An endangered species living in an endangered ecosystem: Population structure and growth of European eel Anguilla anguilla in a Mediterranean coastal lagoon

Abstract

Mediterranean coastal habitats constitute a nonmarginal fraction of the overall continental habitats of the European eel. It has been suggested that the recovery of the eel global stock may depend closely upon the contribution of Southern European and North African countries within the Mediterranean basin, therefore It is essential to know all the aspects related with its biology and populations dynamic to ensure that the European Commission conservation plan works in this habitats. The aims of this study were to ascertain the structure of the endangered A. anguilla populations in the Mar Menor and obtain essential data for future management plans in the Mediterranean catchment area. In total, 1151 wild fish were caught by local fishermen in 2015–2016 and 2016–2017, and their biological traits were determined. Our findings show that the Mar Menor’s A. anguilla population consists of resident females (1:0.008, female:male), yellow and silvering individuals (56.56% and 43.27% respectively), with a mean age of 3 years. The traditional view of long-lived eels with low growth rates does not fit the picture of Mediterranean eel populations. The effect of fishing techniques used, and the eutrophication processes noted during the study period are also discussed.