Ciências da Vida | Artigos em revistas internacionais / Papers in international journals
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Browsing Ciências da Vida | Artigos em revistas internacionais / Papers in international journals by Sustainable Development Goals (SDG) "14:Proteger a Vida Marinha"
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- Adaptive-participative sustainability indicators in marine protected areas: designPublication . Marques, A. S.; Ramos, Tomás B.; Caeiro, Sandra; Costa, Maria HelenaRecently there has been an effort to put in practice integrated management plans in Marine Protected Areas (MPA) not only because of their high natural and cultural importance but also due to usual conflicts related to local activities. These plans should include the use of adaptive sustainability indicators that reflect stakeholders concerns, and community interests, allowing a better assessment, management and reporting. An adequate set of indicators for the MPA should help their managers to improve management policies in order to achieve better decision making processes. This study aimed to develop a set of adaptive-participative sustainability indicators (SDI) for the assessment, management and reporting of MPAs that include, through the all process, the participation of local stakeholders at every levels, integrating the stakeholders knowledge and perceptions about the SDI meaning and a self-assessment of the SDI state produced also by the stakeholders. The proposed approach was tested in Luiz Saldanha’s Marine Park, located in South East of Portugal between the municipalities of Sesimbra and Setúbal. The framework to design the SDI comprised four phases: i) an international analysis of SDI sets for coastal zones and MPAs; ii) a participatory process, where the stakeholders had the possibility to state their concerns through an online and face to face questionnaire surveys about the strengths and weaknesses of the MPA; iii) an analysis conducted by a team of experts to reach a set of indicators that include the main relevant aspects of environmental, socioeconomic, and governance issues, taking into account the information from the first two phases and iv) a workshop and questionnaires held to assess the stakeholders’ global views and perception about the selected set of indicators and each indicator’s relative importance. This study showed the importance of a dynamic participative process involving the local stakeholders. It is concluded that this methodology allows a better understanding of each indicator by the local stakeholders and how it could respond to their concerns. It should also help the MPA managers, to define the most suitable management actions and monitor the management plan itself.
- Assessing heavy metal contamination in Sado EstuaryPublication . Caeiro, Sandra; Costa, Maria Helena; Ramos, Tomás B.; Fernandes, F.; Silveira, N.; Coimbra, Ana Paula; Medeiros, G.; Painho, MarcoThe Sado Estuary in Portugal is a good example of a site where human pressures and ecological values collide with each other. An overall contamination assessment has never been conducted in a way that is comprehensible to estuary managers. One of the aims of this work was to select different types of index to aggregate and assess heavy metal contamination in the Sado Estuary in an accessible manner. Another aim was to use interpolation surfaces per metal to compare and gauge the results of the indices and to assess the contamination separately per metal. Seventy-eight stations were sampled within the main bay of the estuary and a set of heavy metals and metalloids was established, Cd, Cu, Pb, Cr, Hg, Al, Zn and As. The sediment fine fraction content, organic matter and redox potential were also analysed. Various indices for contamination, background enrichment and ecological risk were used, tested, compared and performance-evaluated. All metals and metalloids were strongly correlated, and the indices appear to reflect heavy metal variability satisfactorily. Difficulties were found in some indices regarding boundary definition (minimum and maximum) and comparability with other estuaries, thus better methods of standardization should be a priority issue. According to the index that has the highest performance score within the group of ecological risk indices – the Sediment Quality Guideline Quotient – only 3% of the stations are highly contaminated and register a high potential for observing adverse biological effects, whereas 47% display moderate contamination. This index can be complemented with the contamination index, which allows more site-specific and accurate information on contaminant levels. If the aim of work on contamination evaluation is to assess the overall contamination of a study area, the indices are highly appropriate. For spatial and source evaluation per metal, interpolation surfaces should also be used.
