Bristol Zoo has been given more than £100,000 to protect the River Avon's crayfish.

Natural England has given the zoo £105,000 to conserve the endangered white-clawed crayfish, which has been lost from three of its four breeding sites in the River Avon in the last decade.

It also gave the Avon Wildlife Trust, based in Brandon Hill, a grant of £113,000 to restore the area's wildflower-rich grasslands.

The zoo's funding will help monitor the remaining crayfish in the river and pay for moving some of the most threatened populations to safer areas.

It will also help establish a captive breeding population at Bristol Zoo Gardens for use in any future reintroduction programme.

The white-clawed crayfish is the UK's only native crayfish and has suffered extensive decline throughout its European range, including in Britain.

Threats include changes to habitat and water quality, pollution and the introduction of non-indigenous crayfish species – which has had the biggest effect.

This has severely affected native populations, particularly through a fungal disease that has been called the crayfish plague.

Outbreaks have caused mass mortalities and anglers, walkers and animals can spread it between watercourses.

"This funding is wonderful news, said Neil Maddison, Bristol Zoo's head of conservation programmes.

"We have been working on this project with our partners – the Environment Agency South West and the Avon Wildlife Trust – and this funding will give a substantial boost our efforts to save this species – which is probably one of the UK's most important species from a global perspective.

"In the last decade many of the most important native crayfish populations in the South West have been lost, including three of the four most abundant in the Bristol Avon catchment alone.

"Our aim to is save the species from extinction, and this support will go a long way towards achieving it."

The funding announcement is part of a drive by Natural England to support key conservation projects across the country.

Sharks, butterflies, toads, wetlands and woodlands are among the other habitats and species due to benefit from a £5.5 million investment from the Countdown 2010 biodiversity action fund, intended to help England's most threatened biodiversity.

Natural England's chairman, Sir Martin Doughty, said: "We want to improve the fortunes of some our most precious species and habitats and today's funding will help our conservation partners to meet these challenges."

Chief executive, Dr Helen Phillips, said: "Halting biodiversity loss takes time. We've already seen major biodiversity successes for many species."