Publications by authors named "Irene Martins"

With the growing interest to exploit mineral resources in the deep-sea, there is the need to establish guidelines and frameworks to support hazard and risk assessment schemes. The present study used a subtidal species of filter-feeding bivalve, the clam Spisula solida, as a proxy to better understand the impacts of sediment plumes in marine organisms under hyperbaric conditions. Four concentrations of suspended sediments (0 g/L, 1 g/L, 2 g/L, and 4 g/L) were used in a mixture with different grain sizes at 4 Bar for 96 h.

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The present study aimed to determine the allometric scaling among a selection of morphological traits in European sea bass (Dicentrarchus labrax) to estimate fish body weight. A set of morphological traits (fish body weight, length, height, and width) were directly measured in 146 fish of a recirculating aquaculture system, with body weights ranging from 17.11 to 652.

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Industrial deep-sea mining will release plumes containing metals that may disperse over long distances; however, there is no general understanding of metal effects on marine ecosystems. Thus, we conducted a systematic review in search of models of metal effects on aquatic biota with the future perspective to support Environmental Risk Assessment (ERA) of deep-sea mining. According to results, the use of models to study metal effects is strongly biased towards freshwater species (83% freshwater versus 14% marine); Cu, Hg, Al, Ni, Pb, Cd and Zn are the best-studied metals, and most studies target few species rather than entire food webs.

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Although most deep-sea areas are remote in comparison to coastal zones, a growing body of literature indicates that many sensitive ecosystems could be under increased stress from anthropogenic sources. Among the multiple potential stressors, microplastics (MPs), pharmaceuticals and personal care products (PPCPs/PCPs) and the imminent start of commercial deep-sea mining have received increased attention. Here we review recent literature on these emerging stressors in deep-sea environments and discuss cumulative effects with climate change associated variables.

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Despite the increasing awareness of climate change, few studies have used the Intergovernmental Panel on Climate Change (IPCC) scenarios to simulate the effects of climate change on estuarine populations of crustaceans. The objective of this study was to investigate the effects of temperature and salinity fluctuations on the population dynamics of the shore crab Carcinus maenas at the southern edge of its native range. To this end, a population dynamics model was developed based on experimental and literature data on the biology, ecology and physiology of the species.

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Due to non-linear interactions, the effects of contaminant mixtures on aquatic ecosystems are difficult to assess, especially under temperature rise that will likely exacerbate the complexity of the responses. Yet, under the current climatic crisis, assessing the effects of water contaminants and temperature is paramount to understanding the biological impacts of mixtures of stressors on aquatic ecosystems. Here, we use an ecosystem model followed by global sensitivity analysis (GSA) to prioritize the effects of four single emerging contaminants (ECs) and their mixture, combined with two temperature rise scenarios, on the biomass production of a NE Atlantic estuary.

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Fifty four Trichoderma strains were isolated from soil samples collected from garlic and onion crops in eight different sites in Brazil and were identified using phylogenetic analysis based on combined ITS region, tef1-α, cal, act and rpb2 sequences. The genetic variability of the recovered Trichoderma species was analysed by AFLP and their phenotypic variability determined using MALDI-TOF. The strain clusters from both typing techniques coincided with the taxonomic determinations made from phylogenetic analysis.

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Here we summarize the overarching issues that emerged from a workshop held to discuss scientific challenges and future directions on the use of numerical models to predict the amount, distribution and effects of plastic pollution on marine ecosystems. The need for multi-disciplinary approaches, standardized protocols for plastic quantification and analyses, using realistic contaminant concentrations in laboratorial experiments and targeting early-life stages of marine organisms were pointed out as needs to improve data accuracy. Participants also enumerated a list of gaps that include, identification of indicator organisms of plastic contamination, selection of biomarkers and the role of extreme events on plastic dynamics.

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Floating marine litter is known to be currently a widespread pollution problem, especially in the Mediterranean basin, but records on the levels of floating debris in the eastern part are less known. By using an observation platform (32 days, 137 transects, 1784 km), this study provides evidence of a high amount of floating debris in the Levantine sub-basin, within the eastern Mediterranean Sea. The density of floating litter varied between 18 and 1593 items km (average 232 ± 325 items km), and small plastic debris accounted for >90% of the items surveyed.

