Browsing by Author "Henriques, Sofia"
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- Biogeographical region and environmental conditions drive functional traits of estuarine fish assemblages worldwidePublication . Henriques, Sofia; Guilhaumon, François; Villéger, Sébastien; Amoroso Ferreira Jorge, Sandra; França, Susana; Pasquaud, Stéphanie; Cabral, Henrique; P Vasconcelos, RitaAssessing trait-environment relationships is crucial for predicting effects of natural and human-induced environmental change on biota. We compiled a global database of fish assemblages in estuaries, functional traits of fishes and ecosystem features of estuaries. And we quantified the relative importance of ecosystem features as drivers of patterns of fish functional traits among estuaries worldwide (i.e. drivers of the proportions of fish traits). In addition to biogeographical context, two main environmental gradients regulate traits patterns: firstly temperature, and secondly estuary size and hydrological connectivity of the estuary with the marine ecosystem. Overall, estuaries in colder regions, with larger areas and with higher hydrological connectivity with the marine ecosystem, have higher proportions of marine fish (versus freshwater), macro-carnivores and planktivores (versus omnivores, herbivores and detritivores) and larger fish, with greater maximum depth of distribution and longer lifespan. The observed trait patterns and trait–environment relationships are likely generated by multiple causal processes linked to physiological constraints due to temperature and salinity, size-dependent biotic interactions, as well as habitat availability and connectivity. Biogeographical context and environmental conditions drive species richness and composition, and present results show that they also drive assemblage traits. The observed trait patterns and trait-environment relationships suggest that assemblage composition is determined by the functional role of species within ecosystems. Conservation strategies should be coordinated globally and ensure protection of an array of estuaries that differ in ecosystem features, even if some of those estuaries do not support high species richness.
- Current limitations of global conservation to protect higher vulnerability and lower resilience fish speciesPublication . P Vasconcelos, Rita; Batista, Marisa Isabel; Henriques, SofiaEstuaries are threatened by intense and continuously increasing human activities. Here we estimated the sensitivity of fish assemblages in a set of estuaries distributed worldwide (based on species vulnerability and resilience), and the exposure to cumulative stressors and coverage by protected areas in and around those estuaries (from marine, estuarine and freshwater ecosystems, due to their connectivity). Vulnerability and resilience of estuarine fish assemblages were not evenly distributed globally and were driven by environmental features. Exposure to pressures and extent of protection were also not evenly distributed worldwide. Assemblages with more vulnerable and less resilient species were associated with estuaries in higher latitudes (in particular Europe), and with higher connectivity with the marine ecosystem, moreover such estuaries were generally under high intensity of pressures but with no concomitant increase in protection. Current conservation schemes pay little attention to species traits, despite their role in maintaining ecosystem functioning and stability. Results emphasize that conservation is weakly related with the global distribution of sensitive fish species in sampled estuaries, and this shortcoming is aggravated by their association with highly pressured locations, which appeals for changes in the global conservation strategy (namely towards estuaries in temperate regions and highly connected with marine ecosystems).
- A framework for the assessment of MPA effectiveness based on life history of fishesPublication . Batista, Marisa Isabel; Henriques, Sofia; Pais, Miguel Pessanha; Cabral, HenriqueChanges in ecosystems structure and function due to the high impacts human pressures on oceans have led to the increasing numbers of Marine Protected Areas (MPA), since MPA are widely accepted as adequate tools to protect, maintain, and restore ocean ecosystems. Increases in density, size and biomass of organisms within protected areas have often been found. However, their worldwide effectiveness is compromised by the interaction of several factors, such as inadequate conduction of processes (e.g. due to political reasons) and the common lack of appropriate scientific datasets to support planning and management decisions. This study proposes a framework for assessing the potential effectiveness of an already implemented MPA and identifying major gaps. The framework is based on three components: species–habitat association, species' life history and functional groups and pressures affecting the MPA. The potential of the MPA to support the lifecycle of fish species was assessed in order to identify effective management actions. The theoretical framework was applied to Arrábida MPA (Portugal) in order to exemplify its practical results. Arrábida MPA showed potential to support the lifecycle of most species, although some key life phases (spawning and nursery) are not efficiently protected by the actual limits/level of protection of the MPA, namely for some of the most important fisheries’ target species. This framework is particularly useful as an alternative or a complementary support to early decisions for MPA management and the identification of priority actions needed to ensure the accomplishment of initial objectives or the suitability of their adaptation. This approach can be implemented in MPA worldwide, although the accuracy of results will be closely related with the quality of input data. The present framework can contribute to improve the effectiveness of global MPA networks and to fulfill international conservation targets, such as OSPAR, Convention for Biological Diversity and European Natura 2000 network.
