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Результаты 1741-1750 из 4,896
The chemical behaviors of microplastics in marine environment: A review
2019
Guo, Xuan | Wang, Jianlong
Microplastics are widely existed in marine and coastal environments, which aroused global concern in recent years. This review mainly summarized the interactions of organic pollutants and metals with microplastics based on environmental monitoring results and laboratory results reported by literatures. Firstly, the type, properties, and distribution of microplastics in the environment were briefly reviewed. Secondly, the property changes of microplastics after degradation were discussed. Thirdly, the concentrations of pollutants on microplastics in global environments were summarized. Then the effect of the factors (e.g. types and properties of microplastics, types of pollutants, and environmental conditions) on the sorption behaviors of microplastics were discussed in detail. Finally, the influences of microplastics on marine organisms were briefly evaluated.
Показать больше [+] Меньше [-]Evaluation of bioconcentration and metabolism of diclofenac in mussels Mytilus trossulus - laboratory study
2019
Świacka, Klaudia | Szaniawska, Anna | Caban, Magda
Interest in the presence of pharmaceutically active compounds in the aquatic environment has been growing for over 20 years, yet very few studies deal with the metabolism of pharmaceuticals in marine organisms. In this study, the bioaccumulation under short-term conditions and metabolism of diclofenac were investigated. Mytilus trossulus was used as a representative of the Baltic benthic fauna. The mussels were exposed to diclofenac at a concentration of 133.33 μg/L for five days, following a five-day depuration phase. The highest concentration of diclofenac (7.79 μg/g dw) in tissues was determined on day 3. Subsequently, the concentration of diclofenac in tissues decreased rapidly to 0.86 μg/g dw on day 5. After five days of depuration, the concentration of diclofenac was 0.21 μg/g dw. Hydroxylated diclofenac metabolites were found both in tissues of mussels and water. This study shows that M. trossulus has the potential to accumulate diclofenac and metabolize it to 4-OH and 5-OH diclofenac.
Показать больше [+] Меньше [-]Insight into tidal disturbance on colonization surveys for marine bioassessment using periphytic ciliates based on biological trait analysis
2019
Zhong, Xiaoxiao | Xu, Guangjian | Min, Gi-Sik | Kim, Sanghee | Xu, Henglong
To understand tidal disturbance on the colonization dynamics in community functioning of the ciliates in marine ecosystems, a 1-month survey was conducted using the conventional slide system (CS) and the polyurethane foam enveloped slide system (PFES) in Korean coastal waters. The results showed considerable differences were detected in community functioning parameters between the two systems. The vagile, flattened forms feeding on periphytic microalgae showed a higher community-weighted mean (CWM) value, and the solitary-colonial pattern represented a more stable temporal variability during the colonization in the PFES system than the CS system. The temporal shift in community functioning of the ciliates showed different ways in both systems. The functional diversity measures generally levelled off at more stable values in the communities with ages of 13–15 days in the PFES system than the CS system. These results imply that the PFES system may be a workable method for bioassessment in marine ecosystems.
Показать больше [+] Меньше [-]Pinniped entanglement in oceanic plastic pollution: A global review
2019
Jepsen, Emma M. | de Bruyn, P.J Nico
Oceanic plastic pollution is a growing worldwide environmental concern, endangering numerous marine species. Pinnipeds are particularly susceptible to entanglement, especially in abandoned, lost or discarded fishing gear and packaging straps. We searched three international databases to compile a comprehensive review of all reported pinniped entanglements over the last 40 years, with the aim to identify areas of concern and foci for mitigation. The majority of published records of entanglement emanate from North America and Oceania and are focused on a few populous species (notably, Zalophus californianus and Arctocephalus gazella). Reporting bias, skewed research effort and incomplete understanding of plastic pollution and pinniped abundance overlap, combine to cloud our understanding of the entanglement problem. Broader geographical effort in entanglement data collection, reporting of such data, and improved quantification of the proportions of populations, sexes and ages that are most susceptible, will aid our efforts to pinpoint priority mitigation measures.
