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  • Is it possible to use "twin cores" as a unique sedimentary record? An experimental design based on sediment color
    Publication . Veiga-Pires, C.; Mestre, Nélia
    Sedimentary cores are widely used for studying Quaternary records. However, the amount of sediment that is available is proportional to the diameter of the core, which is rarely bigger than 15 cm. One way to obtain more sediment is to use two cores retrieved from almost the same location and use them as if they represent a unique sedimentary record. In the present work, an experimental design has been applied to verify if “twin cores” from an estuary can be considered as representing the same sedimentary record with twice the amount of sediment to study. Because sediment can be characterized based on its color, the variables used as replicates in the experimental design are the three Lab CIE colors acquired with a X-Rite Colortron spectrophotometer. Sediment cores were retrieved from the upper saltmarsh of Gilão River’s estuary, southern Portugal. Twin cores, with in between distances of 50 cm, 100 cm and 200 cm, from two different sites were analysed. Results from a nested ANOVA show that even for the closest twin cores (50 cm apart) there is at least one color variable that shows significant variations between the profiles of both cores. These results clearly show that “twin cores” cannot be used as a unique sedimentary record without any previous testing, at least in such transitional regions.
  • Cytotoxic responses of the anticancer drug cyclophosphamide in the mussel Mytilus galloprovincialis and comparative sensitivity with human cells lines
    Publication . Fernandes, Elna; Fonseca, Tainá; Carriço, Tania; Mestre, Nélia; Tavares, Alvaro; Bebianno, Maria
    the rise of cancer cases worldwide led to an increase in production and consumption of anticancer drugs, that ultimately end up in the marine environment and are accumulated in aquatic organisms. Cyclophosphamide (CP) is a cytotoxic alkylating agent frequently prescribed in cancer treatments. This study assess ecotoxicological effects of CP on mussels Mytilus galloprovincialis, through in vivo and ex vivo approaches and compares the sensitivity of mussel haemocytes with well-established human cell lines (RPE and HeLa). Mussels were exposed in vivo to CP (1000 ng L-1) and several biomarkers analysed in gills and digestive glands namely neurotoxicity (AChE activity), oxidative stress (GPx activity), biotransformation (GST activity), lipid peroxidation (LPO) and apoptosis (caspase activity), whereas genotoxicity was determined in mussels' haemocytes. Cytotoxicity was also assessed in haemocytes (in vivo and ex vivo) and human cell lines (in vitro) exposed to a range of CP concentrations (50, 100, 250, 500 and 1000 ng L-1) over 24 h, via neutral red assay. In in vivo exposure, detoxification of CP did not efficiently occur in the gills while in digestive glands GPx and GST activities were induced, jointly with a decrease in lipid peroxidation, indicating a potential outcome of the protective antioxidant mechanisms, whereas no apoptosis was noted. Moreover, cytotoxicity and DNA damage were detected in haemocytes. the ex vivo exposure haemocytes to CP caused cytotoxicity (from 100 ng L-1), whereas no effects occurred in human cell lines. This suggests that, at relevant environmental concentrations, CP cause subtle and irreversible impacts on M. galloprovincialis. (C) 2020 Elsevier Ltd. All rights reserved.
  • Environmental protection requires accurate application of scientific evidence
    Publication . Smith, Craig R.; Tunnicliffe, Verena; Colaco, Ana; Drazen, Jeffrey C.; Gollner, Sabine; Levin, Lisa A.; Mestre, Nélia; Metaxas, Anna; Molodtsova, Tina N.; Morato, Telmo; Sweetman, Andrew K.; Washburn, Travis; Amon, Diva J.
  • Assessing cadmium-based quantum dots effect on the gonads of the marine mussel Mytilus galloprovincialis
    Publication . Gonçalves, Joanna M.; Rocha, Thiago Lopes; Nélia Mestre, N. C. Mestre, N. Mestre; Fonseca, T. G.; Bebianno, M.
