Eels are on the move

Like salmon, eels once thrived in the waterways around Stroud – but habitat loss, overfishing and artificial barriers blocking rivers has meant that European eel numbers have drastically reduced, including the in River Frome.

Now, thanks to a groundbreaking development by local charity Stroud Valleys Project (SVP), the slippery customers appear to have made a comeback.

In late 2021, SVP worked with a range of partners to build an eel pass at Arundel Mill Pond near the town centre. While much of the hard landscaping work was done by contractors, the rest was undertaken by SVP’s own band of highly motivated environmental volunteers, who come from all walks of life.

“The sluice gate at Arundel Millpond, which has been there for the last couple of hundred years, has made it nearly impossible for eels to travel upstream to find suitable places to live and feed,” explains SVP project officer Tamsin Bent.

“They need to spend many years in our rivers preparing for their long journey back to the Sargasso Sea to spawn.”

“We worked with partners including Severn Rivers Trust, Wildfowl and Wetlands Trust (Slimbridge), the Environment Agency and Farming and Wildlife Advisory Group to install an eel ‘ladder’ or pass so they can travel upstream. Our volunteers worked really hard, pulling debris out of the river, planting new water plants and clearing the land of invasive species such as Himalayan Balsam.

“Eels can wriggle around some structures if there is foliage and grass next to the river, but the sluice gate at Arundel Mill Pond is made of concrete and metal, and they can’t get around it.”

In August, Dr Laura Weldon from WWT Slimbridge came along to lead an eel-focused session as part of SVP’s Garden Guardians project, which supports people to encourage wildlife into their garden. As well as enjoying some eel-ly fun activities, people could also take part in collecting water samples which were then taken back to the lab to be tested for eel DNA by Laura.

“There was a tantalising wait while the samples went off to the lab to be tested!” recalls Tamsin.

When the results came in a few weeks later, Laura shared the results on her Twitter feed, saying, ‘In year 1, we didn’t detect eel DNA. In year 2, we detected eel DNA below Arundel Mill but not above.

This year, we detected eel DNA in multiple samples along the [River] Frome. Well done, SVP Charity – it’s been lovely working with you and your volunteers and great to see evidence of increased eel activity in the Frome now the eel pass is established.’

Funding for the project came from the Environment Agency and Stroud District Council.

The eel pass is just one example of the ways in which Stroud Valleys Project works across the district to improve green spaces and waterways for nature and for communities.

“It’s wonderful to know our work is having an impact that we can see right now,” says Tamsin. “Sometimes it can take years or even decades to see the results of environmental work, so it’s very exciting to be part of a project that produces beneficial changes so quickly.”