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Geochemical characteristics of rare earth elements in the surface sediments from the Spratly Islands of China 全文
2017
Li, Jingxi | Sun, Chengjun | Zheng, Li | Yin, Xiaofei | Chen, Junhui | Jiang, Fenghua
The geochemistry of rare earth elements (REE) in surface sediment from Cuarteron reef (N1), Johnson reef (N2), Hugh reef (N3), Gaven reef (N4), Fiery cross reef (N5), and Subi reef (N6) were firstly studied. The total REE abundance (∑REE) varied from 2.244μg·g−1 to 21.661μg·g−1, with an average of 4.667μg·g−1. The LREE/HREE was from 2.747 to 9.869, with an average of 3.687, which indicated that the light REE was evidently enriched. Fractionation was observed between LREE and HREE. Gd with a negative anomaly was also detected in all of the stations. The negative anomalies of δEu from 0.11 to 0.25, with an average of 0.22, and the positive anomalies of δCe from 1.38 to 3.86, with an average of 1.63. The REE individual correlation values with Ca, Mn, Mg, Sr were rCa=−0.05, rMn=0.26, rMg=−0.14, and rSr=0.08.
显示更多 [+] 显示较少 [-]Foraging preferences influence microplastic ingestion by six marine fish species from the Texas Gulf Coast 全文
2017
Peters, Colleen A. | Thomas, Peyton A. | Rieper, Kaitlyn B. | Bratton, Susan P.
This study evaluated the influence of foraging preferences on microplastic ingestion by six marine fish species from the Texas Gulf Coast. A total of 1381 fish were analyzed and 42.4% contained ingested microplastic, inclusive of fiber (86.4%), microbead (12.9% %), and fragment (<1.0%) forms. Despite a substantial overlap in diet, ordination of ingested prey items clustered samples into distinctive species groupings, reflective of the foraging gradient among species. Orthopristis chrysoptera displayed the lowest overall frequency of microplastic ingestion and the most distinctive ordination grouping, indicating their selective invertebrate foraging preferences. Cluster analysis of O. chrysoptera most closely classified microplastic with the ingestion of benthic invertebrates, whereas the ingestion of microplastic by all other species most closely classified with the ingestion of vegetation and shrimp. O. chrysoptera, as selective invertebrate foragers, are less likely to ingest microplastics than species exhibiting generalist foraging preferences and methods of prey capture.
显示更多 [+] 显示较少 [-]Physicochemical characterization of Atlantic Canadian seafood processing plant effluent 全文
2017
Jamieson, Bryan Lee | Gagnon, Graham A. | Gonçalves, Alex Augusto
The purpose of this study was to conduct a preliminary assessment of the potential impacts of Atlantic Canadian seafood processing effluents on the aquatic environment through physical-chemical characterization. Shellfish and finfish effluent samples were collected and characterized by biochemical oxygen demand (BOD5), chemical oxygen demand (COD), turbidity, total suspended solids (TSS), ammonia nitrogen (NH3-N), adsorbable organic halides (AOX), soluble BOD5 and soluble COD. Effluent concentration ranges were BOD5 (179 to 276mgL−1), COD (458 to 1717mgL−1), turbidity (28.8 to 88.3NTU), TSS (27.2 to 120.1mgL−1), NH3-N (1.5 to 12.9mgL−1) and AOX (3.2 and 0.4mgL−1) for flatfish and salmon processing effluents respectively, and cleanup shift AOX (3.5 and 0.5mgL−1). The characteristics of these effluents assessed have the potential to contaminate and degrade receiving water body environments. Improved performance may be possible with further treatment technology optimization on an effluent-specific basis.
显示更多 [+] 显示较少 [-]The Persistent Environmental Relevance of Soil Phosphorus Sorption Saturation 全文
2017
Kleinman, Peter J. A.
