Linking 19th century European settlement to the disruption of a seabird’s natural population dynamics

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Duda, Matthew, Allen-Mahé, Sylvie, Barbraud, Christophe, Blais, Jules, Boudreau, Amaël, Bryant, Rachel, Delord, Karine, Grooms, Christopher, Kimpe, Linda, Letournel, Bruno, Lim, Joeline, Lormée, Hervé, Michelutti, Neal, Robertson, Gregory, Urtizbéréa, Frank, Wilhelm, Sabina, Smol, John
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Office National de la Chasse et de la Faune Sauvage (ONCFS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: paleolimnology; shifting baselines; population decline; conservation; islands; [SDE]Environmental Sciences; Northwest Atlantic
• Online Access: https://hal.archives-ouvertes.fr/hal-03105945; https://doi.org/10.1073/pnas.2016811117

International audience Recent estimates indicate that ∼70% of the world’s seabird populations have declined since the 1950s due to human activities. However, for almost all bird populations, there is insufficient long-term monitoring to understand baseline (i.e., preindustrial) conditions, which are required to distinguish natural versus anthropogenically driven changes. Here, we address this lack of long-term monitoring data with multiproxy paleolimnological approaches to examine the long-term population dynamics of a major colony of Leach’s Storm-petrel (Hydrobates leucorhous) on Grand Colombier Island in the St. Pierre and Miquelon archipelago—an overseas French territory in the northwest Atlantic Ocean. By reconstructing the last ∼5,800 y of storm-petrel dynamics, we demonstrate that this colony underwent substantial natural fluctuations until the start of the 19th century, when population cycles were disrupted, coinciding with the establishment and expansion of a European settlement. Our paleoenvironmental data, coupled with on-the-ground population surveys, indicate that the current colony is only ∼16% of the potential carrying capacity, reinforcing concerning trends of globally declining seabird populations. As seabirds are sentinel species of marine ecosystem health, such declines provide a call to action for global conservation. In response, we emphasize the need for enlarged protected areas and the rehabilitation of disturbed islands to protect ecologically critical seabird populations. Furthermore, long-term data, such as those provided by paleoecological approaches, are required to better understand shifting baselines in conservation to truly recognize current rates of ecological loss.