They compete with our native crayfish for food and places to live, and ruin the pond's natural environment."

Discussing how alien species ended up in the UK, Andrew said signal crayfish were brought over from America in the late 1970s and early 1980s.

"They are far bigger than our native white-clawed crayfish, and so better to breed for food," he said.

dead cray fish

The walker compared a dead crayfish to the size of his foot - Credit: Nick Kaufmann

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However, the species proved to be aggressively invasive, and now dominates water sources across England, Wales and Scotland.

He added: "They've had a devastating effect on wildlife."

Similarly,  the red swamp crayfish found on the Heath can damage biome, and Buglife has been calling for them to be eliminated from the park.

According to the charity, red swamp crayfish have inhabited the area for around 10 years, and there is a "decent, well-established" number of them living in the ponds.

"We worry they will spread to nearby water and cause further damage," Andrew said.

"They also have quite an attitude, as you can see from the claws waving in the air."

The expert assured visitors that the crustaceans caused "no major risk" to humans, though swimmers could be nipped.

red swamp crayfish

Nick Kaufmann filmed a 'feisty' red swamp crayfish in Hampstead Heath Ponds. - Credit: Nick Kaufmann

They tend to hang around the bottom of the ponds, Andrew said.

For those wondering whether the lobster-like shellfish would make a tasty meal, the conservationist urged people not to take them home.

"Firstly, you have to have a licence to fish at the Heath," Andrew added.

"And there's a serious risk that if it's removed and then escapes, this could be a route into new water.

"Please don't take the crayfish out of the ponds, as this can cause real harm to our native wildlife."

The City of London Corporation declined to comment.