T-206B-2
Gerem (Glass-Eel Recruitment Estimation Model) : A Model to Estimate Glass-Eel Recruitment at Different Nested Spatial Scales

Tuesday, August 19, 2014: 8:40 AM
206B (Centre des congrès de Québec // Québec City Convention Centre)
Hilaire Drouineau , Irstea, UR EABX, Aquatic Ecosystems and Global Change Research Unit, 50 avenue de Verdun, 33612 Cestas Cedex, France, Cestas cedex, France
Cédric Briand , Institution d’Aménagement de la Vilaine, La Roche-Bernard, France
Patrick Lambert , Irstea, UR EABX, Aquatic Ecosystems and Global Change Research Unit, 50 avenue de Verdun, 33612 Cestas Cedex, France, Cestas, France
Laurent Beaulaton , Pôle GEST'AQUA, ONEMA, Rennes, France
Despite the importance of reliable recruitment estimates to assess eel stocks and enforce appropriate management measures, few analytical tools have been developed to estimate yearly glass-eel recruitments. Among existing models, large-scale models generally rely on strong assumptions regarding fishing activity while other models generally estimates recruitment at the river catchment scale. In this context, we develop GEREM model that aims at estimating glass-eel recruitment at different nested spatial scales. More specifically the model estimates yearly recruitments at the river catchment level and at the eel management units scale, which are two relevant spatial scales for management, and at the distribution area scale, which is consistent with the stock biological scale. The model has been applied to France and Europe on data-series lasting from 1970 to 2012 and provides trends that are consistent with current knowledge, and absolute recruitment estimates that are consistent with expert knowledge on exploitation rates.