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Mercury in the ecosystem of Admiralty Bay, King George Island, Antarctica: Occurrence and trophic distribution Full text
2017
Cipro, Caio V.Z. | Montone, Rosalinda C. | Bustamante, Paco
Mercury (Hg) can reach the environment through natural and human-related sources, threatening ecosystems all over the planet due to its well known deleterious effects. Therefore, Antarctic trophic webs, despite being relatively isolated, are not exempt of its influence. To evaluate Hg concentrations in an Antarctic ecosystem, different tissues from 2 species of invertebrates, 2 of fish, 8 of birds, 4 of pinnipeds and at least 5 of vegetation were investigated (n=176). For animals, values ranged from 0.018 to 48.7μgg−1 dw (whole Antarctic krill and Antarctic Fur Seal liver). They were generally correlated to trophic position (assessed by δ15N and δ13C) but also to cephalopods and myctophids consumption. For vegetation, values ranged from 0.014 to 0.227μgg−1 dw (Colobanthus quitensis and an unidentified lichen), with lichens presenting significantly higher values than mosses, likely due to year-round exposure and absorption of animal derived organic matter, as hypothesized by literature.
Show more [+] Less [-]A multivariate approach to analyzing functional redundancy of marine periphytic ciliates during the colonization process for bioassessment in coastal ecosystems Full text
2017
Xu, Guangjian | Zhong, Xiaoxiao | Warren, Alan | Xu, Henglong
Functional redundancy is a useful tool for determining functional compensation and for reducing “signal to noise” ratios of full-species datasets in community-based monitoring programs. The functional redundancy of marine periphytic ciliate communities during the colonization process in coastal waters of the Yellow Sea, China, was analyzed using a peeling procedure (BVSTEP). Four response units (RUs) with trophic-functional equivalents were identified from the full 77-species dataset. These RUs, which comprised four, seven, six and six species respectively, represented a clear variation in trophic-functional structures across the levels of functional redundancy. RU1 was dominated by bacterivores, RU2 and RU3 first by bacterivores then by algivores, and RU4 first by non-selectives and bacterivores then by algivores. The colonization process and growth curve of each RU were significantly well-fitted to the MacArthur-Wilson and logistic models, respectively. These results suggest that RUs can be used as changeable trophic-functional equivalents for bioassessment in marine ecosystems.
Show more [+] Less [-]A pilot study on remediation of muddy tidal flat using porous pile Full text
2017
Ryu, Sung-Hoon | Nakashita, Shinya | Lee, In-Cheol | Kim, Dong-Sun | Kim, Jong Ryol | Hibino, Tadashi | Yamamoto, Tamiji | Asaoka, Satoshi | Kim, Kyunghoi
In order to prove that porous piles are effective in remediating muddy tidal flat sediments and increasing the biomass, field experiments were carried out at the tidal flat of a brackish river located in Hiroshima City, Japan. Porous piles with a diameter of 16cm and height of 50cm were installed in the muddy sediment that covers the sand layer of the tidal flat. After installation, concentrations of dissolved oxygen in interstitial water in and around the porous piles increased to a maximum concentration of 6mg/l due to enhancement of the groundwater flow. The increase of dissolved oxygen in the interstitial water produced a decrease in the concentration of ammonia and an increase in the individual number of benthos at the porous pile site. From these results, we concluded that the porous pile is an effective technology for remediation of muddy tidal flats.
Show more [+] Less [-]Distribution and antimicrobial susceptibility of Vibrio species associated with zooplankton in coastal area of Korea Full text
2017
Yang, Ji Hye | Mok, Jong Soo | Jung, Yeoun Joong | Lee, Ka Jeong | Kwon, Ji Young | Park, Kunbawui | Moon, Seong Yong | Kwon, Soon Jae | Ryu, A Ra | Lee, Tea Seek
Vibrio parahaemolyticus and V. vulnificus are the most common pathogens causing seafood-borne illnesses in Korea. This study determines the abundance and antimicrobial resistance of pathogenic Vibrio species in seawater and zooplankton samples from the Geoje Island coast in Korea, which is an important area for coastal fisheries, the fishing industry, and tourism. The two Vibrio species were detected more in mesozooplankton samples than in seawater samples. V. parahaemolyticus isolates showed greater resistance than those of V. vulnificus for antimicrobials. Of V. parahaemolyticus isolates, 93.3% exhibited resistance to three or more antimicrobial agents. Conversely, more than 80% of V. vulnificus isolates showed susceptibility to all antimicrobials examined, with the exception of rifampicin. Our findings show that strong antimicrobial resistance of V. parahaemolyticus in the surveyed area was exposed to conventionally used antibiotics, therefore necessitating proper surveillance programs for the monitoring of antimicrobial resistance patterns in seawater bodies and aquatic animals.
