Persistence of a southern Atlantic salmon population: Diversity of natal origins from otolith elemental and Sr isotopic signatures

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Martin, J., Bareille, G., Berail, S., Pécheyran, C., Gueraud, Francois, Lange, F., Daverat, Françoise, Bru, Noëlle, Beall, E., Barracou, D., Donard, O.
• Other Authors: Institut Jean Lamour (IJL), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie Analytique Bio-Inorganique et Environnement (LCABIE), Université de Pau et des Pays de l'Adour (UPPA)-Centre National de la Recherche Scientifique (CNRS), Ecologie Comportementale et Biologie des Populations de Poissons (ECOBIOP), Institut National de la Recherche Agronomique (INRA)-Université de Pau et des Pays de l'Adour (UPPA), Ecosystèmes estuariens et poissons migrateurs amphihalins (UR EPBX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Laboratoire de Mathématiques et de leurs Applications Pau (LMAP), Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux (IPREM), Research was funded by the regional administration (Conseil Général 64) and the regional water agency (Agence de l'eau Adour- Garonne)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [MATH.MATH-PR]Mathematics [math]/Probability [math.PR]; Atlantic salmon; Salmo salar
• Online Access: https://hal.archives-ouvertes.fr/hal-00867071; https://doi.org/10.1139/cjfas-2012-0284

International audience We investigated the use of Sr: Ca, Ba: Ca, and 87Sr:86Sr ratios as natural tags for determining the natal origins of juvenile and adult Atlantic salmon (Salmo salar) from 12 tributaries in the Adour basin (southwestern France) and estimated homing on a tributary scale. Geochemical signatures from core regions of the otolith were also used to identify fish from hatchery or naturally spawned sources. Quadratic discriminant function analysis (QDFA) was on average 80% successful at classifying juveniles according to their natal rivers. Adults of unknown natal origin were assigned to their natal rivers using the juvenile fingerprints from QDFA approach. Only 18 adults originated from streams not included in the juvenile database. Although most of the adults showed a marked homing instinct, homing was not perfect, and some wild fish strayed into non-natal spawning areas. Returns of hatchery-reared fish as adult spawners represented 10% of the total sampled fish. Allocation of fish to natal tributaries or hatcheries illustrated the abundance and relative contributions of natal sources, important for the recovery of Atlantic salmon in this area.