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Effects of anthropogenic metallic contamination on cholinesterases of Gambusia holbrooki Texte intégral
2013
Brandão, Fátima | Correia, Alberto Teodorico | Gonçalves, Fernando | Nunes, Bruno
Effects of anthropogenic metallic contamination on cholinesterases of Gambusia holbrooki Texte intégral
2013
Brandão, Fátima | Correia, Alberto Teodorico | Gonçalves, Fernando | Nunes, Bruno
Metal contamination causes multiple biological dysfunctions, including impairment of key physiological functions by targeting enzymes. This feature is a matter of concern, since it may imply significant disturbances in energy allocation, behaviour, reproduction, and survival. Inhibition of the cholinesterase (ChE) activity of aquatic organisms by metals has been described, and systematically used in biomonitoring studies as effect criterion of environmental exposure to these compounds. The present paper addresses the feasibility of using ChE inhibition to quantify the adverse acute and chronic effects of metals (copper, zinc, lead, and cadmium) on nervous tissue of Gambusia holbrooki. With the exception of acute exposure to copper, ChE activity was not significantly impaired. The meanings of the reported findings are further discussed, aiming at a more comprehensive use of this biomarker in environmental assessment. Based on the obtained results, the role of ChE inhibition in environmental metal contamination scenarios should be questioned or even discarded.
Afficher plus [+] Moins [-]Effects of anthropogenic metallic contamination on cholinesterases of Gambusia holbrooki Texte intégral
2013
Brandão, Fátima | Correia, Alberto Teodorico | Gonçalves, Fernando | Nunes, Bruno
Metal contamination causes multiple biological dysfunctions, including impairment of key physiological functions by targeting enzymes. This feature is a matter of concern, since it may imply significant disturbances in energy allocation, behaviour, reproduction, and survival. Inhibition of the cholinesterase (ChE) activity of aquatic organisms by metals has been described, and systematically used in biomonitoring studies as effect criterion of environmental exposure to these compounds. The present paper addresses the feasibility of using ChE inhibition to quantify the adverse acute and chronic effects of metals (copper, zinc, lead, and cadmium) on nervous tissue of Gambusia holbrooki. With the exception of acute exposure to copper, ChE activity was not significantly impaired. The meanings of the reported findings are further discussed, aiming at a more comprehensive use of this biomarker in environmental assessment. Based on the obtained results, the role of ChE inhibition in environmental metal contamination scenarios should be questioned or even discarded. | The present work was funded by Fundação para a Ciência e a Tecnologia: project “BiOtoMetal” (PTDC/AMB/70431/2006). We would like to acknowledge the contribution of Jonathan Wilson, for his decisive contribution to the final format of this article. | published
Afficher plus [+] Moins [-]Concentration and composition of polycyclic aromatic hydrocarbons (PAHs) in plastic pellets: Implications for small-scale diagnostic and environmental monitoring Texte intégral
2013
Fisner, Mara | Taniguchi, Satie | Majer, Alessandra P. | Bícego, Márcia C. | Turra, Alexander
Plastic pellets may serve as a carrier of toxic contaminants, including polycyclic aromatic hydrocarbons (PAHs). Considering that beach morphodynamics and pellet distribution varied along the shore, and that contaminant sources may vary on different scales, it is expected that this variability is reflected in the concentration and composition of contaminants. This hypothesis was tested through a sampling of plastic pellets at 30 sites along the shore in Santos Bay (Brazil). The total PAH concentrations and the priority PAHs showed high variability, with no clear pattern. Their composition differed among the sampling sites; some of the compounds represent a potential risk to organisms. The sources of contamination, as indicated by the isomer ratios, were also variable among sites. The high small-scale spatial variability found here has implications for estimating the plastic pellet contamination on beaches, since a sample from a single site is unlikely to be representative of an entire beach.
