Invasive Quagga mussel found at Wraysbury Reservoir

The invasive non-native Quagga mussel has been recorded in the UK for the first time according to the Wildfowl and Wetland Trust (WWT). The discovery was made at Wraysbury Reservoir near Heathrow Airport, which is upstream from the WWT's London Wetlands Centre. Further investigation has revealed that the species is also present in a number of other locations including parts of the Lee Valley.

This species had already been identified by a group of scientists at the Centre for Ecology and Hydrology (CEH) as the single greatest threat to the UK's wildlife of any alien species, and one of the most likely non-native species to arrive and establish itself in the UK in the near future. The molluscs are similar to another invasive species, the Zebra Mussel, and form large colonies on hard surfaces which can block pipes and cause flooding as well as having a harmful effect on water quality. Once established they are virtually impossible to eradicate.

If you spot a Quagga Mussel, you must report it:
Send a photograph along with details of the record to: or submit a sighting here
Remember: Quagga mussels are hard to distinguish from the more common zebra mussel. Ensure your specimen has some of the key features of quagga before sending in your record.

For more information on this species and how to recognise it please see the Factsheet and Briefing Notes from the invasive non-native species secretariat (NNNS), below. Guidance on biosecurity measures to prevent the spread of this and other aquatic species is also available here.