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NMR-based metabolomics for the environmental assessment of Kaohsiung Harbor sediments exemplified by a marine amphipod (Hyalella azteca) Полный текст
2017
Chiu, K.H. | Dong, C.D. | Chen, C.F. | Tsai, M.L. | Ju, Y.R. | Chen, T.M. | Chen, C.W.
Inflow of wastewater from upstream causes a large flux of pollutants to enter Kaohsiung Harbor in Taiwan daily. To reveal the ecological risk posed by Kaohsiung Harbor sediments, an ecological metabolomic approach was employed to investigate environmental factors pertinent to the physiological regulation of the marine amphipod Hyalella azteca. The amphipods were exposed to sediments collected from different stream inlets of the Love River (LR), Canon River (CR), Jen-Gen River (JR), and Salt River (SR). Harbor entrance 1 (E1) was selected as a reference site. After 10-day exposure, metabolomic analysis of the Hyalella azteca revealed differences between two groups: {E1, LR, CR} and {JR, SR}. The metabolic pathways identified in the two groups of amphipods were significantly different. The results demonstrated that NMR-based metabolomics can be effectively used to characterize metabolic response related to sediment from polluted areas.
Показать больше [+] Меньше [-]Degradation of common polymer ropes in a sublittoral marine environment Полный текст
2017
Welden, Natalie A. | Cowie, Phillip R.
Contamination by microplastic particles and fibres has been observed in sediment and animals sampled from the Firth of Clyde, West Scotland. In addition to microplastics released during clothes washing, a probable source is polymer ropes in abandoned, lost and discarded fishing and recreational sailing gear. The fragmentation of polypropylene, polyethylene, and nylon exposed to benthic conditions at 10m depth over 12months was monitored using changes in weight and tensile properties. Water temperature and light levels were continuously monitored. The degree of biofouling was measured using chlorophyll a, the weight of attached macroalgae, and colonising fauna. Results indicate microplastic fibres and particles may be formed in benthic environments despite reduced photodegradation. Polypropylene, Nylon, and polyethylene lost an average of 0.39%, 1.02%, and 0.45% of their mass per month respectively. Microscope images of the rope surface revealed notable surface roughening believed to be caused by abrasion by substrate and the action of fouling organisms.
Показать больше [+] Меньше [-]Vertical distribution, composition profiles, sources and toxicity assessment of PAH residues in the reclaimed mudflat sediments from the adjacent Thane Creek of Mumbai Полный текст
2017
Basavaiah, N. | Mohite, R.D. | Singare, P.U. | Reddy, A.V.R. | Singhal, R.K. | Blaha, U.
A study on vertical distribution of magnetic susceptibility, carcinogenic and endocrine disrupting PAHs was performed in the reclaimed mudflat sediments adjacent to the Thane Creek of Mumbai. The 5-rings PAHs and ΣC-PAHs were more dominant at 120cm depth contributing 52.23% and 60.19% respectively to ∑PAHs. The average ratio values of LMW/HMW PAHs (0.58); Fla/(Fla+Pyr) (0.50); Ant/(Ant+Phe) (0.50); BaA/(Chry+BaA) (0.48); BaP/BghiP (2.06), Phe/Ant (1.03) and BaA/Chr (0.93) indicate that the PAH contamination might have raised due to inefficient combustion and pyrogenic emissions during the open burning of solid waste in the vicinity. This was further supported by the anthropogenic ferri(o)magnetic loading over the last 100years influencing the Creek sediments. The PAHs toxicity estimation was performed by calculating the toxic equivalent quantity (TEQ) value of 8.62ng TEQ/g which was below the safe level (600ng TEQ/g) suggested by the Canadian risk-based soil criterion for protection of human health.
Показать больше [+] Меньше [-]Abundance and composition of juvenile corals reveals divergent trajectories for coral assemblages across the United Arab Emirates Полный текст
2017
Pratchett, Morgan S. | Baird, Andrew H. | Bauman, Andrew G. | Burt, John A.
