Beyond safe land: revealing the oceanic distribution and exposure to anthropogenic contaminants of the globally endangered Bermuda petrel

• Main Authors: 3rd World Seabird Conference 2021, Campioni, Letizia
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Underline Science Inc. 2021
• Subjects: Animal Science; Ornithology; Canada; Jeremy; Silvia; North Atlantic
• Online Access: https://dx.doi.org/10.48448/06eb-4x45; https://underline.io/lecture/34767-beyond-safe-land-revealing-the-oceanic-distribution-and-exposure-to-anthropogenic-contaminants-of-the-globally-endangered-bermuda-petrel

Abstract: Gadfly petrels (Pterodroma genus) are pelagic seabirds of increasing conservation concern most of which are endemic to oceanic islands. In the North Atlantic, the Pterodroma cahow recovered from near-extinction due to the implementation of a recovery plan initiated in the 60s. The remnant population of 18 pairs has steadily increased to 131 pairs in 2019 but breeding failure due to decreased egg hatchability has increased over the last decade (25%-44%). Similarly, to promote population recovery reducing disturbance, fundamental aspects of P. Cahow behavioural-ecology have remained little understood. To fill this gap of knowledge, in 2019, we investigated, for the first time, the at-sea distribution, trophic ecology and exposure to contaminants of adult individuals. GPS-tracked birds (n=28) spent 56.2% of their foraging time in areas beyond national jurisdiction followed by 34.8% in the EEZ of the Bermudas and, 4.5% in waters of both Canada and of the United States. There were no significant differences in trip extension between sexes or seasons but, the amount of time spent at-sea tended to be higher during incubation than during chick-rearing. The areas used for foraging in both seasons did not coincide, and consequently deferred in terms of oceanographic conditions i.e., bathymetry and SST. Moreover, birds isotopic niche (blood δ15N and δ13C) resulted completely segregated between seasons with individuals feeding at higher trophic positions during chick-rearing. PCBs were the most ubiquitous persistent organic pollutant in terms of detection rate although mean concentration in blood was moderately low (7.87 ng/g w.w). Total PCBs and OCPs concentrations decreased with increasing bird body mass but were unrelated to δ15N or δ13C levels. Concurrently, egg hatching probability was negatively related to PCBs and OCPs concentrations suggesting potential adverse effects on reproduction. Totally, we provided new information with important implications for the management and conservation of a globally endangered species Authors: Letizia Campioni¹, Jeremy Madeiros², José Pedro Granadeiro³, Bernat Oró-Nolla⁴, Silvia Lacorte⁴, Ilaria Marengo⁵, Marcello D'Amico⁶, Monica Silva⁷ ¹ISPA-Istituto Universitario, ²Ministry of the Environment, PO Box FL588, Flatts, FL BX, Bermuda, ³Faculdade de Ciências da Universidade de Lisboa, CESAM, ⁴Institute of Environmental Assessment and Water Research (IDAEA-CSIC), ⁵InnovPlantProtect, ⁶Doñana Biological Station (CSIC), ⁷Faculdade de Ciências, Universidade de Lisboa