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Oil spill experiment using airborne DLR ESAR off the coast of Diu, India Full text
2015
Sasamal, S.K. | Rao, M.V.
Oil spill experiment results in the coastal waters of Diu, India, with an airborne DLR ESAR sensor are discussed with reference to the SAR frequency, polarization and viewing angle. The SAR data acquired in the quad polarization of the L band and dual polarization of the C band over two spills are studied. A higher oil and water contrast is observed in the L-VV polarization than in the C-HH mode. Oil spill discrimination is possible over a wider view angle of the airborne SAR sensor data in L band than in C band. This study has also analyzed the spread and drift of oil in coastal waters.
Show more [+] Less [-]Polybrominated Diphenyl Ethers (PBDEs) in Concepción Bay, central Chile after the 2010 Tsunami Full text
2015
Pozo, Karla | Kukučka, Petr | Vaňková, Lenka | Přibylová, Petra | Klánová, Jana | Rudolph, Anny | Banguera, Yulieth | Monsalves, Javier | Contreras, Sergio | Barra, Ricardo | Ahumada, Ramón
PBDEs (10 congeners) were analyzed using GC–MS in superficial sediments and organisms of the Concepción Bay after the 2010 Tsunami. From all congeners analyzed PBDE-47, -99, -100 and -209 were the most frequently detected. Concentrations (ngg−1 d.w.) in sediments for ΣPBDE-47, -99, -100 were low (0.02–0.09). However, PBDE-209 showed significantly higher values ∼20ngg−1 d.w. This result were ∼10 times lower than those reported in a previous study of the 2010 Tsunami. The high result might be influenced by the massive urban debris dragged by the 2010 Tsunami. In organisms, concentrations of PBDE-47, -99, -100 (∼0.4ngg−1 d.w.) were higher than those found in sediments (∼0.04ngg−1 d.w.). Differences in PBDE pattern were also observed between different levels of the trophic food chain (primary and secondary consumers). This is the first attempt to assess the current status of Concepción Bay after the 2010 Tsunami.
Show more [+] Less [-]Ecophysiological responses of three Mediterranean invasive seaweeds (Acrothamnion preissii, Lophocladia lallemandii and Caulerpa cylindracea) to experimental warming Full text
2015
Samperio-Ramos, Guillermo | Olsen, Ylva S. | Tomas, Fiona | Marbà, Núria
The Mediterranean Sea is a hotspot for invasive species and projected Mediterranean warming might affect their future spreading. We experimentally examined ecophysiological responses to the temperature range 23–31°C in three invasive seaweeds commonly found in the Mediterranean: Acrothamnion preissii, Caulerpa cylindracea and Lophocladia lallemandii. The warming range tested encompassed current and projected (for the end of 21st Century) maximum temperatures for the Mediterranean Sea. Optimal ecophysiological temperatures for A. preissii, C. cylindracea and L. lallemandii were 25°C, 27°C and 29°C, respectively. Warming below the optimal temperatures enhanced RGR of all studied invasive seaweeds. Although sensitive, seaweed photosynthetic yield was less temperature-dependent than growth. Our results demonstrate that temperature is a key environmental parameter in regulating the ecophysiological performance of these invasive seaweeds and that Mediterranean warming conditions may affect their invasion trajectory.
Show more [+] Less [-]Polybrominated diphenyl ethers in mussels (Mytilus galloprovincialis) collected from Central Adriatic Sea Full text
2015
Piersanti, Arianna | Tavoloni, Tamara | Bastari, Eleonora | Lestingi, Carmela | Romanelli, Sara | Saluti, Giorgio | Moretti, Simone | Galarini, Roberta
One-hundred and thirty-four samples of mussels (Mytilus galloprovincialis) collected along Central Adriatic Sea in 2013 were examined to determine the levels of fifteen congeners of polybrominated diphenyl ethers (PBDEs). The purified samples were analysed by gas-chromatography coupled to tandem mass spectrometry (GC-MS/MS) applying the isotopic dilution. Only four congeners (PBDE 47, PBDE 99, PBDE 49 and PBDE 100) were present above the established limits of quantification with mean concentrations equal to 73, 30, 19 and 18pgg−1, respectively. The concentrations of PBDEs (sum) ranged from 27 to 386pgg−1, with the highest levels around the coastal area of Ancona town. The here found levels were comparable to those measured in mussels collected along Southern Adriatic Sea.
Show more [+] Less [-]Sources and Impacts of Atmospheric NH3: Current Understanding and Frontiers for Modeling, Measurements, and Remote Sensing in North America Full text
2015
Zhu, Liye | Henze, Daven K. | Bash, Jesse O. | Cady-Pereira, Karen E. | Shephard, Mark W. | Luo, Ming | Capps, Shannon L.
Ammonia (NH₃) contributes to widespread adverse health impacts, affects the climate forcing of ambient aerosols, and is a significant component of reactive nitrogen, deposition of which threatens many sensitive ecosystems. Historically, the scarcity of in situ measurements and the complexity of gas-to-aerosol NH₃ partitioning have contributed to large uncertainties in our knowledge of its sources and distributions. However, recent progress in measurements and modeling has afforded new opportunities for improving our understanding of NH₃ and the role it plays in these important environmental issues. In the past few years, passive measurements of NH₃ have been added to monitoring networks throughout the USA, now in place at more than 60 stations, while mobile measurements aboard aircrafts and vehicles have provide detailed observations during several recent field campaigns. In addition, new remote sensing observations from multiple satellite instruments have begun to provide vast amounts of NH₃ observations throughout the globe. These sources of information have collectively driven new air quality modeling capabilities, by revealing deficiencies in current air quality models and spurring development of mechanistic enhancements to models’ physical representation of the diurnal variability and bidirectional nature of NH₃ fluxes. In turn, these advanced models require further observational constraints, as existing NH₃ measurements are still limited in spatiotemporal coverage. We thus evaluate the potential value of a new geostationary remote sensing instrument (GCIRI) for providing constraints on NH₃ fluxes through multiple Observing System Simulation Experiments (OSSEs).