- Functional diversity in marine fish assemblagesPublication . Henriques, Sofia; Dolbeth, Marina; Matos, Paula; Pecuchet, Laurene; Bernardo, Cristiane Palaretti; Weigel, Benjamin; McLean, Matthew; Hidalgo, Manuel; Tzanatos, Evangelos; Vasconcelos, Rita P.In the last decades, the rising interest in trait-based ecology is closely related to a growing demand for knowledge on ecosystems’ functioning and on mechanisms generating ecological patterns and processes, and with the urgency for approaches that allow to predict the consequences of climate change and anthropogenic impacts (McGill et al., 2006; De Bello et al., 2021a,b). This fundamental knowledge is difficult to obtain when considering specific species (i.e., taxonomic-based ecology), therefore ecologists are increasingly using functional diversity approaches (i.e., trait-based ecology), with the added advantage of allowing the comparison across different ecosystems and biogeographical regions, which due to biogeographical reasons support different species compositions (e.g., Henriques et al., 2017a,b). Functional diversity (FD) refers to the distribution and range of what species do (as determined by their functional traits) in a given ecosystem, influencing how the ecosystem operates or functions (e.g., stability, dynamics, productivity; Tilman, 2001; Petchey and Gaston, 2006). Currently, the most accepted definition of the trait was proposed by Violle and colleagues in which a trait is defined as “any morphological, physiological or phenological feature measurable at the individual level, from the cell to the whole organism” (Violle et al., 2007). For a trait to be considered a functional trait, it needs to influence organismal performance (fitness), meaning its growth, reproduction, and/or survival (McGill et al., 2006; Violle et al., 2007). Additionally, traits can also be related to the effect of organisms on ecosystem properties, or on the other hand, to how they respond to a disturbance or environmental change (Hooper et al., 2005). In this way, traits can be further divided into the following: (1) effect traits, those that significantly affect another trophic level (e.g., predator-prey interactions) and/or an ecosystem process (e.g., nutrient cycling, primary productivity), regardless of whether they affect or not the organismal performance; (2) response traits, those that allow organisms to survive, grow, and reproduce under different disturbances and/or environmental conditions (biotic and abiotic factors; Lavorel and Garnier, 2002).
- Global patterns and predictors of fish species richness in estuariesPublication . P Vasconcelos, Rita; Henriques, Sofia; França, Susana; Pasquaud, Stéphanie; Cardoso, Inês; Laborde, Marina I; Cabral, Henrique1. Knowledge of global patterns of biodiversity and regulating variables is indispensable to develop predictive models. 2. The present study used predictive modelling approaches to investigate hypotheses that explain the variation in fish species richness between estuaries over a worldwide spatial extent. Ultimately, such models will allow assessment of future changes in ecosystem structure and function as a result of environmental changes. 3. A comprehensive worldwide data base was compiled of the fish assemblage composition and environmental characteristics of estuaries. Generalized Linear Models were used to quantify how variation in species richness among estuaries is related to historical events, energy dynamics and ecosystem characteristics, while controlling for sampling effects. 4. At the global extent, species richness differed among marine biogeographic realms and continents and increased with mean sea surface temperature, terrestrial net primary productivity and the stability of connectivity with a marine ecosystem (open vs. temporarily open estuaries). At a smaller extent (within a marine biogeographic realm or continent), other characteristics were also important in predicting variation in species richness, with species richness increasing with estuary area and continental shelf width. 5. The results suggest that species richness in an estuary is defined by predictors that are spatially hierarchical. Over the largest spatial extents, species richness is influenced by the broader distributions and habitat use patterns of marine and freshwater species that can colonize estuaries, which are in turn governed by history contingency, energy dynamics and productivity variables. Species richness is also influenced by more regional and local parameters that can further affect the process of community colonization in an estuary including the connectivity of the estuary with the adjacent marine habitat, and, over smaller spatial extents, the size of these habitats. In summary, patterns of species richness in estuaries across large spatial extents seem to reflect from global to local processes acting on community colonization. The importance of considering spatial extent, sampling effects and of combining history and contemporary environmental characteristics when exploring biodiversity is highlighted.
