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Environmental implications of the use of sulfidic back-bay sediments for dune reconstruction — Lessons learned post Hurricane Sandy
2016
Plumlee, Geoffrey S. | Benzel, William M. | Hoefen, Todd M. | Hageman, Philip L. | Morman, Suzette A. | Reilly, Timothy J. | Adams, Monique | Berry, Cyrus J. | Fischer, Jeffrey M. | Fisher, Irene
Some barrier-island dunes damaged or destroyed by Hurricane Sandy's storm surges in October 2012 have been reconstructed using sediments dredged from back bays. These sand-, clay-, and iron sulfide-rich sediments were used to make berm-like cores for the reconstructed dunes, which were then covered by beach sand. In November 2013, we sampled and analyzed partially weathered materials collected from the cores of reconstructed dunes. There are generally low levels of metal toxicants in the reconstructed dune materials. However oxidation of reactive iron sulfides by percolating rainwater produces acid-sulfate pore waters, which evaporate during dry periods to produce efflorescent gypsum and sodium jarosite salts. The results suggest use of sulfidic sediments in dune reconstruction has both drawbacks (e.g., potential to generate acid runoff from dune cores following rainfall, enhanced corrosion of steel bulwarks) and possible benefits (e.g., efflorescent salts may enhance structural integrity).
Показать больше [+] Меньше [-]New direction for environmental water management
2016
Tomita, Akio | Nakura, Yoshio | Ishikawa, Takuya
Japan experienced severe environmental problems including water pollution and damages to aquatic organisms and fishery industry through and after the high economic growth period in the 1960s.One of the countermeasures to address these problems was the Total Pollutant Load Control System (TPLCS), which has been implemented with the aim of reducing the total amount of pollutant loads, specifically targeting Chemical Oxygen Demand (COD), total nitrogen and total phosphorus.The TPLCS has significantly improved the quality of the coastal sea water. However, while the accumulated pollutant loads from the past industrialization have still remained, new environmental concerns have arisen. Our new environmental policies are thus to deal with conservation of biological diversity and other related marine environmental issues.Japan has entered a new phase of environmental management, setting the new direction and framework toward a beautiful, bio-diverse, bustling-with-people and bountiful sea.
Показать больше [+] Меньше [-]Air quality over a populated Andean region: Insights from measurements of ozone, NO, and boundary layer depths
2016
Cazorla, Maria
In this study, a hypothesis based on observations is offered to explain levels of ambient ozone in Quito, a busy urban center located at high altitude along the equatorial Andes. Supporting data includes first-time measurements of boundary layer depths in addition to ozone, NO (nitric oxide), and oxidized nitrogen observations. Mixing layer measurements were taken in June and July 2014 and in April 2015. The air quality data set is presented for the months of July through September 2014. From a total of four midday soundings launched under sunny conditions, a deep mixing layer up to 2200 magl (meters above ground level) was found only once when surface temperature was unusually high. In the other three cases, layered structures were found with the top of the mixing layer at 687 magl on average. These measurements were obtained when surface temperatures were within the usual range. Furthermore, the morning boundary layer depth was measured twice between 07:00 and 08:00. On average, a depth of 185 magl was determined. Air quality measurements for the study period show that ozone stayed below 55 ppbv while NO levels were routinely higher than 100 ppbv in the morning rush hour, and oxidized nitrogen stayed high during daytime. Observations of a generally shallow boundary layer indicate that the environment at this Andean location has the potential to accumulate pollutants. Thus, vertical dilution alone is unable to explain the observed low levels of ambient ozone. When ozone reached the highest values in the second half of September 2014, it was found that it increases with decreasing NO levels during daylight hours between 11:00 and 16:00. Therefore, air quality observations along with findings of shallow mixing layers suggest that inhibition of ozone production potentially occurs due to a NOx-saturated chemical regime.
