Percorrer por autor "Costello, Mark John"
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- Marine biodiversity exposed to prolonged and intense subsurface heatwavesPublication . Fragkopoulou, Eliza; Sen Gupta, Alex; Costello, Mark John; Wernberg, Thomas; Araújo, Miguel B.; Serrao, Ester; De Clerck, Olivier; Assis, JorgeMarine heatwaves (MHWs) are becoming increasingly common, with devastating ecosystem impacts. However, MHW understanding has almost exclusively relied on sea surface temperature with limited knowledge about their subsurface characteristics. Here we estimate global MHWs from the surface to 2,000 m depth, covering the period 1993-2019, and explore biodiversity exposure to their effects. We find that MHWs are typically more intense in the subsurface at 50-200 m and their duration increases up to twofold with depth, although with large spatial variability linked to different oceanographic conditions. Cumulative intensity (a thermal stress proxy) was highest in the upper 250 m, exposing subsurface biodiversity to MHW effects. This can be particularly concerning for up to 22% of the ocean, where high cumulative intensity overlapped the warm range edge of species distributions, thus being more sensitive to thermal stress. Subsurface MHWs can hence drive biodiversity patterns, with consequent effects on ecological interactions and ecosystem processes. The authors estimate the intensity, duration and number of global marine heatwaves from 1993 to 2019, from the surface to 2,000 m. They show generally higher intensity of marine heatwaves at 50-200 m, but increased duration with depth, and predict ocean regions of higher biodiversity exposure.
- No significant projected climate change effects on the geographic ranges of marine aquaculture species under the sustainable scenario (SSP 1-1.9, 1.5°C warming)Publication . Mackintosh, Amy Leigh; Hill, Griffin Goldstein; Costello, Mark John; Assis, JorgeAquaculture is increasingly relied upon for global seafood production, projected to be the leading supplier by 2030. Climate change impacts on species health and industry productivity are already evident, creating uncertainties around long-term aquaculture development. While these impacts have been projected for some species, around 62% of aquaculture production remains unassessed. We utilized climate dissimilarity to assess the exposure of 327 species—including those previously unassessed—in their native ranges to changing climates under three climate scenarios: SSP1-1.9, SSP3-7.0, and SSP5-8.5. We projected that under a sustainability scenario (SSP1-1.9), 41% of Exclusive Economic Zones (EEZ) remained unexposed, including high-value aquaculture regions. However, under increased emissions scenarios (SSP3-7.0 and SSP5-8.5) all current aquaculture EEZ are projected to be exposed. Semi-enclosed seas, like the Baltic, Black, and Red Seas, experience the largest dissimilarity, alongside equatorial regions. Our findings suggest widespread mitigation efforts are necessary to ensure the long-term resilience of marine aquaculture.
- Oceanographic connectivity explains the intra-specific diversity of mangrove forests at global scalesPublication . Gouvêa, Lidiane; Fragkopoulou, Eliza; Cavanaugh, Kyle; Serrao, Ester; Araújo, Miguel B.; Costello, Mark John; Westergerling, E. H. Taraneh; Assis, JorgeThe distribution of mangrove intra-specific biodiversity can be structured by historical demographic processes that enhance or limit effective population sizes. Oceanographic connectivity (OC) may further structure intra-specific biodiversity by preserving or diluting the genetic signatures of historical changes. Despite its relevance for biogeography and evolution, the role of oceanographic connectivity in structuring the distribution of mangrove's genetic diversity has not been addressed at global scale. Here we ask whether connectivity mediated by ocean currents explains the intra-specific diversity of mangroves. A comprehensive dataset of population genetic differentiation was compiled from the literature. Multigenerational connectivity and population centrality indices were estimated with biophysical modeling coupled with network analyses. The variability explained in genetic differentiation was tested with competitive regression models built upon classical isolation-by-distance (IBD) models considering geographic distance. We show that oceanographic connectivity can explain the genetic differentiation of mangrove populations regardless of the species, region, and genetic marker (significant regression models in 95% of cases, with an average R-square of 0.44 +/- 0.23 and Person's correlation of 0.65 +/- 0.17), systematically improving IBD models. Centrality indices, providing information on important stepping-stone sites between biogeographic regions, were also important in explaining differentiation (R-square improvement of 0.06 +/- 0.07, up to 0.42). We further show that ocean currents produce skewed dispersal kernels for mangroves, highlighting the role of rare long-distance dispersal events responsible for histori- cal settlements. Overall, we demonstrate the role of oceanographic connectivity in structuring mangrove intra-specific diversity. Our findings are critical for mangroves' biogeography and evolution, but also for management strategies considering climate change and genetic biodiversity conservation.
