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Natural radionuclides tracing in marine surface waters along the northern coast of Oman Sea by combining the radioactivity analysis, oceanic currents and the SWAN model results
2015
Zare, Mohammad Reza | Mostajaboddavati, Mojtaba | Kamālī, Mahdī | Tari, Marziyeh | Mosayebi, Sanaz | Mortazavi, Mohammad Seddigh
This study aims to establish a managed sampling plan for rapid estimate of natural radio-nuclides diffusion in the northern coast of the Oman Sea. First, the natural radioactivity analysis in 36 high volume surface water samples was carried out using a portable high-resolution gamma-ray spectrometry. Second, the oceanic currents in the northern coast were investigated. Then, the third generation spectral SWAN model was utilized to simulate wave parameters. Direction of natural radioactivity propagation was coupled with the preferable wave vectors and oceanic currents direction that face to any marine pollution, these last two factors will contribute to increase or decrease of pollution in each grid. The results were indicated that the natural radioactivity concentration between the grids 8600 and 8604 is gathered in the grid 8600 and between the grids 8605 and 8608 is propagated toward middle part of Oman Sea.
Show more [+] Less [-]Weak acid extractable metals in Bramble Bay, Queensland, Australia: Temporal behaviour, enrichment and source apportionment
2015
Brady, James P. | Ayoko, G. A. (Godwin A.) | Martens, Wayde N. | Goonetilleke, Ashantha
Sediment samples were taken from six sampling sites in Bramble Bay, Queensland, Australia between February and November in 2012. They were analysed for a range of heavy metals including Al, Fe, Mn, Ti, Ce, Th, U, V, Cr, Co, Ni, Cu, Zn, As, Cd, Sb, Te, Hg, Tl and Pb. Fraction analysis, Enrichment Factors and Principal Component Analysis–Absolute Principal Component Scores (PCA–APCS) were carried out in order to assess metal pollution, potential bioavailability and source apportionment. Cr and Ni exceeded the Australian Interim Sediment Quality Guidelines at some sampling sites, while Hg was found to be the most enriched metal. Fraction analysis identified increased weak acid soluble Hg and Cd during the sampling period. Source apportionment via PCA–APCS found four sources of metals pollution, namely, marine sediments, shipping, antifouling coatings and a mixed source. These sources need to be considered in any metal pollution control measure within Bramble Bay.
Show more [+] Less [-]The positive relationship between ocean acidification and pollution
2015
Zeng, Xiangfeng | Chen, Xijuan | Zhuang, Jie
Ocean acidification and pollution coexist to exert combined effects on the functions and services of marine ecosystems. Ocean acidification can increase the biotoxicity of heavy metals by altering their speciation and bioavailability. Marine pollutants, such as heavy metals and oils, could decrease the photosynthesis rate and increase the respiration rate of marine organisms as a result of biotoxicity and eutrophication, facilitating ocean acidification to varying degrees. Here we review the complex interactions between ocean acidification and pollution in the context of linkage of multiple stressors to marine ecosystems. The synthesized information shows that pollution-affected respiration acidifies coastal oceans more than the uptake of anthropogenic carbon dioxide. Coastal regions are more vulnerable to the negative impact of ocean acidification due to large influxes of pollutants from terrestrial ecosystems. Ocean acidification and pollution facilitate each other, and thus coastal environmental protection from pollution has a large potential for mitigating acidification risk.
Show more [+] Less [-]Using a forensic science approach to minimize environmental contamination and to identify microfibres in marine sediments
2015
Woodall, Lucy C. | Gwinnett, Claire | Packer, Margaret | Thompson, Richard C. | Robinson, Laura F. | Paterson, Gordon L.J.
There is growing evidence of extensive pollution of the environment by microplastic, with microfibres representing a large proportion of the microplastics seen in marine sediments. Since microfibres are ubiquitous in the environment, present in the laboratory air and water, evaluating microplastic pollution is difficult. Incidental contamination is highly likely unless strict control measures are employed. Here we describe methods developed to minimize the amount of incidental post-sampling contamination when quantifying marine microfibre pollution. We show that our protocol, adapted from the field of forensic fibre examination, reduces fibre abundance by 90% and enables the quick screening of fibre populations. These methods therefore allow an accurate estimate of microplastics polluting marine sediments. In a case study from a series of samples collected on a research vessel, we use these methods to highlight the prevalence of microfibres as marine microplastics.
Show more [+] Less [-]Air Quality in a Cleaner Energy World
2015
Wuebbles, Donald J. | Sanyal, Swarnali
Two major environmental issues, air quality and climate change, are interlinked because of their large dependence on atmospheric emissions from human activities, especially from the burning of fossil fuels. Emission of air pollutants and heat trapping gases have greatly increased over the last five decades from our dependence throughout the world on conventional fossil fuel sources in production of electricity and in transportation systems, resulting in significant environmental issues with air quality and climate change throughout our planet. Future emissions of pollutants will depend on the choices made about our use of energy and transportation. The purpose of this study is to examine for now and into the future the relationship between energy production, the associated use of fossil fuels, and resulting effects on air pollution. In the process, we examine a clean energy future, imagined in this case for 2050, and then consider the resulting potential effects on air quality.
