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- Impacto da ETAR de Faro-Noroeste nas comunidades bentónicas da Ria FormosaPublication . Piló, David; Chícharo, Luís; Chícharo, AlexandraCom o presente trabalho pretendeu-se avaliar o impacto da ETAR de Faro Noreste nas estrutura das comunidades macro e meiobentónicas da Ria Formosa. A amostragem decorreu ao longo do ano de 2006, caracterizando-se o local nas várias estações do ano. As estações de amostragem foram estabelecidas a diferentes distâncias do ponto de descarga de onde se recolheram dados dos parâmetros da água e amostras de sedimento para o estudo da macro e meiofauna bentónica. Os resultados evidenciaram que os efluentes da ETAR impõem um forte impacto na estrutura das comunidades bentónicas mais próximas, essencialmente devido à alteração brusca dos valores de salinidade e ao enriquecimento orgânico que podem provocar períodos de insuficiência na disponibilidade de oxigénio dissolvido. Estes, foram os factores estruturantes das comunidades, tendo sido responsáveis pela baixa diversidade observada perto do ponto de descarga, onde apenas alguns taxa como os nemátodes, as poliquetas da família Nereidae e os bivalves Scrobicularia plana na prevalecem. Estes organismos oportunistas beneficiam de uma grande capacidade de adaptação a estes ambientes , ocorrendo em grandes abundâncias, desempenhando um papel ecológico fundamental nestas zonas afectadas. O efeito dos efluentes foi-se atenuando com o aumento da distância à ETAR, onde a maior circulação e renovação da água terá eliminado o efeito das suas descargas, verificando-se uma maior diversidade de taxa sugerindo um ambiente não impactado. Temporalmente não ocorreram diferenças significativas na estrutura das comunidades bentónicas, com excepção de algumas situações consideradas pontuais. A continuidade do estudo é necessária de modo a poder avaliar mais correctamente a componente temporal e minimizar os erros registados em alguns dos métodos de avaliação utilizados.
- Seawater acidification by CO2 in a coastal lagoon environment: Effects on life history traits of juvenile mussels Mytilus galloprovincialisPublication . Range, Pedro; Piló, David; Ben-Hamadou, Radhouan; Chicharo, Maria Alexandra Teodosio; Matias, Domitília; Joaquim, Sandra; Oliveira, A. P.; Chícharo, LuísThe carbonate chemistry of seawater from the Ria Formosa lagoon was experimentally manipulated, by diffusing pure CO2, to attain two reduced pH levels, by−0.3 and−0.6 pH units, relative to unmanipulated seawater. After 84 days of exposure, no differences were detected in terms of growth (somatic or shell) or mortality of juvenile mussels Mytilus galloprovincialis. The naturally elevated total alkalinity of the seawater (≈3550 μmol kg−1)prevented under-saturation of CaCO3, evenunder pCO2 values exceeding 4000 μatm, attenuating the detrimental effects on the carbonate supply-side. Even so, variations in shell weight showed that net calcification was reduced under elevated CO2 and reduced pH, although the magnitude and significance of this effect varied among size-classes. Most of the loss of shell material probably occurred as post-deposition dissolution in the internal aragonitic nacre layer. Our results show that, even when reared under extreme levels of CO2-induced acidification, juvenileM. galloprovincialis can continue to calcify and grow in this coastal lagoon environment. The complex responses of bivalves to ocean acidification suggest a large degree of interspecific and intraspecific variability in their sensitivity to this type of perturbation. Further research is needed to assess the generality of these patterns and to disentangle the relative contributions of acclimation to local variations in seawater chemistry and genetic adaptation.
- Tanaidaceans (Crustacea: Peracarida: Apseudidae) from southern Portugal with description of the new species Apseudopsis formosus, report of five first records and a biogeographic overview: unexpected expansion or understudied hotspot?Publication . Carvalho, Andre N.; Pereira, Fabio; Piló, David; Gaspar, Miguel; Esquete, PatriciaThis study describes Apseudopsis formosus sp. nov., a new apseudomorph tanaidacean species from the Ria Formosa lagoon (southern Portugal). Species description was based on 223 individuals (22 juveniles, 60 males and 141 females), comprising diverse developmental stages (juveniles II, males I and II, preparatory, copulatory and intermediate females). The total length of the studied population ranged from 2.2 to 3.0 mm in juveniles, 2.5 to 4.8 mm in males and 2.9 to 4.9 mm in females. Overall, Apseudopsis formosus sp. nov. differs from congeneric tanaidaceans from the Atlantic Ocean and Mediterranean Sea by the presence of combined different morphological characters such as short pointed rostrum, posterolateral pointed corners on pereonites 2-6, hyposphenium only on pereonite 6, antennular outer flagellum 7- to 10-segmented, inner flagellum 3-segmented and five spines on propodus of pereopod 1, and sexual dimorphism evidenced by a pronounced mid-dorsal triangular wing-shaped protuberance on male merus cheliped, unique in Apseudopsis genus. At each studied developmental stage, some individuals presented abnormalities in spination, having only four spines in one of the propodus of pereopod 1. Additionally, five first records of Apseudopsis from the Algarve coast (A. adami, A. bacescui, A. elisae, A. mediterraneus and A. uncidigitatus) are reported for Portuguese waters. A biogeographic overview of the genus Apseudopsis is presented through the compilation and mapping of all worldwide reported occurrences. Passive dispersion can explain the most recent species distribution, yet not disregarding that the study area is taxonomically understudied. This study contributes to improve the current knowledge on tanaidacean taxonomy and updates the geographical distribution range of the Apseudopsis-complex.
