Refinar búsqueda
Resultados 1441-1450 de 4,045
Use of baited remote underwater video (BRUV) and motion analysis for studying the impacts of underwater noise upon free ranging fish and implications for marine energy management Texto completo
2016
Roberts, Louise | Pérez-Dominguez, Rafael | Elliott, Michael
Free-ranging individual fish were observed using a baited remote underwater video (BRUV) system during sound playback experiments. This paper reports on test trials exploring BRUV design parameters, image analysis and practical experimental designs. Three marine species were exposed to playback noise, provided as examples of behavioural responses to impulsive sound at 163–171dB re 1μPa (peak-to-peak SPL) and continuous sound of 142.7dB re 1μPa (RMS, SPL), exhibiting directional changes and accelerations. The methods described here indicate the efficacy of BRUV to examine behaviour of free-ranging species to noise playback, rather than using confinement. Given the increasing concern about the effects of water-borne noise, for example its inclusion within the EU Marine Strategy Framework Directive, and the lack of empirical evidence in setting thresholds, this paper discusses the use of BRUV, and short term behavioural changes, in supporting population level marine noise management.
Mostrar más [+] Menos [-]An assessment of Qatar's coral communities in a regional context Texto completo
2016
Burt, John A. | Smith, Edward G. | Warren, Christopher | Dupont, Jennifer
Qatar's once extensive coral communities have undergone considerable change in recent decades. We quantitatively surveyed three coral assemblages in Qatar to assess current status, and compared these against 14 sites in Bahrain and the United Arab Emirates to evaluate Qatar in a larger biogeographic context. Umm Al-Arshan had the highest species richness of 17 sites examined in the southern Arabian Gulf, as well as the highest coral cover and the only Acropora observed on sites in Qatar. Coral cover and richness were more modest at Fuwayrit and Al-Ashat, reflecting greater impacts from earlier stress events. Two distinct communities were identified across the southern Gulf, with Umm Al-Arshan clustering with high-cover, mixed merulinid/poritid assemblages that were less impacted by earlier bleaching and long-term stress, while Fuwayrit and Al-Ashat grouped with a lower-cover, stress-tolerant community characteristic of more extreme environments in the southern Gulf. We recommend implementation of a nation-wide baseline assessment of coral communities to guide development of an MPA network and long-term coral monitoring program for Qatar.
Mostrar más [+] Menos [-]Distribution, sources and ecological risk assessment of PAHs in surface sediments from the Luan River Estuary, China Texto completo
2016
Zhang, Daolai | Liu, Jinqing | Jiang, Xuejun | Cao, Ke | Yin, Ping | Zhang, Xunhua
The distribution, sources and risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) of surface sediments in the Luan River Estuary, China, have been investigated in the research. The results indicated that the total concentrations of 16 PAHs in surface sediments of the Luan River Estuary ranged from 5.1 to 545.1ngg−1dw with a mean value of 120.8ngg−1dw, which is relatively low in comparison with other estuaries around the world. The PAHs in the study area were mainly originated from pyrogenic sources. Besides, PAHs may be contaminated by petrogenic PAHs as indicated by the selected ratios of PAHs, the 2-tailed Pearson correlation analysis and principal components analysis at different sites. The result of the ecological risk assessment shows little negative effect for most individual PAHs in surface sediments of the Luan River Estuary, China.
Mostrar más [+] Menos [-]The changing dynamics of coral reef science in Arabia Texto completo
2016
Vaughan, Grace O. | Burt, John A.
Six percent of the world's coral reefs occur around the Arabian Peninsula, providing a valuable ecological, economic and scientific resource for the nations bordering its shores. We provide the first region-wide assessment of the current status and historical trends in coral reef research, focusing on research in the Red Sea, Arabian Sea, and Arabian Gulf. In total, 633 regional reef publications have been produced since the 1930s, covering a wide variety of themes and taxa. Our results show a great deal of commonality in regional reef research, but also highlight important differences in research among the various seas as well as knowledge gaps that represent opportunities for future research. A regionally-integrated approach to future research is essential. There is a growing need for large-scale research to guide management of reefs and their stressors, as these operate at much larger scales than the national borders within which most research currently occurs.
