Dikerogammarus villosus, commonly known as invasive or killer shrimp, was discovered in UK waters for the first time in 2010.
It has been found in four places:
- Grafham Water in Cambridgeshire
- Cardiff Bay in South Wales
- Eglwys Nunydd Reservoir in Port Talbot, South Wales
- Barton Broad in the Norfolk Broads
This invasive 'killer' shrimp kills a range of native species such as shrimp, young fish and insect larvae, often leaving them uneaten. It tends to dominate the habitats it invades, sometimes causing the extinction of native species.
However, it does not have an impact on larger fish, and it does not have any impact on drinking water quality.
Further tests are underway to establish if the shrimp is more widespread. In the meantime we would like the help of all water users to control its spread.
Check Clean Dry campaign
We are supporting the Check Clean Dry campaign to stop the spread of invasive species.
You can help protect the water sports you love by following three simple steps when you leave the water:
- Check your equipment and clothing for living organisms
- Clean all equipment, clothing and shoes
- Clean and wash all equipment, footwear and clothes thoroughly
- If you do come across any organisms, leave them at the water body where you found them
- Dry all equipment and clothing - some species can live for many days in moist conditions
- Make sure you don't transfer water elsewhere.
Look out for this species
Look out for the shrimp and report any sightings. If you think you have found invasive shrimp, contact a member of staff at the water site where you found it. You can also:
To help you identify it, the Non-Native Species Secretariat have issued a 'Killer Shrimp' wanted poster:
More information is available from the BBC news website:
What Are We Doing?
We have developed criteria to help us identify sites that are at the highest risk of being colonised by killer shrimp. We have identified 291 high risk sites in England and Wales and we are checking them for the presence of killer shrimp. Natural England and Countryside Council for Wales have developed complementary monitoring regimes. If we find it we will implement biosecurity measures to contain it.
Our work at other locations to identify small animal species will also highlight the presence of killer shrimp. Water companies in England and Wales also look out for killer shrimp in the lakes and reservoirs they manage. The population at Barton Broads was identified by Natural England as part of this dedicated monitoring programme and its discovery meant biosecurity measures and advice were in place before the peak recreational season. We are monitoring the spread of the shrimp within the Norfolk Broads.
What are the criteria for high risk sites?
- Do people use the site for water recreation?
- Is the site linked to areas that are used by people for water recreation?
- Does the site provide a suitable habitat for killer shrimp? (eg hard surfaces, gravel, pebbles, boulders)
- Does the site have a high conservation value (for example, are white fish (Coregonids) present?