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A baseline study of tropical coastal water quality in Port Dickson, Strait of Malacca, Malaysia Полный текст
2013
Praveena, Sarva Mangala | Ahmad Zaharin Aris,
Tidal variation in tropical coastal water plays an important role on physicochemical characteristics and nutrients concentration. Baseline measurements were made for nutrients concentration and physicochemical properties of coastal water, Port Dickson, Malaysia. pH, temperature, oxidation reduction potential, salinity and electrical conductivity have high values at high tides. Principal Components Analysis (PCA) was used to understand spatial variation of nutrients and physicochemical pattern of Port Dickson coastal water at high and low tide. Four principal components of PCA were extracted at low and high tides. Positively loaded nutrients with negative loadings of DO, pH and ORP in PCA outputs indicated nutrients contribution related with pollution sources. This study output will be a baseline frame for future studies in Port Dickson involving water and sediment samples. Water and sediment samples of future monitoring studies in Port Dickson coastal water will help in understanding of coastal water chemistry and pollution sources.
Показать больше [+] Меньше [-]Mercury (Hg) and methyl mercury (MeHg) concentrations in fish from the coastal lagoon of Orbetello, central Italy Полный текст
2013
Miniero, R. | Beccaloni, E. | Carere, M. | Ubaldi, A. | Mancini, L. | Marchegiani, S. | Cicero, M.R. | Scenati, R. | Lucchetti, D. | Ziemacki, G. | De Felip, E.
Total mercury (Hgtot) and methyl mercury (MeHg) were quantified in several specimens of Dicentrarchus labrax and Sparus aurata from the east basin of the Orbetello lagoon, central Italy. The size of each specimen was recorded to estimate body burdens (BBs); =Hgtot and MeHg were measured in fillets of both species. Hgtot and MeHg in S. aurata ranged between 0.355–1.58 and 0.341–1.53μg/g wet weight (ww), respectively; in D. labrax, their ranges were 0.284–2.54 and 0.214–2.35μg/g ww. Approximately 90% of the concentrations measured exceeded Hgtot regulatory maximum level of 0.5μg/g ww; however, exceedance rate was different in the two species studied. No correlations between specimen size and Hgtot or MeHg BBs were detected in this study.
Показать больше [+] Меньше [-]Small-scale modelling of the physiochemical impacts of CO2 leaked from sub-seabed reservoirs or pipelines within the North Sea and surrounding waters Полный текст
2013
Dewar, Marius | Wei, Wei | McNeil, David | Chen, Baixin
A two-fluid, small scale numerical ocean model was developed to simulate plume dynamics and increases in water acidity due to leakages of CO2 from potential sub-seabed reservoirs erupting, or pipeline breaching into the North Sea. The location of a leak of such magnitude is unpredictable; therefore, multiple scenarios are modelled with the physiochemical impact measured in terms of the movement and dissolution of the leaked CO2. A correlation for the drag coefficient of bubbles/droplets free rising in seawater is presented and a sub-model to predict the initial bubble/droplet size forming on the seafloor is proposed. With the case studies investigated, the leaked bubbles/droplets fully dissolve before reaching the water surface, where the solution will be dispersed into the larger scale ocean waters. The tools developed can be extended to various locations to model the sudden eruption, which is vital in determining the fate of the CO2 within the local waters.
Показать больше [+] Меньше [-]Polychlorinated biphenyls in sediments of the Yellow Sea: Distribution, source identification and flux estimation Полный текст
2013
Duan, Xiaoyong | Li, Yanxia | Li, Xianguo | Zhang, Dahai | Li, Mengfang
Although there is no direct major riverine input, a large quantity of waste produced in mainland China and Korea is transported continuously to the Yellow Sea (YS) through atmospheric deposition, currents and tides; therefore, the environment is distinctly influenced by man-made pollution. This study focuses on the associated pollutant transport mechanisms and fluxes by sampling polychlorinated biphenyls (PCBs). PCBs (Σ24PCB) in YS sediments ranged between 99pg/g and 3.13ng/g of dry sediment (with a mean value of 715pg/g). PCBs produced unintentionally by industrial and other processes appeared to be the major source of PCBs in the sediments, accounting for 60.5%. Industrially synthesized PCBs with 3Cl and 5Cl accounted for 15.5% and 24.0%, respectively. PCBs were mainly from atmospheric deposition (84.5%), followed by continental runoff (15.5%). The average atmospheric deposition flux of technical PCBs was 789ng/(m2a) and flux of surface runoff was 2.27ng/L.
