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Resultados 1801-1810 de 5,137
Evaluation of polycyclic aromatic hydrocarbons bioavailability on Santos Bay (Brazil) through levels of biliary metabolites
2018
de Albergaria-Barbosa, Ana Cecília Rizzatti | da Silva, Denis Albuquerque Moreira | da Silva Rocha, Arthur José | Taniguchi, Satie | Patire, Vinicius Faria | Dias, June Ferraz | Fernandez, Wellington Silva | Bícego, Marcia Caruso
This study evaluated the PAH bioavailability from Santos Bay (Brazil) in 4 species of fish, using PAH biliary metabolites. The collection was done monthly, between July and December, in three different regions of Santos Bay. The metabolites were analyzed through a high performance liquid chromatograph with fluorescence detectors. Total metabolites concentrations ranged from 65.5 to 589μgg−1 of bile, evidencing PAH bioavailability on Santos Bay. Levels of phenanthrene and benzo[a]pyrene metabolites were in the classification range of areas moderate contaminated. Those concentrations were lower in Nebris microps and higher in Sphoeroides testudineus (p<0.05). Naphthalene metabolites concentrations did not differ significantly among fish species and were in the classification range of low contaminated areas. There were no significant spatial and temporal differences in levels among sampled areas. These results are environmentally important given the high levels of urbanization and the absence of biomonitoring data in this area.
Mostrar más [+] Menos [-]Plastic pollution in the Labrador Sea: An assessment using the seabird northern fulmar Fulmarus glacialis as a biological monitoring species
2018
Avery-Gomm, Stephanie | Provencher, Jennifer F. | Liboiron, Max | Poon, Florence E. | Smith, Paul A.
Plastic is now one among one of the most pervasive pollutants on the planet, and ocean circulation models predict that the Arctic will become another accumulation zone. As solutions to address marine plastic emerge, is essential that baselines are available to monitor progress towards targets. The northern fulmar (Fulmarus glacialis), a widely-distributed seabird species, has been used as a biological monitor for plastic pollution in the North Sea, and could be a useful monitoring species elsewhere. We quantified plastic ingested by northern fulmars from the southeastern Canadian waters of the Labrador Sea with the objective of establishing a standardized baseline for future comparisons. Over two years we sampled 70 fulmars and found that 79% had ingested plastic, with an average of 11.6 pieces or 0.151g per bird. Overall, 34% of all fulmars exceeded the Ecological Quality Objective for marine litter, having ingested >0.1g of plastic.
Mostrar más [+] Menos [-]Plastic ingestion in aquatic-associated bird species in southern Portugal
2018
Nicastro, Katy R. | Lo Savio, Roberto | McQuaid, Christopher D. | Madeira, Pedro | Valbusa, U. (Ugo) | Azevedo, Fábia | Casero, Maria | Lourenço, Carla | Zardi, Gerardo I.
Excessive use of plastics in daily life and the inappropriate disposal of plastic products are severely affecting wildlife species in both coastal and aquatic environments. Birds are top-predators, exposed to all threats affecting their environments, making them ideal sentinel organisms for monitoring ecosystems change. We set a baseline assessment of the prevalence of marine plastic litter affecting multi-species populations of aquatic birds in southern Portugal. By examining 160 stomach contents from 8 species of aquatic birds, we show that 22.5% were affected by plastic debris. Plastic was found in Ciconia ciconia, Larus fuscus and L. michahellis. Ciconia ciconia ingested the highest amount (number of items and total mass) of plastic debris. Polydimethylsiloxane (PDMS, silicones) was the most abundant polymer and was recorded only in C. ciconia. Plastic ingestion baseline data are of crucial importance to evaluate changes through time and among regions and to define management and conservation strategies.
