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Temporal variability and climatology of hydrodynamic, water property and water quality parameters in the West Johor Strait of Singapore
2013
Behera, Manasa Ranjan | Chun, Cui | Palani, Sundarambal | Tkalich, Pavel
The study presents a baseline variability and climatology study of measured hydrodynamic, water properties and some water quality parameters of West Johor Strait, Singapore at hourly-to-seasonal scales to uncover their dependency and correlation to one or more drivers. The considered parameters include, but not limited by sea surface elevation, current magnitude and direction, solar radiation and air temperature, water temperature, salinity, chlorophyll-a and turbidity. FFT (Fast Fourier Transform) analysis is carried out for the parameters to delineate relative effect of tidal and weather drivers. The group and individual correlations between the parameters are obtained by principal component analysis (PCA) and cross-correlation (CC) technique, respectively. The CC technique also identifies the dependency and time lag between driving natural forces and dependent water property and water quality parameters. The temporal variability and climatology of the driving forces and the dependent parameters are established at the hourly, daily, fortnightly and seasonal scales.
Show more [+] Less [-]Changes in zooplankton communities along a mercury contamination gradient in a coastal lagoon (Ria de Aveiro, Portugal)
2013
Cardoso, Patrícia Gonçalves | Marques, Sónia Cotrim | D’Ambrosio, Mariaelena | Pereira, Eduarda | Duarte, Armando Costa | Azeiteiro, Ulisses | Pardal, Miguel Ângelo
The main objective of this paper was to evaluate the impact of mercury on the zooplankton communities’ structure and functioning and their bioaccumulation patterns along a contamination gradient in a temperate coastal lagoon. Our results demonstrated that total abundance was not negatively affected by Hg contamination, since the most contaminated areas presented the highest values, being the copepod Acartia tonsa the dominant species, which means that it is a very well adapted and tolerant species to mercury. Nevertheless, negative effects were observed in terms of species diversity, since the most contaminated areas presented the lowest values of species richness, evenness and heterogeneity. Moreover, the spatial mercury gradient was reflected on the bioaccumulation patterns of the zooplankton communities. This reinforces the idea that zooplankton can be considered as an important vehicle of mercury transfer through the food pelagic web since it constitutes a primordial food resource for several commercial fish species.
Show more [+] Less [-]Distribution of local 137Cs anomalies on the seafloor near the Fukushima Dai-ichi Nuclear Power Plant
2013
Thornton, B. (Blair) | Ohnishi, Seiki | Ura, Tamaki | Odano, Naoteru | Sasaki, Shun | Fujita, Tsuneo | Watanabe, Tomowo | Nakata, Kaoru | Ono, Tsuneo | Ambe, Daisuke
An estimated 3.5±0.7×1015Bq of 137Cs is thought to have been discharged into the ocean following the melt down at Fukushima Dai-ichi Nuclear Power Plant (F1NPP). While efforts have been made to monitor seafloor radiation levels, the sampling techniques used cannot capture the continuous distribution of radionuclides. In this work, we apply in situ measurement techniques using a towed gamma ray spectrometer to map the continuous distribution of 137Cs on the seafloor within 20km of the F1NPP. The results reveal the existence of local 137Cs anomalies, with levels of 137Cs an order of magnitude higher than the surrounding seafloors. The sizes of the anomalies mapped in this work range from a few meters to a few hundreds of meters in length, and it is demonstrated that the distribution of these anomalies is strongly influenced by meter scale features of the terrain.
Show more [+] Less [-]Advanced diagnostics applied to fish liver tumours: Relating pathology to underlying molecular aetiology
2013
Lerebours, Adélaïde | Bignell, John P. | Stentiford, Grant D. | Feist, Stephen W. | Lyons, Brett P. | Rotchell, Jeanette M.
Liver tumours in flatfish have been diagnosed using histopathology for decades in order to monitor the impacts of marine pollution in coastal and estuarine environments. This traditional method has been coupled with molecular analyses of tumours in the liver of the dab, Limanda limanda, in order to elucidate underpinning molecular level aetiology of such disease. A laser capture microdissection technique for molecular investigation of cancer has been applied in fish. The present study provides optimized steps for environmental sample utilisation: a procedure for field sample collection and handling; a method allowing reliable identification of lesions on frozen tissue sections; and, downstream molecular analyses of tumourigenesis markers (retinoblastoma gene) in laser microdissected samples. This approach facilitates the use of wild flatfish as a model of environmentally-induced tumourigenesis, and has wide applicability to any disease pathology for which the underpinning molecular aetiology is required.
Show more [+] Less [-]Influence of waste management policy on the characteristics of beach litter in Kaohsiung, Taiwan
2013
Liu, Dagang | Wang, Meng-Wei | Chen, Ping
Marine debris is a ubiquitous problem that poses a serious threat to the global oceans; it has motivated public participation in clean-up campaigns, as well as governmental involvement in developing mitigation strategies. While it is known that the problem of marine litter may be affected by waste management practices on land, beach survey results have seldom been compared with them. In this study, marine litter surveys on four beaches of Cijin Island were conducted to explore the effects of waste management and policy implications. Indirect evidence shows that chances for land-based litter, such as plastic bags and bottles, entering the marine environment can be greatly decreased if they can be properly reduced, reused and recycled. We suggest that mitigation measures should focus on source reduction, waste recycling and management, utilizing effective economic instruments, and pursuing a long-term public education campaign to raise the public awareness of this problem.
