Browsing by Author "Vinagre, Catarina"
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- Biodiversity of intertidal food webs in response to warming across latitudesPublication . Gauzens, Benoit; Rall, Bjoern C.; Mendonca, Vanessa; Vinagre, Catarina; Brose, UlrichGlobal warming will affect food-web structure and species persistence, and real world data is needed for better prediction. Combining species counts and temperature data from rock pools with dynamic modelling predicts biodiversity increases in arctic to temperate regions and declines in the tropics. Global warming threatens community stability and biodiversity around the globe. Knowledge of the mechanisms underlying the responses to rising temperatures depends heavily on generic food-web models that do not account for changes in network structure along latitudes and temperature gradients. Using 124 marine rock-pool food webs sampled across four continents, we show that despite substantial variation in ambient temperature (mean 11.5-28.4 degrees C), similar empirical food-web and body-mass structures emerge. We have used dynamic modelling to test whether communities from warmer regions are more sensitive to warming and found a general hump-shaped relationship between simulated biodiversity and temperature (gradient from 0-50 degrees C). This implies that an expected anthropogenic global warming of 4 degrees C should increase biodiversity in arctic to temperate regions while biodiversity in tropical regions should decrease. Interestingly, simulations of synthetic networks did not yield similar results, which stresses the importance of considering the specificities of natural food webs for predicting community responses to environmental changes.
- Changing webs—Variation of complex networks over a tidal cycle in an intertidal rocky reefPublication . Vinagre, Catarina; Mendonça, VanessaIncorporating temporal variation in models is one of the most important challenges in food web research. One of the environments where time causes profound changes is the intertidal zone, where the immersion-emersion cycle drastically changes the abiotic and biotic conditions. Intertidal rocky shores have been intensively studied, however the variation in the complex food web network that occurs during a tidal cycle remains undescribed. Highly resolved food web networks were assembled for an intertidal reef depicting the food web during low and high tide, and with and without tide pools. It was concluded that high tide adds new species to the web, but it does not add complexity since network connectance was not changed. This occurs because incoming species are mostly highly generalist fish, which add many new links to the web. Tide pools, however, add not only diversity but also complexity. Webs were dominated by intermediate species, with the proportion of top consumers fluctuating throughout the tidal cycle, being lowest during low tide and highest at high tide, due to the incoming larger vertebrate predators. Consumer taxa outnumbered resource taxa, except at low tide when pools are present. Mean trophic level was lowest at low tide (2.3) and highest at high tide with pools (2.6). Omnivory was high and showed little change. "Chain", the number of links connecting top to basal species, was stable but low. This implies that disturbance can rapidly travel bottom-up or top-down through predator-prey links. The increased connectance given by the addition of tide pools likely increases robustness to disturbances, an important feature in coastal areas so often impacted by human action.
- Conserved fatty acid profiles and lipid metabolic pathways in a tropical reef fish exposed to ocean warming – An adaptation mechanism of tolerant species?Publication . Madeira, Carolina; Madeira, Diana; Ladd, Nemiah; Schubert, Carsten J.; Diniz, Mário S.; Vinagre, Catarina; Leal, Miguel C.Climate warming is causing rapid spatial expansion of ocean warm pools from equatorial latitudes towards the subtropics. Sedentary coral reef inhabitants in affected areas will thus be trapped in high temperature regimes, which may become the "new normal". In this study, we used clownfish Amphiprion ocellaris as model organism to study reef fish mechanisms of thermal adaptation and determine how high temperature affects multiple lipid aspects that influence physiology and thermal tolerance. We exposed juvenile fish to two different experimental conditions, implemented over 28 days: average tropical water temperatures (26 °C, control) or average warm pool temperatures (30 °C). We then performed several analyses on fish muscle and liver tissues: i) total lipid content (%), ii) lipid peroxides, iii) fatty acid profiles, iv) lipid metabolic pathways, and v) weight as body condition metric. Results showed that lipid storage capacity in A. ocellaris was not affected by elevated temperature, even in the presence of lipid peroxides in both tissues assessed. Additionally, fatty acid profiles were unresponsive to elevated temperature, and lipid metabolic networks were consequently well conserved. Consistent with these results, we did not observe changes in fish weight at elevated temperature. There were, however, differences in fatty acid profiles between tissue types and over time. Liver showed enhanced α-linolenic and linoleic acid metabolism, which is an important pathway in stress response signaling and modulation on environmental changes. Temporal oscillations in fatty acid profiles are most likely related to intrinsic factors such as growth, which leads to the mobilization of energetic reserves between different tissues throughout time according to organism needs. Based on these results, we propose that the stability of fatty acid profiles and lipid metabolic pathways may be an important thermal adaptation feature of fish exposed to warming environments.