- Bacterioplankton dynamics in the Mondego estuary (Portugal)Publication . Nicolau, Paula Bacelar; Nicolau, Leonor Bacelar; Marques, J. C.; Morgado, Fernando; Azeiteiro, UlissesIn this work, the density of bacterioplankton and environmental parameters were monitored over a 11 month period (July 1999-June 2000), and also during one tidal cycle (15 June 2000), at two sampling stations, in the estuary of River Mondego. These data were treated by multivariate analyses methods in order to identify the key factors that control the dynamics of the bacterioplankton in the estuary. Bacterial dynamics were dominated by temporal gradients (annual seasons and tide-related) and less by the spatial structure of the estuary. Three main metabolic groups of bacterioplankton—aerobic heterotrophic bacteria, sulphate-reducing bacteria (SRB) and nitrate-reducing bacteria (NRB)—involved in the cycling of organic matter, were present in the water column of the estuary.Their relative abundance depended on the particular physical, chemical and biological environment. The abundance of aerobic heterotrophic bacteria, during the 11 month study, was modelled as a function of nitrate (the most important variable, with a negative effect), temperature, salinity and pH (with positive effects). SRB appeared to be limited to the water-sediment interface, where concentrations of sulphate and POM were greater.A competition between SRB and NRB for carbon has also been suggested.
- Benthic biotope index for classifying habitats in the sado estuary: PortugalPublication . Caeiro, Sandra; Costa, Maria Helena; Goovaerts, Peter; Marco, Painho; Flavio, MartinsAn integration of sediment physical, chemical, biological, and toxicity data is necessary for a meaningful interpretation of the complex sediment conditions in the marine environment. Assessment of benthic community is a vital component for that interpretation, yet their evaluation is complex and requires a large expenditure of time and funds. Thus, there is a need for new tools that are less expensive and more understandable for managers. This paper presents a benthic biotope index to predict from physical and chemical variables the occurrence of macrobenthic habitats. Parameters such as sediment type, organic matter, depth, and hydrodynamic parameters were selected, through a discriminant analysis, to compute the index. Other authors have used multivariate methods to determine the benthic biotopes for Sado Estuary. The index proved to be a valid tool to classify and assess the spatial patterns of benthic habitat and to synthesize stress biotope gradients.
- Composition and trophic structure of zooplankton in a shallow temperate estuary (Mondego estuary, western Portugal)Publication . Morgado, Fernando; Quintaneiro, Carla; Rodrigues, Elsa; Pastorinho, Ramiro; Nicolau, Paula Bacelar; Vieira, Luís; Azeiteiro, UlissesThe south arm of Mondego Estuary, western Portugal is characterized by shallow depths and marked longitudinal spatial gradients, namely the tidally induced salinity gradient and an eutrophication gradient. The aims of this work were to study the zooplankton composition and trophic structure of the 335 μm taxocenosis in 2 different locations of the salinity and eutrophication gradients in the south arm. The 2 sampling stations displayed significantly different patterns of temporal variations in environmental variables. The total zooplankton density at each station showed significant spatial and temporal variabilities. However, the number of taxa did not show significant differences among months or between sites. The densities of the most abundant taxa significantly differed between the sampling stations and throughout the study period. The zooplankton assemblages were dominated by omnivores, representing 43.9% of the total zooplankton (with herbivores and carnivores representing 4.4% and 0.5%, respectively). Omnivores were significantly more abundant during autumn, winter, and spring, particularly in Oct., Mar., and May, at station 2, and during Jan., Mar., and Apr., at station 1. Herbivores were significantly more abundant during autumn, late winter, and spring particularly at station 1. Carnivores showed low densities throughout the year, being more abundant in summer and autumn. Despite the detected similarities to other temperate estuaries, the results of this work may indicate environmental stresses in this ecosystem: the spatial structure dominates seasonal patterns; and there are low diversities and high numbers of resident populations. This kind of ecological pattern has been previously reported for other biological communities. The prevailing conditions in Mondego Estuary, namely eutrophication, should result in the development of opportunistic adaptive strategies among invertebrates.
