Modeling Atlantic juvenile salmon behavior approaching downstream migration passage facility

• Main Author: Ben Jebria, Noor
• Other Authors: RiverLy - Fonctionnement des hydrosystèmes (RiverLy), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Lyon, Hervé Capra
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2022
• Subjects: Downstream migration; Salmo salar; Fish behavior; Computational fluid dynamics; Fish passage solutions; Bayesian modelling; Dévalaison; Comportement des poissons; Dynamique des fluides computationnelle; Solutions de franchissement des poissons; Modélisation bayésienne; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Atlantic salmon
• Online Access: https://theses.hal.science/tel-04198810; https://theses.hal.science/tel-04198810/document; https://theses.hal.science/tel-04198810/file/TH2022BENJEBRIANOOR.pdf

Ecosystem fragmentation is a major threat to biodiversity and one of the main challenges for the conservation and restoration of aquatic environments. In aquatic ecosystems, human-induced longi-tudinal barriers, such as dams, are partly responsible for the decline in fish populations. The impact is even greater on diadromous species with life cycles spanning marine and freshwater ecosystems. One of the most common means of restoring the continuity of watercourses is fish passage solutions (FPS), with variable effectiveness. The development of effective fish passage depends on unders-tanding the behavioral response to hydraulic conditions that may attract or repel fishes. While much attention has been paid to upstream passage solutions, knowledge is still lacking, especially for downstream passage. Most studies have focused on large dam structures with high powerhouse discharge. Yet, less studies have been conducted on dams with large reservoirs and low powerhouse discharges, despite these sites’ higher prevalence for relatively quiescent flows known to disorient fish. In this thesis, based on scientific knowledge and our results, we propose a new numerical tool for modeling the behavior of juvenile Atlantic salmon (known as smolt) during their downstream migration upstream of the Poutès dam (Allier, France). This tool aims at providing a new framework for the design of FPS. We first develop a three-dimensional computational fluid dynamic (CFD) model of the reservoir upstream of Poutès dam to better understand the flow field conditions that affect smolts downstream migration, where hydraulic conditions are particularly very low. From CFD model and telemetry data, we then analyze the effect of hydraulic conditions on smolt behavior in a large reservoir upstream of the hydropower plant. Measured fish positions and CFD simulations were used to characterize smolt’s swimming behavior using fish thrust force, swimming orientation and direction. Thrust force was estimated by solving Newton’s second law. The study of fish displacements in ...