Coping with ocean dynamics: Foraging strategy and implications for conservation of a small petrel

Abstract

[eng] Seabirds' distribution is generally influenced by the ecological dynamics of marine environments. Understanding how oceanographic features shape seabird foraging behavior remains a challenge. We combined GPS tracking locations (n = 2883) of 39 European Storm-petrels (Hydrobates pelagicus) breeding in four West Mediterranean colonies during incubation over multiple years (2019-2021) with near-real-time remotely sensed oceanographic drivers. We model habitat selection using GPS tracking data from one colony, Benidorm Island, and use data from other three colonies for validation. We show that suitable foraging areas are strongly characterised by low sea surface temperature, high chlorophyll concentration and eddy kinetic energy. Based on this model, we predict habitat suitability maps for 2018-2022. Cross-validation using data from the other three colonies highlights that the identified suitable areas are universally applicable across other Storm-petrel colonies in the Western Mediterranean. We identified the Alboran Sea, the North African coast, the Gulf of Lion and the Ebro River Delta as the most suitable regions. These areas are characterized by high mesoscale variability, suggesting the importance of dynamic oceanographic features in determining foraging habitat. Identified main foraging areas are largely outside of Marine Protected Areas (MPAs), thus vulnerable to anthropogenic threats such as overfishing and energy infrastructure development. The critical foraging areas identified for this species underscore the need to expand the MPA network and/or adopt sustainable resource extraction in unprotected marine areas.