Afficher plus [+] Moins [-]Occurrence and distribution of antifouling biocide Irgarol-1051 in coastal waters of Peninsular Malaysia Texte intégral
2013
Ali, Hassan Rashid | Arifin, Marinah Mohd | Sheikh, Mohammed Ali | Mohamed Shazili, Noor Azhar | Zainudin Bachok,
Emerging booster biocides contamination raises particular attention in the marine ecosystem health. This study provides the baseline data on the occurrence of Irgarol-1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamiono-s-triazine) in the selected coastal water around Malaysia. The maximum detected concentration of Irgarol was 2021ng/L at Klang West, commercial and cargo port. Coral reef Islands (Redang and Bidong) were relatively less contaminated compared to other coastal areas. The temporal variation revealed that only 1% of 28 stations sampled on November, 2011 was above the environmental risk limit of 24ng/L as suggested by Dutch Authorities, while in January and April, 2012; 46% and 92% of the stations were above the limit respectively. The present findings demonstrate the wide detection of novel antifouling materials Irgarol-1051 which advocates the need for proper monitoring and conservation strategies for the coastal resources.
Afficher plus [+] Moins [-]Persistent organic pollutants in benthic and pelagic organisms off Adélie Land, Antarctica Texte intégral
2013
Goutte, A. | Chevreuil, M. | Alliot, F. | Chastel, O. | Cherel, Y. | Eléaume, M. | Massé, G.
The concentrations of polychlorinated biphenyls (PCB), hexachlorobenzene (HCB), pentachlorobenzene (PeCB) and polybrominated diphenylethers (PBDE) were described in benthic and pelagic species collected off Adélie Land, Antarctica. Strong differences were observed among species, with reduced PeCB and HCB levels in benthic species, and elevated PCB levels in the Antarctic yellowbelly rockcod, the Antarctic sea urchin and the snow petrel. Lower-chlorinated congeners were predominant in krill; penta-PCBs in benthic organisms; hexa- and hepta-PCBs in seabirds and cryopelagic fish. This segregation may result from sedimentation process, specific accumulation and excretion, and/or biotransformation processes. The presence of PBDEs in Antarctic coastal organisms may originate from atmospheric transport and partly from a contamination by local sources. Although POP levels in Antarctic marine organisms were substantially lower than in Arctic and temperate organisms, very little is known about their toxic effects on these cold-adapted species, with high degree of endemism.
Afficher plus [+] Moins [-]Extraction of bioavailable contaminants from marine sediments: An approach to reducing toxicity using adsorbent parcels Texte intégral
2013
Goodsir, Freya | Fisher, Tom T. | Barry, Jon | Bolam, Thi | Nelson, Leah D. | Rumney, Heather S. | Brant, Jan L.
This paper demonstrates an approach to reducing acute toxicity in marine sediments using adsorbent parcels. Acute toxicity tests were carried using the marine amphipod Corophium volutator. Marine sediments were spiked with two know contaminants tributyltin and naphthalene and then treated with adsorbent parcels containing either amberlite XAD4 or activated carbon. Results showed that both types of adsorbent parcels were effective in reducing acute toxicity, not only within spiked sediments containing naphthalene and/or tributyltin, but also in an environmental field samples form an expected contaminated site. Adsorbent parcels such as these could provide a practical approach to remediate areas of contaminated sediment within marine environments. Furthermore adsorbents can be used as an identification tool for problematic contaminants using a toxicity identification evaluation approach.
Afficher plus [+] Moins [-]Role of shellfish hatchery as a reservoir of antimicrobial resistant bacteria Texte intégral
2013
Miranda, Claudio D. | Rojas, Rodrigo | Garrido, Marcela | Geisse, Julieta | González, Gerardo
The main aim of this study was to determine the occurrence of resistant bacteria in florfenicol-treated and untreated scallop larval cultures from a commercial hatchery and to characterize some selected florfenicol-resistant strains. Larval cultures from untreated and treated rearing tanks exhibited percentages of copiotrophic bacteria resistant to florfenicol ranging from 0.03% to 10.67% and 0.49–18.34%, respectively, whereas florfenicol resistance among oligotrophic bacteria varied from 1.44% to 35.50% and 3.62–95.71%, from untreated and treated larvae, respectively. Florfenicol resistant microbiota from reared scallop larvae mainly belonged to the Pseudomonas and Pseudoalteromonas genus and were mainly resistant to florfenicol, chloramphenicol, streptomycin and co-trimoxazole. This is the first study reporting antimicrobial resistant bacteria associated to a shellfish hatchery and the results suggest that a continuous surveillance of antimicrobial resistance even in absence of antibacterial therapy is urgently required to evaluate potential undesirable consequences on the surrounding environments.