- Evaluation of macrobenthic community responses to dredging through a multimetric approach: Effective or apparent recovery?Publication . Piló, David; Carvalho, A. N.; Pereira, F.; Coelho, H. E.; Gaspar, MiguelMacrobenthic responses to dredging activities were evaluated in a mesotidal coastal lagoon (Ria Formosa South Portugal). Four areas (2 dredged and 2 non-dredged) were analysed along different dredging situations (pre-dredging, during dredge 1, during dredge 2 and post-dredging). Beyond the evaluation of sediment descriptors and classical ecological indicators (number of species and abundance), the beta diversity component (partitioned into turnover and nestedness) was used to detect dredging effects on macrobenthic communities, together with a multivariate analysis (both quantitative and qualitative) including the ecological status assessment. Results confirmed the limitations of alpha diversity indicators in detecting dredging effects in naturally stressed systems, given the absence of clear patterns regarding number of species, abundance and equitability among areas and dredging situations. Moreover, post-dredging presented a higher number of species compared to pre-dredging, suggesting a positive disequilibrium induced by these activities. In contrast, partitioned beta diversity analysis revealed higher nestedness values at dredged areas, while turnover clearly prevailed at non-dredged ones. Such results suggest an effective impact of dredging on these communities, namely through the decrease of rarer species after sediment removal. This qualitative analysis, based on presence absence data (Sorensen dissimilarity), was complemented by multivariate analysis (SIMPER and PERMANOVA) based on quantitative data (Bray-Curtis dissimilarity), highlighting the importance of adopting both approaches to detect dredging impacts on benthic communities. Lower effectiveness was found for M-AMBI index when evaluating benthic Ecological Status, since the apparent absence of organic matter and sediment composition shifts induced by dredging, together with the noticeable high diversity even during dredging situations, strongly limited the analysis. The multimetric approach here proposed can contribute to detect dredging effects on lagoonal benthic communities by disentangling the responses caused by dredging from those resulting from the system natural dynamics.
- Application and demonstration of the ecohydrology approach for the sustainable functioning of the Guadiana estuary (South Portugal)Publication . Chícharo, Luís; Ben-Hamadou, Radhouan; Araújo Amaral, Ana Margarida; Range, Pedro; Mateus, Carmen; Piló, David; Marques, Rute; Morais, P.; Teodosio, MariaThe implementation of the UNESCO demosite at the Guadiana estuary represents an excellent opportunity to demonstrate how to adapt, mitigate and restore functioning of estuaries and coastal areas impacted by dams and climatic changes, using the Ecohydrology approach. Worldwide estuaries are suffering similar anthropogenic impacts that affect ecosystem functioning, biodiversity and resources. Therefore, the mesocosms experiments at the Guadiana Ecohydrology demosite constitute a collection of case studies, whose results can be used for testing solutions for the sustainable management of other estuarine systems. We applied the Ecohydrology concepts and methods to test: a) the usefulness of freshwater inflow pulses to regulate biodiversity and to control microalgal blooms , by regulating nutrient ratios and thus enhancing the bottom-up control of water quality; b) the usefulness of using the feeding ability of bivalve assemblages to control microalgal blooms (top-down control of water quality, and; c) the role of salt marsh plants (Salicornia ramosissima) to reduce excessive concentrations of nutrients and control estuarine water quality. Results show that the interplay between organisms (bivalves, plants) and hydrological factors is a key for improving water quality and sustaining biodiversity and the good ecological status of this estuarine ecosystem.
