The Trans-European Swimways Network hosted its second public webinar, Monitoring European Swimways, on Thursday 30th of November 2023.
The webinar aimed at exchanging experiences concerning monitoring techniques, by hearing insights from eDNA and telemetry researchers. We also wanted to learn how to communicate on ongoing monitoring programmes to catch the attention of policy-makers, public authorities and communities. With regards to communities and the public, one of our goals was to better understand the roles volunteers and citizen-science could play in monitoring programmes.
Heather Bond, Swimways Coordinator at Wetlands International Europe, opened the webinar by introducing the Swimways Programme and Network to the dozen participants who joined the event. She shared insights on ongoing work, highlighting the importance of addressing the topic of monitoring when dealing with migratory freshwater fish conservation.
Caterina Maria Antognazza, post-doc at the University of Insubria (Italy), shared her research carried out in the UK in the framework of the “Unlocking the Severn” LIFE Project, on restoring longitudinal continuity on the Severn and its tributary (river Teme). This work aimed at identifying the presence of the European shad (A. alosa and A. fallax) upstream and downstream, to understand how fish were impacted by habitat fragmentation and the effects of mitigation and restoration measures in Severn tributaries. Environmental DNA (eDNA) was used to monitor fish migration and presence over the whole river length. As it only requires collecting water at various strategic locations to look for shad’s DNA traces in the water samples, this method is non-invasive, and allows coverage over large areas with a potentially higher resolution thanks to numerous sampling sites. Caterina also shared insights on her current research on eDNA monitoring of H. huso and A. naccarrii in the Ticino and Po rivers in Italy.
Pieterjan Verhelst, fish biologist at the Belgian Research Institute for Nature and Forest, presented the results from case-study research on Critically endangered European eels’ migration. The movements of the eels were studied through acoustic telemetry, allowing researchers to follow a cohort of individuals to observe their behaviour when encountering barriers and obstacles. The case studies, respectively carried out in Belgian agricultural lowland areas on the Scheldt River and in a shipping canal, demonstrated once more that eels are heavily impacted by anthropogenic pressures on freshwater ecosystems. With a 20% mortality rate at one of the pumping stations where eel passage was monitored, and 50% of the individuals tagged with acoustic telemetry stuck between the gates of the shipping canal, it appears that telemetry studies help to better comprehend the issues eels are faced with and in doing so, lead the way towards the establishment of mitigation measures. Pieterjan also referred to the need to increase transboundary research, knowledge and data-sharing, mentioning the benefits offered by projects such as the European Tracking Network for users of acoustic telemetry to track aquatic animals.
A short questions and answers session allowed participants to connect with presenters, learn how they monitor the success of reintroduction schemes of species such as the sturgeon in Italy, and how to effectively communicate on the results to raise awareness on migratory freshwater fish conservation. For example, to communicate on eel monitoring, Pieterjan and his team created a “Save the eel” game, along with an animated video, allowing the public to easily understand the hurdles eels are faced with when migrating.
Thanks to the insights shared by the researchers in migratory fish monitoring, this webinar not only allowed us to better understand monitoring techniques, but also revealed the importance of communication when it comes to migratory freshwater fish research and results. Whether it is with the public, local communities, public authorities or policy-makers, it is essential to open the discussion, translating technical terms and research into approachable information. Simplifying key results can change the perception these actors have of migratory freshwater fish conservation, leading them to participate through volunteering, raising awareness and triggering the development of improved conservation measures or policies.