Making sense of the relationships between Ne, Nb and Nc towards defining conservation thresholds in Atlantic salmon (Salmo salar)

• Published in: Heredity
• Main Authors: Ferchaud, A-L, Perrier, Charles, April, J, Hernandez, C., Dionne, M, Bernatchez, L.
• Other Authors: Institut de Biologie Intégrative et des Systèmes Québec (IBIS), Centre d’Ecologie Fonctionnelle et Evolutive (CEFE), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Université Paul-Valéry - Montpellier 3 (UPVM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut de Recherche pour le Développement (IRD France-Sud ), Direction de la Faune Aquatique, Ministère du Développement Durable, de l'Environnement, de la Faune et des Parcs du Québec, Ministère des Forêts, de la Faune et des Parcs du Québec, This research was funded by the MFFP and the Canadian Research Chair in Genomics and Conservation of Aquatic Resources.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2016
• Subjects: [SDV.GEN]Life Sciences [q-bio]/Genetics; Canada; Atlantic salmon; Salmo salar
• Online Access: https://hal.inrae.fr/hal-02921366; https://doi.org/10.1038/hdy.2016.62

International audience Effective population size over a generation (Ne) or over a reproductive cycle (Nb) and the adult census size (Nc) are important parameters in both conservation and evolutionary biology. Ne provides information regarding the rate of loss of genetic diversity and can be tracked back in time to infer demographic history of populations, whereas Nb may often be more easily quantified than Nc for short-term abundance monitoring. In this study, we propose (1) an empirical context to Waples et al. (2014) who introduced a correction to bias due to overlapping generations, and (2) a mathematical relationship between Ne and Nb for direct application in Atlantic salmon populations in Quebec, Canada. To achieve this, we investigate the relationships between Ne, Nb and Nc in 10 Atlantic salmon populations, Canada, for which we genotyped 100 randomly sampled young-of-the year individuals for 5 consecutive years. The results show a positive correlation between Ne, Nb and Nc, suggesting that Nb is an indicative parameter for tracking effective population size and abundance of Atlantic salmon. However, our model allows predicting Nc from Nb values at 27% that can be partly explained by high variance in Nb/Nc both among populations (37%) and among years (19%). This result illustrates the need for thorough calibration of Nb/Nc before using Nb in monitoring programs, as well as a full understanding of the limits of such an approach. Finally, we discuss the importance of these results for the management of wild populations.