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Deep-sea mining has gained international interest to provide materials for the worldwide industry. European oceans and, particularly, the Portuguese Exclusive Economic Zone present a recognized number of areas with polymetallic sulphides rich in metals used in high technology developments. A large part of these resources are in the vicinity of sensitive ecosystems, where the mineral extraction can potentially damage deep-ocean life services.

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A population dynamics model was developed to assess the short and long-term effects of temperature and salinity variations in the common goby Pomatoschistus microps in a Portuguese estuary (Minho estuary, NW Portugal). The population was divided into juveniles, females and males, which constituted the model's state variables. Linear regressions between the observed and the predicted density of juveniles, females and the total population were significant.

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In situ assays based on feeding depression can be powerful ecotoxicological tools that can link physiological organism-level responses to population and/or community-level effects. Amphipods are traditional target species for toxicity tests due to their high sensitivity to contaminants, availability in the field and ease of handling. However, cost-effective in situ assays based on feeding depression are not yet available for amphipods that inhabit estuarine ecosystems.

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A population agent-based model of marine amphipod Gammarus locusta was designed and implemented as a basis for ecological risk assessment of chemical pollutants impairing life-history traits at the individual level. We further used the model to assess the toxic effects of aniline (a priority hazardous and noxious substance, HNS) on amphipod populations using empirically-built dose-response functions derived from a chronic bioassay that we previously performed with this species. We observed a significant toxicant-induced mortality and adverse effects in reproductive performance (reduction of newborn production) in G.

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Simvastatin (SIM), a hypocholesterolaemic drug, is among the most widely used pharmaceuticals worldwide and is therefore of emerging environmental concern. Despite the ubiquitous nature of SIM in the aquatic ecosystems, significant uncertainties exist about sublethal effects of the drug in aquatic organisms. Therefore, here we aimed at investigating a multi-level biological response in the model amphipod Gammarus locusta, following chronic exposures to low levels of SIM (64 ng/L to 8 μg/L).

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Understanding the environmental parameters that constrain the distribution of a species at its latitudinal extremes is critical for predicting how ecosystems react to climate change. Our first aim was to predict the variation in the amphipod populations of Echinogammarus marinus from the southernmost limit of its distribution under global warming scenarios. Our second aim was to test whether sex-ratio fluctuations - a mechanism frequently displayed by amphipods - respond to the variations in populations under altered climate conditions.

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The substantial negative impact of some parameters on the germination of low-quality conidia (high proportion of slow-germinating propagules) was demonstrated, whereas for high-quality batches their effect was small or even absent. Germination was increased as the initial hydration status of conidia immediately prior to suspension preparation was increased, being ca. 33% and 80% for dehydrated Metarhizium anisopliae propagules (water activity ≤0.

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The occurrence of intersexuality in populations of the marine amphipod Echinogammarus marinus has been related to several causes, including anthropogenic contamination, microsporidian parasites and environmental sex determination (ESD). At the individual-level, the costs of intersexuality in E. marinus are reflected in reduced reproductive output of intersexes compared to normal specimens.

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A model describing macroalgal early life stages and adult dynamics was used to quantify the effects of non-adult forms on the productivity of adult macroalgae in a eutrophic estuary. Predictions indicate that during years with mild winters and low rainfall, spring blooms will occur at the expense of the growth and reproduction of overwintering adults and without the contribution of the spore bank. In these circumstances, there is a positive correlation between the intensity of the blooms and the biomass of overwintering adults until a maximum threshold value.

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A spatially dynamic model for the productivity of spores and adults of green macroalgae (Enteromorpha sp.) was developed for a mesotidal estuary (Mondego estuary, Portugal). Many of the algal processes and parameters included in the model were experimentally obtained.

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Whilst there have been many studies indicating links between anthropogenic contaminants and reproductive abnormalities in wildlife, very few studies have addressed the effects that might be occurring at the population level. In this study we aimed to assess the mid and long-term population effects of different levels of intersexuality in an amphipod species, Echinogammarus marinus. This aim was achieved by modelling the dynamics of a population of E.

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Improved understanding of the importance of different surfaces in supporting attached nitrifying and denitrifying bacteria is essential if we are to optimize the N removal capacity of treatment wetlands. The aim of this study was therefore to examine the nitrifying and denitrifying capacity of different surfaces in a constructed treatment wetland and to assess the relative importance of these surfaces for overall N removal in the wetland. Intact sediment cores, old pine and spruce twigs, shoots of Eurasian watermilfoil (Myriophyllum spicatum L.

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