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Diversity of culturable yeasts associated with zoanthids from Brazilian reef and its relation with anthropogenic disturbance 全文
2017
Paulino, Gustavo Vasconcelos Bastos | Félix, Ciro Ramon | Broetto, Leonardo | Landell, Melissa Fontes
Some of the main threats to coral reefs come from human actions on marine environment, such as tourism, overfishing and pollution from urban development. While several studies have demonstrated an association between bacteria and corals, demonstrating how these communities react to different anthropogenic stressors, yeast communities associated with corals have received far less attention from researchers. The aim of this work was therefore to describe cultivable yeasts associated with three coral species and to evaluate the influence of sewage discharge on yeasts community. We obtained 130 isolates, mostly belonging to phylum Ascomycota and many of them had previously been isolated from human samples or are considered pathogens. The mycobiota was more similar among corals collected from the same reef, indicating that the composition of reef yeast community is more influenced by environmental conditions than host species. We suggest further studies to elucidate which factors are most influential on the composition of the coral-associated yeast community.
显示更多 [+] 显示较少 [-]Estrogenic compound profiles in an urbanized industry-impacted coastal bay and potential risk assessment by pollution indices and multivariative statistical methods 全文
2017
Wang, Zaosheng | Li, Rui | Wu, Fengchang | Feng, Chenglian | Ye, Chun | Yan, Changzhou
The occurrence and distribution of target estrogenic compounds in a highly urbanized industry-impacted coastal bay were investigated, and contamination profiles were evaluated by estimating total estradiol equivalents (∑EEQs) and risk quotients (RQs). Phenolic compounds were the most abundant xenoestrogens, but seldom showed contribution to the ∑EEQs. The diethylstilbestrol (DES) and 17α-ethinylestradiol (EE2) were the major contributors followed by 17β-estradiol (E2) in comparison with a slight contribution from estrone (E1) and estriol (E3). Both ∑EEQs and RQs indicated likely adverse effects posed on resident organisms. Further, multivariate statistical method comprehensively revealed pollution status by visualized factor scores and identified multiple “hotspots” of estrogenic sources, demonstrating the presence of complex pollution risk gradients inside and particularly outside of bay area. Overall, this study favors the integrative utilization of pollution indices and factor analysis as powerful tool to scientifically diagnose the pollution characterization of human-derived chemicals for better management decisions in aquatic environments.
显示更多 [+] 显示较少 [-]The first assessment of marine debris in a Site of Community Importance in the north-western Adriatic Sea (Mediterranean Sea) 全文
2017
Melli, Valentina | Angiolillo, Michela | Ronchi, Francesca | Canese, Simonepietro | Giovanardi, Otello | Querin, Stefano | Fortibuoni, Tomaso
At present, few studies have investigated the marine litter abundance, composition and distribution on rocky bottoms due to sampling constraints. We surveyed by means of the ROV imaging technique a system of biogenic rocky outcrops classified as a Site of Community Importance in the Adriatic Sea. A mean density of 3.3 (±1.8) items/100m2 was recorded, with a strong dominance of fishing- and aquaculture-related debris, accounting for 69.4% and 18.9% of the total, respectively. The abundance of litter over the rocky bottoms was significantly higher than that on soft substrates, and its spatial distribution proved to be related to hydrographic factors. Litter-fauna interactions were high, with most of the debris (65.7%) entangling or covering benthic organisms, in particular habitat constructors such as the endangered sea sponge Geodia cydonium. Unless appropriate measures are undertaken to address this problem, the abundance of marine litter in the area is likely to increase.
显示更多 [+] 显示较少 [-]Distribution and source of organic matter in surface sediment from the muddy deposit along the Zhejiang coast, East China Sea 全文
2017
Xu, Gang | Liu, Jian | Hu, Gang | Jonell, Tara N. | Chen, Lilei
To constrain organic matter compositions and origins, elemental (TOC, TN, C/N) and stable carbon (δ13C) and nitrogen isotope (δ15N) compositions are measured for surface sediments collected from muddy deposit along the Zhejiang coast, East China Sea. The results showed that the TOC, TN, C/N, δ13C, and δ15N were 0.19–0.67%, 0.03–0.09%, 6.76–9.22, −23.43 to −20.26‰, and 3.93–5.27‰, respectively. The δ13C values showed that the mixing inputs of terrigenous and marine organic matter generally dominated sedimentary organic matter in the west part, and the sedimentary organic matters were mainly influenced by the marine organic matter in the east part of the study area. A stable carbon isotope two end member mixing model estimates ~38% terrestrial -derived and ~62% marine-derived inputs to sedimentary organic matter. Microbial mineralization strongly controls δ15N values, and therefore cannot be used to identify the provenance of organic matter for the Zhenjiang coast.