- Consistent predator-prey biomass scaling in complex food websPublication . Perkins, Daniel M.; Hatton, Ian A.; Gauzens, Benoit; Barnes, Andrew D.; Ott, David; Rosenbaum, Benjamin; Vinagre, Catarina; Brose, UlrichThe ratio of predator-to-prey biomass is a key element in food webs. Here, the authors report a unified analysis of predator-prey biomass scaling in complex food webs, finding general patterns of sub-linear scaling across ecosystems and levels of organization. The ratio of predator-to-prey biomass is a key element of trophic structure that is typically investigated from a food chain perspective, ignoring channels of energy transfer (e.g. omnivory) that may govern community structure. Here, we address this shortcoming by characterising the biomass structure of 141 freshwater, marine and terrestrial food webs, spanning a broad gradient in community biomass. We test whether sub-linear scaling between predator and prey biomass (a potential signal of density-dependent processes) emerges within ecosystem types and across levels of biological organisation. We find a consistent, sub-linear scaling pattern whereby predator biomass scales with the total biomass of their prey with a near 3/4-power exponent within food webs - i.e. more prey biomass supports proportionally less predator biomass. Across food webs, a similar sub-linear scaling pattern emerges between total predator biomass and the combined biomass of all prey within a food web. These general patterns in trophic structure are compatible with a systematic form of density dependence that holds among complex feeding interactions across levels of organization, irrespective of ecosystem type.
- Different sensitivity to heatwaves across the life cycle of fish reflects phenotypic adaptation to environmental nichePublication . Madeira, Diana; Madeira, Carolina; Costa, Pedro M.; Vinagre, Catarina; Portner, Hans-Otto; Diniz, Mario S.Predicting responses of marine organisms to global change requires eco-physiological assessments across the complex life cycles of species. Here, we experimentally tested the vulnerability of a demersal temperate fish (Sparus aurata) to long-lasting heatwaves, on larval , juvenile and adult life-stages. Fish were exposed to simulated coastal (18 degrees C), estuarine (24 degrees C) summer temperatures, and heatwave conditions (30 degrees C) and their physiological responses were assessed based on cellular stress response biomarkers (heat shock protein 70 kDa, ubiquitin, antioxidant enzymes, lipid peroxidation) and phenotypic measures (histopathology, condition and mortality). Life-stage vulnerability can be ranked as larvae > adults > juveniles, based on mortality , tissue pathology and the capacity to employ cellular stress responses, reflecting the different environmental niches of each life stage. While larvae lacked acclimation capacity, which resulted in damage to tissues and elevated mortality, juveniles coped well with elevated temperature. the rapid induction of cytoprotective proteins maintained the integrity of vital organs in juveniles, suggesting adaptive phenotypic plasticity in coastal and estuarine waters. Adults displayed lower plasticity to heatwaves as they transition to deeper habitats for maturation, showing tissue damage in brain, liver and muscle. Life cycle closure of sea breams in coastal habitats will therefore be determined by larval and adult stages.