- Quality of marine protected areas is critical to achieving global biodiversity targetsPublication . Stephenson, Fabrice; Horta e Costa, Barbara; Addamo, Anna M.; Bueno, Paula; Costello, Mark John; Dudley, Nigel; Eskuche-Keith, Patrick A.; Fox, Helen E.; Gill, David; Gordó-Vilaseca, Cesc; Grorud-Colvert, Kirsten; Klein, Carissa; Moore, Pippa J.; Morgan, Lance E.; Nalven, Katharine B.; Paredes, Felipe; Pike, Elizabeth P.; Rao, Madhu; Sullivan-Stack, Jenna; Weiskel, Heidi S. W.; Wenzel, Lauren; Wells, Sue; Claudet, JoachimSummarising CBD target 3 to “30 × 30” emphasizes area coverage, but conservation success depends on MPA quality. Many existing MPAs are underprotected, and rapidly designating new areas risks creating ‘paper parks’ without ecological or social benefits. Prioritizing strictly or fully managed MPAs, supported by a clear and shared definition, is essential to achieve meaningful biodiversity outcomes. Quality-focused strategies ensure that global targets benefit both nature and people, rather than merely meeting numerical goals.
- Trophic convergence of marine vertebrate communities worldwidePublication . González-Trujillo, Juan David; Assis, Jorge; Serrao, Ester A.; Costello, Mark John; Fragkopoulou, Eliza; Mendoza, Manuel; Araújo, Miguel B.Biogeographic regions arise due to constraints on species ranges, fostering lineage divergence as a result. Yet, convergent evolution means that evolutionary distinct lineages can share similar characteristics when subjected to similar environmental conditions. The ecological convergence of distinct regions has been demonstrated in terrestrial communities, but it remains uncertain if marine systems exhibit similar patterns, given the greater ease of dispersal in the ocean. Using information on the dietary preferences of marine vertebrates, we develop an ocean regionalization that groups regions with similar trophic communities, describing how species are organized into trophic guilds and how guilds overlap with one another. Six types of trophic communities emerge globally, largely explained by temperature, productivity, and depth. Regions with analogous environments support similar numbers of species with analogous feeding strategies, even if the species do not share the same evolutionary origins. These findings support the notion that independently evolving sets of marine species can converge into functionally analogous trophic communities when exposed to similar environmental conditions. They also provide a benchmark for studying the functional consequences of global environmental change.
- Vulnerability of marine species to low oxygen under climate changePublication . Shi, Zhiyuan; Assis, Jorge; Costello, Mark JohnIn recent decades, the ocean is becoming less oxygenated due to the combined effect of global warming and the spread of coastal eutrophication, with extensive consequences to marine ecosystems. Past mass extinctions were at least in part due to anoxic conditions in the oceans. Thus, we should be concerned about ongoing and projected declining availability of well-oxygenated habitats in the oceans. Tolerance to low oxygen is greater in smaller than larger, and less mobile than mobile taxa. The most vulnerable taxa to low oxygen are large active fish, and the least include mussels, hydrozoans, and jellyfishes. Climate change is thus likely to causes shifts in the relative abundance of species due to oxygen constraints.