52 research outputs found

    Assessment of oil contamination in the bay of Porto Grande (Cape Verde) using the mullet Chelon bispinosus

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    Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic pollutants, some of which are mutagenic and carcinogenic so PAH concentrations in fish used for human consumption are crucial to assess impact to human health. Total PAH concentrations in muscle and liver of mullets Chelon bispinosus from the Bay of Porto Grande (Cape Verde) (four sites in the bay and a control) ranged from 112.7 to 779.5 and 291.5 to 7548.7 ng/g d. w., respectively. Two and three ring PAHs were the most frequent (72.8 to 90.8% in the muscle and 75.9 to 98.3% in the liver), but levels of carcinogenic PAHs (mainly Dibenzo (a,h) antracene) in certain sites (CN and PG) are of concern. Results reflect a chronic PAH pollution in the bay and sources are a mixture of anthropogenic (petrogenic and pyrolytic) and natural sources, making their identification extremely complex. Although, BaP levels were below the threshold established by Cape Verde and the European Union, BaPEs levels in muscle ranged from 0.28 to 3.66 ng/g w. w. and BAPEs and TPAHs exposure for the average adult was 0.02 to 0.26 and 1.6 to 11.2 μg/day, respectively. Further knowledge of PAH concentrations in other species are necessary for a proper environmental risk assessment policy.Key words: Bay of Porto Grande, Cape Verde, Chelon bispinosus, mullets, PAHs, BaPEs, daily intake

    Discerning natural and anthropogenic organic matter inputs to salt marsh sediments of Ria Formosa lagoon (South Portugal)

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    Sedimentary organic matter (OM) origin and molecular composition provide useful information to understand carbon cycling in coastal wetlands. Core sediments from threors' Contributionse transects along Ria Formosa lagoon intertidal zone were analysed using analytical pyrolysis (Py-GC/MS) to determine composition, distribution and origin of sedimentary OM. The distribution of alkyl compounds (alkanes, alkanoic acids and alkan-2-ones), polycyclic aromatic hydrocarbons (PAHs), lignin-derived methoxyphenols, linear alkylbenzenes (LABs), steranes and hopanes indicated OM inputs to the intertidal environment from natural-autochthonous and allochthonous-as well as anthropogenic. Several n-alkane geochemical indices used to assess the distribution of main OM sources (terrestrial and marine) in the sediments indicate that algal and aquatic macrophyte derived OM inputs dominated over terrigenous plant sources. The lignin-derived methoxyphenol assemblage, dominated by vinylguaiacol and vinylsyringol derivatives in all sediments, points to large OM contribution from higher plants. The spatial distributions of PAHs (polyaromatic hydrocarbons) showed that most pollution sources were mixed sources including both pyrogenic and petrogenic. Low carbon preference indexes (CPI > 1) for n-alkanes, the presence of UCM (unresolved complex mixture) and the distribution of hopanes (C-29-C-36) and steranes (C-27-C-29) suggested localized petroleum-derived hydrocarbon inputs to the core sediments. Series of LABs were found in most sediment samples also pointing to domestic sewage anthropogenic contributions to the sediment OM.EU Erasmus Mundus Joint Doctorate fellowship (FUECA, University of Cadiz, Spain)EUEuropean Commission [FP7-ENV-2011, 282845, FP7-534 ENV-2012, 308392]MINECO project INTERCARBON [CGL2016-78937-R]info:eu-repo/semantics/publishedVersio

    The composition of phosphate granules in the digestive glands of marine prosobranch gastropods: Variation in relation to taxonomy

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    The composition of some 1150 phosphate granules in the digestive glands of over 40 species of marine prosobranch gastropods has been surveyed using a simple preparation technique and semiquantitative SEM x-ray microanalysis. Spectral peaks for Mg, K, Ca, Mn, Fe and Zn were compared to that of P. Four major types of phosphate granule can be recognised, each generally characteristic of a taxonomic grouping: high Mg in archaeogastropods and littorinids, multiple metal in higher mesogastropods, and, in neogastropods, Mg-Ca in muricoideans and high Zn in buccinoideans. At least one Conus species (C. ventricosus) has high-Mg granules. Some causes of variation in granule composition are discussed: speculatively, it is suggested a palaeoenvironmental influence seems possible

    Biomarkers of exposure to metal contamination and lipid peroxidation in the benthic fish Cathorops spixii from two estuaries in South America, Brazil

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    Biomarkers as lipid peroxidation, metallothionein and delta-aminolevulinic acid dehydratase were determined in Cathorops spixii to compare the biological responses of this fish from estuaries with distinct anthropogenic influence. Three areas were selected in two estuaries in accordance with the levels of contamination for the polluted (Santos/São Vicente) and with the hydrodynamic characteristics for the non-polluted (Cananéia) estuary. Water characteristics and mercury levels in C. spixii confirmed a high human influence in the polluted system. In general, the biomarkers showed differences between the estuaries, suggesting disturbances in the specific cell mechanisms due to the presence of multiple xenobiotics in the contaminated system. Therefore, these biomarkers are recommended to promote more accurate information about the exposure to pollutants. Additionally, the study of the effect of the multiple xenobiotics on resident species such as the benthic fish C. spixii can favor a better assessment of the environmental quality of these systems.info:eu-repo/semantics/publishedVersio

    Source and impact of lead contamination on delta-aminolevulinic acid dehydratase activity in several marine bivalve species along the Gulf of Cadiz

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    Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme (δ-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagón, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ((206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50±1.09 μg g(-1) Pb d.w.) and D. trunculus (1.95±0.10 μg g(-1) Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels (<0.38 μg g(-1) Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD=-0.36[Pb]+0.79; r=0.837; or exponential for M. galloprovincialis ALAD=2.48e(-8.3[Pb]); r=0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in marine bivalve species with different feeding habits. Lead isotope data showed significant seasonal and spatial changes in bivalve isotopic composition reflecting seasonal and geographic differences in bioaccumulation. Within the study area, Pb can be modelled as a mixing between geogenic Pb and mine-related, discharges of Pb from the IPB. For some sites at the mouth of the Guadiana River, the bivalves show contamination from other anthropogenic sources, such as leaded boat/aviation fuel and/or leaded paint. Finally, the study demonstrates convincingly the need to consider species-specific variation when using bivalve ALAD activity as a biomarker for Pb.European Union (EU) - UTPIA/SP5.P9/02-INTERREG IIIAinfo:eu-repo/semantics/publishedVersio
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