Показать больше [+] Меньше [-]Health Effects of Climate Change Through Temperature and Air Pollution
2019
Lou, Jianing | Wu, Yangyang | Liu, Penghui | Kota, Sri Harsha | Huang, Lei
PURPOSE OF REVIEW: Recognizing health effects of changes in temperature caused by climate change and changes in air pollution affected by temperature changes on human health, predicting the health effects of both future temperature changes and air quality changes caused by climate change is critical to adopting a range of measures to respond to future climate change. The purpose of this review is to summarize studies on the health effects of temperature and air quality changes affected by climate change directly or indirectly, and to summarize the limitations of these studies. RECENT FINDINGS: After summarizing the main methods and results, we conclude that past temperature changes and air pollution caused by climate change directly or indirectly have a serious impact on the mortality or morbidity of human diseases, and climate change does impact human health and will exacerbate these effects. Moreover, it may have spatial and socioeconomic differences in the world. Nonetheless, these studies also indicate that policies about climate change and emission reduction can reduce these effects. The evaluation focuses on the interaction between temperature change and air quality caused by climate change and assesses the impact of both on human health. There are still some uncertainties in existing research, and future health predictions related to climate change should focus on quantitative exploration of temperature and air pollution changes, eliminate interference caused by factors such as industrialization, and demographic changes, while the choice of meteorological conditions should be further extended, not just limited to the temperature and air quality.
Показать больше [+] Меньше [-]Presence of plastic debris and retained fishing hooks in oceanic sharks
2019
Mucientes, Gonzalo | Queiroz, Nuno
In a context where the problem of plastic pollution is globally increasing, more studies are needed to assess the real impact in oceanic megafauna. Here, we reported on the incidence of plastic and also retained hooks in two species of commercially exploited pelagic sharks in two ocean basins, the North Atlantic and South Pacific. In the South Pacific, 1.18% of caught blue sharks were observed with plastic debris on their body and 4.82% and with retained hooks, while 0.00% of shortfin makos had plastic debris and 1.76% were recorded with retained hooks. In the North Atlantic, 0.21% of blue sharks had plastic debris and 0.37% of blue, and 0.78% of shortfin makos were observed with retained hooks.
Показать больше [+] Меньше [-]Response planning for accidental oil spills in Persian Gulf: A decision support system (DSS) based on consequence modeling
2019
Amir-Heidari, Payam | Raie, Mohammad
Different causes lead to accidental oil spills from fixed and mobile sources in the marine environment. Therefore, it is essential to have a systematic plan for mitigating oil spill consequences. In this research, a general DSS is proposed for passive and active response planning in Persian Gulf, before and after a spill. The DSS is based on NOAA's advanced oil spill model (GNOME), which is now linked with credible met-ocean datasets of CMEMS and ECMWF. The developed open-source tool converts the results of the Lagrangian oil spill model to quantitative parameters such as mean concentration and time of impact of oil. Using them, two new parameters, emergency response priority number (ERPN) and risk index (RI), are defined and used for response planning. The tool was tested in both deterministic and probabilistic modes, and found to be useful for evaluation of emergency response drills and risk-based prioritization of coastal areas.