- Ichthyofauna of the Selvagens Islands. Do small coastal areas show high species richness in the northeastern Atlantic?Publication . Almada, Frederico; Abecasis, David; Villegas-Ríos, David; Henriques, Sofia; Pais, Miguel Pessanha; Batista, Marisa Isabel; Costa, Bárbara Horta e; Martins, Joana; Tojeira, Inês; Rodrigues, Nuno Vasco; Araújo, Ricardo; Souto, Miguel; Alonso, Hany; Falcón, Jesús M.; Henriques, Filipe; Catry, Paulo; Cabral, Henrique; Biscoito, Manuel; Almada, Vitor C.The Selvagens Islands are located in the northeastern Atlantic between the Canary Islands and Madeira Island. As a result of their small size, remote location and harsh sea conditions only a few studies have been conducted to describe their marine species diversity. We were able to identify 29 new coastal fish species, an increase of 33% in the ichthyofauna described for these islands (n = 88). There is a prevalence of species with tropical affinities and only 2.3% (n = 2) are endemic to Macaronesia. Considered a stepping-stone colonization vector from the nearest continental shore, as proposed by other authors for this region, the Selvagens Islands host 34.1% of the ichthyofauna described for the much larger Canary Islands (nspecies = 258, submerged area nSelvagensIs. = 2.3%) and 47.3% of the ichthyofauna described for the more distantly located Madeira Island (nspecies = 186, submerged area nSelvagensIs. = 17.9%). Interestingly, 6.8% (n = 6) of the species failed to bridge the gap between the Selvagens Islands and Madeira Island. Data collected so far showed no trend toward an increasing number of species with high dispersal capability. The Selvagens Islands are an example of a high coastal species diversity occurring even in very small areas of the northeastern Atlantic Ocean.
- Processes underpinning fish species composition patterns in estuarine ecosystems worldwidePublication . Henriques, Sofia; Cardoso, Pedro; Cardoso, Inês; Laborde, Marina I; Cabral, Henrique; P Vasconcelos, RitaAim We present the first global biogeographical regionalization of estuaries, assessing how dispersal limitation and/or environmental filtering mechanisms drive the patterns of fish assemblage composition among and within biogeographical regions. Location Estuaries worldwide. Methods A bootstrapped hierarchical cluster analysis was applied to define biogeographical regions based on pairwise beta diversity (βsim) of fish assemblages among 393 estuaries worldwide. Variables representing dispersal limitation and environmental features were used to disentangle the possible effects of assembly processes acting among and within biogeographical regions, through hierarchical partitioning of variation. Finally, we assessed the contribution of species to beta diversity through a method newly developed in this article. Results Estuaries were grouped into seven major biogeographical regions explained by geographical dispersal variables. Dissimilarity in species composition within each biogeographical region was mainly determined by ecosystem‐connectivity dispersal variables, with a minor influence of environmental variables (chiefly sea surface temperature). Marine species contributed highly to beta diversity between estuaries but less than expected by chance, whilst freshwater species had low contributions yet also less than expected. Estuarine (i.e. brackish) and diadromous species had low contributions to beta diversity but higher than expected by chance. Main conclusions Fish assemblage composition in estuaries seems to be driven by dispersal limitation processes both among and within biogeographical regions, with only a minor role of environmental filtering evident within biogeographical regions. These findings contrast with the acknowledged importance of environmental variables as drivers of species richness patterns. Irrespective of biogeographical region, the ecosystem affinity of a species determined its contribution to beta diversity between estuaries. The new method presented here offers new opportunities for assessing the effects of taxonomic and functional aspects on beta diversity (βsim) across taxa and ecosystems, and thus contributes to improving knowledge of assembly processes.