Mostrar más [+] Menos [-]Method and application of ocean environmental awareness measurement: Lessons learnt from university students of China Texto completo
2016
Umuhire, Marie Louise | Fang, Qinhua
Different studies have proved that enhancing public Ocean Environmental Awareness (OEA) will lead to increased public support for ocean environmental protection. Our study develops a questionnaire to investigate current levels of students’ OEA from three aspects including ocean environmental concerns, ocean environment knowledge and willingness to participate in ocean related activities. This questionnaire was applied to students from Xiamen University to understand the OEA of university students in China, of which there are few studies. Using data gathered from a random purposive sample, the OEA level of students in Xiamen University was investigated and then the influencing factors (education, geographical situation, age and gender etc.) were further analyzed. Findings suggest that most students are concerned about the ocean environment but their knowledge is not enough that makes the willingness to participate in ocean related actions limited as well. The results show there is an urgent need to improve students’ OEA.
Mostrar más [+] Menos [-]A combined input–output and sensitivity analysis of CO2 emissions in the high energy-consuming industries: A case study of China Texto completo
2016
Yuan, Rong | Zhao, Tao
This paper employed an input–output approach combined with a sensitivity analysis to explore the impact of technological changes on CO2 emissions in the high energy-consuming industries. In contrast to most papers in the literature, which focused on the changes between two input–output tables in two different periods, this study analyzed the sensitivity of variations in the quantity of emissions caused by small changes in technical coefficients. An indicator, namely TCE (technical coefficient elasticity), was established to identify the transactions between economic sectors which lead to a large impact on CO2 emissions in the high energy-consuming industries. Additionally, by analyzing factors affecting TCE, this paper divided TCE into structure-relevant TCE and technology-relevant TCE. Sectors have a higher structural TCE value because their products are much demanded by other sectors. Sectors have a higher technological TCE value because they have a large propensity to consume inputs which require many products of the high energy-consuming industries. Our results show that technical coefficients with a higher TCE value correspond to the direct requirements by the high energy-consuming industries themselves. However, the impacts of technological changes in the non-high energy-consuming industries on high energy-consuming industries cannot be overlooked, especially in Transportation industry, Construction industry and manufacturing industries. Several industries have a higher structural TCE value, thus, their influence on CO2 emissions in the high energy-consuming industries is related to a high level of demand of their respective products. However, several industries have a higher technological TCE value, thus, technology innovation will be more effective to decrease CO2 emissions. Therefore, different measures should be adopted for reducing CO2 emissions in the high energy-consuming industries according to different conditions.
Mostrar más [+] Menos [-]Urban air quality evaluations under two versions of the national ambient air quality standards of China Texto completo
2016
Chen, Wei | Tang, Hongzhao | Zhao, Haimeng
The air quality of urban areas is of a great concern for residents living in cities. China has released a new National Ambient Air Quality Standard (NAAQS) in 2012 to improve the air quality evaluation index because the reported air quality situation from governments is inconsistent with public sensing. In total, 190 cities' hourly monitoring data are publicized in the national web platform. By using the above data, the air pollution indexes (APIs) under the previous NAAQS and air quality indexes (AQI) for all 190 cities' were calculated. With the new NAAQS, the national attainment rate has fallen from 73.63% to 59.62% with regional differences. 8 of the 10 cities with the worst air quality are located in North China around Beijing, while 9 of the 10 cities with the best air quality are located in South China. These results indicate that cities in North China, including Beijing, need to address the air pollution together as the pollution in North China is a regional issue and not a local issue.
Mostrar más [+] Menos [-]The role of metallothioneins, selenium and transfer to offspring in mercury detoxification in Franciscana dolphins (Pontoporia blainvillei) Texto completo
2016
Romero, M.B. | Polizzi, P. | Chiodi, L. | Das, K. | Gerpe, M.
The role of metallothioneins, selenium and transfer to offspring in mercury detoxification in Franciscana dolphins (Pontoporia blainvillei) Texto completo
2016
Romero, M.B. | Polizzi, P. | Chiodi, L. | Das, K. | Gerpe, M.
The concentrations of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal Franciscana dolphin (Pontoporia blainvillei) from Argentina. Mercury concentrations varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations in all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two elements. Furthermore, dark granules of HgSe were observed in Kupffer cells in the liver by electron microscopy, suggesting the role of this macrophage in the detoxification of Hg. A transfer of Hg through placenta was proved. The presence of Hg in brain in all age classes did not show concentrations associated with neurotoxicity.
Mostrar más [+] Menos [-]The role of metallothioneins, selenium and transfer to offspring in mercury detoxification in Franciscana dolphins (Pontoporia blainvillei) Texto completo
2016
Romero, M.B. | Pollizi, P. | Chiodi, L. | Das, Krishna | Gerpe, M.
peer reviewed | The concentrations of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal Franciscana dolphin (Pontoporia blainvillei) from Argentina. Mercury concentrations varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations in all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two elements. Furthermore, dark granules of HgSe were observed in Kupffer cells in the liver by electron microscopy, suggesting the role of this macrophage in the detoxification of Hg. A transfer of Hg through placenta was proved. The presence of Hg in brain in all age classes did not show concentrations associated with neurotoxicity.