Mostrar más [+] Menos [-]Dispersal of alien invasive species on anthropogenic litter from European mariculture areas
2018
Rech, Sabine | Salmina, Simone | Borrell Pichs, Yaisel J. | García Vázquez, Eva
The importance of mariculture areas for the dispersal of alien invasive species (AIS) on artificial floating items has recently been highlighted as a priority research need. Here we present the results of surveys in two important European shellfish culture areas that release rafting AIS, the Venetian lagoon and the Portuguese Algarve region. We found eight aquaculture-related non-native, invasive species attached to anthropogenic litter items mostly related to aquaculture: Amphibalanus amphitrite, Austrominius modestus, Balanus trigonus, Hesperibalanus fallax, Hydroides elegans, Hydroides sanctaecrucis, and Magallana angulata. These species are well-adapted to rafting on artificial surfaces and have a high potential to disperse via this vector. This is the first record of the notorious nuisance species H. sanctaecrucis both in the Mediterranean and Eastern Atlantic, as well as on floating litter. We also present the first records of M. angulata, H. sanctaecrucis, Sabellaria alveolata, Mytilus edulis and Chthamalus montagui on stranded anthropogenic litter.
Mostrar más [+] Menos [-]Comparison of radiocesium and stable isotope ratios of carbon and nitrogen among three stocks of Pacific cod (Gadus macrocephalus) around Hokkaido, Japan
2018
Nakamura, Tsugiya | Tanaka, Toshiyasu | Kimura, Osamu | Fujii, Yukiko | Haraguchi, Koichi | Endo, Tetsuya
Hokkaido, the northernmost of the main islands of Japan, is surrounded by the North Pacific Ocean, the Japan Sea and the Okhotsk Sea, and three independent stocks of Pacific cod are thought to inhabit those three areas. The Fukushima Dai-ichi Nuclear Power Plant (FDNPP), which is located in the north of Honshu, the main island of Japan, was disputed in 2011. Most of the radiocesium from the FDNPP was released into the western North Pacific Ocean, and the biota in those areas were considerably contaminated soon after the FDNPP accident. We analyzed radiocesium in Pacific cod caught around Hokkaido between 2011 and 2015. The radiocesium was predominantly detected in the cod caught in the North Pacific Ocean, and not in those caught the Japan Sea and the Okhotsk Sea. These results suggest that the cod caught in the Pacific Ocean around Hokkaido moved through the contaminated area off the FDNPP.
Mostrar más [+] Menos [-]Perturbation of seafloor bacterial community structure by drilling waste discharge
2018
Nguyen, Tan T. | Cochrane, Sabine K.J. | Landfald, Bjarne
Offshore drilling operations result in the generation of drill cuttings and localized smothering of the benthic habitats. This study explores bacterial community changes in the in the upper layers of the seafloor resulting from an exploratory drilling operation at 1400m water depth on the Barents Sea continental slope. Significant restructurings of the sediment microbiota were restricted to the sampling sites notably affected by the drilling waste discharge, i.e. at 30m and 50m distances from the drilling location, and to the upper 2cm of the seafloor. Three bacterial groups, the orders Clostridiales and Desulfuromonadales and the class Mollicutes, were almost exclusively confined to the upper two centimeters at 30m distance, thereby corroborating an observed increase in anaerobicity inflicted by the drilling waste deposition. The potential of these phylogenetic groups as microbial bioindicators of the spatial extent and persistence of drilling waste discharge should be further explored.
Mostrar más [+] Menos [-]Heavy metal assessment in surface sediments off Coromandel Coast of India: Implication on marine pollution
2018
N., Anbuselvan | D., Senthil Nathan | M., Sridharan
The present study investigates the distribution of heavy metals (Fe, Cd, Co, Cr, Cu, Ni, Zn and Pb) in the surface sediments along the Coromandel Coast of Bay of Bengal as an indicator of marine pollution. Pollution indices such as Contamination factor (CF), Enrichment factor (EF) and Geo-accumulation index (I) were performed to assess the spatial distribution and pollution status of the study area. The heavy metal concentration in the study area is closely associated with grain size and organic matter. Both geoaccumulation index and metal contamination factor indicate that the sediments are free from contamination with regards to the metals Cr and Ni, followed by uncontamination to moderate contamination of Co, Cu and Zn. However, sediments are found to be extremely polluted with respect to Cd and Pb. Factor analysis reveals that the accumulation of these heavy metals in the shelf sediments are due to anthropogenic inputs from the adjacent land area.