- A proteção patrimonial nas relações conjugais e paraconjugais : a necessidade de um novo paradigmaPublication . Henriques, Sofia; Sousa, Miguel Teixeira de, 1954-Esta tese faz um estudo analítico da atual proteção patrimonial conferida ao cônjuge e ao unido de facto, visando questionar a necessidade de construção de um novo paradigma em termos patrimoniais. A visão será transversal, abrangendo quer o direito da família, quer o direito sucessório, em Portugal e nos ordenamentos jurídicos estrangeiros mais próximos do nosso. Após a análise da estrutura das situações jurídico-familiares de comunhão plena de vida, quando projetadas para a constituição de uma família, entendida esta como a concretização de um projeto de vida em comum – em especial as relações conjugais e paraconjugais, aborda-se a proteção patrimonial atribuída a cada tipo de relacionamento, em vida do casal (quer durante a vigência do relacionamento, quer após a sua rutura), para posteriormente se debruçar sobre a proteção patrimonial pós-morte em cada tipo de relacionamento. Analisada a problemática da cristalização da autonomia da vontade durante o relacionamento, e após concluir pela crise do atual paradigma da proteção patrimonial nas relações conjugais e paraconjugais e apurada a urgência da sua superação, ensaia-se uma nova conceção patrimonial da família, através da construção de um novo paradigma de regulação. O principal objetivo da presente tese é determinar qual a relevância que a autonomia da vontade deverá ter neste campo versus o nível de interferência legislativa. Efetivamente, o nosso legislador regula, cada vez mais de forma imperativa, as diferentes vertentes que pode assumir um relacionamento, com a justificação da proteção do membro mais fraco do relacionamento, apesar de se tratar de uma área com uma grande vertente afetiva. Analisaremos os atuais limites à autonomia da vontade em sede de regime patrimonial da família, em especial nos regimes de bens, no estatuto patrimonial primário e na proteção patrimonial conferida ao unido de facto, passando pela crise dos relacionamentos, aí refletindo sobre as consequências patrimoniais do divórcio e da rutura da união de facto, bem como os limites à expressão da vontade na sucessão. Como novo paradigma, quanto ao casamento, defende-se a separação de bens como regime supletivo e a abolição do princípio da imutabilidade, permitindo-se a alteração do regime de bens na vigência do casamento; quanto ao regime patrimonial primário, consideramos que o mesmo deve perder a sua injuntividade, permitindo-se aos cônjuges a construção do regime patrimonial que regerá os seus bens, sempre com a proteção dos direitos de terceiros. Em caso de rutura, advogamos a possibilidade dos cônjuges definirem os efeitos patrimoniais do divórcio por acordo; em caso de desacordo, a culpa deverá ser apreciada exclusivamente para efeitos patrimoniais, onde deverá ter reflexos. Por morte, exclui-se o cônjuge de herdeiro legitimário, mas assegurando-lhe sempre a proteção da casa de morada de família e do respetivo recheio e a posição de herdeiro legítimo; defende-se a bondade dos pactos renunciativos entre os cônjuges. Em suma, o novo paradigma assenta numa flexibilização do casamento, com uma ampliação da autonomia privada a todas as matérias que não ponham em causa os interesses dos cônjuges e de terceiros. No que toca à união de facto, consideramos desnecessária a sua tutela de forma injuntiva. Os interessados deverão ter a liberdade de se excluírem da aplicação dos efeitos patrimoniais resultantes da união de facto, quando assim o entendam, por ato autêntico. Em caso de rutura e em caso de morte, a proteção a assegurar deve ser mínima e supletiva, podendo ser afastada pelo autor da sucessão. No que respeita à casa de morada de família e respetivo recheio, deverão ser tidas em conta as necessidades do unido de facto sobrevivo. Sempre que existam descendentes do falecido, deverá o legislador ter especial cautela, e assegurar a melhor forma de dirimir esse conflito de interesses.
- Worldwide patterns of fish biodiversity in estuaries: Effect of global vs. local factorsPublication . Pasquaud, Stéphanie; P Vasconcelos, Rita; França, Susana; Henriques, Sofia; Costa, Maria José; Cabral, HenriqueThe main ecological patterns and the functioning of estuarine ecosystems are difficult to evaluate due to natural and human induced complexity and variability. Broad geographical approaches appear particularly useful. This study tested, at a worldwide scale, the influence of global and local variables in fish species richness in estuaries, aiming to determine the latitudinal pattern of species richness, and patterns which could be driven by local features such as estuary area, estuary mouth width, river flow and intertidal area. Seventy one estuarine systems were considered with data obtained from the literature and geographical information system. Correlation tests and generalized linear models (GLM) were used in data analyses. Species richness varied from 23 to 153 fish species. GLM results showed that estuary area was the most important factor explaining species richness, followed by latitude and mouth width. Species richness increased towards the equator, and higher values were found in larger estuaries and with a wide mouth. All these trends showed a high variability. A larger estuary area probably reflects a higher diversity of habitats and/or productivity, which are key features for estuarine ecosystem functioning and biota. The mouth width effect is particularly notorious for marine and diadromous fish species, enhancing connectivity between marine and freshwater realms. The effects of river flow and intertidal area on the fish species richness appear to be less evident. These two factors may have a marked influence in the trophic structure of fish assemblages.