Seabird distribution is better predicted by abundance of prey than oceanography. A case study in the Gulf of Cadiz (SW, Iberian Peninsula)

• Published in: ICES Journal of Marine Science
• Main Authors: de-la-Cruz, A. (Andrés), Ramos, F. (Fernando), Tornero, J. (Jorge), Rincón-Hidalgo, M. (Margarita), Jiménez, M.P. (María Paz), Muñoz-Arroyo, G. (Gonzalo)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Centro Oceanográfico de Cádiz 2021
• Subjects: Gulf of Cadiz; Marine top predators; Oceanographic factors; Overlapping distribution; Predator–prey relationship; Seabirds; fish; predation; oceanography; abundance; distribution; North Atlantic
• Online Access: http://hdl.handle.net/10508/16137; https://doi.org/10.1093/icesjms/fsab256

Quantifying factors that influence marine predator distributions is essential to understanding the current and future change inmarine biodiversity. Here, we test whether marine predator distribution relates to prey, or is better predicted by other specific habitat features.We examine the correlation between spatial distribution of three seabird species and their prey, as well as environmental proxies (oceanographic characteristics) in the Gulf of Cadiz, NE Atlantic. We modeled the at-sea distribution of Cory’s shearwater, Balearic shearwater and Northern gannet, based on: (i) pelagic fish abundance according to acoustic surveys, and (ii) a forecast-model of remotely sensed environmental variables (productivity, sea surface temperature, and salinity). In general, seabird distributions were better predicted by abundance of fish than by environmental variables at the habitat scale. We obtained consistent correlations between seabird presence and the abundance of medium-sized (10–20 cm) sardines, anchovies and Mediterranean horse mackerel, providing information on their preferred prey. Additionally, oceanographic productivity variables moderately contributed to seabird distributionmodels, with better predictive value for the critically endangered Balearic shearwater and Northern gannet in the summer, whilst themodel for Cory’s shearwater’s produced poorer predictions. Predator–prey combined studiesmay represent essential tools for an efficient ecosystem-based management of marine environments. Versión del editor 2,277