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Assessment of trace metal contamination level and toxicity in sediments from coastal regions of West Bengal, eastern part of India Texto completo
2015
Antizar-Ladislao, Blanca | Mondal, Priyanka | Mitra, Soumita | Sarkar, Santosh Kumar
The work investigated concentration of trace metals in surface sediments (0–10cm; < 63μm grain size) from 15 sampling sites of diverse environmental stresses covering Hugli River Estuary (HRE) and Sundarban Mangrove Wetland (SMW), eastern coastal part of India. The trace metal concentrations in sediments exhibited an overall decreasing trend as follows: Cr (21.2–60.9)>Cu (11.60–102.47)>Ni (19.10–52.60)>Pb (7.09–183.88)>As (4.41–11.46)>Cd (0.02–4.4)>Ag (0.02–0.87). Both the geo-accumulation index (Igeo) and contamination factor (CF) values revealed significant pollution by Ag, Cd and Pb at Nurpur of HRE. Potential Ecological Risk Index (RI) (61.21±112.40) showed wide range of variations from low (19.76) to serious (463.20) ecological risk. A positive significant correlation was found between metals and organic carbon in sediments. The ecological risk associated with the trace metals in sediment was considered on the consensus based Sediment Quality Guidelines (SQGs). The work suggests that the trace metals present in sediments posed adverse effects on the sediment-dwelling organisms.
Mostrar más [+] Menos [-]Quality Index of Subtidal Macroalgae (QISubMac): A suitable tool for ecological quality status assessment under the scope of the European Water Framework Directive Texto completo
2015
Le Gal, A. | Derrien-Courtel, S.
Despite their representativeness and importance in coastal waters, subtidal rocky bottom habitats have been under-studied. This has resulted in a lack of available indicators for subtidal hard substrate communities. However, a few indicators using subtidal macroalgae have been developed in recent years for the purpose of being implemented into the Water Framework Directive (WFD). Accordingly, a quality index of subtidal macroalgae has been defined as a French assessment tool for subtidal rocky bottom habitats in coastal waters. This approach is based on 14 metrics that consider the depth penetration, composition (sensitive, characteristic and opportunistic) and biodiversity of macroalgae assemblages and complies with WFD requirements. Three ecoregions have been defined to fit with the geographical distribution of macroalgae along the French coastline. As a test, QISubMac was used to assess the water quality of 20 water bodies. The results show that QISubMac may discriminate among different quality classes of water bodies.
Mostrar más [+] Menos [-]Toxic metal (Pb, Cd, Cr, and Hg) levels in Rapana venosa (Valenciennes, 1846), Eriphia verrucosa (Forskal, 1775), and sediment samples from the Black Sea littoral (Thrace, Turkey) Texto completo
2015
Mülayim, A. | Balkıs, H.
Rapana venosa (Valenciennes, 1846) and Eriphia verrucosa (Forskal, 1775) are the dominant benthic invertebrate species along the Thrace Coast of the western Black Sea. The aim of this study was to determine toxic metal (Hg, Cr, Cd, and Pb) accumulation levels in these species, as well as within littoral sediments from this area. Our results showed that all of the metals, except for Cd, were below that in average shale. The measured accumulation levels were mostly within the range of what is naturally found within the earth’s crust. However, some study stations did have increased concentrations, indicating anthropogenic pollution in these areas.The Cd contents of E. verrucosa collected from all our study stations were well above the limits set by the Turkish Food Codex, especially in Kıyıköy, whereas Pb content was close to the limit at all stations and exceeded the limit in Kıyıköy, but Hg content was below the limit at all stations. Cd content of R. venosa exceeded the limit only in Kumköy. Pb content was below the limit, and Hg was at or slightly above the limit at all stations.
Mostrar más [+] Menos [-]Source determination of benzotriazoles in sediment cores from two urban estuaries on the Atlantic Coast of the United States Texto completo
2015
Cantwell, Mark G. | Sullivan, Julia C. | Katz, David R. | Burgess, Robert M. | Bradford Hubeny, J. | King, John
Benzotriazoles (BZTs) are used in a broad range of commercial and industrial products, particularly as metal corrosion inhibitors and as ultraviolet (UV) light stabilizer additives in plastics and polymers. In this study, dated sediment cores from two east coast estuaries were analyzed for commonly used BZTs. In Narragansett Bay, UV stabilizing BZTs (UV-BZTs) were present at high levels from 1961 on, reflecting their patent date, local production and long-term preservation in sediment. In Salem Sound, UV-BZTs were present at concentrations consistent with other coastal marine locations not influenced by BZT production. Anticorrosive BZTs (AC-BZTs) were found in both cores, with the highest levels reported to date present in Narragansett Bay, indicating sorption to, and preservation in, sediments. This study revealed that both classes of BZTs have remained structurally intact over time in coastal sediment cores, demonstrating their resistance to degradation and persistence in environmental compartments.
Mostrar más [+] Menos [-]Determination of typical lipophilic marine toxins in marine sediments from three coastal bays of China using liquid chromatography–tandem mass spectrometry after accelerated solvent extraction Texto completo
2015
Wang, Yanlong | Chen, Junhui | Li, Zhaoyong | Wang, Shuai | Shi, Qian | Cao, Wei | Zheng, Xiaoling | Sun, Chengjun | Wang, Xiaoru | Zheng, Li
A method based on sample preparation by accelerated solvent extraction and analysis by liquid chromatography–tandem mass spectrometry was validated and used for determination of seven typical lipophilic marine toxins (LMTs) in marine sediment samples collected from three typical coastal bays in China. Satisfactory specificity, reproducibility (RSDs≤14.76%), stability (RSDs≤17.37%), recovery (78.0%–109.0%), and detection limit (3.440pg/g–61.85pg/g) of the developed method were achieved. The results obtained from the analysis of samples from Hangzhou Bay revealed okadaic acid as the predominant LMT with concentrations ranging from 186.0 to 280.7pg/g. Pecenotoxin-2 was quantified in sediment samples from Laizhou Bay at the concentrations from 256.4 to 944.9pg/g. These results suggested that the proposed method was reliable for determining the typical LMTs in marine sediments and that the sediments obtained from Hangzhou Bay, Laizhou Bay and Jiaozhou Bay were all contaminated by certain amounts of LMTs.