Mostrar más [+] Menos [-]A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter Texto completo
2016
L., Frère | I., Paul-Pont | J., Moreau | P., Soudant | C., Lambert | A., Huvet | E., Rinnert
A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter Texto completo
2016
L., Frère | I., Paul-Pont | J., Moreau | P., Soudant | C., Lambert | A., Huvet | E., Rinnert
Every step of microplastic analysis (collection, extraction and characterization) is time-consuming, representing an obstacle to the implementation of large scale monitoring. This study proposes a semi-automated Raman micro-spectroscopy method coupled to static image analysis that allows the screening of a large quantity of microplastic in a time-effective way with minimal machine operator intervention. The method was validated using 103 particles collected at the sea surface spiked with 7 standard plastics: morphological and chemical characterization of particles was performed in <3h. The method was then applied to a larger environmental sample (n=962 particles). The identification rate was 75% and significantly decreased as a function of particle size. Microplastics represented 71% of the identified particles and significant size differences were observed: polystyrene was mainly found in the 2–5mm range (59%), polyethylene in the 1–2mm range (40%) and polypropylene in the 0.335–1mm range (42%).
Mostrar más [+] Menos [-]A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter Texto completo
2016
Frere, L. | Paul-pont, I. | Moreau, Julien | Soudant, P. | Lambert, C. | Huvet, Arnaud | Rinnert, Emmanuel
Every step of microplastic analysis (collection, extraction and characterization) is time-consuming, representing an obstacle to the implementation of large scale monitoring. This study proposes a semi-automated Raman micro-spectroscopy method coupled to static image analysis that allows the screening of a large quantity of microplastic in a time-effective way with minimal machine operator intervention. The method was validated using 103 particles collected at the sea surface spiked with 7 standard plastics: morphological and chemical characterization of particles was performed in < 3 h. The method was then applied to a larger environmental sample (n = 962 particles). The identification rate was 75% and significantly decreased as a function of particle size. Microplastics represented 71% of the identified particles and significant size differences were observed: polystyrene was mainly found in the 2–5 mm range (59%), polyethylene in the 1–2 mm range (40%) and polypropylene in the 0.335–1 mm range (42%).
Mostrar más [+] Menos [-]Contamination and distribution of heavy metals, polybrominated diphenyl ethers and alternative halogenated flame retardants in a pristine mangrove Texto completo
2016
Wu, Qihang | Leung, Jonathan Y.S. | Tam, Nora F.Y. | Peng, Yisheng | Guo, Pengran | Zhou, Song | Li, Qing | Geng, Xinhua | Miao, Shenyu
Contamination and distribution of heavy metals, polybrominated diphenyl ethers and alternative halogenated flame retardants in a pristine mangrove Texto completo
2016
Wu, Qihang | Leung, Jonathan Y.S. | Tam, Nora F.Y. | Peng, Yisheng | Guo, Pengran | Zhou, Song | Li, Qing | Geng, Xinhua | Miao, Shenyu
Owing to the expanding metal and electronics industries, pollution in the Pearl River Estuary needs special concern. Given the hydrodynamic effect, the pristine mangrove in Qi'ao Island would be contaminated by tidal flushing. Thus, we examined (1) the contamination of pollutants in this mangrove, including heavy metals, polybrominated diphenyl ethers (PBDEs) and alternative halogenated flame retardants (AHFRs), and (2) how habitat characteristics and sediment properties affect their distribution. Results showed that the sediment in Qi'ao mangrove had higher concentrations of heavy metals, PBDEs and AHFRs than that in other pristine mangroves, and similar concentrations to those mangroves impacted by point sources. Heavy metal concentrations were lower in the vegetated areas than mudflat, while the opposite was found for PBDEs and AHFRs. The findings imply that tidal flushing was an important pollution source, while mangrove plants have the capacity to minimize the impact of heavy metals, but not PBDEs and AHFRs.
Mostrar más [+] Menos [-]Contamination and distribution of heavy metals, polybrominated diphenyl ethers and alternative halogenated flame retardants in a pristine mangrove Texto completo
2016
Wu, Q. | Leung, J. | Tam, N. | Peng, Y. | Guo, P. | Zhou, S. | Li, Q. | Geng, X. | Miao, S.
Abstract not available | Qihang Wu, Jonathan Y.S. Leung, Nora F.Y. Tam, Yisheng Peng, Pengran Guo, Song Zhou, Qing Li, Xinhua Geng, Shenyu Miao
Mostrar más [+] Menos [-]