Phenology and environmental drivers of glass eel entrance in a Mediterranean lagoon

Abstract The European eel, Anguilla anguilla, is an emblematic facultative catadromous species that spawns in the Sargasso Sea and grow continental waters of Europe North Africa. In most its growing habitats population has dropped since 1980. Although Mediterranean lagoons represent particularly important for knowledge eel ecology not as developed it rivers. Particularly, data on phenology, drivers biometrics characteristics glass entering are scarce. To address this lack data, abundance, pigmentation stage, size, weight Bages-Sigean lagoon (western French Mediterranean) were monitored during 647 d from December 2018 to April 2021 using passive floating traps. Simultaneously, different environmental measured (flow velocity, temperature, rainfalls…). highest abundances eels observed between mid-November mid-March especially when discharge main tributary was higher than base flow. captured peak entrance less pigmented, longer, bigger other months. This work enabled us identify periods anthropogenic activities should be limited decrease human-based impact similar habitats.