Show more [+] Less [-]Ports and pests: Assessing the threat of aquatic invasive species introduced by maritime shipping activity in Cuba Full text
2017
O'Brien, Charleen E. | Johnston, Matthew W. | Kerstetter, David W.
Aquatic invasive species (AIS) are biological pollutants that cause detrimental ecological, economic, and human-health effects in their introduced communities. With increasing globalization through maritime trade, ports are vulnerable to AIS exposure via commercial vessels. The Cuban Port of Mariel is poised to become a competitive transshipment hub in the Caribbean and the intent of this study was to evaluate present and potential impacts AIS pose with the likely future increase in shipping activity. We utilized previous assessment frameworks and publicly accessible information to rank AIS by level of threat. Fifteen AIS were identified in Cuba and one, the Asian green mussel Perna viridis (Linnaeus, 1758), had repeated harmful economic impacts. Five species associated with trade partners of Port Mariel were considered potentially detrimental to Cuba if introduced through shipping routes. The results presented herein identify species of concern and emphasize the importance of prioritizing AIS prevention and management within Cuba.
Show more [+] Less [-]Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers Full text
2017
Gueguen, Yannick | Denis, Saulnier | Adrien, Santini | Kevin, Magre | Pierre, Garen | Solène, Bernagout | Marine, Nohl | Patrick, Bouisset | Herehia, Helme | Serge, Planes | Gilles, Le Moullac
Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers Full text
2017
Gueguen, Yannick | Denis, Saulnier | Adrien, Santini | Kevin, Magre | Pierre, Garen | Solène, Bernagout | Marine, Nohl | Patrick, Bouisset | Herehia, Helme | Serge, Planes | Gilles, Le Moullac
This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10μgL−1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.
Show more [+] Less [-]Response of the pearl oyster Pinctada margaritifera to cadmium and chromium: Identification of molecular biomarkers Full text
2017
Gueguen, Yannick | Saulnier, Denis | Santini, Adrien | Magre, Kevin | Garen, Pierre | Bernagout, Solene | Nohl, Marine | Bouisset, Patrick | Helme, Herehia | Planes, Serge | Le Moullac, Gilles
This study was designed to identify in the pearl oyster Pinctada margaritifera, used as a bio-accumulator, molecular biomarkers for the presence of heavy metals in the lagoon environment. Pearl oysters were exposed to 2 concentrations (1 and 10 μg L− 1) of cadmium (Cd) and chromium (Cr) compared to a control. Twelve target genes encoding proteins potentially involved in the response to heavy metal contamination with antioxidant, detoxification or apoptosis activities were selected. P. margaritifera accumulated Cd but not Cr, and mortality was related to the amount of Cd accumulated in tissues. In response to Cd-Cr contamination, metallothionein (MT) was significantly up-regulated by Cd-Cr at both concentrations, while 7 others (SOD, CAT, GPX, GSTO, GSTM, CASP, MDR) were down-regulated. Based on the development of these molecular tools, we propose that the pearl oyster, P. margaritifera, could be used as a sentinel species for heavy metal contamination in the lagoons of tropical ecosystems.
Show more [+] Less [-]A facile and cost-effective method for removal of indoor airborne psychrotrophic bacterial and fungal flora based on silver and zinc oxide nanoparticles decorated on fibrous air filter Full text
2017
Pokhum, Chonlada | Intasanta, Varol | Yaipimai, Wittaya | Subjalearndee, Nakarin | Srisitthiratkul, Chutima | Pongsorrarith, Voraluck | Phanomkate, Nipon | Chawengkijwanich, Chamorn
In tropical countries, food and agricultural crops need to be kept cool to reduce spoilage and quality losses. Airborne psychrotrophic bacteria and fungi can cause adverse effects on food quality and consumers' health safety. The present study aimed to present a facile and cost-effective approach to remove airborne microbes from indoor air by employing silver (Ag) and zinc oxide (ZnO) to decorate fibrous air filters. A water-based anti-germ solution containing Ag/ZnO nanoparticles was first prepared using high-speed homogenization. Second, a commercially available washable non-woven air filter (thickness 50 mm) was coated by aerosol generated from the mixture using spray coating process. This facile method successfully led to homogeneous coating of active nanomaterials on the filter's surface as unveiled by scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX). On laboratory scale, the Ag/ZnO air filter was shown to exhibit antibacterial effectiveness against Staphylococcus aureus and Escherichia coli under contact mode following an antibacterial standard method (AATCC 147-2011). Finally, the Ag/ZnO filter was assembled into a commercial air filtration system (670 × 820 × 1420 mm) containing two UVA light lamps (365 nm). The Ag/ZnO air-filtration unit was placed in a 45-m3 cold storage room (4–5 °C) for evaluation of airborne psychrotrophic microbial reduction efficiency. The developed Ag/ZnO air filter reduced the airborne psychrotrophic germs concentrations by ∼50% and its efficiency increased to ∼70% when combined with UVA illumination. Based on these results, a simple and low-cost ZnO/Ag air filter was successfully introduced as an effective strategy for removal of psychrotrophic microbes from indoor air.
