Abundance Trends of Glass Eels between 1978 and 1999 from Fisheries Data in the Gironde Basin, France

• Main Authors: Beaulaton, L., Castelnaud, Gérard
• Other Authors: Office National de l'Eau et des Milieux Aquatiques, Office National de l'eau et des milieux aquatiques, Ecosystèmes estuariens et poissons migrateurs amphihalins (UR EPBX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
• Format: Book Part
• Language: English
• Published: HAL CCSD 2009
• Subjects: ANGUILLA ANGUILLA; PECHE; MODELISATION; DYNAMIQUE DE POPULATION; ANALYSE DE DONNEES; ABONDANCE D'ESPECE; GIRONDE BASSIN; [SDV.SA.STP]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of fishery; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST]; [STAT.TH]Statistics [stat]/Statistics Theory [stat.TH]; [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation; Anguilla anguilla
• Online Access: https://hal.archives-ouvertes.fr/hal-00493147; https://hal.archives-ouvertes.fr/hal-00493147/document; https://hal.archives-ouvertes.fr/hal-00493147/file/BX2009-PUB00026367.pdf

The glass eel is fished in the Gironde Basin, France, with large push nets, scoop nets, and the recently introduced small push net. This study uses fishery data to generate fisheries and abundance indicators for glass eels. Total catch, total effort, and catch per unit effort (CPUE) were calculated for the period 19781999 by classical statistical methods and by general linear models (GLM). Use of GLM enabled the correction of sampling variation and offered better trend estimation than classical CPUE. During the study period, the principal source of glass eel landings shifted from the scoop net fishery in the tidal river to the large push net fishery in the estuary. General linear model-based CPUEs for large push nets and for scoop nets showed that glass eel abundance declined by a factor of two to three at the beginning of the 1980s. Since 1985, abundance has stabilized at a low level and shows no sign of recovering. The abundance trend of glass eels in the Gironde Basin confirms the decline in glass eel populations observed elsewhere in Europe.