Children and politicians have been urged by a charity to appreciate the importance of rivers and "globally rare" chalk streams during a county's first ever Rivers Week.

Herts and Middlesex Wildlife Trust hosted events to showcase the local watercourses and children were encouraged to spot wildlife at Stanborough Park, Panshanger Park and Waterford Marsh in Hertfordshire.

The charity joined other wildlife trusts, including Hampshire and the Isle of Wight, to lobby MPs for greater protection for chalk rivers.

"It was fantastic to see so many people exploring our rivers and learning how they can play a part in protecting them," said Kate Sheard, the trust's community officer.

Hertfordshire and Middlesex have 10% of the world's 260 chalk streams.

The trust said chalk streams support some of the most "vulnerable species", including the water vole, kingfisher and wild brown trout.

The group of trusts behind the campaign met with Chris Hinchliff, the MP for North East Hertfordshire, in Buntingford to "discuss the urgent challenges" facing rivers.

The Labour MP has led a cross-party group that is working to safeguard the future of chalk streams.

A spokesperson for the Department for Environment, Food and Rural Affairs said: "Chalk streams are vital ecosystems and part of our national heritage and this government is committed to cleaning up our waterways.

"Water companies must now spend £22bn on restoring the environment, including chalk streams, over the next five years."

Rivers Week, which included the trust running online talks about managing invasive species, was funded by the government's Species Survival Fund and supported by Affinity Water and the Environment Agency.

Sarah Perry, the trust's river catchment coordinator, said: "The platform of Herts Rivers Week saw us engage with local dignitaries, decision makers and policy influencers to talk about the value of our chalk rivers and the urgent challenges these unique habitats face.

"As a result of this focus, we've strengthened our position on calling for better protections for our chalk rivers and it's gratifying to know that some of those in a position of power are listening and trying to take action."