Show more [+] Less [-]Field experimental observations of highly graded sediment plumes Full text
2015
Jensen, Jacob Hjelmager | Saremi, Sina | Jimenez, Carlos | Hadjioannou, Louis
A field experiment in the waters off the south-eastern coast of Cyprus was carried out to study near-field formation of sediment plumes from dumping. Different loads of sediment were poured into calm and limpid waters one at the time from just above the sea surface. The associated plumes, gravitating towards the seafloor, were filmed simultaneously by four divers situated at different depths in the water column, and facing the plume at different angles. The processes were captured using GoPro-Hero-series cameras. The high-quality underwater footage from near-surface, mid-depth and near-bed positions gives unique insight into the dynamics of the descending plume and near-field dispersion processes, and enables good understanding of flow and sediment transport processes involved from-release-to-deposition of the load in a non-scaled environment. The high resolution images and footages are available through the link provided herein. Observations support the development of a detailed multi-fractional sediment plume model.
Show more [+] Less [-]Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy Full text
2015
Nilssen, Ingunn | Ødegård, Øyvind | Sørensen, Asgeir J. | Johnsen, Geir | Moline, Mark A. | Berge, Jørgen
New technology has led to new opportunities for a holistic environmental monitoring approach adjusted to purpose and object of interest. The proposed integrated environmental mapping and monitoring (IEMM) concept, presented in this paper, describes the different steps in such a system from mission of survey to selection of parameters, sensors, sensor platforms, data collection, data storage, analysis and to data interpretation for reliable decision making. The system is generic; it can be used by authorities, industry and academia and is useful for planning- and operational phases. In the planning process the systematic approach is also ideal to identify areas with gap of knowledge. The critical stages of the concept is discussed and exemplified by two case studies, one environmental mapping and one monitoring case. As an operational system, the IEMM concept can contribute to an optimised integrated environmental mapping and monitoring for knowledge generation as basis for decision making.
Show more [+] Less [-]The Marine Strategy Framework Directive and the ecosystem-based approach – pitfalls and solutions Full text
2015
Berg, Torsten | Fürhaupter, Karin | Teixeira, Heliana | Uusitalo, Laura | Zampoukas, Nikolaos
The European Marine Strategy Framework Directive aims at good environmental status (GES) in marine waters, following an ecosystem-based approach, focused on 11 descriptors related to ecosystem features, human drivers and pressures. Furthermore, 29 subordinate criteria and 56 attributes are detailed in an EU Commission Decision. The analysis of the Decision and the associated operational indicators revealed ambiguity in the use of terms, such as indicator, impact and habitat and considerable overlap of indicators assigned to various descriptors and criteria. We suggest re-arrangement and elimination of redundant criteria and attributes avoiding double counting in the subsequent indicator synthesis, a clear distinction between pressure and state descriptors and addition of criteria on ecosystem services and functioning. Moreover, we suggest the precautionary principle should be followed for the management of pressures and an evidence-based approach for monitoring state as well as reaching and maintaining GES.
Show more [+] Less [-]Klebsiella sp. FIRD 2, a TBT-resistant bacterium isolated from contaminated surface sediment along Strait of Johor Malaysia Full text
2015
Abubakar, Abdussamad | Mustafa, Muskhazli B. | Johari, Wan Lutfi Wan | Zulkifli, Syaizwan Zahmir | Ismail, Ahmad | Mohamat-Yusuff, Ferdaus Binti
A possible tributyltin (TBT)-degrading bacterium isolated from contaminated surface sediment was successfully identified as Klebsiella sp. FIRD 2. It was found to be the best isolate capable of resisting TBT at a concentration of 1000μgL−1. This was a concentration above the reported contaminated level at the sampling station, 790μgL−1. Further studies revealed that the isolate was Gram negative and resisted TBT concentrations of up to 1500μgL−1 in a Minimal Salt Broth without the addition of any carbon source within the first 48h of incubation. It is expected that additional work could be conducted to check the degradation activity of this new isolate and possibly improve the degradation capacity in order to contribute to finding a safe and sustainable remediation solution of TBT contamination.
Show more [+] Less [-]Heavy metal contamination and ecological risk assessment in the surface sediments of the coastal area surrounding the industrial complex of Gabes city, Gulf of Gabes, SE Tunisia Full text
2015
El Zrelli, Radhouan | Courjault-Radé, Pierre | Rabaoui, Lotfi | Castet, Sylvie | Michel, Sylvain | Bejaoui, Nejla
In the present study, the concentrations of 6 trace metals (Hg, Cd, Cu, Pb, Cr and Zn) were assessed in the surface sediments of the central coastal area of Gabes Gulf to determine their contamination status, source, spatial distribution and ecological risks. The ranking of metal contents was found to be Zn>Cd>Cr>Pb>Cu>Hg. Correlation analysis indicated that Cd and Zn derived mainly from the Tunisian Chemical Group phosphogypsum. The other pollutants may originate from other industrial wastes. Metallic contamination was detected in the south of chemical complex, especially in the inter-harbor zone, where the ecological risk of surface sediments is the highest, implying potential negative impacts of industrial pollutants. The spatial distribution of pollutants seems to be due to the effect of harbor installations and coastal currents. The metallic pollution status of surface sediments of Gabes Gulf is obvious, very worrying and requires rapid intervention.
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