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Near-port air quality assessment utilizing a mobile measurement approach Texte intégral
2017
Steffens, Jonathan | Kimbrough, Sue | Baldauf, Richard | Isakov, Vlad | Brown, Ryan | Powell, Alan | Deshmukh, Parikshit
Mobile monitoring is a strategy to characterize spatially and temporally variable air pollution in areas near sources. EPA's Geospatial Measurement of Air Pollution (GMAP) vehicle – an all-electric vehicle is outfitted with a number of measurement devices to record real-time concentrations of particulate matter and gaseous pollutants – was used to map air pollution levels near the Port of Charleston in South Carolina. High-resolution monitoring was performed along driving routes near several port terminals and rail yard facilities, recording geospatial coordinates and concentrations of pollutants including black carbon, size-resolved particle count ranging from ultrafine to coarse (6 nm–20 μm), carbon monoxide, and nitrogen dioxide. Additionally, a portable meteorological station was used to characterize local conditions. The primary objective of this work was to characterize the impact of port facilities on local scale air quality. The study determined that elevated concentration measurements of black carbon and PM correlated to periods of increased port activity and a significant elevation in concentration was observed downwind of ports. However, limitations in study design prevented a more complete analysis of the port effect.
Afficher plus [+] Moins [-]Delayed fluorescence as an indicator of the influence of the herbicides Irgarol 1051 and Diuron on hard coral Acropora digitifera Texte intégral
2017
Katsumata, Masakazu | Takeuchi, Ichirō
We examined the effect of two herbicides (Irgarol 1051 and Diuron) on symbiotic dinoflagellates in the hard coral Acropora digitifera using delayed fluorescence (DF), specifically assessing changes in molecular membrane transport, i.e. inflow and outflow rates, and the binding of the herbicides to target proteins in photosystem II. The DF approach is rapid (e.g. measurement time, 60 s) and non-invasive, and can provide data on the extent of a photosynthetic system and the activity of its electron carriers. The DF of A. digitifera is inhibited 2 h after exposure to 1 μg/L of either Irgarol or Diuron. Analysis of DF inhibition over time by a compartment model suggests that Irgarol exposure results in a relatively higher inflow rate and lower outflow rate than does Diuron exposure. This suggests that Irgarol exposure more strongly inhibits photosynthesis and that the coral symbiotic dinoflagellates recover less from inhibition.
Afficher plus [+] Moins [-]Molecular pathology of skeletal growth anomalies in the brain coral Platygyra carnosa: A meta-transcriptomic analysis Texte intégral
2017
Zhang, Yu | Sun, Jin | Mu, Huawei | Lun, Janice C.Y. | Qiu, Jian-Wen
Coral skeletal growth anomaly (GA) is a common coral disease. Although extensive ecological characterizations of coral GA have been performed, the molecular pathology of this disease remains largely unknown. We compared the meta-transcriptome of normal and GA-affected polyps of Platygyra carnosa using RNA-Seq. Approximately 50 million sequences were generated from four pairs of normal and GA-affected tissue samples. There were 109 differentially expressed genes (DEGs) in P. carnosa and 31 DEGs in the coral symbiont Symbiodinium sp. These differentially expressed host genes were enriched in GO terms related to osteogenesis and oncogenesis. There were several differentially expressed immune genes, indicating the presence of both bacteria and viruses in GA-affected tissues. The differentially expressed Symbiodinium genes were enriched in reproduction, nitrogen metabolism and pigment formation, indicating that GA affects the physiology of the symbiont. Our results have provided new insights into the molecular pathology of coral GA.