Show more [+] Less [-]Impacts of Regional Transport on Particulate Matter Pollution in China: a Review of Methods and Results Full text
2017
Sun, Jinjin | Huang, Lin | Liao, Hong | Li, Jingyi | Hu, Jianlin
China has been suffering serious particulate matter (PM) pollution in recent decades. Local emission and regional transport both contribute to PM pollution. Determining the contributions of local emissions vs. regional transport to PM concentrations is crucial in making effective PM control policies. This paper reviews the recent research on the contributions of regional transport to PM pollution in four regions in China, i.e., the northern China, eastern China, southern China, and the western China, respectively. The major findings include (1) HYSPLIT is the most popular methods in studies in all regions and often is used in combination with the CA, PSCF, and CWT techniques to investigate the transport pathways and source origins; (2) during the relatively polluted period, transport contributes over 50% of the PM concentrations in Beijing, Shanghai, Hangzhou, Guangzhou, Hong Kong, and Chengdu. Regional transport is important for PM pollution in major cities of China; and (3) regional transport exhibits clear seasonal variations and long term trends. The findings have important implication for emission control programs in these regions.
Show more [+] Less [-]Intraspecific variations in responses to ocean acidification in two branching coral species Full text
2017
Sekizawa, Ayami | Uechi, Hikaru | Iguchi, Akira | Nakamura, Takashi | Kumagai, Naoki H. | Suzuki, Atsushi | Sakai, Keinan | Nojiri, Yukihiro
Ocean acidification is widely recognised to have a negative impact on marine calcifying organisms by reducing calcifications, but controversy remains over whether such organisms could cope with ocean acidification within a range of phenotypic plasticity and/or adapt to future acidifying ocean. We performed a laboratory rearing experiment using clonal fragments of the common branching corals Montipora digitata and Porites cylindrica under control and acidified seawater (lower pH) conditions (approximately 400 and 900μatm pCO2, respectively) and evaluated the intraspecific variations in their responses to ocean acidification. Intra- and interspecific variations in calcification and photosynthetic efficiency were evident according to both pCO2 conditions and colony, indicating that responses to acidification may be individually variable at the colony level. Our results suggest that some corals may cope with ocean acidification within their present genotypic composition by adaptation through phenotypic plasticity, while others may be placed under selective pressures resulting in population alteration.
Show more [+] Less [-]Chemical composition and source apportionment of PM2.5 – A case study from one year continuous sampling in the Chang-Zhu-Tan urban agglomeration Full text
2017
Tang, Xiangbo | Chen, Xiaohong | Tian, Yun
To understand the characteristics and source of atmospheric PM2.5 in Chang-Zhu-Tan urban agglomeration, PM2.5 samples were simultaneously collected at 11 monitoring sites within three cities of Changsha, Zhuzhou and Xiangtan from September 2013 to August 2014. Spatial and temporal variations of PM2.5 mass concentration and chemical compositions were analyzed based on the average values over the measurement sites in a specific urban area, including a comparison of PM2.5 at urban and urban background sites. Source apportionment was performed by PMF 5.0 (positive matrix factorization) model and potential source area affecting PM2.5 mass concentration was simulated using CWT (concentration-weighted trajectory analysis) analysis. The result showed the seasonal variation of PM2.5 mass concentration followed the order of winter > autumn > spring > summer. The OC/EC ratio in each season and each city were greater than 4.0, secondary inorganic ions accounted for at least 91% of the total water soluble inorganic ion concentration, presenting obvious secondary pollution characteristics. Coal combustion and vehicle emissions were two major sources of PM2.5 in all three cities, which accounted for about 35 percent and nearly 26 percent of contributions respectively. In addition, industrial emission and biomass burning were also significant sources in Changsha, while urban dust and biomass burning were significant sources in Zhuzhou and Xiangtan. Chang-zhu-tan urban agglomeration was the main source area of its PM2.5 and easy to form overlapping pollution areas. Meanwhile, northern neighboring city Yueyang and western bordering region Pingxiang also had a certain transmission influence on the formation of PM2.5.
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