Показать больше [+] Меньше [-]Rhamnolipids enhance marine oil spill bioremediation in laboratory system Полный текст
2013
Chen, Qingguo | Bao, Mutai | Fan, Xiaoning | Liang, Shengkang | Sun, Peiyan
This paper presents a simulated marine oil spill bioremediation experiment using a bacterial consortium amended with rhamnolipids. The role of rhamnolipids in enhancing hydrocarbon biodegradation was evaluated via GC–FID and GC–MS analysis. Rhamnolipids enhanced total oil biodegradation efficiency by 5.63%, with variation in normal alkanes, polyaromatic hydrocarbons (PAHs) and biomakers biodegradation. The hydrocarbons biodegradation by bacteria consortium overall follows a decreasing order of PAHs>n-alkanes>biomarkers, while in different order of PAHs>biomarkers>n-alkanes when rhamnolipids was used, and the improvement in the removal efficiency by rhamnolipids follows another order of biomarkers>n-alkanes>PAHs. Rhamnolipids played a negative role in degradation of those hydrocarbons with relatively volatile property, such as n-alkanes with short chains, PAHs and sesquiterpenes with simple structure. As to the long chain normal alkanes and PAHs and biomakers with complex structure, the biosurfactant played a positive role in these hydrocarbons biodegradation.
Показать больше [+] Меньше [-]Determining trigger values of suspended sediment for behavioral changes in a coral reef fish Полный текст
2013
Wenger, Amelia S. | McCormick, Mark I.
Sediment from land use increases water turbidity and threatens the health of inshore coral reefs. This study performed experiments with a damselfish, Pomacentrus moluccensis, in four sediment treatments, control (0mgl−1), 10mgl−1(∼1.7NTU), 20mgl−1(∼3.3NTU) and 30mgl−1 (∼5NTU), to determine when sediment triggers a change in habitat use and movement. We reviewed the literature to assess how frequently P. moluccensis would experience sub-optimal sediment conditions on the reef. Preference for live coral declined from 49.4% to 23.3% and movement between habitats declined from 2.1 to 0.4times between 20mgl−1 and 30mgl−1, suggesting a sediment threshold for behavioral changes. Inshore areas of the Great Barrier Reef, P. moluccensis may encounter sub-optimal conditions between 8% and 53% of the time. Changes in these vital processes may have long-term effects on the persistence of populations, particularly as habitat loss on coral reefs increases.
Показать больше [+] Меньше [-]The effects of heavy metals on germination and seedling characteristics in two halophyte species in Mediterranean marshes Полный текст
2013
Márquez-García, B. | Márquez, C. | Sanjosé, I. | Nieva, F.J.J. | Rodríguez-Rubio, P. | Muñoz-Rodríguez, A.F.
The influence of different concentrations (10–2000μM) of heavy metals (Cu, Mn, Ni, Zn) was analysed in Atriplex halimus and Salicornia ramosissima germination pattern and seedling size. They are two halophyte species that grow in the Estuary of Huelva (Southwest Iberian Peninsula, Spain), one of the most heavy metal-polluted environments in the world.All of the metals tested affected the final germination percentage in A. halimus and only Ni reduced germination in S. ramosissima. The germination rate was unaffected in both species.The study of seedling development shows that S. ramosissima, an intertidal annual species, has a higher tolerance of metals than A. halimus, a bush that inhabits the upper part of the marshes.Taking into account the metal concentrations in the estuary and the effects of these on the seedling development of the species analysed, we conclude that metals might limit plant colonisation in some parts of the marshes.
