The red swamp crayfish, Procambarus clarkii, has earned the dubious title of one of Europe’s most unwanted species.

Identified as a major threat to native wildlife, riverbanks, and ponds in 14 countries, it has become a prime target for a new Europe-wide organisation trying to eliminate alien species.

Originally from North America, this highly adaptable crayfish has so far been recorded at 16 locations in England, including the ponds on Hampstead Heath in London. More concerningly, it has also been found in the Grand Union canal, which could provide it with access to much of the country’s waterways.

Unlike many aquatic species, the red swamp crayfish does not require constant water to survive. It can travel across land, tolerate low-oxygen and saline environments, and despite its modest size of 90mm (3.5 inches), it is highly aggressive.

It digs deep burrows into banks, leading to erosion and structural damage in canals and dams. Additionally, it carries crayfish plague, posing a serious threat to the native white-clawed crayfish, which it also outcompetes for food.

With the ability to lay up to 600 eggs in a single breeding season, the species spreads rapidly, consuming plants, small fish, and amphibians. While natural predators such as herons, foxes, and eels help curb its population, scientists are actively searching for methods to contain and eliminate this invasive species.