    This study assesses the sex-specific effects induced by CdTe QDs, on the marine mussel Mytilus galloprovincialis in comparison to its dissolved counterpart. A 14 days exposure to CdTe QDs and dissolved Cd was conducted (10 mu g Cd L-1), analysing Cd accumulation, oxidative stress, biotransformation, metallothionein and oxidative damage in the gonads. Both Cd forms caused significant antioxidant alterations, whereby QDs were more pro-oxidant, leading to oxidative damage, being females more affected. Overall, biochemical impairments on gonads of M. galloprovincialis demonstrate that the reproductive toxicity induced by CdTe QDs in mussels are sex-dependent and mediated by oxidative stress and lipid peroxidation. It is crucial to acknowledge how gametes are affected by metal-based nanoparticles, such as Cd-based QDs. As well as understanding the potential changes they may undergo at the cellular level during gametogenesis, embryogenesis and larval development potentially leading to serious impacts on population sustainability and ecosystem health.
  • A decade to study deep-sea life
    Publication . Howell, Kerry L.; Hilario, Ana; Allcock, A. Louise; Bailey, David; Baker, Maria; Clark, Malcolm R.; Colaco, Ana; Copley, Jon; Cordes, Erik E.; Danovaro, Roberto; Dissanayake, Awantha; Escobar, Elva; Esquete, Patricia; Gallagher, Austin J.; Gates, Andrew R.; Gaudron, Sylvie M.; German, Christopher R.; Gjerde, Kristina M.; Higgs, Nicholas D.; Le Bris, Nadine; Levin, Lisa A.; Manea, Elisabetta; McClain, Craig; Menot, Lenaick; Mestre, Nélia; Metaxas, Anna; Milligan, Rosanna; Muthumbi, Agnes W. N.; Narayanaswamy, Bhavani E.; Ramalho, Sofia P.; Ramirez-Llodra, Eva; Robson, Laura M.; Rogers, Alex D.; Sellanes, Javier; Sigwart, Julia D.; Sink, Kerry; Snelgrove, Paul V. R.; Stefanoudis, Paris V.; Sumida, Paulo Y.; Taylor, Michelle L.; Thurber, Andrew R.; Vieira, Rui; Watanabe, Hiromi K.; Woodall, Lucy C.; Xavier, Joana R.
    The United Nations Decade of Ocean Science for Sustainable Development presents an exceptional opportunity to effect positive change in ocean use. We outline what is required of the deep-sea research community to achieve these ambitious objectives.
  • Potential mitigation and restoration actions in ecosystems impacted by seabed mining
    Publication . Cuvelier, Daphne; Gollner, Sabine; Jones, Daniel O. B.; Kaiser, Stefanie; Arbizu, Pedro Martínez; Menzel, Lena; Mestre, Nélia; Morato, Telmo; Pham, Christopher; Pradillon, Florence; Purser, Autun; Raschka, Uwe; Sarrazin, Jozée; Simon-Lledó, Erik; Stewart, Ian M.; Stuckas, Heiko; Sweetman, Andrew K.; Colaço, Ana
    Mining impacts will affect local populations to different degrees. Impacts range from removal of habitats and possible energy sources to pollution and smaller-scale alterations in local habitats that, depending on the degree of disturbance, can lead to extinction of local communities. While there is a shortage or even lack of studies investigating impacts that resemble those caused by actual mining activity, the information available on the potential long-lasting impacts of seabed mining emphasise the need for effective environmental management plans. These plans should include efforts to mitigate deep-sea mining impact such as avoidance, minimisation and potentially restoration actions, to maintain or encourage reinstatement of a resilient ecosystem. A wide range of mitigation and restoration actions for deep-sea ecosystems at risk were addressed. From an ecological point of view, the designation of set-aside areas (refuges) is of utmost importance as it appears to be the most comprehensive and precautionary approach, both for well-known and lesser studied areas. Other actions range from the deployment of artificial substrates to enhance faunal colonisation and survival to habitat recreation, artificial eutrophication, but also spatial and temporal management of mining operations, as well as optimising mining machine construction to minimise plume size on the sea floor, toxicity of the return plume and sediment compression. No single action will suffice to allow an ecosystem to recover, instead combined mitigation/restoration actions need to be considered, which will depend on the specific characteristics of the different mining habitats and the resources hosted (polymetallic sulphides, polymetallic nodules and cobalt-rich ferromanganese crusts). However, there is a lack of practical experience regarding mitigation and restoration actions following mining impacts, which severely hamper their predictability and estimation of their possible effect and success. We propose an extensive list of actions that could be considered as recommendations for best environmental practice. The list is not restricted and, depending on the characteristics of the site, additional actions can be considered. For all actions presented here, further research is necessary to fully encompass their potential and contribution to possible mitigation or restoration of the ecosystem.