- Differential effects of food restriction and warming in the two-spotted goby: impaired reproductive performance and stressed offspringPublication . Lopes, Ana F.; Murdoch, Robyn; Martins-Cardoso, Sara; Madeira, Carolina; Costa, Pedro M.; Félix, Ana S.; Oliveira, Rui F.; Bandarra, Narcisa M.; Vinagre, Catarina; Lopes, Ana R.; Gonçalves, Emanuel J.; Faria, Ana MargaridaClimate change is a growing threat to marine organisms and ecosystems, and it is already modifying ocean properties by, for example, increasing temperature and decreasing pH. Increasing water temperature may also lead to an impairment of primary productivity and an overall depletion of available zooplankton. Understanding how the crossover between warming and zooplankton availability impacts fish populations has paramount implications for conservation and mitigation strategies. Through a cross factorial design to test the effects of ocean temperature and food availability in a temperate marine teleost, Pomatochistus flavescens, we showed that hindered feeding impacted sheltering and avoidance behaviour. Also, low food availability impaired fish reproduction, particularly male reproduction, as the expression of cyp11b1, a gene with a pivotal role in the synthesis of the most important fish androgen, 11-ketotestosterone, was significantly reduced under a low food regime. In contrast, temperature alone did not affect reproductive success, but offspring showed increased saturated fatty acid content (embryos) and increased lipid peroxidation (larvae). Altogether, food availability had a stronger effect on fitness, showing that coping with elevated temperatures, an ability that may be expected in shallow-water fish, can be indirectly impacted, or even overwhelmed, by the effects of ocean warming on primary productivity and downstream ecological processes.
- Does heat tolerance actually predict animals' geographic thermal limits?Publication . Camacho, Agustín; Rodrigues, Miguel Trefaut; Jayyusi, Refat; Harun, Mohamed; Geraci, Marco; Carretero, Miguel A.; Vinagre, Catarina; Tejedo, MiguelThe "climate extremes hypothesis" is a major assumption of geographic studies of heat tolerance and climatic vulnerability. However, this assumption remains vastly untested across taxa, and multiple factors may contribute to uncoupling heat tolerance estimates and geographic limits. Our dataset includes 1000 entries of heat tolerance data and maximum temperatures for each species' known geographic limits (hereafter, Tmax). We gathered this information across major animal taxa, including marine fish, terrestrial arthropods, amphibians, non-avian reptiles, birds, and mammals. We first tested if heat tolerance constrains the Tmax of sites where species could be observed. Secondly, we tested if the strength of such restrictions depends on how high Tmax is relative to heat tolerance. Thirdly, we correlated the different estimates of Tmax among them and across species. Restrictions are strong for amphibians, arthropods, and birds but often weak or inconsistent for reptiles and mammals. Marine fish describe a non-linear relationship that contrasts with terrestrial groups. Traditional heat tolerance measures in thermal vulnerability studies, like panting temperatures and the upper set point of preferred temperatures, do not predict Tmax or are inversely correlated to it, respectively. Heat tolerance restricts the geographic warm edges more strongly for species that reach sites with higher Tmax for their heat tolerance. These emerging patterns underline the importance of reliable species' heat tolerance indexes to identify their thermal vulnerability at their warm range edges. Besides, the tight correlations of Tmax estimates across on -land microhabitats support a view of multiple types of thermal challenges simultaneously shaping ranges' warm edges for on -land species. The heterogeneous correlation of Tmax estimates in the ocean supports the view that fish thermoregulation is generally limited, too. We propose new hypotheses to understand thermal restrictions on animal distribution.
- Does predation exacerbate the risk of endosymbiont loss in heat stressed hermatypic corals? molecular cues provide insights into species-specific health outcomes in a multi-stressor oceanPublication . Madeira, Carolina; Dias, Marta; Ferreira, Ana; Gouveia, Raúl; Cabral, Henrique; Diniz, Mário S.; Vinagre, CatarinaOcean warming has been a major driver of coral reef bleaching and mass mortality. Coupled to other biotic pressures, corals' ability for acclimatization and adaptation may become compromised. Here, we tested the combined effects of warming scenarios (26, 30, and 32 degrees C) and predation (wound vs. no wound) in coral health condition (paleness, bleaching, and mortality), cellular stress responses (heat shock protein 70 kDa Hsp70, total ubiquitin Ub, and total antioxidant capacity TAC), and physiological state (integrated biomarker response index, IBR) of seven Scleractinian coral species, after being exposed for 60 days. Results show that although temperature was the main factor driving coral health condition, thermotolerant species (Galaxea fascicularis, Psammocora contigua, and Turbinaria reniformis) displayed increased paleness, bleaching, and mortality in predation treatments at high temperature, whereas thermosensitive species (Acropora tenuis, Echinopora lamellosa, and Montipora capricornis brown and green morphotypes) all died at 32 degrees C, regardless of predation condition. At the molecular level, results show that there were significant main and interactive effects of species, temperature, and predation in the biomarkers assessed. Temperature affected Hsp70, Ub, and TAC, evidencing the role of protein folding and turnover, as well as reactive oxygen species scavenging in heat stress management. Predation increased Hsp70 and Ub, suggesting the activation of the pro-phenoloxidase system and cytokine activity, whereas the combination of both stressors mainly affected TAC during moderate stress and Ub under severe stress, suggesting that redox balance and defense of homeostasis are crucial in tissue repair at high temperature. IBR levels showed an increasing trend at 32 degrees C in predated coral fragments (although non-significant). We conclude that coral responses to the combination of high temperature and predation pressure display high inter-species variability, but these stressors may pose a higher risk of endosymbiont loss, depending on species physiology and stress intensity.
