Join the Eel Force on Ravensbourne and Brent river catchments

Press Release: June 21

Volunteers are being invited by Thames21 to train to become members of a citizen science Eel Force on the Ravensbourne and Brent river catchments to help the survival of the critically endangered European Eel.

The ObstacEELS sessions will train local communities to assess and map the physical barriers, such as weirs, sluices and locks, that the critically endangered European eel faces when migrating.

The data collected by residents will be used to shape future projects to protect this once-common species and aid their survival. Eel numbers reaching Europe fell by as much as 99% in the 1980s.

Eels are born in the Sargasso Sea (near the Caribbean) in the West of the Atlantic Ocean. They drift 6,500km on the Gulf Stream to get to us, before making their way into our rivers where they live the majority of their lives. Then, as adults, they begin their long migration back to the Sargasso Sea where they lay their eggs and the process starts again.

Thames21, the London-based waterways charity, will work with groups in Bromley, Lewisham and Greenwich in the South East, and Brent, Harrow, Barnet, in the West. Work will focus on the Ravensbourne, including on the River Quaggy, River Pool, and on the River Brent.

The work is part of the Thames Catchment Community Eels Project, led by the Thames Rivers Trust. This programme stretches across several river catchments and counties, including the Mole in Surrey/Sussex and the Kennet and the Pang, both in Berkshire. Work in these regions is delivered by the South East Rivers Trust and Action for the River Kennet (ARK).

Project partners also offer free guided walks and talks along rivers, plus workshops for schools and community groups to educate and engage residents about the European eel. Oli Back, the project officer for Thames21’s work on the project, said: “European eels are a fascinating species but they face many issues. Not least are the river obstacles such as weirs, sluices and locks which can prevent their migration and have resulted in the European Eel being listed as critically endangered. Migration is a vital part of their life cycle.

A barrier to eel migration on the Brent

“By joining our Eel Force, you’ll be contributing to efforts to save the species. You’ll be helping to collect data to inform action plans across the Thames Basin about where best to target practical work to reconnect rivers and enable eels to reach areas they haven’t been able to for years. ”

The Thames Catchment Community Eels Project is funded by the Government’s Green Recovery Challenge Fund. The fund is being delivered by The National Lottery Heritage Fund in partnership with Natural England and the Environment Agency.

Working closely with the Zoological Society of London (ZSL) and the Thames Estuary Partnership, the project partners have developed a standard methodology for citizen science eel barrier walkover surveys. Mapping barriers to eel migration will allow strategic prioritisation for future eel projects.

ObstacEELS training sessions take 90 minutes on Zoom and are followed by a practical session on a riverside

Dates for these are listed on the Thames21 events calendar at as follows:

Monday 19th July – 6pm – Brent focused

Wednesday 21st July – 6pm – Ravensbourne focused

Monday 26th July – 2pm – Ravensbourne focused

Wednesday 28th July – 2pm – Brent focused

For eel walks and talks, keep an eye on the Thames21 events calendar at

To enquire about sessions for schools or community groups, contact Oli Back on 07597 577793 or via email at


The European Eel
The European Eel

Notes for editors

About Thames21

Thames21 connects people with rivers by putting healthy rivers back at the heart of everyday life. We improve and restore rivers, educate and empower the community and campaign for positive change for the good of people and the environment. | Registered Charity No. 1103997

Media Contact

Ian Lamont

Communications at Thames21

07711 701 696

020 7248 7171