Eel project highlights the value of citizen science

A pilot environmental project has highlighted that there are more barriers in rivers than existing data sets show and this is not good news for the critically endangered European eel.
Comparing new data with existing data the Thames Catchment Community Eels Project identified a 61% underestimate on 24 rivers and a 52% underestimate on the 5 target rivers for the project.

The European eel is a species of fish that spend the majority of its life in our freshwater rivers, yet starts life hatching out of a tiny egg 6,500 kilometres away in the Sargasso Sea, in the Atlantic Ocean. The tiny eels that make it to the Thames and migrate up our rivers are currently blighted by a range of in river obstacles that prevent them from dispersing further upstream.

Thames Catchment Community Eels Project (TCCEP) developed and trialled ObstacEELS a citizen science method to train volunteer teams to identify different barriers in rivers and assess their ‘passability’ for eels. Of the 457 barriers recorded and mapped over 7 months 278 were ‘new’ (not present in existing baseline data). ‘Having up to date data available is enabling strategic decisions through a prioritisation process when planning future river barrier removal or modification, so eels can disperse freely up our rivers, ‘said TCCEP Project Manager Anna Forbes.

The project has trained 97 volunteers from communities on the Rivers Mole, Pang, upper Brent, Ravensbourne, middle and lower Kennet to walk in ‘Eel Force’ groups along riverbanks and map obstacles on a modified app. Thames Catchment Community Eels project is a partnership, led by Thames Rivers Trust working with Action for the River Kennet (ARK), South East Rivers Trust (SERT) and Thames21 (T21); working closely with Zoological Society of London (ZSL) and Thames Estuary Partnership (TEP) to aid the long-term survival of the European eel.

Eels need river connectivity to find places to hide and plentiful food sources to successfully grow and eventually mature to make the immense journey back to the Sargasso Sea. Eels only breed once in their life time and it is thought this happens upon successfully returning to the Sargasso Sea, so ensuring eels thrive in our rivers is critical.

The new data has fed into Thames Estuary Partnership’s Fish Migration Roadmap and the Environment Agency’s Thames River Basin Eel Management Plan.
‘The European eel is an iconic fish and plays an important role in the ecosystems of the Thames and its tributaries. We are very pleased to have been able to give local communities along five rivers in the Thames catchment a range of opportunities to discover more about their rivers, eels and their local Rivers Trust. The next step is to secure funding to expand the project to other rivers in the Thames area and for barrier removal or eel passes at the priority sites for eel passage identified during this project’, said TRT Chairman Dave Wardle.

The project has also had success with a huge community and educational outreach programme, connecting all ages with nature at their local rivers. In just over a year, together the project partners have inspired more than 2,500 school children through innovative eel workshops and assemblies; and over 680 people have enjoyed led riverbank eel walks or have attended eel talks.

The project also has meant an increase in scientific knowledge, funding from the project made it possible to train South East Rivers Trust volunteers to monitor an eel pass on the Ember. Volunteers counted and measured over 2,000 eels, contributing to ZSL’s long-term eel monitoring programme.
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.

For more information about Thames Catchment Community Eels Project email: [email protected]: www.thamesriverstrust.org.uk