Percorrer por autor "Fernandez, Marc"
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- Common dolphin's shipping noise risk assessment on the Portuguese coastPublication . Spadoni, Giulia; Duarte, Ricardo; Soares, Cristiano; Fernandez, Marc; Jesus, SergioOcean noise generated by human activities at sea has been increasing over the decades, affecting marine eco systems. Ship traffic flow between the Mediterranean or South Atlantic and northern Europe makes the coast of Portugal one of the most intense shipping highways on a global scale. Among the cetaceans of the coast of Portugal, the common dolphin (Delphinus delphis) was selected as a target species. Based on 15 years of obser vations, the common dolphins' habitat suitability was estimated, together with the shipping noise maps for the year 2019, to produce seasonal risk maps for the same year. A large number of areas with a high noise risk index (≥0.85) were found in Portugal's southern and southwestern coasts, especially during the summer and fall seasons. Comparably, the 0.50 risk index exceeds 7 % and 3.5 % of the total area in summer and fall, respec tively. These percentages decrease to 1 % in spring and winter.
- Isotope-based inferences of the trophic niche of short-finned pilot whales in the WebbnesiaPublication . Escánez, Alejandro; Marrero-Pérez, Jacobo; Dromby, Morgane; Pimentel-González, Atenary; Dias, Ester; García-Pastor, Ester M.; Weyn, Mieke; Ferreira, Rita; Montañés-Pérez, Alexandra; Fernandez, Marc; Dinis, Ana; Alves, FilipeKnowledge of predator-prey interactions is key in ecological studies and understanding ecosystem function, yet this is still poorly explored in the deep-sea environment. Carbon (delta C-13: C-13/C-12) and nitrogen (delta N-15: N-15/N-14) stable isotope ratios of a deep-diving species, the short-finned pilot whale (Globicephala macrorhynchus), were used to explore knowledge gaps on its ecological niche and foraging habitats in the Webbnesia marine ecoregion (Tenerife Island, n = 27 animals vs. Madeira, n = 31; 500 km apart) where animals display distinct levels of site fidelity. Specifically, we tested whether intraspecific isotopic variation results from differences between geographic areas (due to possible foraging plasticity between regions), sexes, and/or years (2015-2020) using Generalized Linear Models. In general, significant differences (p < 0.05) were found in the stable isotope profiles of pilot whales between the two archipelagos, which were also reflected in their isotopic niche. The higher mean and wider range of delta N-15 values in Tenerife suggest that pilot whales consume prey of higher trophic levels and more diverse than Madeira. The higher mean and wider range of delta C-13 values in Madeira suggest that in that island, pilot whales rely on prey from more diverse habitats. There was significant variation between some years, but not between sexes. Finally, we discuss pilot whales' foraging strategies worldwide and infer the reliance on benthic or benthopelagic food sources in the Webbnesia.