显示更多 [+] 显示较少 [-]3D modeling of phytoplankton seasonal variation and nutrient budget in a southern Mediterranean Lagoon 全文
2017
Béjaoui, Béchir | Solidoro, Cosimo | Harzallah, Ali | Chevalier, Cristèle | Chapelle, Annie | Zaaboub, Noureddine | Aleya, Lotfi
A 3D coupled physical-biogeochemical model is developed and applied to Bizerte Lagoon (Tunisia), in order to understand and quantitatively assess its hydrobiological functioning and nutrients budget. The biogeochemical module accounts for nitrogen and phosphorus and includes the water column and upper sediment layer. The simulations showed that water circulation and the seasonal patterns of nutrients, phytoplankton and dissolved oxygen were satisfactorily reproduced. Model results indicate that water circulation in the lagoon is driven mainly by tide and wind. Plankton primary production is co-limited by phosphorus and nitrogen, and is highest in the inner part of the lagoon, due to the combined effects of high water residence time and high nutrient inputs from the boundary. However, a sensitivity analysis highlights the importance of exchanges with the Mediterranean Sea in maintaining a high level of productivity. Intensive use of fertilizers in the catchment area has a significant effect on phytoplankton biomass increase.
显示更多 [+] 显示较少 [-]Immunotoxic effects of single and combined pharmaceuticals exposure on a harbor seal (Phoca vitulina) B lymphoma cell line 全文
2017
Kleinert, Christine | Lacaze, Emilie | Mounier, Méryl | De Guise, Sylvain | Fournier, Michel
The potential risk of pharmaceuticals in the environment to top-predators is still largely unknown. In this study, we assessed the immunotoxic effects of ten pharmaceuticals individually and as mixtures on a harbor seal (Phoca vitulina) B lymphoma cell line. A significant reduction in lymphocyte transformation was observed following an exposure to 12,500μg/L 17α-ethinyl estradiol and 25,000μg/L naproxen. Exposure to 12,500μg/L 17α-ethinyl estradiol decreased the percentage of cell in the G0/G1 phase of the cell cycle while increasing the percentage of cells in the S phase. Carbamazepine exposure increased the amount of cells in the G2/M phase. Binary mixtures showed synergistic effects in lymphocyte transformation, cell cycle and apoptosis assays. Concentrations inducing toxic effects in the cell line were similar to those affecting fish in previous studies. A reduction of functional activities of the immune system may lead to altered host resistance to pathogens in free-ranging pinnipeds.
显示更多 [+] 显示较少 [-]Detection of metal induced cytopathological alterations and DNA damage in the gills and hepatopancreas of green mussel Perna viridis from Ennore Estuary, Chennai, India 全文
2017
Vasanthi, Lourduraj A. | Revathi, Peranandam | Babu Rajendran, Ramaswamy | Munuswamy, Natesan
This study report the impact of heavy metals on cytopathology and DNA damage in the gills and hepatopancreas of Perna viridis collected from Ennore estuary and the Kovalam coastal waters. Principal Component Analysis (PCA) showed significant differences among all variables at the scale of plots. The ultrastructural alterations such as lack of microvilli, distorted mitochondria, electron dense particles and the presence of large mucous droplets were common in the gill and hepatopancreatic cells of mussels from Ennore estuary. However, the gill and hepatopancreatic cells of P. viridis from Kovalam revealed normal compartmentalization of cells. The percentage of tail DNA in the mussels from Ennore estuary was recorded as 12.44 and 10.14% in the gills and hepatopancreas respectively. Overall, it has been demonstrated that the Comet and cytopathological assays are useful biomarkers to assess the level of pollution and it provide reliable information on ecotoxicology and genotoxicology of coastal waters.
显示更多 [+] 显示较少 [-]Modelling dispersal of radioactive contaminants in Arctic waters as a result of potential recovery operations on the dumped submarine K-27 全文
2017
Karcher, M. | Hosseini, A. | Schnur, R. | Kauker, F. | Brown, J.E. | Dowdall, M. | Strand, P.