Показать больше [+] Меньше [-]Chemical characterization and source apportionment of aerosol at an urban area of Central Delhi, India
2016
Sharma, Sudhir Kumar | Sharma, Ashima | Saxena, Mohit | Choudhary, Nikki | Masiwal, Renu | Mandal, Tuhin Kumar | Sharma, C. (Chhemendra)
The concentrations of organic carbon (OC), elemental carbon (EC), water soluble inorganic ionic components (WSIC), and major & trace elements of PM10 were studied in Delhi, an urban site of the Indo Gangetic Plain (IGP), India during January 2013 to June 2014. The average mass concentration of PM10 recorded as 249.7 ± 103.9 μg m−3 (average ± standard deviation) with a range of 61.4–584.8 μg m−3. The strong seasonal variation was noticed in the mass concentration of PM10 and its chemical composition with maxima during winter (PM10: 293.9 ± 95.6 μg m−3; OC: 30.5 ± 13.7 μg m−3; EC: 15.2 ± 7.4 μg m−3) and minima during monsoon (PM10: 143.9 ± 36.3 μg m−3; OC: 19.9 ± 16.2 μg m−3; EC: 7.4 ± 5.4 μg m−3). The average concentration of major and trace elements (Na, Mg, Al, P, S, Cl, K, Ca, Si, Cr, Ti, As, Br, Pb, Fe, Zn and Mn) was accounted for ∼18.5% of PM10 mass. Results of Positive Matrix Factorization (PMF) model, HYSPLIT4 trajectory model, PSCF analysis and cluster analysis provide region of sources and its strength and types of sources of PM10 over Delhi. Positive PMF provides that the major source of PM10 are soil dust (22.7%) followed by secondary aerosols (20.5%), vehicle emissions (17.0%), fossil fuel burning (15.5%), biomass burning (12.2%), industrial emissions (7.3%) and sea salts (4.8%) at the observational site of Delhi. The cluster analysis of air mass trajectories calculated by HYSPLIT model indicates that the air mass approaches to the observational site mainly from 4 sides (north-western IGP, Pakistan (10%); north-western IGP, Northwest Asia (45%); eastern IGP (38%); Pakistan and Arabian Sea (6%)) during study. Potential Source Contribution Function (PSCF) analysis also supports the cluster analysis indicating that the concentration of PM10 mass contributed, is mainly from IGP region (Uttar Pradesh, Haryana and Punjab etc.), Afghanistan, Pakistan and surrounding areas.
Показать больше [+] Меньше [-]Ballast water sediment elemental analysis
2016
Maglić, Lovro | Zec, Damir | Frančić, Vlado
Sediment samples from the ballast water tanks of ships calling at the port of Rijeka in the Northern Adriatic were analysed using X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) using caesium, argon and oxygen ion beams. The research was carried out in order to determine the sediment composition and relative abundance of the dominant elements. The results indicate that the sediment samples mostly consisted of compounds that originated from the deterioration of tank plates, tank coating residues and ballast operations such as clay, silt, sand and organic materials. No significant heavy metals or highly toxic elements were found. The research revealed some advantages and significant drawbacks of using XPS and SIMS for the routine analysis of sediment composition as a decision supporting tool for ballast water and sediment management.
Показать больше [+] Меньше [-]Ontogenetic variability in the feeding behavior of a marine amphipod in response to ocean acidification
2016
Benítez, Samanta | Duarte, Cristian | López, Jorge | Manríquez, Patricio H. | Navarro, Jorge M. | Bonta, Cesar C. | Torres, Rodrigo | Quijón, Pedro A.
Global stressors like ocean acidification (OA) are expected to influence the quality or palatability of primary producers like algae. Such changes can trigger a response on algal consumers' feeding strategies, and this response may not necessarily be the same for the consumers during the ontogeny. We used a mesocosm's system to expose algae to current and projected OA conditions (390 and 1000ppm, respectively) and then compared the feeding behavior and absorption efficiency of juvenile and adult stages of the amphipod Orchestoidea tuberculata. Specifically, we measured consumption rates (with and without a choice) and absorption efficiency on algae exposed and not exposed to OA. Our results show that OA affect the amphipod's consumption and feeding preferences, and that these effects were related with the analyzed ontogenetic stage (juveniles versus adults). These results support the existence of an ontogenetic change in the response of this species and others similar marine invertebrates to OA, which highlight the need to incorporate different life stages in the study of OA or others global stressors.