- Distribution, production histology and histochemistry in Acartia tonsa (Copepoda: Calanoida) as means for life history and determination in a temperate estuaryPublication . Pastorinho, Ramiro; Vieira, Luís; Ré, Pedro; Pereira, Mário; Nicolau, Paula Bacelar; Morgado, Fernando; Marques, João C.; Azeiteiro, UlissesAcartia tonsa is a key species in the Mondego estuary and a widespread species in all temperate estuarine zooplankton communities; a fact that bestows high relevance upon the outcome of this study. One of the purposes of this study was to estimate the distribution, production and production/biomass ratio values of A. tonsa. Biomass/length relationship was estimated as follows: Y = 0.15e3.04x. Length-weight relationships were used to estimate production taking into account cohort growth and mortality. The annual production was calculated to be 43.12 mg Cm–3 year–1 and the production/biomass (P/B) ratio was estimated to be 10.56. The other purpose of this study was to use histology, histochemistry and biometry to determine as to whether fecundity is a limiting factor in itself or are zooplankters constrained to respond to an ever changing environment. Analyses of the maturation stage of oocytes in adult ovigerous females performed in two different periods of opposed abundance (February— high abundance, representing maximum fertility—and September—low abundance, representing “sterility”) demonstrated the presence of all three considered oocytical development stages: immature, vitellogenic and mature; with emphasis on the latter since it indicates a permanent capability for reproduction despite the registered population abundances. Taking into account the relevance of the species, this fact demonstrates the modulating influence of ecological parameters on general zooplankton reproductive traits.
- Ecological risk assessment of impacted estuarine areas: integratingPublication . Gonçalves, Cátia; Martins, M.; Costa, Maria Helena; Caeiro, Sandra; Costa, Pedro M.The analysis of multiple biomarker responses is nowadays recognized as a valuable tool to circumvent potential confounding factors affecting biomonitoring studies and allows a better understanding of the mechanisms underlying exposure to natural mixtures of toxicants. For the purpose of an environmental risk assessment (ERA) in an impacted estuary in SW Europe (the Sado, Portugal), juvenile Solea senegalensis from commercial fishing areas were surveyed for histopathological liver alterations and biochemical biomarkers. Although the findings revealed moderate differences in the patterns of histopathological traits between urban/industrial- and agricultural-influenced areas within the same estuary, no significant distinction was found between the cumulative alterations in animals from the two sites. The overall level of histopathological injury was low and severe traits like neoplasms or preneoplastic foci were absent. While metallothionein induction and lipid peroxidation could relate to histopathological condition indices, the activity of anti-oxidant enzymes appeared to be impaired in animals collected off the estuary's heavy-industry belt (the most contaminated site), which may partially explain some degree of hepatic integrity loss. Overall, the results are consistent with low-moderate contamination of the estuary and indicate that oxidative stress is the most important factor accounting for differences between sites. The study highlights the need of integrating multiple biomarkers when multiple environmental stressors are involved and the advantages of surveying toxicity effects in fieldcollected, foraging, organisms.
- Ecotoxicological heterogeneity in transitional coastal habitatsPublication . Carreira, S.; Costa, Pedro M.; Martins, M.; Lobo, J.; Costa, Maria Helena; Caeiro, SandraTransitional waterbodies, such as estuaries, are highly diversified environments with respect to ecology, geophysics, and nature of anthropogenic impacts. This spatial heterogeneity may pose important constraints when developing monitoring programmes for aquatic pollution. The present study compared three distinct coastal ecosystems located in Southern Portugal (subjected to different anthropogenic stressors), namely, two estuaries and a coastal lagoon, through the characterisation of sediment contamination and a biomarker approach to an important commercial clam (Ruditapes decussatus) obtained from local fishing grounds. The results showed high heterogeneity of sediment contamination for both estuaries and a marked distinction between industrially and agriculturally influenced areas as well as between natural and artificialized sites. Hydrodynamics and oceanic influence (in essence dictating sediment type) play a major role in environmental quality. Environmental heterogeneity constituted an important confounding factor for biomarker analysis in the clams’ digestive glands since the animals appeared to respond to their immediate surroundings’ characteristics rather than the geographical area where they were collected from, despite the relative distance to pollution hot spots. Still, oxidative stress biomarkers (lipid peroxidation and catalase activity) could correlate with each other and to both organic and metallic contamination, whereas metallothionein- like protein induction failed to correlate to any class of sediment toxicants (albeit metals being the most representative pollutants) and appeared to be strongly affected (unlike the previous) by clam size and probably other unknown internal and external variables, among which contaminant interactions should play a major role.
