Recruitment of glass eels (Anguilla anguilla) on the french mediterranean coast: A comparative analysis of biometric and pigmentation characteristics during the 1974-75 and 2000-01 sampling seasons

• Main Authors: Lefebvre, F., Sergent, E., Acou, Anthony, Lecomte-Finiger, R., Crivelli, A.
• Other Authors: Institut de biochimie et génétique cellulaires (IBGC), Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS), Pôle OFB-INRAE-Institut Agro-UPPA pour la gestion des migrateurs amphihalins dans leur environnement (MIAME), Université de Pau et des Pays de l'Adour (UPPA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Office français de la biodiversité (OFB)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Patrimoine naturel (PatriNat), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Office français de la biodiversité (OFB), Station Biologique de la Tour du Valat, Laboratoire Insulaire du Vivant et de l'Environnement (LIVE), Université de la Nouvelle-Calédonie (UNC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2003
• Subjects: glass eels; Anguilla anguilla; recruitment; biometry; pigmentation; civelle; recrutement; biométrie; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Fourcade
• Online Access: https://hal.science/hal-04611105; https://doi.org/10.1051/kmae:2003038

International audience A sampling of glass eels, Anguilla anguilla, took place at the Fourcade sluice (Saintes-Maries-de-la-Mer, French Mediterranean coast) between November 2000 and May 2001. Glass eels were captured throughout the sampling period but abundance maxima occur in January-February and, to a lesser degree, in April. In order to optimise recruitment in the interior coastal lagoons, the suggested management measure would therefore be to open the sluice gates in mid-winter.The monitoring of monthly proportions of different pigmentation stages (from V A to VI A4) allows to conclude that there is a general aging of recruited glass eels from November to March followed by a second influx of young glass eels in April. At the same time, a clear reduction in mean monthly masses and lengths is observed even when considering a single pigmentation stage (V B). These results on the evolution of biometric and pigmentation characteristics support the conclusions of studies already carried out on the French Mediterranean coast (1930’s and 1970’s) as well as published data from different sites on the Atlantic coast.A comparative analysis of these data with those resulting from the most recent study on the French Mediterranean coast (Bages-Sigean, Languedoc-Roussillon, 197475, LECOMTE-FINIGER, 1976) shows a completely different monthly pigmentation composition and reveals a significative decline in the length of glass eels in the range of 5 % over 25 years.