- Is metal contamination responsible for increasing aneuploidy levels in the Manila clam Ruditapes philippinarum?Publication . Piló, David; Carvalho, S.; Pereira, P.; Gaspar, Miguel; Leitao, A.The present study assessed the metal genotoxicity potential at chromosome-level in the bivalve Ruditapes philippinarum collected along different areas of the Tagus estuary. Higher levels of aneuploidy on gill cells were detected at the most sediment contaminated area both in May (31.7%) and October (36.0%) when compared to a less contaminated area over the same periods (203% and 29.0% respectively). Interestingly, metal bioaccumulation in gills was higher in the specimens collected at the least contaminated area with the exception of Pb. Indeed, the multivariate analysis revealed a stronger relation between aneuploidy and sediment contamination than between aneuploidy and the bioaccumulation of the metals. The temporal and spatial inconsistency found for the bioaccumulation of metals in It philippinarum and the positive correlation between sediment contamination and aneuploidy at the most contaminated area suggest that these chromosome-level effects might be due to chronic metal contamination occurring in the Tagus estuary, rather than a direct result of the temporal variation of bioavailable contaminants. The vertical transmission phenomenon of bivalve aneuploidy levels may then be perpetuating those levels on clams from the most contaminated area. The present results shed light about the effect of metal toxicity at the chromosome-level in species inhabiting chronic contaminated areas and highlight the use of aneuploidy as an effective tool to identify persistent contamination in worldwide transitional waters. (C) 2016 Elsevier B.V. All rights reserved.
- Relative sensitivity of soft-bottom intertidal macrofauna to increased CO2 and experimental stressPublication . Range, Pedro; Martins, M.; Cabral, Sara; Piló, David; Ben-Hamadou, Radhouan; Chicharo, Maria Alexandra Teodosio; Miguel de Sousa Leitão, Francisco; Drago, T.; Oliveira, A. P.; Matias, D.; Chícharo, LuísWe used a controlled CO2 perturbation experiment to test hypotheses about changes in diversity, composition and structure of soft-bottom intertidal macrobenthic assemblages, under realistic and locally relevant scenarios of seawater acidification. Patches of undisturbed sediment were collected from 2 types of intertidal sedimentary habitat in the Ria Formosa coastal lagoon (South Portugal) and exposed to 2 levels of seawater acidification (pH reduced by 0.3 and 0.6 units) and 1 unmanipulated (control) level. After 75 d the assemblages differed significantly between the 2 types of sediment and between field controls and the ex situ treatments, but not among the 3 pH levels tested. The naturally high values of total alkalinity buffered seawater from the changes imposed on carbonate chemistry and may have contributed to offsetting acidification at the local scale. Observed differences on biota were strongly related to the organic matter content and grain-size of the sediments, particularly to the fractions of medium and coarse sand. Soft-bottom intertidal macrofauna was significantly affected by the stress of being held in an artificial environment, but not by CO2-induced seawater acidification. Given the previously observed variations in the sensitivities of marine organisms to seawater acidification, direct extrapolations of the present findings to different regions or other types of assemblages do not seem advisable. However, the contribution of ex situ studies to the assessment of ecosystem-level responses to environmental disturbances could generally be improved by incorporating adequate field controls in the experimental design.
- How functional traits of estuarine macrobenthic assemblages respond to metal contamination?Publication . Piló, David; Ben-Hamadou, Radhouan; Pereira, F.; Carrico, A.; Pereira, P.; Corzo, A.; Gaspar, Miguel; Carvalho, S.The effects of metal contamination on estuarine macrobenthic communities were investigated using the Biological Traits Analysis (BTA). The study was carried out in the Tagus estuary (western Portugal). Samples of macrobenthic communities and associated environmental variables were taken in four surveys (September 2012, and February, May and October 2013) across the contamination gradient from three main zones: a slightly contaminated, a moderately contaminated and a highly contaminated zone. Functional traits for the most abundant species were assigned using seven categories based on "Feeding mode", "Life span", "Body size", "Motility", "Position in sediments", "Larval type" and "AMBI ecological group". To investigate whether the macroinvertebrate community structure was associated with the environmental parameters and biological traits an integrative multivariate analysis, combining the RLQ analysis and the fourth-corner method, was applied. Within this analysis, human-induced estuarine variables (metals) were rendered independent from natural ones (sediment fine particles) through partial correlations. Following this approach, it was possible to decouple the effects of two typically highly correlated environmental descriptors with different origins. Overall, the study identified significant relationships between sediment environmental descriptors and the functional traits of macrobenthic communities. Further, RLQ/Fourth-corner combined analysis successfully isolated the traits and corresponding species that were most correlated with the measured concentration of trace metals in sediments, supporting the knowledge that benthic organisms exhibit distinct responses to different levels of disturbance. A shift in species dominance occurred along the contamination gradient with epifaunal tolerant species with very small size, long life span, and crawling motility dominating the highest contaminated area. This area was also related with surface deposit-feeder species. The most representative species associated with this area was the gastropod Peringia ulvae. Less contaminated sites revealed large-sized specimens, carnivores and swimmers, mainly represented by the polychaete Nephtys hombergii. This finding is consistent with other studies addressing different kinds of disturbance, where a shift in dominance from carnivore/predators, long-lived and large animals to the predominance of small-size, short-lived and deposit-feeders has been observed across increasing gradients of disturbance. Our results reinforce the importance of macrobenthic functional traits analysis to assess human disturbances driven impacts in multi-stressed estuarine ecosystems. By analysing the environmental variables with different origins independently, we were able to draw conclusions about the effects of human pressures (metals) on macrobenthic traits. Such distinction can be particularly useful to isolate different environmental descriptors and assess their effects on functional diversity, making the current approach promising in evaluation the ecological effects of anthropogenic stressors in estuarine areas. (C) 2016 Elsevier Ltd. All rights reserved.
