Study of large baleen whales in the Mediterranean to better adapt the conservation measures

• Main Author: Tardy, Céline
• Other Authors: Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres, Serge Planes
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2021
• Subjects: Balaenoptera physalus; Fin whale; Mediterranean Sea; Abundance; Demographic history; Parentage links; Rorqual commun; Mer Méditerranée; Abondance; Histoire démographique; Liens de parenté; [SDV.SA]Life Sciences [q-bio]/Agricultural sciences; Rorqual; baleen whales
• Online Access: https://theses.hal.science/tel-04089946; https://theses.hal.science/tel-04089946/document; https://theses.hal.science/tel-04089946/file/2021UPSLP064_archivage_pdf.pdf

The fin whale, Balaenoptera physalus, is the largest mysticete in the Mediterranean Sea. Its Mediterranean population is considered as resident and distinct from that of the Atlantic. This species is threatened by human activities and scientific knowledge on this species is limited. This thesis has improved our collective understanding of fin whale demographics and life history traits (current and effective size, population structure, parentage links, demographic history) and will help to protect the species. Using newly developed microsatellite markers and photo-identification data, we estimated the population size at 1,300 individuals and the effective size between 400 and 500 individuals. Furthermore, we identified a decrease (by 3.6) in effective size which began 260,000 years ago. Over the course of this thesis, other important discoveries were made, including the finding that the Mediterranean population lacks a genetic structure, and is a population composed of large families. Further, and for the first time ever in whales, full-siblings were discovered within these families. The results of this thesis not only contribute to enhancing our general knowledge for the fin whale, but will be used to define further conservation measures to protect this vulnerable species and other cetaceans present in the Mediterranean and beyond. Le Rorqual commun, Balaenoptera physalus, est le plus grand mysticète présent en Méditerranée. Sa population Méditerranéenne est considérée comme résidente et distincte de celle présente dans l'Atlantique. Cette espèce est largement menacée par les activités anthropiques et les connaissances sur cette population sont limitée. Ce travail de thèse a permis d'augmenter les connaissances (taille réelle et efficace, structure de la population, liens de parenté, histoire démographique) afin de pouvoir protéger au mieux l'espèce. Les différentes analyses réalisées sur des marqueurs microsatellites nouvellement développés ainsi que sur des données de photo-identification ont permis ...