Mostrar más [+] Menos [-]Contamination, Fate and Management of Metals in Shooting Range Soils—a Review
2018
Sanderson, Peter | Qi, Fangjie | Seshadri, Balaji | Wijayawardena, Ayanka | Naidu, R.
Pollution of shooting range soils by lead from bullets represents a widespread and potentially significant concern for impact on the environment. High concentrations of lead in particular are reported in bullet impact berms and shot fall zones. The other components of bullets used in shooting including antimony, copper and zinc may also be present at elevated concentrations. Antimony is a concern due to its mobility in the environment. It has been recognised that the status of contamination is important for the risk presented by shooting ranges. Lead bullets are subject to weathering in the soil, forming secondary minerals, which may be solubilised and may release lead and co-contaminants into the soil. The mobility and availability of contaminants in the soil affect their potential for spreading in the environment and for uptake and toxicity in organisms. Soil physicochemical properties affect bullet weathering and availability of contaminants in the soil. A number of strategies have been researched for management of shooting range pollution such as chemical stabilisation, phytoremediation and soil washing. This review considers the current state of knowledge and research of contamination and management of shooting ranges from recent literature (2014–2017) reflecting on new knowledge and novel management strategies for shooting range soil management. Ultimately, management of pollution in shooting range soils should seek to remove bullets from soil, reduce the weathering of bullets and reduce the mobility and bioavailability of contaminants. Adopted management practices should be based an understanding of site-specific condition, to achieve the most optimal outcome.
Mostrar más [+] Menos [-]Metal detoxification in the marine teleost fish Sparus aurata L. and Dicentrarchus labrax L
2018
Morcillo, Patricia | Esteban, María A. | Cuesta Arranz, Alberto
Transcription of ATP-binding cassette (ABC) transporters has been evaluated in cell lines and primary cultures from gilthead seabream and European sea bass teleost fish exposed to methylmercury (MeHg), arsenic, cadmium or lead. The mRNA expression levels showed abcb1, abcc2 and abcc5 constitutive gene expression in all seabream tissues analyzed; however, we were unable to detect any constitutive transcription of abcb1 in many of the sea bass tissues. Furthermore, ABC mRNA expression levels were all affected by metal exposure, especially in the case of fish cell lines and erythrocytes, and greatly depended on cell type and fish species. Thus, while ABC transcription was up-regulated in the seabream cell line it was down-regulated in the sea bass cell line, while the opposite occurred in the primary cultures. All these data point to the importance of ABC transporters in metal detoxification and in the differential regulation in seabream and sea bass cells.
Mostrar más [+] Menos [-]Comparative feeding rates of native and invasive ascidians
2018
Hoxha, Tedi | Crookes, Steve | Lejeusne, Christophe | Dick, Jaimie T.A. | Chang, Xuexiu | Bouchemousse, Sarah | Cuthbert, Ross N. | MacIsaac, Hugh J.
Ascidians have a recent history of species introductions globally, often with strong ecological impacts. Comparisons of per capita effects of invaders and comparable natives are useful to assess such impacts. Here, we explore ingestion rates (IR) and clearance rates (CR) of Ciona intestinalis and Ciona robusta, co-occurring native and non-native ascidians, respectively, from Brittany, France. IR was positively related to food concentration, with the invader responding more strongly to increasing food concentration. CR also differed by species, with the invader demonstrating higher values. C. robusta exhibited a higher functional response (Type I) than did C. intestinalis (Type II). Relative impact measured using seasonal abundance and IR revealed that C. robusta has a much greater impact than C. intestinalis at all food concentrations tested, though the former has a constrained distribution which limits its regional impact. Nevertheless, when abundant, we expect C. robusta to exert a greater impact on algal foods.
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