Afficher plus [+] Moins [-]Diurnal variation of CO2, CH4, and N2O emission fluxes continuously monitored in-situ in three environmental habitats in a subtropical estuarine wetland Texte intégral
2017
Yang, Wen-Bin | Yuan, Chung-Shin | Tong, Chuan | Yang, Bin | Yang, Lei | Huang, Bang-Qin
Wetlands play a crucial role in modulating atmospheric concentrations of greenhouse gases (GHGs) such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). The key factors controlling GHG emission from subtropical estuarine wetlands were investigated in this study, which continuously monitored the uptake/emission of GHGs (CO2, CH4, and N2O) by/from a subtropical estuarine wetland located in the Minjiang estuary in the coastal region of southeastern China. A self-designed floating chamber was used to collect air samples on-site at three environmental habitats (Phragmites australis marsh, mudflats, and river water). The CO2, CH4, and N2O concentrations were then measured using an automated nondispersive infrared analyzer. The magnitudes of the CO2 and N2O emission fluxes at the three habitats were ordered as river water>P. australis>mudflats. P. australis emitted GHGs through photosynthesis and respiration processes. Emissions of CH4 from P. australis and the mudflats were revealed to be slightly higher than those from the river water. The total GHG emission fluxes at the three environmental habitats were quite similar (4.68–4.78gm−2h−1). However, when the total carbon dioxide equivalent fluxes (CO2-e) were considered, the river water was discovered to emit the most CO2-e compared with P. australis and the mudflats. Based on its potential to increase global warming, N2O was the main contributor to the total GHG emission, with that emitted from the river water being the most considerable. Tidal water carried onto the marsh had its own GHG content and thus has acted as a source or sink of GHGs. However, water quality had a large effect on GHG emissions from the river water whereas the tidal water height did not. Both high salinity and large amounts of sulfates in the wetlands explicitly inhibited the activity of CH4-producing bacteria, particularly at nighttime.
Afficher plus [+] Moins [-]Differences in the structure of copepod assemblages in four tropical estuaries: Importance of pollution and the estuary hydrodynamics Texte intégral
2017
Araujo, Adriana V. | Dias, Cristina O. | Bonecker, Sérgio L.C.
We examined the relationship between pollution and structure of copepod assemblages in estuaries, using sampling standardization of salinity range to reduce the effects of “Estuarine Quality Paradox”. Copepod assemblages were analyzed in four Southeast Brazilian estuaries with different water quality levels and different hydrodynamic characteristics. The pollution negatively impacted the descriptors of the assemblage structure. The distribution of structure of copepod assemblages also showed a main separation trend between the most polluted estuaries and those less polluted. Temperature was the main factor affecting the assemblage structuring in the four estuaries. This factor acted in synergism with the effects of pollution impact and physical characteristics of the estuaries on the structure of copepod assemblages, supporting the potential vulnerability of coastal environments due to nutrient enrichment associated with climate change. Our study demonstrated the importance of sampling standardization of the salinity range in estuaries for reliable analysis of pollution effects on biota.
Afficher plus [+] Moins [-]Baseline aquatic contamination and endocrine status in a resident fish of Biscayne National Park Texte intégral
2017
Bargar, Timothy A. | Whelan, Kevin R.T. | Alvarez, David | Echols, Kathy | Peterman, Paul H.
Surface water, sediment, and fish from Biscayne Bay, coastal wetlands adjacent to the Bay, and canals discharging into the Bay were sampled for determination of baseline contamination in Biscayne National Park. While the number of contaminants detected in canal waters was greater during the wet season than the dry season, no seasonal difference was evident for Biscayne Bay or coastal wetland waters. Estrogen equivalency (as 17β-estradiol equivalents), as predicted by the Yeast Estrogen Screen, for extracts of passive water samplers deployed in canals and wetlands was elevated during the wet relative to the dry season. Generally, contamination in water, sediments, and fish was greater in the canals than in Biscayne Bay and the wetlands. Guideline levels for sediment contaminant were exceeded most frequently in canals relative to the coastal wetlands and the Bay. Further investigation is necessary to better understand the impact of contaminants in Biscayne National Park.
Afficher plus [+] Moins [-]Distribution and source analysis of heavy metals in soils and sediments of Yueqing Bay basin, East China Sea Texte intégral
2017
Yang, Xiaohui | Wu, Pengbao | Yin, Aijing | Zhang, Huan | Zhang, Ming | Gao, Chao
Concentrations of heavy metals in coastal soils, stream sediments and intertidal sediments of Yueqing Bay basin were analyzed to study their distribution and trace the possible sources. According to various single- and multi-index methods, heavy metal enrichment, especially for Cu, Zn, Cr and Ni in stream sediments, should draw environmental concern. Controlling factors such as inorganic scavengers, organic matter, sample grain size and hydrodynamic conditions were identified to influence the transportation and distribution of metals within coastal soils and sediments. Principal component analysis indicated that most metals in soils and stream sediments originate primarily from natural and anthropogenic sources, respectively. Most metals in intertidal sediments, originating both from natural processes and human activities, tend to be concentrated in fine particles. The exchange of water and sediment between the bay and open waters is strong enough to keep the metals in the tidal flats from rising to very high levels.
