Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what assessment her Department has made of the damage from non-native crayfish to fish populations in chalk streams.

The Environment Agency’s ecological monitoring programmes have demonstrated a broad range of impacts caused by non-native crayfish on various river types. Most harm is attributed to the North American signal crayfish, which is now widespread in England. Studies have shown that signal crayfish can affect river quality in a number of ways, such as by direct predation of fish, invertebrates and plants, damaging our native crayfish populations and leading to increased siltation from bankside burrowing. Research on Yorkshire limestone headwater streams also indicates serious impacts on native trout populations.

The Environment Agency has supported a number of research programmes seeking ways to manage crayfish and is looking to prevent the further spread of non-native crayfish, wherever possible, through good biosecurity.

In 2010 we launched the Check,Clean,Dry campaign which promotes good biosecurity by users of water bodies to reduce the risk of spreading non-native species.