  • Microplastics effects in Scrobicularia plana
    Publication . Ribeiro, Francisca; Garcia, Ana; Pereira, Beatriz P.; Fonseca, Maria; Mestre, Nélia; Fonseca, Tainá; Ilharco, Laura M.; Bebianno, Maria João
    One of the most common plastics in the marine environment is polystyrene (PS) that can be broken down to micro sized particles. Marine organisms are vulnerable to the exposure to microplastics. This study assesses the effects of PS microplastics in tissues of the clam Scrobicularia plana. Clams were exposed to 1mgL-1(20μm) for 14days, followed by 7days of depuration. A qualitative analysis by infrared spectroscopy in diffuse reflectance mode period detected the presence of microplastics in clam tissues upon exposure, which were not eliminated after depuration. The effects of microplastics were assessed by a battery of biomarkers and results revealed that microplastics induce effects on antioxidant capacity, DNA damage, neurotoxicity and oxidative damage. S. plana is a significant target to assess the environmental risk of PS microplastics.
  • Working with spectrophotometry on sedimentary cores from estuaries of south Portugal
    Publication . Veiga-Pires, C.; Mestre, Nélia; Moura, Delminda; Boski, T.
    The study of estuarine sediments to document Late Quatemary coastal changes had always benn of extreme importance, as they reflect the combination of sea-level and sedimentary changes, either at a local, regional or global scale.(...)
  • Ecotoxicological effects of chemical contaminants adsorbed to microplastics in the clam Scrobicularia plana
    Publication . O'Donovan, Sarit; Mestre, Nélia; Abel, Serena; Fonseca, Tainá; Carteny, Camilla C.; Cormier, Bettie; Keiter, Steffen H.; Bebianno, Maria João
    Although microplastics (MPs) are distributed globally in the marine environment, a great deal of unknowns relating to their ecotoxicological effects on the marine biota remains. Due to their lipophilic nature, microplastics have the potential to adsorb persistent organic pollutants present in contaminated regions, which may increase their detrimental impact once assimilated by organisms. This study investigates the ecotoxicological effects of exposure to low-density polyethylene (LDPE) microplastics (11-13 beta m), with and without adsorbed contaminants (benzo[a]pyrene- BaP and perfluorooctane sulfonic acid-PFOS), in the peppery furrow shell clam, Scrobicularia plana. Environmentally relevant concentrations of contaminants (BaP-16.87 +/- 0.22 mu g g(-1) and PFOS-70.22 +/- 12.41 mu g g(-1)) were adsorbed to microplastics to evaluate the potential role of plastic particles as a source of chemical contamination once ingested. S. plana were exposed to microplastics, at a concentration of 1 mg L-1, in a water-sediment exposure setup for 14 days. Clams were sampled at the beginning of the experiment (day 0) and after 3, 7, and 14 days. BaP accumulation, in whole clam tissues, was analyzed. A multi-biomarker assessment was conducted in the gills, digestive gland, and haemolymph of clams to clarify the effects of exposure. This included the quantification of antioxidant (superoxide dismutase, catalase, glutathione peroxidase) and biotransformation (glutathione-Stransferases) enzyme activities, oxidative damage (lipid peroxidation levels), genotoxicity (single and double strand DNA breaks), and neurotoxicity (acetylcholinesterase activity). Results suggest a potential mechanical injury of gills caused by ingestion of microplastics that may also affect the analyzed biomarkers. The digestive gland seems less affected by mechanical damage caused by virgin microplastic exposure, with the MPs-adsorbed BaP and PFOS exerting a negative influence over the assessed biomarkers in this tissue.
  • An attempt to use color as a tool for high resolution correlations between estuarine sedimentary cores from Algarve (Portugal)
    Publication . Mestre, Nélia; Veiga-Pires, C.
    Nowadays, paleoenvironmental and climatological researches focus on studying shortterm climatic changes and one of the more sensitive environments for recording those short-term climatic variations are the high sedimentation rate of coastal regions. Accordingly, 4 estuaries from the Algarve region, south of Portugal, have been cored in order to study sedimentary and climatic variations during recent times (c.a. 5000 yrs). For this purpose, we applied sampling and analytical techniques from deep-sea studies, allowing the acquirement of almost continuous data profiles, as the color data obtained with the spectrophotometer Colortron.