Afficher plus [+] Moins [-]Nuclear reprocessing-related radiocarbon (14C) uptake into UK marine mammals Texte intégral
2017
Tierney, Kieran M. | Muir, Graham K.P. | Cook, Gordon T. | Heymans, Johanna J. | MacKinnon, Gillian | Howe, John A. | Xu, Sheng | Brownlow, Andrew | Davison, Nicholas J. | Doeschate, Mariel ten | Deaville, Rob
To evaluate the transfer of Sellafield-derived radiocarbon (14C) to top predators in the UK marine environment, 14C activities were examined in stranded marine mammals. All samples of harbour porpoise (Phocoena phocoena) obtained from the Irish Sea showed 14C enrichment above background. Mammal samples obtained from the West of Scotland, including harbour porpoise, grey seals (Halichoerus grypus) and harbour seals (Phoca vitulina) showed 14C enrichment but to a lesser extent. This study demonstrates, for the first time, enriched 14C is transferred through the marine food web to apex predators as a consequence of ongoing nuclear reprocessing activities at Sellafield. Total Sellafield 14C discharge activity 24months prior to stranding and, in particular, distance of animal stranding site from Sellafield are significant variables affecting individual 14C activity. 14C activities of West of Scotland harbour porpoises suggest they did not forage in the Irish Sea prior to stranding, indicating a high foraging fidelity.
Afficher plus [+] Moins [-]Micro- and mesoplastics in Northeast Levantine coast of Turkey: The preliminary results from surface samples Texte intégral
2017
Gündoğdu, Sedat | Çevik, Cem
The determination of the microplastic distribution will be beneficial as a measure of the potential effects on the environment. The Mediterranean Sea had a high risk of pollution as it was enclosed by highly populated and industrialized countries. Here, we determined the level of micro- and mesoplastic pollution in Iskenderun and Mersin Bays, located in the Northeastern Levantine coast of Turkey. The average level of both micro- and mesoplastic was determined to be 0.376 item/m2 at seven stations. The highest level was determined in Mersin Bay at the mouth of the Seyhan river (Station no. 7, with 906 items), and the lowest level was found in Station no. 4 in Iskenderun Bay (78 items). As a result of this study, it was determined that the microplastic pollution level in the Mediterranean coast of Turkey was similar to the other regions of the Mediterranean Sea.
Afficher plus [+] Moins [-]Contamination of the Upper Class: Occurrence and Effects of Chemical Pollutants in Terrestrial Top Predators Texte intégral
2017
Rodríguez-Jorquera, I. A. | Vitale, N. | Garner, L. | Perez-Venegas, D. J. | Galbán-Malagón, C. J. | Duque-Wilckens, N. | Toor, G. S.
PURPOSE OF REVIEW: Knowledge of the occurrence and effects of pollutants on terrestrial top predators will serve to better understand the issue and propose measurements to conserve biodiversity and ecosystems. We reviewed literature on the occurrence and effects of pollutants on terrestrial top predators, which was particularly scarce in comparison to the literature available on aquatic top predators. We have asked the following questions: Does chemical pollution affect terrestrial top predator population? What are the mechanisms (if known) behind chemical pollution effects on top predators? What types of chemical pollution most commonly affect top predator species? RECENT FINDINGS: Pollutants present in the terrestrial top predators are industrial derived (PCBs), pesticides (insecticides and rodenticides), and trace metals (lead and mercury). Recent investigations on the effect of second-generation rodenticides (SGRs) are an emerging topic since these are causing deleterious effects on terrestrial top predator populations. On the other hand, eggshell thinning effects due to the old and known compounds such as DDT are still being observed in avian top predators. Further, lead pollution from spent ammunition affects predators after the hunting season. This information demonstrates that the occurrence and effects of chemical pollutants on terrestrial top predators is a relevant issue for species and ecosystem conservation. Topics such as biomagnification of pollutants, the impact of SGRs on carnivore populations, and alternatives of lead ammunition for hunting are relevant topics that warrant further research.
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