- Seawater acidification by CO2 in a coastal lagoon environment: Effects on life history traits of juvenile mussels Mytilus galloprovincialisPublication . Ben-Hamadou, Radhouan; Range, Pedro; Piló, DavidThe carbonate chemistry of seawater fromthe Ria Formosa lagoon was experimentallymanipulated, by diffusing pure CO2, to attain two reduced pH levels, by−0.3 and−0.6 pH units, relative to unmanipulated seawater. After 84 days of exposure, no differences were detected in terms of growth (somatic or shell) or mortality of juvenile mussels Mytilus galloprovincialis. The naturally elevated total alkalinity of the seawater (≈3550 μmol kg−1) prevented under-saturation of CaCO3, evenunder pCO2 values exceeding 4000 μatm, attenuating the detrimental effects on the carbonate supply-side. Even so, variations in shell weight showed that net calcification was reduced under elevated CO2 and reduced pH, although the magnitude and significance of this effect varied among size-classes. Most of the loss of shell material probably occurred as post-deposition dissolution in the internal aragonitic nacre layer. Our results show that, even when reared under extreme levels of CO2- induced acidification, juvenileM. galloprovincialis can continue to calcify and grow in this coastal lagoon environment. The complex responses of bivalves to ocean acidification suggest a large degree of interspecific and intraspecific variability in their sensitivity to this type of perturbation. Further research is needed to assess the generality of these patterns and to disentangle the relative contributions of acclimation to local variations in seawater chemistry and genetic adaptation.
- Impacts of CO2-induced seawater acidification on coastal Mediterranean bivalves and interactions with other climatic stressorsPublication . Range, Pedro; Chicharo, Maria Alexandra Teodosio; Ben-Hamadou, Radhouan; Piló, David; Fernandez-Reiriz, M. J.; Labarta, U.; Marin, María Gabriella; Bressan, M.; Matozzo, V.; Chinellato, A.; Munari, M.; El Menif, N. T.; Dellali, M.; Chícharo, LuísThe effects of seawater acidification caused by increasing concentrations of atmospheric carbon dioxide (CO2), combined with other climatic stressors, were studied on 3 coastal Mediterranean bivalve species: the mussel Mytilus galloprovincialis and the clams Chamelea gallina and Ruditapes decussatus. CO2 perturbation experiments produced contrasting responses on growth and calcification of juvenile shells, according to species and location. In the Northern Adriatic (Italy), long-term exposure to reduced pH severely damaged the shells of M. galloprovincialis and C. gallina and reduced growth for the latter species. Seawater in the Ria Formosa lagoon (Portugal) was consistently saturated in carbonates, which buffered the impacts on calcification and growth. After 80 days, no shell damage was observed in Portugal, but mussels in the acidified treatments were less calcified. Reduced clearance, ingestion and respiration rates and increased ammonia excretion were observed for R. decussatus under reduced pH. Clearance rates of juvenile mussels were significantly reduced by acidification in Italy, but not in Portugal. Both locations showed a consistent trend for increased ammonia excretion with decreasing pH, uggesting increased protein catabolism. Respiratory rates were generally not affected. Short-term factorial experiments done in Italy revealed that acidification caused alterations in immunological parameters of adult bivalves, particularly at temperature and salinity values far from the optimal for the species in the Mediterranean. Overall, our results showed large variations in the sensitivities of bivalves to climatic changes, among different species and between local populations of the same species. Expectations of impacts, mitigation and adaptation strategies have to consider such local variability.
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