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- A multibiomarker approach in Mytilus galloprovincialis to assess environmental qualityPublication . Cravo, Alexandra; Lopes, Belisandra; Serafim, M.A.; Company, Rui; Barreira, Luísa; Gomes, Tânia; Bebianno, Maria JoãoA multibiomarker approach was carried out for the first time in the South Portuguese Coast using Mytilus galloprovincialis, to assess environmental quality, establish if there are adverse biological responses associated to different sources of anthropogenic contamination and to determine spatial and seasonal trends. For this purpose the battery of biomarkers selected was: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx total and Se dependent), Cytochrome P450 component system, Glutathione-S-transferase (GST) and acetylcholinesterase (AChE), metallothionein (MT) and lead-delta-aminolevulinic acid dehydratase (ALAD), lipid peroxidation (LPO) and Condition Index (CI) along with the determination of PAHs and metals (Cd, Cu, Ni, Pb and Zn). Results show that despite the levels of both organic and metallic contaminants in these eight spots in the South Coast of Portugal not being particularly high compared with other contaminated/polluted sites worldwide, the selected battery of biomarkers responded efficiently to the environmental changes and allowed an environmental assessment between seasons and sites. Different spatial and seasonal responses were evident along the South Coast of Portugal, meaning that the contamination is not homogeneous. This does not only reflect different competition, origin and intensity of contamination, but also different environmental conditions (e.g. temperature, salinity). Along the South Portuguese Coast site 8 was the most contaminated, while site 2 was considered the least contaminated. Despite environmental factors possibly causing difficulties in the general interpretation of biomarker data, those that better responded to environmental contamination were CYP450, SOD-mit and T-GPx for the summation SigmaPAHs, MT (digestive gland) for metals (especially Cu), ALAD for Pb and LPO for both organic and metallic contamination. These biomarkers were also positively correlated with temperature in summer, revealing this as a more stressful/critical season. In future environmental contamination assessments there is no need to analyse the components b5, P418, NADH and NADPH of phase I MFO system, and MT in the gills, since their responses are not evident.
- Evaluation of sediment toxicity in different Portuguese estuaries: ecological impact of metals and polycyclic aromatic hydrocarbonsPublication . Serafim, M.A.; Company, Rui; Lopes, Belisandra; Pereira, Catarina; Cravo, Alexandra; Fonseca, V. F.; França, S.; Bebianno, Maria João; Cabral, H. N.Estuaries are exposed to multiple sources of different pollutants which tend to be trapped in sediments. Estuarine sediments can become reservoirs of contaminants that under certain circumstances may be released back to the water column, increasing their availability to the biota. Therefore, assessing sediment quality, of which toxicity testing is one of the lines-of-evidence, is a key element in ecological risk assessment strategies for these ecosystems. The use of Vibrio fischeri as luminescence bacteria is particularly effective in evaluating contaminated sediment. In this study, the ecotoxicity of sediments from five Portuguese estuaries (Aveiro, Tejo, Sado, Mira and Guadiana), was evaluated with a bioassay considering the 50% bioluminescence reduction of V. fischeri bacterium (EC50). Also, the levels of metals and polycyclic aromatic hydrocarbon contaminants (PAHs) were determined in the same sites. Moreover the Sediment Quality Guideline Quotient index (SQG-Q) was assessed for all sediments. The EC50 values varied significantly between estuaries but were strongly correlated with the metal concentrations in the different sites. In general Tejo estuary show higher toxicity levels compared to the other estuaries (5-min EC50 values of 5.6 mg mL(-1)). The integration of sediment contamination data shows that regarding the metallic contamination all sites are moderately impacted, with a higher SQG-Q in the Tejo estuary. On the other hand, when this index is applied to the PAHs levels, all sites are considered unimpacted. This suggests that metal contaminants are the most significant cause of toxicity in these sediments. Nevertheless, other factors can be relevant for this outcome due to the geochemical complexity of estuarine sediments (which affects contaminant speciation and bioavailability) and probably the presence of multiple xenobiotics in these sediments. (c) 2013 Elsevier Ltd. All rights reserved.
- A multi-biomarker approach in cross-transplanted mussels Mytilus galloprovincialisPublication . Serafim, M.A.; Lopes, Belisandra; Company, Rui; Cravo, Alexandra; Gomes, Tânia; Serrão Sousa, Vânia; Bebianno, Maria JoãoThe present work integrates the active biomonitoring (ABM) concept in mussels Mytilus galloprovincialis from the South coast of Portugal transplanted during 28 days between two sites with different sources of contamination, and vice versa, in order to assess biological effects in these mussels. For that purpose a multibiomarker approach was used. The suit of biomarkers indicative of metal contamination were metallothioneins (MT) and the enzyme δ-aminolevulinic acid dehydratase (ALAD), for organic contamination mixed function oxidase system (MFO), glutathione-S-transferase (GST) and acetylcholinesterase (AChE), as oxidative stress biomarkers superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and lipid peroxidation (LPO). These biomarkers were used to determine an index to evaluate the stress levels in these two sites. Site A is strongly influenced by metallic contamination, with higher Cu, Cr and Pb in M. galloprovincialis, as well as higher MT levels, antioxidant enzymes activities and LPO concentrations, and lower ALAD activity. In site B organic compounds (PAHs) are prevalent and native mussels show higher activities of the MFO system components and GST. Transplanted mussels had significant alterations in some biomarkers that reflect the type of contaminants present in each site, which demonstrates the primary role of the environment in determining the physiological characteristics of resident mussels. Therefore the application of ABM using a battery of biomarkers turns out to be a useful approach in sites where usually complex mixtures of contaminants occurs. In this study the biomarkers that better differentiate the impact of different contaminants at each site were MT, CYP450, SOD and CAT.