Показать больше [+] Меньше [-]Three dimensional marine seismic survey has no measurable effect on species richness or abundance of a coral reef associated fish community Полный текст
2013
Miller, Ian | Cripps, Edward
Underwater visual census was used to determine the effect of a three dimensional seismic survey on the shallow water coral reef slope associated fish community at Scott Reef. A census of the fish community was conducted on six locations at Scott Reef both before and after the survey. The census included small site attached demersal species belonging to the family Pomacentridae and larger roving demersal species belonging to the non-Pomacentridae families. These data were combined with a decade of historical data to assess the impact of the seismic survey. Taking into account spatial, temporal, spatio-temporal and observer variability, modelling showed no significant effect of the seismic survey on the overall abundance or species richness of Pomacentridae or non-Pomacentridae. The six most abundant species were also analysed individually. In all cases no detectable effect of the seismic survey was found on the abundance of these fish species at Scott Reef.
Показать больше [+] Меньше [-]Disinfection by-products and ecotoxicity of ballast water after oxidative treatment – Results and experiences from seven years of full-scale testing of ballast water management systems Полный текст
2013
Delacroix, Stephanie | Vogelsang, Christian | Tobiesen, August | Liltved, Helge
Disinfection by-products and ecotoxicity of ballast water after oxidative treatment – Results and experiences from seven years of full-scale testing of ballast water management systems Полный текст
2013
Delacroix, Stephanie | Vogelsang, Christian | Tobiesen, August | Liltved, Helge
Since 2005, five different ballast water management systems (BWMSs) based on chlorination treatment have been tested by Norwegian Institute for Water Research (NIVA) according to guidelines from the International Maritime Organization (IMO). 25% and >50% of all the tested discharge samples exhibited acute and chronic toxic effects on algae, respectively. In most cases this toxicity was plausibly caused by a high free residual oxidant (FRO) level (>0.08mgCl/l). Of the 22 disinfection by-products (DBPs) that were identified in treated water at discharge, four compounds were at times found at concentrations that may pose a risk to the local aquatic environment. However, there seemed to be no clear indication that the measured DBP concentrations contributed to the observed algal toxicity. The addition of methylcellulose instead of lignin in the test water to comply with IMO requirements seemed to limit the formation of DBP.
Показать больше [+] Меньше [-]Disinfection by-products and ecotoxicity of ballast water after oxidative treatment – Results and experiences from seven years of full-scale testing of ballast water management systems Полный текст
2013
Delacroix, Stephanie | Vogelsang, Christian | Tobiesen, August | Liltved, Helge
Since 2005, five different ballast water management systems (BWMS) based on chlorination treatment have been tested by Norwegian Institute for Water Research (NIVA) according to guidelines from the International Maritime Organization (IMO). 25 % and >50 % of all the tested discharge samples exhibited acute and chronic toxic effects on algae, respectively. In most cases this toxicity was plausibly caused by a high free residual oxidant (FRO) level (>0.08 mg Cl/l). Of the 22 disinfection by-products (DBPs) that were identified in treated water at discharge, four compounds were at times found at concentrations that may pose a risk to the local aquatic environment. However, there seemed to be no clear indication that the measured DBP concentrations contributed to the observed algal toxicity. The addition of methylcellulose instead of lignin in the test water to comply with IMO requirements seemed to limit the formation of DBP.
Показать больше [+] Меньше [-]Marine debris in central California: Quantifying type and abundance of beach litter in Monterey Bay, CA Полный текст
2013
Rosevelt, C. | Los Huertos, M. | Garza, C. | Nevins, H.M.
Monitoring beach litter is essential for reducing ecological threats towards humans and wildlife. In Monterey Bay, CA information on seasonal and spatial patterns is understudied. Central California’s coastal managers require reliable information on debris abundance, distribution, and type, to support policy aimed at reducing litter. We developed a survey method that allowed for trained citizen scientists to quantify the types and abundance of beach litter. Sampling occurred from July 2009–June 2010. Litter abundance ranged from 0.03 to 17.1itemsm−2. Using a mixed model approach, we found season and location have the greatest effect on litter abundance. Styrofoam, the most numerically abundant item, made up 41% of the total amount of litter. Unexpected items included fertilizer pellets. The results of this study provide a baseline on the types and abundance of litter on the central coast and have directly supported policy banning Styrofoam take out containers from local municipalities.
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