A new LIFE R4ever Kent flume in preparation for freshwater pearl mussel release
12 May, 2025
This summer, the first 1000 juvenile freshwater pearl mussels will be released into the River Kent as part of the LIFE R4ever Kent project.
In preparation for this, all mussels must be tagged with a unique number on one side of their shell, and a PIT tag on the other side, which allows us to detect mussels once they are buried in the riverbed. Once mussels are tagged, they are placed into a flume system where they will remain until the day of their release.
Introducing our new Kent mussel flume
At the end of April, the FBA set up the Kent mussel flume, which acts as a mock river system. In the flume, propagated mussels destined for the River Kent will encounter laminar water flow* and flow diversity** and will need to learn to bury into the sediment; this is an essential part of their preparation for being released into the wild. It exposes the juvenile freshwater pearl mussels to river conditions that they will experience once they are released, minimising the shock associated with being moved to a new environment.
*Laminar flow in water, also known as streamline flow, describes the movement of water in smooth, parallel layers without any mixing or eddies. In this type of flow, fluid particles follow a straight-line path, much like layers of cards sliding over each other.
** Flow diversity, in an ecological context, refers to the variety and variability of water flow patterns within an ecosystem. It encompasses factors like water flow rate, frequency, duration, timing, and the rate of change in flow magnitude. Essentially, it's about how diverse and dynamic the natural water flow regimes are.
Image (left): The LIFE R4ever Kent flume, set up to house propagated juvenile mussels that are tagged and ready for release into the River Kent this summer 2025. Image (right): Tagged mussels (11-12 years old) that have been placed into the Kent flume to prepare them for conditions they will experience in the River Kent.
“I joined the LIFE R4ever Kent project three years in, which has meant I get to see the positive impact the work is already having on the Kent catchment. The highly successful Invasive Alien Species strategy, naturalisation of river sections and the positive engagement and training with landowners; this ambitious project is making a real difference to the Kent SSSI. In July 2025, the FBA will start the very exciting stage of releasing 1000 propagated juvenile freshwater pearl mussels into the river. It will be a major step towards the long term aim of restoring a healthy, reproducing population of freshwater pearl mussels into the River Kent.”
Image (left): Sam Bonny, River Kent Project Officer at FBA tagging freshwater pearl mussels. Image (right): Tagged juvenile mussels in the new Kent flume at the FBA species recovery centre.
Image of tagged mussels (11-12 years old) ready to be placed in the Kent flume.
LIFE R4ever Kent – a journey to Revive, Revitalise, Restore our River – a film
The LIFE R4ever Kent project has been quietly working away since late 2021 in beautiful South Cumbria. Natural England is leading a collaboration with the Environment Agency, Freshwater Biological Association and South Cumbria Rivers Trust to revive, revitalise and restore the River Kent and tributaries Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC), including a population reinforcement of the critically endangered freshwater pearl mussel from less than 10 individuals to over 3000.
Promoting a partnership approach at a landscape scale, the project is proud to announce the release of a short film hoping to capture the scale and breadth of works undertaken to date, and planned for the second half of the project.
Thanks to local videographer Mark Battista for the skillful capturing the LIFE R4ever Kent project.
About the LIFE R4ever Kent project
The LIFE R4ever Kent project, funded by the EU LIFE programme aims to restore, revitalise and revive the River Kent and make it more resilient for future challenges.
Over the course of this five-year project (2021 – 2026), we are working with our project partners to improve and restore habitats in the River Kent for the species for which this Special Area of Conservation (SAC) is designated.
This unique river, located on the fringes of the English Lake District is home to internationally important populations of bullhead, white-clawed crayfish, freshwater pearl mussel and water crowfoot (Ranunculus) habitat. The project will work with local stakeholders to improve existing habitat, decrease the amount of nutrient and sediment run-off within the catchment, control invasive non-native species, re-naturalise the river where it has been modified and to increase the extent of important species such as the freshwater pearl mussel.
Interested in discovering more?
LIFE R4ever Kent is led by Natural England, working in partnership with the Environment Agency, South Cumbria Rivers Trust and the Freshwater Biological Association.
For more information please contact hello@r4everkent.co.uk or visit the LIFE R4ever Kent website.