Mostrar más [+] Menos [-]East Asian seas: A hot spot of pelagic microplastics Texto completo
2015
Isobe, Atsuhiko | Uchida, Keiichi | Tokai, Tadashi | Iwasaki, Shinsuke
To investigate concentrations of pelagic micro- (<5mm in size) and mesoplastics (>5mm) in the East Asian seas around Japan, field surveys using two vessels were conducted concurrently in summer 2014. The total particle count (pieceskm−2) was computed based on observed concentrations (piecesm−3) of small plastic fragments (both micro- and mesoplastics) collected using neuston nets. The total particle count of microplastics within the study area was 1,720,000pieceskm−2, 16 times greater than in the North Pacific and 27 times greater than in the world oceans. The proportion of mesoplastics increased upstream of the northeastward ocean currents, such that the small plastic fragments collected in the present surveys were considered to have originated in the Yellow Sea and East China Sea southwest of the study area.
Mostrar más [+] Menos [-]Effects of light pollution on the emergent fauna of shallow marine ecosystems: Amphipods as a case study Texto completo
2015
Navarro-Barranco, Carlos | Hughes, Lauren Elizabeth
Light pollution from coastal urban development is a widespread and increasing threat to biodiversity. Many amphipod species migrate between the benthos and the pelagic environment and light seems is a main ecological factor which regulates migration. We explore the effect of artificial lighting on amphipod assemblages using two kind of lights, LED and halogen, and control traps in shallow waters of the Great Barrier Reef. Both types of artificial light traps showed a significantly higher abundance of individuals for all species in comparison to control traps. LED lights showed a stronger effect over the amphipod assemblages, with these traps collecting a higher number of individuals and differing species composition, with some species showing a specific attraction to LED light. As emergent amphipods are a key ecological group in the shallow water environment, the impact of artificial light can affect the broader functioning of the ecosystem.
Mostrar más [+] Menos [-]Fate of Deepwater Horizon oil in Alabama’s beach system: Understanding physical evolution processes based on observational data Texto completo
2015
Hayworth, Joel S. | Prabakhar Clement, T. | John, Gerald F. | Yin, Fang
The impact of MC252 oil on northern Gulf of Mexico (GOM) beaches from the 2010 Deepwater Horizon (DWH) catastrophe was extensive along Alabama’s beaches. While considerable amount of cleanup has occurred along these beaches, as of August 2014, DWH oil spill residues continue to be found as surface residual balls (SRBs), and also occasionally as submerged oil mats (SOMs). Four years of field observations informing the fate and transport of DWH SRBs in Alabama’s beach system are presented here, along with a conceptual framework for describing their physical evolution processes. The observation data show that SRBs containing MC252 residues currently remain in Alabama’s beach system, although their relationship to SOMs is not fully known. Based on our field observations we conclude that small DWH SRBs are likely to persist for several years along the Alabama shoreline.
Mostrar más [+] Menos [-]Polycyclic aromatic hydrocarbons alter the structure of oceanic and oligotrophic microbial food webs Texto completo
2015
Cerezo, Maria Isabel | Agusti, Susana
One way organic pollutants reach remote oceanic regions is by atmospheric transport. During the Malaspina-2010 expedition, across the Atlantic, Indian, and Pacific Oceans, we analyzed the polycyclic aromatic hydrocarbon (PAH) effects on oceanic microbial food webs. We performed perturbation experiments adding PAHs to classic dilution experiments. The phytoplankton growth rates were reduced by more than 5 times, being Prochlorococcus spp. the most affected. 62% of the experiments showed a reduction in the grazing rates due to the presence of PAHs. For the remaining experiments, grazing usually increased likely due to cascading effects. We identified changes in the slope of the relation between the growth rate and the dilution fraction induced by the pollutants, moving from no grazing to V-shape, or to negative slope, indicative of grazing increase by cascade effects and alterations of the grazers' activity structure. Our perturbation experiments indicate that PAHs could influence the structure oceanic food-webs structure.
Mostrar más [+] Menos [-]Baseline monitoring of organic sunscreen compounds along South Carolina's coastal marine environment Texto completo
2015
Bratkovics, Stephanie | Wirth, Edward | Sapozhnikova, Yelena | Pennington, Paul | Sanger, Denise
Organic ultraviolet filters (UV-F) are increasingly being used in personal care products to protect skin and other products from the damaging effects of UV radiation. In this study, marine water was collected monthly for approximately one year from six coastal South Carolina, USA sites and analyzed for the occurrence of seven organic chemicals used as UV filters (avobenzone, dioxybenzone, octocrylene, octinoxate, oxybenzone, padimate-o and sulisobenzone). The results were used to examine the relationship between beach use and the distribution of UV-F compounds along coastal South Carolina, USA. Five of the seven target analytes were detected in seawater along coastal South Carolina during this study. Dioxybenzone and sulisobenzone were not detected. The highest concentrations measured were >3700ng octocrylene/L and ~2200ng oxybenzone/L and beach use was greatest at this site; a local beach front park. Patterns in concentrations were assessed based on season and a measure of beach use.
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