The zebra mussel (Dreissena polymorpha) is an invasive freshwater bivalve in the UK, first recorded in the 19th century. Native to the Ponto-Caspian region, it has spread widely through waterways, often transported by boats and equipment. Zebra mussels are highly problematic, forming dense colonies that clog water infrastructure, outcompete native species, and alter aquatic ecosystems by filtering large volumes of water and changing nutrient dynamics. Their rapid reproduction and resilience make them a significant ecological and economic concern.