Marked shifts in the composition of coral assemblages are occurring at many locations, but it is unknown whether these are permanent shifts reinforced by patterns of population replenishment. This study examined the composition of juvenile coral assemblages across the United Arab Emirates (UAE). Densities of juvenile corals varied significantly among locations, but were highest where coral cover was highest. Juvenile coral assemblages within the Persian Gulf were dominated by Porites, while no Acropora were recorded. We expect therefore, continued declines in Acropora abundance, while observed dominance of Porites is likely to persist. In the Oman Sea, Pocillopora was the dominant juvenile coral, with Acropora and Stylophora also recorded. This study shows that taxonomic differences in replenishment are reinforcing temporal shifts in coral composition within the southern Persian Gulf, but not in the Oman Sea. Differences in environmental conditions and disturbance regimes likely explain the divergent responses between regions.
Показать больше [+] Меньше [-]Microplastics elutriation system. Part A: Numerical modeling Полный текст
2017
Kedzierski, Mikaël | Le Tilly, Véronique | Bourseau, Patrick | Bellegou, Hervé | César, Guy | Sire, Olivier | Bruzaud, Stéphane
The elutriation process has shown its efficiency to extract microplastics from sand and began to spread in the scientific community. This extraction technic requires knowing with accuracy the extraction velocities of particles. This study aims to test whether numerical modeling could help to calculate these velocities. From hydrodynamic equations, a numerical model has been developed and the outputs are compared to experimental extraction data. The results show, for the calculated velocities, the experimental plastic extraction yields will be higher than 90% for <10% of sand contamination. The model also allows determining that, with the actual protocol, the maximum plastic density which can be extracted is about 1450kg·m−3 whereas the detrimental resuspension, which may occur during the column filling step, is highlighted. From model calculations, it arises that changes in the column dimensioning and the protocol operations need to be considered.
Показать больше [+] Меньше [-]Trace metals in sediments and benthic animals from aquaculture ponds near a mangrove wetland in Southern China Полный текст
2017
Wu, Hao | Liu, Jinling | Bi, Xiangyang | Lin, Guanghui | Feng, Christopher C | Li, Zhengjie | Qi, Fei | Zheng, Tianling | Xie, Liqi
In this study, we measured the concentrations of trace metals (Cr, Cu, Zn, As, Cd, Pb and Hg) in typical cultured animals (crabs, clams, and shrimps) and sediments from aquaculture ponds nearby mangrove wetlands in Zhangjiang estuary, China. The contents of Cr, Cu, Cd, and Pb in mangrove sediments were significantly higher than those in pond sediments, while an inverse distribution was observed for Zn, As, and Hg. Significantly higher concentrations of trace metals were found in clams from the mangrove mudflats compared to those from the aquaculture ponds. The sources of trace metals in the clams were primarily from organic fertilizer, whereas those in the shrimp were from contaminated sediment. The results of geo-accumulation index and the ecological risk assessment indicated that the aquaculture ponds near the mangrove wetlands in this subtropical estuary posed a special risk of endogenous and exogenous trace metal pollution to nearby systems.
Показать больше [+] Меньше [-]Surface sediment properties and heavy metal pollution assessment in the Shallow Sea Wetland of the Liaodong Bay, China Полный текст
2017
Wang, Jin | Ye, Siyuan | Laws, Edward A. | Yuan, Hongming | Ding, Xigui | Zhao, Guangming
Liaodong Bay, a semi-enclosed bay located in northeastern China, is impacted by the discharges of five rivers. We analyzed 100 surface sediment samples from the Shallow Sea Wetland of Liaodong Bay for grain size and concentrations of organic carbon (Corg) and heavy metals. The ranges of the heavy metal concentrations were 2.32–17μg/g (As), 0.025–1.03μg/g (Cd), 18.9–131μg/g (Cr), 4.6–36.1μg/g (Cu), 0.012–0.29μg/g (Hg), 13.7–33.9μg/g (Pb), and 17.4–159μg/g (Zn). Pollution assessments revealed that some stations were moderately to highly polluted with As, Cd, and Hg. Severe pollution was apparent in the Xiaoling River estuary; lower concentrations of heavy metals were observed in other river mouths, where the sediments were more coarse. The distributions of the heavy metals were closely associated with Corg and grain size.
