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Restoring rocky intertidal communities: Lessons from a benthic macroalgal ecosystem engineer
2017
Bellgrove, Alecia | McKenzie, Prudence F. | Cameron, Hayley | Pocklington, Jacqueline B.
As coastal population growth increases globally, effective waste management practices are required to protect biodiversity. Water authorities are under increasing pressure to reduce the impact of sewage effluent discharged into the coastal environment and restore disturbed ecosystems. We review the role of benthic macroalgae as ecosystem engineers and focus particularly on the temperate Australasian fucoid Hormosira banksii as a case study for rocky intertidal restoration efforts. Research focussing on the roles of ecosystem engineers is lagging behind restoration research of ecosystem engineers. As such, management decisions are being made without a sound understanding of the ecology of ecosystem engineers. For successful restoration of rocky intertidal shores it is important that we assess the thresholds of engineering traits (discussed herein) and the environmental conditions under which they are important.
Afficher plus [+] Moins [-]Occurrence and spatial distribution of organophosphorus flame retardants and plasticizers in the Bohai and Yellow Seas, China
2017
Zhong, Mingyu | Tang, Jianhui | Mi, Lijie | Li, Fei | Wang, Runmei | Huang, Guopei | Wu, Huifeng
Seawater samples from 50 sites in the BS and YS were collected to investigate the spatial distribution of 7 OPs. Concentrations of the total OPs (ƩOPs) in the BS and YS ranged from 8.12ngL−1 to 98.04ngL−1 with a geometric mean (GM) of 23.70ngL−1. Tris(1-chloro-2-propyl) phosphate (TCPP) was the dominant compound, followed by tris(2-chloroethyl) phosphate (TCEP) and triphenylphosphine oxide (TPPO). The ƩOPs together with the most commonly detected individual OPs (TCPP, TCEP, tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tri-iso-butyl phosphate (TiBP), triphenyl phosphate (TPhP), and TPPO) tended to decrease from nearshore to offshore and from the surface to the bottom seawaters, indicating major land-based sources. Furthermore, the Yellow Sea Cold Water Mass (YSCWM), Changjiang Diluted Water (CDW), Taiwan Warm Current (TaWC), and Subei Coastal Water (SCW) influenced the horizontal and vertical distributions of the OPs in the study area.
Afficher plus [+] Moins [-]Estrogenic compound profiles in an urbanized industry-impacted coastal bay and potential risk assessment by pollution indices and multivariative statistical methods
2017
Wang, Zaosheng | Li, Rui | Wu, Fengchang | Feng, Chenglian | Ye, Chun | Yan, Changzhou
The occurrence and distribution of target estrogenic compounds in a highly urbanized industry-impacted coastal bay were investigated, and contamination profiles were evaluated by estimating total estradiol equivalents (∑EEQs) and risk quotients (RQs). Phenolic compounds were the most abundant xenoestrogens, but seldom showed contribution to the ∑EEQs. The diethylstilbestrol (DES) and 17α-ethinylestradiol (EE2) were the major contributors followed by 17β-estradiol (E2) in comparison with a slight contribution from estrone (E1) and estriol (E3). Both ∑EEQs and RQs indicated likely adverse effects posed on resident organisms. Further, multivariate statistical method comprehensively revealed pollution status by visualized factor scores and identified multiple “hotspots” of estrogenic sources, demonstrating the presence of complex pollution risk gradients inside and particularly outside of bay area. Overall, this study favors the integrative utilization of pollution indices and factor analysis as powerful tool to scientifically diagnose the pollution characterization of human-derived chemicals for better management decisions in aquatic environments.
Afficher plus [+] Moins [-]Antioxidant response to metal pollution in Phragmites australis from Anzali wetland
2017
Esmaeilzadeh, Marjan | Karbassi, Abdolreza | Bastami, Kazem Darvish
This research was conducted to examine variations of antioxidant enzyme activity in Phragmites australis as a biomarker for metals such as As, Pb, Cu, and Cd. Samples of sediment and plants were collected from 7 stations located in Anzali wetland. Biochemical parameters including Catalase, Peroxidase and Ascorbate Peroxidase activity were analyzed in the roots, stems and leaves of P. australis. The obtained results indicated that there were significant differences among activities of antioxidant enzymes in three organs (p<0.05). Antioxidant enzyme activities in the organs for all studied stations were as the following order: stem<leaf<root. Overall, significant positive correlations were observed among concentrations of metals in sediments and activities of antioxidant enzymes in P. australis. As a result, it can be concluded from this study that antioxidant enzymes are good biomarkers reflecting metal contamination in sediments of Anzali wetland.
