Non Native Species Alert: An invasive species of shrimp, commonly known as the ‘killer shrimp’ (Dikerogammarus villosus),has been found at Grafham Water reservoir in Cambridgeshire. This is the first time the shrimp has been found in this country.
The shrimp is a voracious predator (hence its common name of ‘killer shrimp’). It kills a range of native species, such as freshwater invertebrates, particularly native shrimps and even young fish. This alters the ecology of the habitats it invades. It often kills its prey and leaves it uneaten. It tends to dominate the habitat, sometimes causing the extinction of native species.
Insects such as damselflies and water boatmen, common sights on British lakes and rivers, could be at risk, with knock-on effects on the species which feed on them.
It has spread across most of Western Europe over the last 10 years. It can be as small as 3mm but may grow up to 30mm long, much larger than our native freshwater shrimp.
The shrimp could have arrived at Grafham in a variety of ways, including boating, angling, fish-stocking or naturally via birds.
The actions being requested on-site include checking equipment for shrimp when they leave the water and removing any that they find. They should also ensure their equipment is thoroughly cleaned and dried before it is put into any other water.