Показать больше [+] Меньше [-]Impact of vineyard cover cropping on carbon dioxide and nitrous oxide emissions in Portugal Полный текст
2017
Marques, Francisco J.M. | Pedroso, Vanda | Trindade, Henrique | Pereira, José L.S.
Scarce studies have been published reporting field measurements of nitrous oxide (N2O) emissions from vineyards, particularly for European conditions. The aim this study was to assess the effect of conventional tillage and no-tillage cover crops on direct N2O emission factor from vineyards (Vitis vinifera L.) in Portugal. A two-year field study was carried out in central Portugal (Nelas, Portugal). The experiment was established in a mature non-irrigated vineyard. The following four treatments with three replications were considered: soil tillage of the inter-row (Till), treatment Till followed by application of mineral fertiliser (50 kg N ha−1) (Till + N), permanent resident vegetation in the inter-row (NoTill), and treatment No-Till followed by application of mineral fertiliser (50 kg N ha−1) (NoTill + N). The carbon dioxide (CO2) and N2O fluxes were measured by the closed chamber technique and analysed by gas chromatography during two consecutive growing seasons (Mars-September of 2015 and 2016) of the grapevine crop. The results showed that the average direct N2O EF for vineyards managed with conventional soil tillage in the inter-row was 0.57 ± 0.12% of N input and cover cropping by permanent resident vegetation in the inter-row reduces N2O emission in 60% (0.23 ± 0.29% of N input). Thus, the vineyard cover cropping was recommended as mitigation measure in order to reduce N2O emissions. The defaults direct N2O EF currently recommended by IPCC was not appropriated for vineyards and N2O emissions are currently potentially overestimated in the Portuguese inventory.
Показать больше [+] Меньше [-]Significance of beach geomorphology on fecal indicator bacteria levels Полный текст
2017
Donahue, Allison | Feng, Zhixuan | Kelly, Elizabeth | Reniers, Ad | Solo-Gabriele, Helena M.
Large databases of fecal indicator bacteria (FIB) measurements are available for coastal waters. With the assistance of satellite imagery, we illustrated the power of assessing data for many sites by evaluating beach features such as geomorphology, distance from rivers and canals, presence of piers and causeways, and degree of urbanization coupled with the enterococci FIB database for the state of Florida. We found that beach geomorphology was the primary characteristic associated with enterococci levels that exceeded regulatory guidelines. Beaches in close proximity to marshes or within bays had higher enterococci exceedances in comparison to open coast beaches. For open coast beaches, greater enterococci exceedances were associated with nearby rivers and higher levels of urbanization. Piers and causeways had a minimal contribution, as their effect was often overwhelmed by beach geomorphology. Results can be used to understand the potential causes of elevated enterococci levels and to promote public health.
Показать больше [+] Меньше [-]Marine debris ingestion by the South American Fur Seal from the Southwest Atlantic Ocean Полный текст
2017
Denuncio, Pablo | Mandiola, María Agustina | Pérez Salles, Sofía Belén | Machado González Prada, Rodrigo | Ott, Paulo H. | De Oliveira, Larissa Rosa | Rodríguez, Diego
In this paper, we examined the ingestion of marine debris (MD) in South American fur seals (SAFS), Arctocephalus australis, found dead in coastal beaches of northern Argentina and southern Brazil. Seven percent of 133 SAFS analyzed presented marine debris in their stomach (n=10), with no differences between sampling countries (Brazil n=7, Argentina n=3) and sexes (female=3; male=6). However, significant differences were observed between ages classes, with MD exclusively present in stomach contents of young specimens. Plastics represents 90% of MD ingested by the SAFS, whereas regarding the source, fishery-related items (e.g. monofilament lines) were the main MD (70%), with a lesser proportion of packaging (e.g. pieces of bags). Low numbers but large size pieces of MD were found in each stomach affected. Negative effects on the individuals could not be fully evaluated. Therefore, the potential impacts of the marine debris to the SAFS deserve further elucidation.
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