Dikerogammarus villosus (DV) is an invasive species of shrimp that has spread from the Ponto-Caspian Region of Eastern Europe. It is a voracious predator that kills a range of native species including young fish. It was first found in Pitsford Water in 2015 and it has been present at the Anglian Water Services reservoir since then. It is believed that the shrimp attach themselves to the hulls of ships and travel down the River Danube, resulting in their spread across Europe. Recent monitoring detecting a single specimen of DV shrimp revealed that they have made their way into Faxton Brook, downstream of the reservoir. The Environment Agency is continuing to monitor along the Brook to check the number present, however it is likely any established population is small.
There was always the risk the shrimp might escape from Pitsford Water when the overspill of the reservoir was operated. Fortunately, over the last two years, due to low rainfall and dry summers, the water level in Pitsford Water remained low and the shrimp were contained until April this year. However, following a prolonged period of wet weather the overspill operated in April 2018. Two individual DV specimens were recorded after the overspill in late July. Following this, the Environment Agency are working together with our partners to reduce and slow the spread of the invasive species.
Various improvements have been made to the habitat in the River Nene, designed to favour our native species and to make the local ecology more resilient to a number of threats. The best defence against these shrimp is to follow excellent biosecurity; therefore, Anglian Water Services have introduced strict measures at Pitsford Water to achieve this and limit the negative impact of the invasive species.
I would like to assure constituents that the shrimp does not pose a significant threat to floral and forna and the environment agency are keeping the situation under control.