Show more [+] Less [-]Environmental impacts of tourism in the Gulf and the Red Sea
2013
Gladstone, William | Curley, Belinda | Shokri, Mohammad Reza
The Gulf and Red Sea possess diverse coastal and marine environments that support rapidly expanding mass tourism. Despite the associated environmental risks, there is no analysis of the tourism-related literature or recent analysis of impacts. Environmental issues reported in 101 publications (25 from the Gulf, 76 from the Red Sea) include 61 purported impacts (27 from the Gulf, 45 from the Red Sea). Gulf literature includes quantitative studies (68% publications) and reviews (32%), and addresses mostly land reclamation and artificial habitats. Most Gulf studies come from Iran and UAE (64%). Red Sea literature includes quantitative studies (81%) and reviews (11%), with most studies occurring in Egypt (70%). The most published topics relate to coral breakage and its management. A full account of tourism’s environmental impacts is constrained by limited tourism data, confounding of impacts with other coastal developments, lack of baseline information, shifting baselines, and fragmentation of research across disciplines.
Show more [+] Less [-]Selected trace metals (As, Cd and Hg) distribution and contamination in the coastal wetland sediment of the northern Beibu Gulf, South China Sea
2013
Gan, Huayang | Lin, Jinqin | Liang, Kai | Xia, Zhen
Contamination with As, Cd and Hg, their spatial and temporal distribution are reported from the coastal wetland sediments of the northern Beibu Gulf, South China Sea. The content of As, Cd, Hg and TOC in surface sediments is 8.1±5.8μgg−1, 0.08±0.14μgg−1, 0.034±0.028μgg−1 and 0.45±0.39%, respectively. The mean sedimentation rates are 0.93–1.37cmyear−1 during 1920s to 2008 determined by 210Pb and 137Cs dating in three cores. The vertical profiles of As, Cd and Hg content in the cores retrieved from Qin and Nanliu River estuaries show increasing trends during 1985–2008 due to anthropogenic impact caused by local economic development. Locally the surface sediments have potential ecological risk of As to benthos according to the NOAA sediment quality guidelines.
Show more [+] Less [-]Allocation of marine environmental carrying capacity in the Xiamen Bay
2013
Liao, Enhui | Jiang, Yuwu | Yan, Xiao-Hai | Chen, Zhaoyun | Wang, Jia | Zhang, Luoping
Three optimization methods are employed to allocate Marine Environmental Carrying Capacity (MECC) in the Xiamen Bay. The hydrodynamic and pollutant fields are first simulated by the Princeton Ocean Model. Taking phosphorus as an index of the water quality, the response fields are then calculated. These response fields represent the relationship between the concentration of the sea zone and the pollution sources. Finally, MECC is optimized and distributed in the Xiamen Bay by three optimization methods. The results show classical linear optimization can only maximize the satisfaction level for one of the stake holders’, e.g., dischargers or environmental protection bureau, satisfaction level. However, the fuzzy and grey fuzzy optimizations can provide a compromise, and therefore a fairer result, by incorporating the conflicting goals of all of the different stakeholders. Compared with fuzzy optimization, the grey fuzzy optimization provides a more flexible choice for the decision-makers.
Show more [+] Less [-]Desorption kinetics of hydrophobic organic contaminants from marine plastic pellets
2013
Endo, Satoshi | Yuyama, Masaki | Takada, Hideshige
This study investigated the desorption behavior of polychlorinated biphenyls (PCBs) from marine plastic pellets. Long-term desorption experiments were conducted using field-collected polyethylene (PE) pellets. The results indicate that the desorption kinetics highly depends on the PE-water partition coefficients of PCB congeners. After 128d of the experiment, the smallest congener considered (CB 8) had desorbed nearly completely (98%), whereas major fractions (90–99%) of highly chlorinated congeners remained in the pellets. An intraparticle diffusion model mostly failed to reproduce the desorption kinetics, whereas an aqueous boundary layer (ABL) diffusion model well approximated the data. The desorption half-lives are estimated to 14d to 210years for CB 8 to CB 209 in an actively stirred solution (ABL thickness: 30μm). Addition of methanol to water enhanced the desorption to a large extent. A need for further work to explore roles of organic matter in facilitating solute transfer is suggested.
Show more [+] Less [-]Chemometric techniques in distribution, characterisation and source apportionment of polycyclic aromatic hydrocarbons (PAHS) in aquaculture sediments in Malaysia
2013
Retnam, Ananthy | Zakaria, Mohamad Pauzi | Juahir, Hafizan | Ahmad Zaharin Aris, | Zali, Munirah Abdul | Kasim, Mohd Fadhil
This study investigated polycyclic aromatic hydrocarbons (PAHs) pollution in surface sediments within aquaculture areas in Peninsular Malaysia using chemometric techniques, forensics and univariate methods. The samples were analysed using soxhlet extraction, silica gel column clean-up and gas chromatography mass spectrometry. The total PAH concentrations ranged from 20 to 1841ng/g with a mean of 363ng/gdw. The application of chemometric techniques enabled clustering and discrimination of the aquaculture sediments into four groups according to the contamination levels. A combination of chemometric and molecular indices was used to identify the sources of PAHs, which could be attributed to vehicle emissions, oil combustion and biomass combustion. Source apportionment using absolute principle component scores–multiple linear regression showed that the main sources of PAHs are vehicle emissions 54%, oil 37% and biomass combustion 9%. Land-based pollution from vehicle emissions is the predominant contributor of PAHs in the aquaculture sediments of Peninsular Malaysia.
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