Predicting variations in coastal seabird habitats to assess marine protected areas

• Main Author: Virgili, Auriane
• Other Authors: AGROCAMPUS OUEST, Observatoire PELAGIS, Pôle Analytique, 5 allée de l'Océan, 17000 La Rochelle, Vincent Ridoux
• Format: Master Thesis
• Language: English
• Published: HAL CCSD 2014
• Subjects: English Channel; Eastern North Atlantic; Coastal seabirds; Gulls; Terns; Cormorants and Shags; Divers; Scoters; Aerial surveys; Habitat modelling; Seabird distribution; Generalized Additive Models; Marine Protected Areas; Conservation areas; Manche; Atlantique Nord-est; France; Oiseaux de mer côtiers; Goélands; Sternes; Cormorans; Plongeons; Macreuses; Campagnes aériennes; Modélisation d'habitat; Distribution; Modèles Additifs Généralisés; Aires Marines Protégées; Zones de conservation; [SDV.SA]Life Sciences [q-bio]/Agricultural sciences; Gam; North Atlantic
• Online Access: https://dumas.ccsd.cnrs.fr/dumas-01101356; https://dumas.ccsd.cnrs.fr/dumas-01101356/document; https://dumas.ccsd.cnrs.fr/dumas-01101356/file/2014%20VIRGILI%20Auriane.pdf

Seabirds, like other predators, need to maximize their nutritional intakes and minimize their energy costs during foraging periods and thereby optimize their strategies of resources and habitats utilization. These strategies mainly depend on environmental conditions and can be described through habitat models for the implementation of conservation plans of species and ecosystems. The objectives of this study were: (1) to determine the mechanisms that mostly influence the distribution of seabirds along the French coasts; (2) to determine the effects of seasonal variations of these mechanisms; (3) to provide an assessment of all conservation sites established or proposed along these coasts and in Channel and Atlantic waters under French jurisdiction. We collected data of coastal seabird sightings from aerial surveys carried out in the English Channel and the eastern North Atlantic in winter and summer. We classified seabirds into morphological groups and described their habitats by using physiographic and oceanographic variables in generalized additive models (GAM). Finally, we provided, for each conservation site, a measure of its importance for the protection of the studied species. It would appear that distribution of coastal seabirds was essentially determined by distance to the coast, highest densities being predicted near the coast, with possible variations depending on the season. Finally, it appears that a majority of protected sites established along the French coasts would not be relevant to the conservation at sea of the studied species. Les oiseaux, comme tous prédateurs, doivent maximiser leurs apports nutritionnels et minimiser leurs dépenses énergétiques lors de leurs périodes d’alimentation et ainsi optimiser leurs stratégies d’utilisation des ressources et des habitats. Ces stratégies dépendent essentiellement des conditions environnementales, déterminantes pour la disponibilité des ressources, et peuvent être décrites grâce à des modèles d’habitat adaptés à la mise en place de plans de ...