Afficher plus [+] Moins [-]Tributyltin exposure increases mortality of nodavirus infected Japanese medaka Oryzias latipes larvae
2017
Kitamura, Shin-Ichi | Akizuki, Masaki | Song, Jun-Young | Nakayama, Kei
We investigated the effect of combined exposure to nodavirus infection and TBT on medaka (Oryzias latipes). Medaka larvae were infected by immersion in medium containing nodavirus at titers of 102.5, 103.5, or 104.5 TCID50/mL. Infected fish then were exposed to TBT at 0, 0.17, 0.52, 1.6, or 4.7μg/L. Of the 12 groups exposed to both stressors, the mortalities of 6 (102.5 TCID50/mL+0.52, 1.6, or 4.7μg/L, 103.5 TCID50/mL+4.7μg/L and 104.5 TCID50/mL+1.6 or 4.7μg/L) were significantly higher than that of each TBT control. Specifically, mortality was 46±5.5% in the group exposed to both 102.5 TCID50/mL virus and 0.52μg/L TBT, which represent the lowest observed effective dose and concentration, respectively, among the 6 groups with increased mortalities. Our results suggest that combined exposure to both stressors suppresses antiviral mechanisms in the fish, thus increasing mortality.
Afficher plus [+] Moins [-]Risk assessment of trace metal-polluted coastal sediments on Hainan Island: A full-scale set of 474 geographical locations covering the entire island
2017
Li, Feng | Lin, Ze-Feng | Wen, Jia-Sheng | Wei, Yan-Sha | Gan, Hua-Yang | He, Hai-Jun | Lin, Jin-Qin | Xia, Zhen | Chen, Bi-Shuang | Guo, Wen-Jie | Tan, Cha-Sheng | Cai, Hua-Yang
Hainan Island is the second largest island and one of the most famous tourist destinations in China, but sediment contamination by trace metals in coastal areas is a major issue. However, full-scale risk assessments of trace metal-polluted coastal sediments are lacking. In this study, coastal surface sediments from 474 geographical locations covering almost the entire island were collected to identify risk-related variables. Controlling factors and possible sources of trace metals were identified, and the toxicity effects were carefully evaluated. Our results suggest that trace-metal pollution in coastal sediments, which was mainly caused by Pb, Zn and Cu emissions, has primarily resulted from industrial sewage and shipping activities and has threatened the offshore ecosystem of Hainan Island and warrants extensive consideration. This is the first study that has systematically investigated trace metal-polluted coastal sediments throughout the entirety of Hainan Island and provides solid evidence for sustainable marine management in the region.
Afficher plus [+] Moins [-]Use of moss biomonitors for turbulent transport coefficient estimation for industrial emissions
2017
Ryzhakova, Nadezhda K. | Borisenko, Alexei L. | Babicheva, Valentina O.
The important mechanism transporting substances in the surface layer of the atmosphere is turbulent diffusion. The intensity of turbulent transport is characterized by the turbulent diffusion coefficient. Calculation is a difficult task without a unique characterization. Distinguished turbulent models of atmospheric flow have been developed for particular atmospheric states and simple landscapes. These restrictions complicate the use of such models when assessing the distribution of industrial emissions in the atmosphere. The aims of the present work are to (i) develop a semi-empirical method for estimating the turbulent diffusion coefficient of the emissions of large industries, and (ii) study the turbulence intensity dependence of fundamental factors: the wind speed and landscape. The method relies on the distribution function of the concentration of contaminants measured along any direction of the altitude of a point source. Epiphytic mosses (Pylaisia polyantha, Sanionia uncinata) were used with an exposure time of 3 years. The chemical contents of the mosses were determined by neutron activation analysis and atomic emissive spectrometry. It is shown that in the territories of the coal-fired thermal power station and aluminum plant, the average values of the turbulent transport coefficient at heights above 1 m are k1¯=0.15 m2/s and k1¯=0.02 m2/s respectively. High turbulence within the location of the thermal power station is explained by obstacles of various heights and a higher wind speed. The proposed method is useful for the estimation and forecast of the spatial distribution of emissions from large industries and for determining the zones of their influence.
