Fishermen in Aveiro are participating in environmental conservation measures to help restore the sustainability of a once economically valuable species: the European eel. Their participation is allowing researchers to go further and faster in their study and giving fishermen a role in assessing eels stocks, and a voice in proposing conservation measures. The European eel, once an economically important species in several EU countries, is facing extinction due to widespread changes to freshwater habitats, unsustainable fisheries practices and other environmental changes. In the Aveiro region of Portugal the species continues to be emblematic and local fishermen are participating in support measures to help it become an economically viable resource once again. Since 2007, this migratory species is covered by the European regulation (CE) nº1100/2007 on eel management, requiring Member States to develop and implement conservation measures. Due to the historical, economic and cultural importance of the species within the region, the Aveiro FLAG decided to support a project in which local fishermen and researchers of the University of Aveiro cooperate to deliver better data and management advice so as to be able to tailor conservation measures to the local context. Under the project, fishermen have been contracted through the Regional Artisanal Fisheries Association to participate in data collection, site selection and specimen sampling. The study provides for the continuation of a sampling record dating back to 1987, with increased support and involvement of fishermen. It also assesses pollution levels of the area, helping to develop a better understanding of the relative impacts of fisheries and pollution on Aveiro’s eel population.