Показать больше [+] Меньше [-]Remote sensing estimation of the biomass of floating Ulva prolifera and analysis of the main factors driving the interannual variability of the biomass in the Yellow Sea
2019
Xiao, Yanfang | Zhang, Jie | Cui, Tingwei | Gong, Jialong | Liu, Rongjie | Chen, Xiaoying | Liang, Xijian
Since 2007, green tide blooms with Ulva prolifera as the dominant species have occurred every summer in the Yellow Sea. Biomass is a critical parameter used to describe the severity of green tide blooms. In this study, we analyzed the relationships between several indices (normalized difference vegetation index (NDVI), floating algae index (FAI), ratio vegetation index (RVI), enhanced vegetation index (EVI), ocean surface algal bloom index (OSABI), Korea Ocean Satellite Center (KOSC) approach) and the biomass per unit area of Ulva prolifera by using the in situ measurements from a water tank experiment. EVI, NDVI, and FAI showed strong exponential relationships with Ulva prolifera biomass per unit area. In order to apply the relationships to satellite remote sensing data, the impacts of the atmosphere (different aerosol optical depth at 550 nm) and mixed pixels to the relationships were analyzed. The results show that atmosphere has little effect on the relationship between EVI and Ulva prolifera biomass per unit area with R2 = 0.94 and APD (the average percentage deviation) = 19.55% when EVI is calculated from Rrc (Rayleigh-corrected reflectance), and R2 = 0.95 and APD = 17.53% when EVI is calculated from Rtoa (top-of-atmosphere reflectance). Due to the low sensitivity to the atmosphere, the EVI relationship can be directly utilized in the top-of-atmosphere (TOA) reflectance without atmospheric correction. In addition, the EVI was slightly affected by mixed pixels with the APD only increased by ~10%. The EVI relationship was then applied to a long MODIS image time series to obtain the maximal total biomass of floating Ulva prolifera in the Yellow Sea from 2007 to 2016. The results showed that the maximum and minimum total biomass occurred in 2016 (~1.17 million tons) and 2012 (~0.074 million tons), respectively. The main factors that caused the inter-annual biomass variability were analyzed. The total amount of nutrients from Sheyang River which was the largest river on the northern coast of Jiangsu Province, and Porphyra cultivation in the Radial Sand Ridges of Jiangsu Province had both strong correlation with Ulva prolifera total biomass.
Показать больше [+] Меньше [-]Spatiotemporal distributions of halocarbons in the marine boundary air and surface seawater of the Changjiang estuary and its adjacent East China Sea
2019
Yuan, Da | He, Zhen | Yang, Gui-Peng
Spatiotemporal distributions of volatile halogenated organic compounds (VHOCs) were investigated in the marine boundary air and surface seawater of the Changjiang (Yangtze River) estuary and its adjacent East China Sea in two cruises from March 11, 2015 to March 21, 2015 and from July 9, 2015 to July 20, 2015. Results revealed that the concentrations of released chlorofluorocarbons (CFCs) such as CFC-12, CFC-11, and CFC-114 in China decreased, suggesting that limitations set by the Chinese government on CFCs production and consumption have taken effect. Atmospheric concentrations of CFCs were affected by local industrial sources of emission and transport of terrestrial pollutants from coastal areas to varying degrees. Seasonal variations in atmospheric VHOCs were probably due to seasonal differences in prevalent monsoon and biogenic production. In the study periods, the investigated area was an essential source of atmospheric CH3Br and CH3I but was a net sink of CFC-12, CFC-11, and CH3Cl.
Показать больше [+] Меньше [-]A multivariate approach and sediment quality index evaluation applied to Baixada Santista, Southeastern Brazil
2019
Kim, Bianca Sung Mi | Angeli, José Lourenço Friedmann | Ferreira, Paulo Alves Lima | Mahiques, Michel Michaelovitch de | Figueira, Rubens Cesar Lopes
Current studies use indices and chemometric approaches to assess the health quality of estuarine systems to support estuarine management. This study aims to use a multivariate approach and a set of indices to evaluate sediment health quality. Levels of Al, As, Cd, Cr, Cu, Fe, Ni, Pb, Sc, V, and Zn were quantified by ICP-OES, and nine indices were applied and evaluated individually. Most of the indices presented high values of Cu, Pb, and Zn, and the aggregative indices differed from each other in magnitude; however, the spatial distribution demonstrated the same trends. From PCA results, it was possible to differentiate lithogenic from the anthropogenic contribution, especially by Cu, Pb, and Zn. Thus, the integration of geochemical approaches and chemometric tools supported the interpretation of elemental contribution in terms of sources and pathway of heavy metals, which was similar to the results of other studies conducted in the area.
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