Multiscale exploiration of European eel population dynamics with simulation tools

• Main Author: Lambert, Patrick
• Other Authors: Ecosystèmes estuariens et poissons migrateurs amphihalins (UR EPBX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Doctorat d'océanographie, Université de Bordeaux I
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2005
• Subjects: thesis; thèse; GIRONDE ESTUAIRE; [SDE]Environmental Sciences; Anguilla anguilla; Anguille européenne
• Online Access: https://hal.inrae.fr/tel-02586511; https://hal.inrae.fr/tel-02586511/document; https://hal.inrae.fr/tel-02586511/file/pub00017411.pdf

European eel is ad diadromous fish whose unique European stock is considered to be out of its safe security limits. We propose to use modelling to study the eel population dynamics within a watershed and the mechanisms of estuarines glass eel migration. The development of a matrix model aims to answer the first point. This model is structured by age, sex and development stage. It integrates the main biological processes, ageing, recruitment, sexual differentiation, sex determinism, silvering, movement and natural mortality. It has been possible to identify 18 parameters sets, equivalent to 18 combinations of life history traits, compatible with the eel stock functioning paradigm in a watershed. The downstream part of a watershed, especially when the resource is rare. The second point led to implement an individual-based model of glass eel movements in the Gironde estuary (france). This model mimics the selective tidal stream transport triggered by an endogenous clock. Thinking before implementing the model led us to reconsider the running or synchronized by low slack waters gives results which disagree with the present description of thte phenomenon. Therefore we need to specify the mechanisms which lead eel to abandon selective tidal transport. Theoretic exploration of the molecular functioning of an endogenous clock highlights a putative increase of the activity span with a synchronization of the clock by tides. This result could considerably modify simulations outputs. Lastly the contribution of these modelling attempts to the knowledge concerning eel ecology are reviewed. L`anguille européenne (Anguilla anguilla) est un poisson migrateur amphihalin dont le stock unique européen est considéré comme en dehors de ses limites de sécurité biologique. Cette thèse se propose d`utiliser la modélisation pour d`une part étudier la dynamique d`une fraction de population au sein d`un réseau hydrographique et d`autre part pour approfondir les mécanismes mis en jeu lors de la migration des civelles en estuaire. Le ...