Eel Conservation

ZSL thames eel survey

Since spring 2005, ZSL has been working to conserve these iconic London inhabitants as part of our Tidal Thames Conservation Project. Most of our research is focused on the upstream elver (young eels) migration and what has driven the decline in returning elvers (known as recruitment) over the past 25-30 years. To find out about our survey methods, engagement with industry and how you can get involved please browse the web pages below..

Why we are there

The European eel (Anguilla anguilla) is classified as ‘Critically Endangered’ by the IUCN Red List of Threatened Species. ZSL’s research has shown that the recruitment of the European eel has declined by up to 95% over the last 25-30 years in some tributaries of the Thames. Reasons for its decline are suggested as being a combination of habitat loss, barriers to migration, parasites, pollution, over-fishing and climate change affecting oceanic currents.

Monitoring elver migration

ZSL is monitoring the upstream migration of the European eel in the Thames and its tributaries. Throughout the summer the ZSL team circumnavigate London on the search for eels in order to understand their unique life-cycle and the pressures on their population.

Since spring 2005, ZSL has been working to conserve these iconic London inhabitants as part of our Tidal Thames Conservation Project. Most of our research is focused on the upstream elver (young eels) migration and what has driven the decline in returning elvers (known as recruitment) over the past 25-30 years. To find out about our survey methods, engagement with industry and how you can get involved please browse the web pages below..

Why we are there

The European eel (Anguilla anguilla) is classified as ‘Critically Endangered’ by the IUCN Red List of Threatened Species. ZSL’s research has shown that the recruitment of the European eel has declined by up to 95% over the last 25-30 years in some tributaries of the Thames. Reasons for its decline are suggested as being a combination of habitat loss, barriers to migration, parasites, pollution, over-fishing and climate change affecting oceanic currents.

Monitoring elver migration

ZSL is monitoring the upstream migration of the European eel in the Thames and its tributaries. Throughout the summer the ZSL team circumnavigate London on the search for eels in order to understand their unique life-cycle and the pressures on their population.

Citizen Science Programme

Do you want to help save London's eels? The citizen science programme works with members of the public to check ZSL elver traps, located on 10 tributaries, twice a week. The volunteers don their waders to count and measure elvers before uploading the data onto the ZSL database. This is a great opportunity for members of the public to get involved in essential conservation work so if you would like to join our growing team of citizen scientists, please do get in touch.   

Find out more

Eel movement in marshland

ZSL is working with the Environment Agency to assess resident eel populations in marshland. These are thought to be important habitats, where the eels can spend up to thirty years feeding and growing before returning to the Sargasso Sea. From June 2014, ZSL conservationists will be working on a tagging project to assess how eels use these wetlands. In addition to monitoring movement of the eels, we are also investigating local ecological and management factors, all of which will inform regional and national conservation strategies.

New monitoring technology 

ZSL and the Environment Agency are embarking on trials of innovative new technology for monitoring downstream migrations of mature European eels. Using ARIS - Adaptative Resolution Imaging Sonar, to record videos of eels, we hope to provide new insights and valuable information on the numbers of eels leaving Thames tributaries on their migration to the Sargasso Sea.

Thames Eel Management Plan 

ZSl works closely with the Environment Agency to develop and deliver the eel managment plan for the Thames region. The management plan outlines key targets and measures to improve the population and conservation of the European eel.

Sustainable Eel Group

ZSL is one of the key organisations involved in the Sustainable Eel Group (SEG) which is a made up of scientists, conservationists, policymakers and commercial sectors to support the recovery of the European eel. Much of their recent work has been in relation to the European eel fishery, highlighting the importance of cross-sector collaborations to manage stocks sustainably.