Afficher plus [+] Moins [-]Biofilm processes in treating mariculture wastewater may be a reservoir of antibiotic resistance genes
2017
Li, Shuai | Zhang, Shenghua | Ye, Chengsong | Lin, Xiongxiang | Zhang, Menglu | Chen, Lihua | Li, Jinmei | Yu, Xin
Antibiotics are heavily used in Chinese mariculture, but only a small portion of the added antibiotics are absorbed by living creatures. Biofilm processes are universally used in mariculture wastewater treatment. In this study, removal of antibiotics (norfloxacin, rifampicin, and oxytetracycline) from wastewater by moving bed biofilm reactors (MBBRs) and the influence of antibiotics on reactor biofilm were investigated. The results demonstrated that there was no significant effect of sub-μg/L–sub-mg/L concentrations of antibiotics on TOC removal. Moreover, the relative abundance of antibiotic resistance genes (ARGs) and antibiotic resistance bacteria (ARB) in MBBR biofilm increased because of selective pressure of antibiotics. In addition, antibiotics decreased the diversity of the biofilm bacterial community and altered bacterial community structure. These findings provide an empirical basis for the development of appropriate practices for mariculture, and suggest that disinfection and advanced oxidation should be applied to eliminate antibiotics, ARGs, and ARB from mariculture wastewater.
Afficher plus [+] Moins [-]Effect of the interaction between transplants of the epiphytic lichen Pseudevernia furfuracea L. (Zopf) and rainfall on the variation of element concentrations associated with the water-soluble part of atmospheric depositions
2017
Gallo, Luana | Corapi, Anna | Apollaro, Carmine | Vespasiano, Giovanni | Lucadamo, Lucio
Water Soluble Bulk Deposition (WSBD) and Water Soluble Leaching (WSL) from Pseudevernia furfuracea thalli transplanted in a anthropized zone were separately collected in four locations where weather stations were set up for monitoring rainfalls rate and daily temperature.The thalli were exposed for three months during which 13 major rainfalls took place. The concentrations of 15 elements (Al, V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Pb, As, Cd, Ti, Sn, Sb) were measured as well in WSBD and WSL as in the lichen thalli at the end of the exposure period. The total bioaccumulation of each element was significantly correlated with its % representation in both the lichen input (WSBD) and output (WSL). Elements with a small water-soluble input-pool were mostly taken up by the thalli (output/input < 1). Among the elements with a high input-pool, Zn was nearly systematically taken up while Al and Mn were lost (output/input > 1). Al showed a significant direct correlation with the increase in mm and hours of rainfall (i.e. transition from net loss to net uptake) while Mn showed an inverse correlation (transition from net uptake to net loss), which may be due to element competition modulated by water-stimulated lichen physiology. Al was strongly bioaccumulated while Mn showed a slight increase in exposed thalli. This suggests that rainfall-induced loss can result in an underestimation by lichen biomonitoring of element concentrations in atmospheric deposition and an increase in the bioavailability of potential toxic elements for other environmental compartments.
Afficher plus [+] Moins [-]Modeling oil spill trajectory in Bosphorus for contingency planning
2017
Bozkurtoğlu, Şafak Nur Ertürk
Bosphorus, is a strongly driven international maritime route between the Black Sea and the Sea of Marmara and is a high risk area for oil spill due to the heavy tanker traffic. In this study an oil spill trajectory model was developed for investigating the potential risks of accidental oil spills in Bosphorus. The proposed oil spill trajectory model combines the surface current velocity data obtained from a calibrated hydrodynamic model with the advection, spreading, and evaporation processes that are effective only on the sea surface and dominant for a couple of hours after the oil spill. Model simulations revealed that spilled oil reaches the shoreline on both sides of Bosphorus in <4h following the spill. We proposed locations for emergency intervention stations in Bosphorus which can be used to devise a suitable oil spill contingency plan to keep the adverse impacts of oil spills at minimum.
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