Show more [+] Less [-]Application, Chemical Interaction and Fate of Iron Minerals in Polluted Sediment and Soils
2015
von der Heyden, Bjorn P. | Roychoudhury, Alakendra N.
Due to the high surface reactivity and redox chemistry, iron (Fe) minerals have a strong control on contaminant speciation, mobility and degradation. This has been well established for sediment and solution systems, and this review evaluates the role of Fe minerals in contaminant cycling from a sediment pollution perspective. Sediment redox conditions govern the Fe mineralogy, and a detailed description is given for Fe mineral interactions with contaminants in both oxic and sub/anoxic sediment horizons. These interactions include contaminant immobilisation through adsorption and co-precipitation mechanisms and contaminant degradation and speciation changes caused by Fe redox chemistry. Based on these reductive and adsorptive capabilities, recent advances in Fe amendment technologies, particularly in the field of engineered zero-valent Fe nanoparticles, have shown promising results for the treatment of polluted soils and sediments. However, the variable chemical and physical dynamics of sediment systems remains a limitation to the global application of these technologies.
Show more [+] Less [-]Marine pollution effects on the southern surf crab Ovalipes trimaculatus (Crustacea: Brachyura: Polybiidae) in Patagonia Argentina
2015
Lezcano, Aníbal Hernán | Rojas Quiroga, María Laura | Liberoff, Ana Laura | Van der Molen, Silvina
We compared the carapace shape and thickness as well as the energy density of Ovalipes trimaculatus inhabiting areas comprising a gradient of marine pollution: high, moderate and undetected, in the Nuevo gulf (Patagonia Argentina). The carapace shape was evaluated by means of individual asymmetry scores (=fluctuating asymmetry) whereas the carapace thickness was assessed by measuring the carapace dry weight. The energy density was analyzed through its negative relationship with water content in muscle tissue. The individual asymmetry scores as well as the percentage of water content in muscle tissue were proportional to the marine pollution gradient, whereas the carapaces thickness did not differ among sampling sites. Our results are consistent with previous findings and demonstrate the direct effect of marine pollution on other taxa different from gastropods, cephalopods and polyplacophora and add to long-standing concerns about detrimental effects caused by marine pollution on the benthic community of the Nuevo gulf.
Show more [+] Less [-]The effects of coastal development on sponge abundance, diversity, and community composition on Jamaican coral reefs
2015
Stubler, Amber D. | Duckworth, Alan R. | Peterson, Bradley J.
Over the past decade, development along the northern coast of Jamaica has accelerated, resulting in elevated levels of sedimentation on adjacent reefs. To understand the effects of this development on sponge community dynamics, we conducted surveys at three locations with varying degrees of adjacent coastal development to quantify species richness, abundance and diversity at two depths (8–10m and 15–18m). Sediment accumulation rate, total suspended solids and other water quality parameters were also quantified. The sponge community at the location with the least coastal development and anthropogenic influence was often significantly different from the other two locations, and exhibited higher sponge abundance, richness, and diversity. Sponge community composition and size distribution were statistically different among locations. This study provides correlative evidence that coastal development affects aspects of sponge community ecology, although the precise mechanisms are still unclear.
Show more [+] Less [-]Effects of sediments on the reproductive cycle of corals
2015
Jones, R. | Ricardo, G.F. | Negri, A.P.
Dredging, river plumes and natural resuspension events can release sediments into the water column where they exert a range of effects on underlying communities. In this review we examine possible cause–effect pathways whereby light reduction, elevated suspended sediments and sediment deposition could affect the reproductive cycle and early life histories of corals. The majority of reported or likely effects (30+) were negative, including a suite of previously unrecognized effects on gametes. The length of each phase of the life-cycle was also examined together with analysis of water quality conditions that can occur during a dredging project over equivalent durations, providing a range of environmentally relevant exposure scenarios for future testing. The review emphasizes the need to: (a) accurately quantify exposure conditions, (b) identify the mechanism of any effects in future studies, and (c) recognize the close interlinking of proximate factors which could confound interpretation of studies.
Show more [+] Less [-]Chattonella (Raphidophyceae) bloom spatio-temporal variations in Tachibana Bay and the southern area of Ariake Sea, Japan: Interregional displacement patterns with Skeletonema (Bacillariophyceae)
2015
Aoki, Kazuhiro | Onitsuka, Goh | Shimizu, Manabu | Yamatogi, Toshifumi | Ishida, Naoya | Kitahara, Shigeru | Hirano, Keiji
In 2010, a massive bloom of the raphidophycean flagellate Chattonella occurred in the Ariake Sea and Tachibana Bay. Bloom dynamics and hydrographical conditions were examined by field survey. The development and decline of the bloom occurred three times in Tachibana Bay. First and third bloom developments synchronized with precipitation, and the second bloom developed in synchronization with a salinity decrease which occurred in relation to an increase of river discharge from the Chikugo River which takes several days to flow from the Ariake Sea. These results imply that the bloom was transported with the low salinity water from the Ariake Sea to Tachibana Bay. During blooms along the northern coast of Shimabara Peninsula, the predominant phytoplankton species changed from Chattonella to Skeletonema. Low salinity water intrusion induced an interregional difference of the Chattonella and Skeletonema bloom spatially-differentiated by the salinity in the Ariake Sea and Tachibana Bay.
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