Controlling phosphorus (P) loss from agricultural soils remains a priority pollution concern in much of the world. Dissolved forms of P loss are among the most difficult to manage. The concept of soil P sorption saturation, the extent to which a soil’s binding sites for P are occupied, emerged from the Netherlands in the 1990s and has broad appeal as both environmental indicator and management paradigm. For hydrologically active and connected soils, P sorption saturation is responsible for the stubborn problem of legacy P, resulting in long-term release of dissolved forms of P from soils. Short- and long-term mitigation options for elevated soil P sorption saturation do exist, all with trade-offs that require adoption of new mitigation and prevention strategies. Ultimately, better incorporation of soil P sorption saturation into both crop fertility and environmental management programs is needed to promote the sustainable management of P in agricultural production systems.
显示更多 [+] 显示较少 [-]Polycyclic aromatic hydrocarbons (PAHs) in traditionally harvested bivalves in northern British Columbia, Canada 全文
2017
Thompson, Kim-Ly | Picard, Chris R. | Chan, Hing Man
Butter clams, blue mussels, and Nuttall's cockle are important traditional food of the Gitga'at First Nation in Canada. Samples were collected and analyzed for polycyclic aromatic hydrocarbon (PAH) from the Gitga'at harvest sites from 2006 to 2015 to: 1) establish baseline conditions; 2) determine the likely source; 3) understand species specific response to spills; and 4) evaluate health risk associated with consumption. Baseline lipid normalized-total PAH in mussels was 2.36 (±2.86, 95%CI) μg/g in mussels, 3.26(±4.14) μg/g in clams and 3.98 (±4.98) μg/g in cockles. PAHs varied according to proximity to point sources and became less petrogenic through time. Concentrations of PAHs were elevated in all three species following diesel spills but returned to baseline levels within 5months. However, Gitga'at harvesters avoided bivalves from spill-affected habitats for several years because of their detection of reduced quality and palatability, highlighting the importance of incorporating local knowledge into future monitoring programs.
显示更多 [+] 显示较少 [-]Presence of plastic litter in pellets from Great Cormorant (Phalacrocorax carbo) in Ireland 全文
2017
Acampora, Heidi | Berrow, Simon | Newton, Stephen | O'Connor, Ian
Plastic pollution has been the subject of much research in the last decade. Seabirds can mistake plastic fragments for prey, which can perforate or block the digestive tract and cause ulcers. Most commonly, seabirds accumulate this indigestible matter in their stomachs, obtaining no nutrition and may die from starvation. Certain species of seabirds however, have the ability of regurgitating indigestible matter in the form of pellets. This study aimed to investigate the ingestion of plastics by live seabirds through the examination of regurgitated pellets (n=92) from a Great Cormorant (Phalacrocorax carbo) breeding colony and a winter roost in Ireland. Plastic prevalence was consistently 3.2% at both sites. The presence of plastic litter highlights the fact that all species of seabird are susceptible to interact with marine litter regardless of feeding habits, although at different rates. More research is needed to understand the driving factors involved in plastic ingestion among different species.
显示更多 [+] 显示较少 [-]Investigation of plastic debris ingestion by four species of sea turtles collected as bycatch in pelagic Pacific longline fisheries 全文
2017
Clukey, Katharine E. | Lepczyk, Christopher A. | Balazs, George H. | Work, Thierry M. | Lynch, Jennifer M.
Ingestion of marine debris is an established threat to sea turtles. The amount, type, color and location of ingested plastics in the gastrointestinal tracts of 55 sea turtles from Pacific longline fisheries from 2012 to 2016 were quantified, and compared across species, turtle length, body condition, sex, capture location, season and year. Six approaches for quantifying amounts of ingested plastic strongly correlated with one another and included: number of pieces, mass, volume and surface area of plastics, ratio of plastic mass to body mass, and percentage of the mass of gut contents consisting of plastic. All olive ridley (n=37), 90% of green (n=10), 80% of loggerhead (n=5) and 0% of leatherback (n=3) turtles had ingested plastic; green turtles ingested significantly more than olive ridleys. Most debris was in the large intestines. No adverse health impacts (intestinal lesions, blockage, or poor body condition) due directly to plastic ingestion were noted.