- Engineered metal nanoparticles in the marine environment: A review of the effects on marine faunaPublication . Roma, Joana; Matos, Ana Rita; Vinagre, Catarina; Duarte, BernardoThere is an increasing awareness of how damaging pollutants in the marine environment can be, however information on the effects of metal engineered nanoparticles (ENPs) on marine biota is still insufficient, despite an exponential rising in related publications in recent years. In order to provide an integrated insight on the present state of the art on metal ENP-related ecotoxicology studies on marine fauna, this review aimed to: (i) highlight the means of toxicity of metal ENPs in the marine environment, (ii) identify the principal biotic and abiotic factors that may alter metal ENP toxicity, and (iii) analyse and categorize results of these studies, including accumulation, molecular and histological biomarkers, genotoxicity and behavioural changes. Data retrieved from Scopus yielded 134 studies that met pre-established criteria. Most often, the target ENPs were titanium, zinc, copper or silver, and most studies (61.2%) focused on the phylum Mollusca. The degree of toxicity of metal ENPs was often dependent on the concentrations tested, length of exposure and the type of tissue sampled. Effects from simple tissue accumulation to DNA damage or behavioural alterations were identified, even when concentrations below environmentally available levels were used. It is proposed that other phyla besides the traditional Mollusca (and within it Bivalvia) should be used more often in this kind of studies, that exact pathways of toxicity be further explored, and lastly that co-stressors be used in order to best mimic conditions observed in nature. In this review, the current knowledge on engineered metal nanoparticles and their effects on marine fauna was summarized, highlighting present knowledge gaps. Guidelines for future studies focusing on under-developed subjects in ENP toxicology are also briefly provided.
- Environmental factors impacting the abundance and distribution of amphipods in intertidal rock poolsPublication . Carvalho, Jéssica; Mendonça, Vanessa; Vinagre, Catarina; Silva, AnaIntertidal rock pools are considered critical habitats along coastal shores. Amphipods play an important role in intertidal rock pool ecosystems, as food resources for higher trophic levels and sometimes by enriching nutrients through grazing. However, the environmental factors driving their rockpool occupation remain largely unknown. We aimed to examine the importance of the large-scale wave action variation and meso-scale shore variation on the abundance and diversity of rockpool amphipods. A total of 32 intertidal rock pools on four Portuguese shores were studied during the summer spring tide of 2015. We applied multivariate analysis to evaluate the potential impact of wave action (sheltered versus wave exposed shores), physical pool structure (length, width, and depth), and relationships within the pool community on the abundance and diversity of amphipods. Wave exposure significantly influenced amphipod abundance and diversity, and some substrata and biodiversity features of the pool were important in explaining the amphipod abundance. The percentage and composition of coverage and physical features of the rock pools had no significant effect on amphipod abundance and diversity. We showed that the amphipod rockpool community displayed a clear positive response of biodiversity and abundance to the extrinsic factor wave action, and a varied and complex response to within-rockpool biotic variables. In addition, we recorded the presence of the invasive Ampithoe valida for the first time on rocky shores of Portugal. Further investigation into the influence that wave action has on associated pool biota (i.e., dislodgment or deposition of species) could give additional insight into the role of the biotic community in the regulation of amphipod populations within intertidal rock pools
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