Seabird conservation priorities: the case of coral reef islands

Abstract

**Abstract:** Low-level islands around the globe are predicted to face a "range of coastal hazards" driven by sea level change throughout the 21st century. These risks include the permanent submergence of land areas due to higher sea level, accelerated coastal erosion and the rise in frequency and intensity of flooding events, all of which threaten the future biodiversity and functioning of insular ecosystems. On tropical coral reef islands (CRI, low-level islands formed through reef construction and the accumulation of coral debris), sea level change will likely reduce breeding habitat availability for multiple seabird species, adding to the effects of long-known ecological disruptions (species invasions, reef decline, decrease in prey availability). However, the extent to which seabird populations in CRI might be affected by sea level change remains broadly uncharacterized due to limited understanding of the large-scale demography and behavioral adaptability of tropical seabird species, along with overall poor knowledge of the geomorphology dynamics of islands threatened by submersion and/or coastal erosion. Here, we present an overview of current information gaps in the assessment of global distribution and vulnerability of seabirds breeding on CRI. Using New Caledonia (South-West Pacific) as a baseline example, we then discuss a prospective research framework for (1) aggregating monitoring data on CRI seabird populations, (2) assessing natural and anthropogenic drivers of colony distribution and (3) identifying long-term conservation and restoration targets in a context of future sea level change. This talk aims to highlight the need for more comprehensive, multiscale and collaborative seabird monitoring on vulnerable, low-lying islands as a tool to prioritize key conservation sites in the inter-tropical region and shape relevant mitigation strategies. **Authors:** Tristan Berr¹, Alexandre Millon², Poetea Guehenneuc³, Matthieu Le Corre⁴, Éric Vidal⁵ ¹Institut de Recherche pour le Développement, Université de Nouvelle-Calédonie, ²Aix Marseille Université, Institut Méditerranéen de Biodiversité et d'Écologie, ³Université de Bordeaux, ⁴Université de la Réunion, ⁵Institut de Recherche pour le Développement