Modelling dispersal of radioactive contaminants in Arctic waters as a result of potential recovery operations on the dumped submarine K-27 全文
2017
Karcher, M. | Hosseini, A. | Schnur, R. | Kauker, F. | Brown, J.E. | Dowdall, M. | Strand, P.
Of the wide variety of dumped objects containing radioactive materials in the Arctic seas, the submarine K-27 constitutes a major risk due to the large amount of highly enriched uranium onboard and its location in shallow waters. As the matter of potential operations involving raising of the submarine have entered the public arena, a priori assessment of the contamination in the Arctic marine environment that could result after a possible accident during such operations is a matter of some interest. The dispersion of contaminants within the Arctic has been assessed using a large scale hydrodynamic model for a series of plausible accident scenarios and locations under different oceanographic regimes. Results indicate that, depending primarily on the nature of a release (i.e. instantaneous or continuous), large areas of the Arctic marine environment will exhibit contamination to varying degrees.
显示更多 [+] 显示较少 [-]Modelling dispersal of radioactive contaminants in Arctic waters as a result of potential recovery operations on the dumped submarine K-27 全文
2017
Karcher, Michael | Hosseini, A. | Schnur, R. | Kauker, Frank | Brown, J.E. | Dowdall, M. | Strand, P.
Of the wide variety of dumped objects containing radioactive materials in the Arctic seas, the submarine K-27 constitutes a major risk due to the large amount of highly enriched uranium onboard and its location in shallow waters. As the matter of potential operations involving raising of the submarine have entered the public arena, a priori assessment of the contamination in the Arctic marine environment that could result after a possible accident during such operations is a matter of some interest. The dispersion of contaminants within the Arctic has been assessed using a large scale hydrodynamic model for a series of plausible accident scenarios and locations under different oceanographic regimes. Results indicate that, depending primarily on the nature of a release (i.e. instantaneous or continuous), large areas of the Arctic marine environment will exhibit contamination to varying degrees.
显示更多 [+] 显示较少 [-]Uncertainty quantification and reliability assessment in operational oil spill forecast modeling system 全文
2017
Hou, Xianlong | Hodges, Ben R. | Feng, Dongyu | Liu, Qixiao
As oil transport increasing in the Texas bays, greater risks of ship collisions will become a challenge, yielding oil spill accidents as a consequence. To minimize the ecological damage and optimize rapid response, emergency managers need to be informed with how fast and where oil will spread as soon as possible after a spill. The state-of-the-art operational oil spill forecast modeling system improves the oil spill response into a new stage. However uncertainty due to predicted data inputs often elicits compromise on the reliability of the forecast result, leading to misdirection in contingency planning. Thus understanding the forecast uncertainty and reliability become significant. In this paper, Monte Carlo simulation is implemented to provide parameters to generate forecast probability maps. The oil spill forecast uncertainty is thus quantified by comparing the forecast probability map and the associated hindcast simulation. A HyosPy-based simple statistic model is developed to assess the reliability of an oil spill forecast in term of belief degree. The technologies developed in this study create a prototype for uncertainty and reliability analysis in numerical oil spill forecast modeling system, providing emergency managers to improve the capability of real time operational oil spill response and impact assessment.
显示更多 [+] 显示较少 [-]Differences in the structure of copepod assemblages in four tropical estuaries: Importance of pollution and the estuary hydrodynamics 全文
2017
Araujo, Adriana V. | Dias, Cristina O. | Bonecker, Sérgio L.C.
We examined the relationship between pollution and structure of copepod assemblages in estuaries, using sampling standardization of salinity range to reduce the effects of “Estuarine Quality Paradox”. Copepod assemblages were analyzed in four Southeast Brazilian estuaries with different water quality levels and different hydrodynamic characteristics. The pollution negatively impacted the descriptors of the assemblage structure. The distribution of structure of copepod assemblages also showed a main separation trend between the most polluted estuaries and those less polluted. Temperature was the main factor affecting the assemblage structuring in the four estuaries. This factor acted in synergism with the effects of pollution impact and physical characteristics of the estuaries on the structure of copepod assemblages, supporting the potential vulnerability of coastal environments due to nutrient enrichment associated with climate change. Our study demonstrated the importance of sampling standardization of the salinity range in estuaries for reliable analysis of pollution effects on biota.
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