显示更多 [+] 显示较少 [-]Understanding ozone formation at two islands of Rio de Janeiro, Brazil 全文
2017
Gioda, Adriana | Oliveira, Rafael C.G. | Cunha, Camilla L. | Corrêa, Sergio M.
This study was to evaluate the influence of vehicular emissions on two islands located in the Guanabara Bay, Metropolitan Area of Rio de Janeiro city, one of them without the presence of vehicles (Paquetá Island - PI) and another with a considerable fleet (Governador Island - GI). The data used correspond to the hourly averages of the years 2012 and 2013 for nitrogen oxides (NOx, NO2 and NO), ozone (O3), carbon monoxide (CO), total hydrocarbons (THC), aromatic hydrocarbons (BTEX), as well as meteorological data. To interpret the results, a multivariate statistic was used in order to characterize the impact of the vehicle fleet on air quality. The results showed that CO and NOx levels were 2–6 times higher in GI than PI. On the other hand, THC levels were similar at both sites. Surprisingly, O3 levels were up to 1.5 times greater in PI than in GI. The possible explanation for these higher levels is related to the formation process from THC and NOx in the presence of sunlight. The THC/NOx and NOx/NO ratios for PI are much higher than those found for GI, thus explaining the high ozone values for a location with virtually no vehicle fleet and industrial activities. The benzene, toluene and xylene levels at both sites were of the same magnitude order, however, ethyl benzene was about 7-fold higher in PI.
显示更多 [+] 显示较少 [-]Differential expression of survival proteins during decreased intracellular oxygen tension in brain endothelial cells of grey mullets 全文
2017
Ekambaram, Padmini | Narayanan, Meenakshi | Parasuraman, Parimala
The brain requires constant oxygen supply to perform its biological functions essential for survival. Because of low oxygen capacity and poor oxygen diffusibility of water, many fish species have evolved various adaptive mechanisms to cope with depleted oxygen. Endothelial cells (EC) are the primary components responsible for controlled environment of brain. Brain homeostasis largely depends on integrity of the EC. To elucidate their adaptive strategy, EC were isolated from the fish brain of Kovalam-control site and Ennore estuary-test/field hypoxic site and were subjected to low oxygen tension in laboratory. Cell viability, 4-hydroxynonenal (4HNE) and total antioxidant capacity (TAC) were analyzed to ascertain stress. Hypoxic insult, cytoprotective role of HSPs and apoptotic effect were analyzed by assessing hypoxia-inducible-factor-α (HIF1α), heat-shock-protein-70 (HSP70), heme-oxygenase 1 (HO-1), and apoptosis signal regulating kinase-1 (ASK1). This study evidenced that HSP70 and HO-1 are the key stress proteins, confer high tolerance to decreased oxygen tension mediated stress.
显示更多 [+] 显示较少 [-]Chlorination induced damage and recovery in marine diatoms: Assay by SYTOX® Green staining 全文
2017
Venkatnarayanan, Srinivas | Sriyutha Murthy, P. | Nancharaiah, Yarlagadda V. | Kirubagaran, Ramalingam | Venugopalan, Vayalam P.
Phytoplankton entrained into cooling water systems of coastal power stations are subjected to acute chemical stress due to biocides (chlorine) used for biofouling control. They are subsequently released into the environment, where they may survive/recover or succumb. Experiments were conducted to evaluate the susceptibility of a centric (Chaetoceros lorenzianus) and pennate (Navicula sp.) diatom to in-plant administered concentrations of chlorine (0.2–0.5mg/L, TRO). Viability of cells exposed to chlorine was assessed by SYTOX® Green fluorimetry and was compared with other conventional end points like total cell counts, chlorophyll a content and cellular autofluorescence. Results showed a concentration-dependant reduction in viability, chlorophyll a and autofluorescence. C. lorenzianus cells were more susceptible to chlorine compared to Navicula sp. SYTOX® Green staining appears to be a sensitive method to assess chlorine-induced damages. The data show that in-use levels of chlorination can potentially impact entrained organisms; however, they can recover when returned to coastal waters.
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