Killer Shrimp Sighting Sparks Concerns in Wales

Cosmeston Country Park in Wales has sparked concerns over the possible presence of invasive killer shrimp, which can reduce biodiversity and lead to the extinction of local species. In August 2025, DNA testing conducted by Natural Resources Wales found a possible presence of dikerogammarus villosus, commonly known as killer shrimp, in the lakes at the park. While the council has confirmed that physical sampling will continue to try and establish the presence of the species, no live or dead samples have been found, and the indication of its possible presence is through initial DNA testing of the water.

Key Takeaways:

• The Vale of Glamorgan community has raised concerns over the possible presence of invasive killer shrimp in Cosmeston Lakes at Cosmeston Country Park.
• DNA testing conducted by Natural Resources Wales in August 2025 suggested the possible presence of dikerogammarus villosus, a species native to eastern Europe but found in lakes and rivers in western Europe.
• The council has confirmed that further physical surveys are needed to confirm the presence of the species.
• The council has implemented strict biosecurity measures to prevent the spread of invasive species, including pre and post-use procedures for lake users.
• Environmental DNA testing in August 2025 detected dikerogammarus villosus at Cosmeston Lakes.
• The Vale of Glamorgan Council has asked the council to carry out physical surveys to confirm the presence of the species.
• Physical sampling of the lake will continue over the winter to try and establish if the species is present.
• No live or dead samples of the shrimp have been found so far.

Statistics:

• 2010: First detection of dikerogammarus villosus in Wales
• 2025: DNA testing conducted by Natural Resources Wales found possible presence of dikerogammarus villosus in Cosmeston Lakes

Sources:

• Natural Resources Wales
• Vale of Glamorgan Council
• The Welsh Government
• Cosmeston Country Park