Browsing by Author "Parra, Hugo"
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- Ervilia castanea (Mollusca, Bivalvia) populations adversely affected at CO₂ seeps in the North AtlanticPublication . Martins, Marta; Silva, Marina Carreiro; Martins, Gustavo M.; Ramos, Joana B.; Viveiros, Fátima; Couto, Ruben P.; Parra, Hugo; Monteiro, João; Gallo, Francesca; Silva, Catarina; Teodósio, Alexandra; Guilini, Katja; Hall-Spencer, Jason M.; Leitão, Francisco; Chícharo, Luís; Range, PedroSites with naturally high CO₂ conditions provide unique opportunities to forecast the vulnerability of coastal ecosystems to ocean acidification, by studying the biological responses and potential adaptations to this increased environmental variability. In this study, we investigated the bivalve Ervilia castanea in coastal sandy sediments at reference sites and at volcanic CO₂ seeps off the Azores, where the pH of bottom waters ranged from average oceanic levels of 8.2, along gradients, down to 6.81, in carbonated seawater at the seeps. The bivalve population structure changed markedly at the seeps. Large individuals became less abundant as seawater CO₂ levels rose and were completely absent from the most acidified sites. In contrast, small bivalves were most abundant at the CO₂ seeps. We propose that larvae can settle and initially live in high abundances under elevated CO₂ levels, but that high rates of post-settlement dispersal and/or mortality occur. Ervilia castanea were susceptible to elevated CO₂ levels and these effects were consistently associated with lower food supplies. This raises concerns about the effects of ocean acidification on the brood stock of this species and other bivalve molluscs with similar life history traits.
- Sea turtle (Reptilia, Testudines) diversity and occurrence in the Azores Archipelago (NE Atlantic)Publication . Barcelos, Luis M. D.; Vandeperre, Frederic; Parra, Hugo; Barreiros, João P.BACKGROUND: Six species of marine turtles occur in the Azores Archipelago. The loggerhead, Caretta caretta (Linnaeus, 1758), is by far the most common species and is being constantly monitored and tagged by a joint project between the University of the Azores and the University of Florida since 1989. With the implementation of the tuna fishery observers (for dolphin safe seals), an increment of sea turtle reports has been verified as expected. The leather back turtle, Dermochelys coriacea (Vandelli, 1761) is the second most observed species in the Azores' EEZ, a fact probably also linked to the tuna fishery observation programme. All other species are occasional/vagrant albeit the green turtle, Chelonia mydas (Linnaeus, 1758) is more commonly seen than the others. Historically, sea turtles were occasionally taken for food in specific fishing villages and ports. Since 1986, sea turtles, as well as all marine mammals, are fully protected in the Azores although human-related activities (e.g. plastics, discarded fishing gear) do generate serious injuries and deaths. NEW INFORMATION: In this paper, we update sea turtle species' checklist for the Azores and give detailed geographic coordinates on their known occurrences.