Percorrer por autor "Hall-Spencer, Jason M."
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- Ervilia castanea (Mollusca, Bivalvia) populations adversely affected at CO2 seeps in the North AtlanticPublication . Martins, Marta; Carreiro-Silva, Marina; Martins, Gustavo M.; Barcelos e Ramos, Joana; Viveiros, Fátima; Couto, Ruben P.; Parra, Hugo; Monteiro, João; Gallo, Francesca; Silva, Catarina; Teodosio, MA; Guilini, Katja; Hall-Spencer, Jason M.; Leitão, Francisco; Chicharo, Luis; 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 to lower food supplies. This raises concerns about the effects of ocean acidification on the brood stock of this species and other bivalve molluscs of similar life history traits.
- How experimental physiology and ecological niche modelling can inform the management of marine bioinvasions?Publication . Koerich, Gabrielle; Assis, Jorge; Costa, Giulia Burle; Sissini, Marina Nasri; Serrao, Ester; Rorig, Leonardo Rubi; Hall-Spencer, Jason M.; Barufi, Jose Bonomi; Horta, Paulo AntunesMarine bioinvasions are increasing worldwide by a number of factors related to the anthroposphere, such as higher ship traffic, climate change and biotic communities' alterations. Generating information about species with high invasive potential is necessary to inform management decisions aiming to prevent their arrival and spread. Grateloupia turuturu, one of the most harmful invasive macroalgae, is capable of damaging ecosystem functions and services, and causing biodiversity loss. Here we developed an ecological niche model using occurrence and environmental data to infer the potential global distribution of G. turuturu. In addition, ecophysiological experiments were performed with G. turuturu populations from different climatic regions to test predictions regarding invasion risk. Our model results show high suitability in temperate and warm temperate regions around the world, with special highlight to some areas where this species still doesn't occur. Thalli representing a potential temperate region origin, were held at 10, 13, 16, 20 and 24 degrees C, and measurements of optimal quantum field (Fv/Fm) demonstrated a decrease of photosynthetic yield in the higher temperature. Thalli from the population already established in warm temperate South Atlantic were held at 18, 24 and 30 degrees C with high and low nutrient conditions. This material exposed to the higher temperature demonstrated a drop in photosynthetic yield and significant reduction of growth rate. The congregation of modelling and physiological approach corroborate the invasive potential of G. turuturu and indicate higher invasion risk in temperate zones. Further discussions regarding management initiatives must be fostered to mitigate anthropogenic transport and eventually promote eradication initiatives in source areas, with special focus in the South America. We propose that this combined approach can be used to assess the potential distribution and establishment of other marine invasive species. (C) 2019 Elsevier B.V. All rights reserved.
- Levelling-up rhodolith-bed science to address global-scale conservation challengesPublication . Tuya, Fernando; Schubert, Nadine; Aguirre, Julio; Basso, Daniela; Bastos, Eduardo O.; Berchez, Flávio; Bernardino, Angelo F.; Bosch, Néstor E.; Burdett, Heidi L.; Espino, Fernando; Fernández-Gárcia, Cindy; Francini-Filho, Ronaldo B.; Gagnon, Patrick; Hall-Spencer, Jason M.; Haroun, Ricardo; Hofmann, Laurie C.; Horta, Paulo A.; Kamenos, Nicholas A.; Le Gall, Line; Magris, Rafael A.; Martin, Sophie; Nelson, Wendy A.; Neves, Pedro; Olivé, Irene; Otero-Ferrer, Francisco; Peña, Viviana; Pereira-Filho, Guilherme H.; Ragazzola, Federica; Rebelo, Ana Cristina; Ribeiro, Cláudia; Rinde, Eli; Schoenrock, Kathryn; Silva, João; Sissini, Marina N.; Tâmega, Frederico T. S.Global marine conservation remains fractured by an imbalance in research efforts and policy actions, limiting progression towards sustainability. Rhodolith beds represent a prime example, as they have ecological importance on a global scale, provide a wealth of ecosystem functions and services, including biodiversity provision and potential climate change mit-igation, but remain disproportionately understudied, compared to other coastal ecosystems (tropical coral reefs, kelp for-ests, mangroves, seagrasses). Although rhodolith beds have gained some recognition, as important and sensitive habitats at national/regional levels during the last decade, there is still a notable lack of information and, consequently, specific conservation efforts. We argue that the lack of information about these habitats, and the significant ecosystem services they provide, is hindering the development of effective conservation measures and limiting wider marine conservation success. This is becoming a pressing issue, considering the multiple severe pressures and threats these habitats are exposed to (e.g., pollution, fishing activities, climate change), which may lead to an erosion of their ecological function and eco-system services. By synthesizing the current knowledge, we provide arguments to highlight the importance and urgency of levelling-up research efforts focused on rhodolith beds, combating rhodolith bed degradation and avoiding the loss of associated biodiversity, thus ensuring the sustainability of future conservation programs.