Browsing by Author "Horta, Paulo"
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- Long range gene flow beyond predictions from oceanographic transport in a tropical marine foundation speciesPublication . Tavares, Ana I; Assis, Jorge; Larkin, Patrick D.; Creed, Joel C.; Magalhães, Karine; Horta, Paulo; Engelen, Aschwin; Cardoso, Noelo; Barbosa, Castro; Pontes, Samuel; Regalla, Aissa; Almada, Carmen; Ferreira, Rogério; Abdoul, Ba Mamadou; Ebaye, Sidina; Bourweiss, Mohammed; dos Santos, Carmen Van-Dúnem; Patrício, Ana R.; Teodosio, Maria; Santos, Rui; Pearson, Gareth; Serrao, Ester AThe transport of passively dispersed organisms across tropical margins remains poorly understood. Hypotheses of oceanographic transportation potential lack testing with large scale empirical data. To address this gap, we used the seagrass species, Halodule wrightii, which is unique in spanning the entire tropical Atlantic. We tested the hypothesis that genetic differentiation estimated across its large-scale biogeographic range can be predicted by simulated oceanographic transport. The alternative hypothesis posits that dispersal is independent of ocean currents, such as transport by grazers. We compared empirical genetic estimates and modelled predictions of dispersal along the distribution of H. wrightii. We genotyped eight microsatellite loci on 19 populations distributed across Atlantic Africa, Gulf of Mexico, Caribbean, Brazil and developed a biophysical model with high-resolution ocean currents. Genetic data revealed low gene flow and highest differentiation between (1) the Gulf of Mexico and two other regions: (2) Caribbean-Brazil and (3) Atlantic Africa. These two were more genetically similar despite separation by an ocean. The biophysical model indicated low or no probability of passive dispersal among populations and did not match the empirical genetic data. The results support the alternative hypothesis of a role for active dispersal vectors like grazers.
- Marine forests forever—A necessary multilateral program for a fair futurePublication . Horta, Paulo; Sissini, Marina N.; Fonseca, Alessandra; Turra, Alexander; Rodrigues, Ana Claudia; Rorig, Leonardo; Bonomi‐Barufi, José; Pagliosa, Paulo; Bastos, Eduardo; Grimaldi, Guido; Dias, Carlos Eduardo Peixoto; Fialho, Fabio; Oliveira, Carlos Yure B.; Frade, Pedro R.; Schubert, Nadine; Silva, João; Assis, Jorge; Rossi, Sergio; Mansilla, Andres; Soares, Marcelo; Gouvêa, Lidiane; Alves-Lima, Cicero; Coelho, Márcio A. G.; Serrao, Ester A.; Anderson, Antonio Batista; Joyeux, Jean‐Christophe; Berchez, Flávio; Otero‐Ferrer, Francisco; Filho, Jorge Luiz Rodrigues; Mies, Miguel; Araujo, Moacyr; Hall‐Spencer, Jason M.Not only advances but also old addictions, setbacks, obstructions and delays are observed during COP16 (on biodiversity), COP29 (on climate change) and G20 in a year full of tragedies resulting from climate change; we need to look in the rearview mirror and plan new paths to be presented and discussed at COP30, in 2025, in the Brazilian Amazon. Worldwide temperature records show that 2023 and 2024 were the warmest in at least the last 2000 years (Esper, Torbenson, and Büntgen 2024). About 90% of the excess heat trapped by greenhouse gases and 30% of human emissions of carbon dioxide are stored in the ocean, shielding the planet from even more rapid changes in the biosphere. The recent acceleration in climate change is a threat not only to terrestrial systems but also to largely neglected marine ecosystems and their socio-biodiversity. Considering the relationship between global warming and biological extinctions (Malanoski et al. 2024), as well as the high vulnerability of marine biodiversity to these global threats (Pinsky et al. 2019), we call for the urgent need to create global and multilateral policies that are based on climate-smart ocean planning and carbon neutrality, focused on climate adaptation and mitigation strategies to protect, restore and foster sustainable management of marine socio-ecological systems (Frazão Santos et al. 2024).
- Seagrass can mitigate negative ocean acidification effects on calcifying algaePublication . Bergstrom, Ellie; Silva, João; Martins, Cíntia; Horta, PauloThe ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.