The European eel (Anguilla anguilla, L.) was historically widely distributed throughout the United Kingdom, in coastal waters, lakes, rivers and wetlands. Recruitment has declined in recent decades and the species is now listed as 'Critically Endangered' on the International Union for Conservation of Nature and Natural Resources (IUCN) Red List. Management of suitable wetland habitats may contribute to species recovery; however, little is known about the stocks in these areas. In this study, yellow (adult stage [ 300 mm) eels were sampled in ditches in five marshes bordering the Thames Estuary in England, UK. Ecological variables, including ditch characteristics, invertebrate abundance and water quality parameters were measured. Habitat features were also observed and recorded, including access, land use and water management regimes. Eels were found in all marshes, but at varying catch-per-uniteffort (CPUE). There were no significant correlations between CPUE and the ecological variables, except ditch width. However, a significant difference in CPUE was found between two of the marshes, which may be explained by variations in local habitat management. Mean lengths showed a high proportion of females and mean body condition of four of the marshes was also found to be greater than in three rivers in the same region. These findings suggest that the marshes are potentially favourable eel habitats and that factors influencing habitat quality, such as land use and water management, may affect eel abundance, production of females and body condition. Effective management of such wetlands may therefore contribute to the conservation of European eel. Keywords North Kent marshes Á Thames RBD Á CPUE Á Yellow eel Á Ecological variables While the continental life stage of European eel (Anguilla anguilla, L.) has attracted substantial research interest over the last century, the majority of published studies have focused on eels in freshwater ecosystems, such as rivers and lakes (Aprahamian and Walker 2009; ICES 2009; Jacoby et al. 2015). However, it is thought that coastal wetlands, including estuaries, lagoons and marshes may provide K. Steele (&) Royal Veterinary College,