Afficher plus [+] Moins [-]Legacy contaminant bioaccumulation in rock crabs in Sydney Harbour during remediation of the Sydney Tar Ponds, Nova Scotia, Canada Texte intégral
2013
Walker, Tony R. | MacAskill, Devin | Weaver, Peter
Concentrations of PAHs, PCBs, metals and lipids in hepatopancreas of rock crabs (Cancer irroratus) were measured in Sydney Harbour (SH) for one year prior to remediation and three years of remediation of the Sydney Tar Ponds (STP), Nova Scotia. Low level concentrations of PCBs and metals were measured, although PAHs were mostly undetected. Metal concentrations showed little spatio-temporal variability, although highest concentrations of As, Cd and Cu were measured at reference stations furthest from the STP remediation site. Mercury concentrations were at least an order of magnitude lower than Canadian guidelines. Moderately elevated PCB concentrations were detected in crabs near Muggah Creek, but these were generally not higher than those measured during baseline. Despite remediation activities, current contaminant burdens measured in crabs were much lower than previously reported in other studies of crabs and lobster in industrial harbours in eastern Canada, due in part to natural recovery of SH sediments.
Afficher plus [+] Moins [-]Coupled hydrodynamic and wastewater plume models of Belfast Lough, Northern Ireland: A predictive tool for future ecological studies Texte intégral
2013
Pritchard, Daniel | Savidge, Graham | Elsäßer, Björn
Wastewater outfalls provide a natural laboratory for the study of nutrient dynamics in coastal seas, however if properly designed and operated their impact can be difficult to detect. A model was developed and applied to investigate the effect of variation in hydrodynamic conditions on the transport and dilution of a treated wastewater plume in Belfast Lough, Northern Ireland. To validate these predictions we measured the physiochemical properties of the waters surrounding the outfall with a specific focus on inherent plume tracers likely to be relevant to the study of macroalgae (salinity, nitrogen and phosphorus). The model performed well and our data show high dilution of the plume, even under neap-tide conditions. This provides a spatially and temporally defined predictive framework for future studies investigating the compliance of Northern Ireland’s coastal waters with European Water Framework Directive objectives and for feasibility studies investigating macroalgal aquaculture near wastewater outfalls.
Afficher plus [+] Moins [-]Source apportionment of sedimentary hydrocarbons in the Segara Anakan Nature Reserve, Indonesia Texte intégral
2013
Syakti, Agung Dhamar | Hidayati, Nuning Vita | Hilmi, Endang | Piram, Anne | Doumenq, Pierre
The study aimed to determine the spatial distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Segara Anakan nature reserve and their potential origins using gas chromatography–mass spectrometry. Total alkane concentrations ranged from 3755 to 129,027μgkg−1, and the concentrations of 16 PAHs ranged from 375 to 29,517μgkg−1. The ratios of specific n-alkanes (e.g., CPI24–34, WaxCn, and Paq), including a new proposed index, terrestrial–marine discriminant (TMD), as well as the ratios of selected PAHs (e.g., Ant/∑178, Fl/∑202, BaAnt/∑228, and IPyr/∑276), showed that the sources of hydrocarbons in the sediments were generally biogenic, including both terrigenous and marine, with an anthropogenic pyrolytic contribution (petrogenic and biogenic combustion). For the environmental risk assessment, a sediment quality guideline (SQGs) comparison indicated that the station risk levels ranged from low to medium-low, except for R6, which has a greater impact on the ecological risk for marine organisms.
Afficher plus [+] Moins [-]Biogeochemical classification of South Florida’s estuarine and coastal waters Texte intégral
2013
Briceño, Henry O. | Boyer, Joseph N. | Castro, Joffre | Harlem, Peter
South Florida’s watersheds have endured a century of urban and agricultural development and disruption of their hydrology. Spatial characterization of South Florida’s estuarine and coastal waters is important to Everglades’ restoration programs. We applied Factor Analysis and Hierarchical Clustering of water quality data in tandem to characterize and spatially subdivide South Florida’s coastal and estuarine waters. Segmentation rendered forty-four biogeochemically distinct water bodies whose spatial distribution is closely linked to geomorphology, circulation, benthic community pattern, and to water management. This segmentation has been adopted with minor changes by federal and state environmental agencies to derive numeric nutrient criteria.
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