- Histological biomarkers in liver and gills of juvenile Solea senegalensis exposedPublication . Costa, Pedro M.; Diniz, Mário S.; Caeiro, Sandra; Lobo, Jorge; Martins, Marta; Ferreira, Ana M.; Caetano, Miguel; Vale, Carlos; DelValls, T. Ángel; Costa, Maria HelenaYoung juvenile Solea senegalensis were exposed to three sediments with distinct contamination profiles collected from a Portuguese estuary subjected to anthropogenic sources of contamination (the Sado estuary, western Portugal). Sedimentswere surveyed formetals (cadmium, chromium, copper, nickel, lead and zinc), ametalloid (arsenic) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide, dichloro-diphenyl-trichloroethane plus itsmetabolites), aswell as total organic matter, redox potential and particle fine fraction. The fish were exposed to freshly collected sediments in a 28-day laboratorial assay and collected for histological analyses at days 0 (T0), 14 (T14) and 28 (T28). Individual weighted histopathological indices were obtained, based on presence/absence data of eight and nine liver and gill pathologies, respectively, and on their biological significance. Although livers sustained more severe lesions, the sediments essentially contaminated by organic substances caused more damage to both organs than the sediments contaminated by both metallic and organic contaminants, suggesting a possible synergistic effect. Correlation analyses showed that some alterations are linked, forming distinctive histopathological patterns that are in accordance with the severity of lesions and sediment characteristics. The presence of large eosinophilic bodies in liver and degeneration of mucous cells in gills (a first-time described alteration)were some of the most noticeable alterations observed and were related to sediment organic contaminants. Body size has been found to be negatively correlated with histopathological damage in livers following longer term exposures. It is concluded that histopathological indices provide reliable and discriminatory data even when biomonitoring as complex media as natural sediments. It is also concluded that the effects of contamination may result not only from toxicant concentrations but also from their interactions, relative potency and sediment characteristics that ultimately determine bioavailability.
- Integration of sediment contamination with multi-biomarkerPublication . Rodrigo, Ana; Costa, Pedro M.; Costa, Maria Helena; Caeiro, SandraFor the purpose of biomonitoring, species that combine ecological and commercial importance may provide a link between ecological and human health risk. The common cuttlefish, Sepia officinalis, holds both characteristics in south-western Europe, albeit remaining unsurveyed in ecotoxicological studies. Cuttlefish collected from an impacted estuary in SW Portugal and a reference location off the coast were analysed for a battery of biomarker responses in the digestive gland and gills. The contrast to reference animals revealed that biomarker responses, especially those related to oxidative stress, were consistent with sediment contamination by PAHs, even in a situation that combines complex toxicant mixtures, moderate levels of contamination and high ecotoxicological diversity. However, environmental parameters related to the differences between shore and estuarine habitats should not be overruled. Also, digestive gland metallothionein retained significant specificity to metals even though previous studies in the area with clams and fish failed to trigger a conclusive response. The highest net differences in biomarker responses were detected in the gills, likely indicating higher sensitivity to environmental stressors. Still, the digestive gland responses were overall the most consistent with sediment contamination and effectively differentiated between estuarine industrial- and ruralimpacted sites. The results indicate that S. officinalis may be a candidate to meet the European Union’s requirements for efficient biomonitoring programmes, with the additional importance of being cosmopolitan, abundant, commercially valuable and combining the molluscan biology that has been granting bivalves their high value for biomonitoring with foraging behaviour, thus better able to reflect anthropogenic stressors impacting a wider area than sedentary organisms. Nevertheless, further investigations in unpolluted sites are needed to better evaluate the background levels of biomarker responses in the species.