Показать больше [+] Меньше [-]The role of transport processes of particulate mercury in modifying marine anthropogenic secondary sources, the case of Haifa bay, Israel
2016
Bareket, Merav M. | Bookman, Revital | Katsman, Regina | de Stigter, Henko | Herut, Barak
We have assessed the redistribution of a secondary source of sedimentary anthropogenic mercury in the Haifa bay (HB) area (SE Levantine basin), which is the northern sink for Nile-driven sand. A long-term (30years) ~80% decrease of the total sedimentary mercury concentrations (THg) was recorded in the inner bay, while an up to 3-fold increase was recorded in the top sediments of the outer bay. Sedimentary THg depth profiles and their temporal variability were used to model the main re-distribution processes, mainly resuspension associated with winter storm-derived transport. This mechanism transforms a secondary, sandy and well-aerated sink into a tertiary, more silty and hypoxic source at adjacent peripheral areas, affecting mercury bioavailability. We revisited the concept of environmental relaxation, i.e. the rate of return of a polluted environment to an acceptable state, showing that sedimentary transport processes may affect the associated ecological risks, mainly at shallow-water coastal sites.
Показать больше [+] Меньше [-]Tolerance to stress differs between Asian green mussels Perna viridis from the impacted Jakarta Bay and from natural habitats along the coast of West Java
2016
Huhn, Mareike | Hattich, Giannina S.I. | Zamani, Neviaty P. | von Juterzenka, Karen | Lenz, Mark
It is an open question whether adverse habitat conditions, characteristic for many anthropogenically impacted coastal habitats, can determine resistance to abiotic stress in populations of residing invertebrates. We tested experimentally for differences in stress tolerance between individuals of the Asian green mussel Perna viridis stemming from the heavily impacted Jakarta Bay and from two natural sites, Lada Bay and Pelabuhan Ratu, West Java. Mussel performance under hyposalinity and hypoxia was assessed in laboratory assays by measuring fitness-related response variables, e.g. body condition index, relative shell weight, byssus production, respiration rates and survival. We found stress-specific and population-specific differences in mussel resistance to adverse conditions: Individuals from the impacted Jakarta Bay performed better under hypoxia than their conspecifics from the natural sites, whereas the latter were more resistant to hyposalinity. We explain these differences by differential acclimation to environmental conditions in the respective habitats and by diverging degrees of food supply.
Показать больше [+] Меньше [-]Long-term underwater sound measurements in the shipping noise indicator bands 63Hz and 125Hz from the port of Falmouth Bay, UK
2016
Garrett, J.K. | Blondel, Ph | Godley, B.J. | Pikesley, S.K. | Witt, M.J. | Johanning, L.
Chronic low-frequency anthropogenic sound, such as shipping noise, may be negatively affecting marine life. The EU's Marine Strategy Framework Directive (MSFD) includes a specific indicator focused on this noise. This indicator is the yearly average sound level in third-octave bands with centre frequencies at 63Hz and 125Hz. These levels are described for Falmouth Bay, UK, an active port at the entrance to the English Channel. Underwater sound was recorded for 30min h−1 over the period June 2012 to November 2013 for a total of 435days. Mean third-octave levels were louder in the 125-Hz band (annual mean level of 96.0dB re 1μPa) than in the 63-Hz band (92.6dB re 1 μPa). These levels and variations are assessed as a function of seasons, shipping activity and wave height, providing comparison points for future monitoring activities, including the MSFD and emerging international regulation.
Показать больше [+] Меньше [-]On the possibility to produce again oysters Crassostrea gigas in the North Médoc salt marshes (Gironde estuary, Southwestern France): A comparison study of metals bioaccumulation in spats 13years after
2016
Baudrimont, Magalie | Chelini, Audrey | Gourves, Pierre-Yves | Maury-Brachet, Régine | Legeay, Alexia
The Gironde Estuary is known for its historic poly-metallic contamination, leading to levels of Cd in oysters Crassostrea gigas above the human consumption limit. However, since 25years, Cd concentrations progressively decreased in the estuary and the question is raised if the same evolution occurred in the North Médoc salt marshes. In this aim, we analyzed 12 metals in juveniles of oysters transplanted from a hatchery on a 12months period in 2 salt marshes. Moreover, the comparison of four metals already measured 13years ago was conducted.The major results showed an overall decrease of the metals in the salt marshes, with a significant decrease of Cd reaching 80% compared to the Gironde estuary where it occurs for only 50% between 2001 and 2014. The concentrations in 2014 remained below the human consumption threshold, suggesting the possibility to produce again oysters in the salt marshes.
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