Restoring Chalk Streams in the South East
Of the world's 200 chalk streams, 85% can be found in Britain - and one of their key inhabitants is under threat
Last updated: 15th October, 2025
Introduction
Chalk streams are largely unique to north-west Europe, with 85% of the world's 200 streams found in England.
These streams support a wide range of wildlife, including the white-clawed crayfish - which once thrived in the chalk streams of south-east England.
However, with chalk streams suffering from habitat loss and the arrival of non-native species, the future of white-clawed crayfish in Britain is in doubt - which is where the Hampshire and Isle of Wight Wildlife Trust is stepping in with its amazing restoration project.
The Mission
White-clawed crayfish have been suffering a dramatic decline in recent years - partly due to the arrival of non-native north-American signal crayfish, which carry what's called the 'crayfish plague'. It's believed this plague is the biggest cause of the drop in Britain's white-clawed crayfish population.
To combat this, the Trust is working with local stakeholders and experts to create Arks - which are areas able to support self-sustained populations of white-clawed crayfish, safe from any existing crayfish species or potentially disruptive activity.
It's hoped this approach will start to foster a growing number of the crayfish in south-east England's chalk streams, reversing recent declines and protecting Britain's only native species of crayfish.
The project is another fantastic example of the amazing restoration projects Meaningful Planet customers are helping to support with their bills.
