细化搜索
结果 1611-1620 的 4,033
Assessment of the environmental quality of coastal sediments by using a combination of in vitro bioassays
2016
Pérez-Albaladejo, Elisabet | Rizzi, Juliane | Fernandes, Denise | Lille-Langøy, Roger | Karlsen, Odd André | Goksøyr, Anders | Oros, Andra | Spagnoli, Federico | Porte, Cinta
The environmental quality of marine sediments collected in the area of influence of the Po and Danube Rivers was assessed by using a battery of bioassays based on the use of PLHC-1 cells, zebrafish-Pxr-transfected COS-7 cells, and sea bass ovarian subcellular fractions. This allowed the determination of multiple endpoints, namely, cytotoxicity, oxidative stress, induction of CYP1A, activation of zebrafish Pxr and inhibition of ovarian aromatase. Organic extracts of sediments influenced by the Danube River and collected near harbors and urban discharges showed significant cytotoxicity, CYP1A induction and inhibition of aromatase activity. An analogous response of CYP1A induction and zfPxr activation was observed, which suggests the existence of common ligands of AhR and PXR in the sediment extracts. The study highlights the usefulness of the selected bioassays to identify those sediments that could pose a risk to aquatic organisms and that require further action in order to improve their environmental quality.
显示更多 [+] 显示较少 [-]Contaminant (PAHs, OCs, PCBs and trace metals) concentrations are declining in axial tissue of sand flathead (Platycephalus bassensis) collected from an urbanised catchment (Port Phillip Bay, Australia)
2016
Gagnon, Marthe Monique | Baker, Jarrad Kyle | Long, Sara M. | Hassell, Kathryn L. | Pettigrove, Vincent J.
Concentrations of PAHs, OCs, PCBs and trace metals were determined in the white muscle of sand flathead Platycephalus bassensis collected at 6 locations in Port Phillip Bay during 2015. No PAHs, OCs or PCBs were detected in the white muscle of sand flathead at any of the locations, however measurable levels of As, Cu, Hg, Se and Zn were detected at all sites. Only As and Hg exhibited regional difference in white muscle concentrations, with As present only in a non-toxic organic form and Hg measured at levels that are comparable to levels reported in reference sites in other studies. All contaminants detected in the white muscle of sand flathead collected in Port Phillip Bay in 2015 were below Australian Food Standards guideline values, and by world standards, the Port Phillip Bay sand flathead population is considered minimally contaminated. Furthermore, tissue contaminant concentrations appear to be decreasing over time.
显示更多 [+] 显示较少 [-]Variability in antioxidant/detoxification enzymes of Sinonovacula constricta exposed to benzo[a]pyrene and phenanthrene
2016
Li, Lei | Jiang, Mei | Shen, Xinqiang
The purpose of this study was to investigate the toxic effects induced by benzo[a]pyrene and phenanthrene. For this purpose, a study was performed on the clam exposed to 0.0, 0.5, 4.5μgL−1 B(a)P and PHE for 15days using parameters of antioxidant defenses and oxidative stress. Antioxidant biomarkers including ethoxyresorufin-O-deethylase, glutathione S-transferase, superoxide dismutase, and glutathione and rylhydrocarbon hydroxylasein gills of Sinonovacula constricta, were analyzed after a 1-, 3-, 9- and 15-day exposure to seawater containing B(a)P and PHE. Integrated biomarker response was calculated by combining multiple biomarkers into a single value. The results showed that the activity of all antioxidant biomarkers was induced throughout the exposure period, and different patterns of variations were detected with exposure time. In addition, the study showed that the two concentrations used caused the activation of different general detoxification mechanisms, and the same concentration at different two PAH compounds induced different toxicity responses.
显示更多 [+] 显示较少 [-]A preliminary approach of the spatio-temporal distribution of cationic aerosol components in the ambient atmosphere of Kochi, India
2016
Gayathree Devi, P.K. | Sujatha, C.H.
Kochi City, situated in the vicinity of the industrial hub and marine niche, is significantly loaded with ionic compounds and get into the atmospheric aerosols which deteriorate the health status of the environment. The distribution of both acid and water extractable cations (Na+, NH4+, K+, Mg2+ and Ca2+) with respect to time and space, in the two phases (I and II) were performed at distinct sites of Kochi, Kerala, India. The study revealed that the water soluble Na+ ion is highlighted in the estuarine site (E1) with momentous load at the coastal site (C1) implying the sea salt influence at these two sites. The average NH4+ and K+ concentration (acid and water soluble fractions) recorded is mostly at the industrial site (R2) which may be endorsed due to the application of NPK fertilizers and also from the process of wood burning sources. Further, K+ is the prominent acid and water soluble cation recorded in the study. Mg2+ ion having both oceanic and anthropogenic origin contributes the present observed pollution load. Average acid soluble Ca2+ content is noted maximum at the estuarine spot E1, where as the hike with respect to water soluble fraction of this ion is noticed at the industrial site, R2. These inferences justify the influence of point sources such as industrial, crustal and construction related activities affecting in and around this metropolis.
显示更多 [+] 显示较少 [-]Testing the efficiency of temperate benthic biotic indices in assessing the ecological status of a tropical ecosystem
2016
Sivadas, Sanitha K. | Nagesh, Rahul | Gupta, G.V.M. | Gaonkar, Udaykumar | Mukherjee, Indranil | Ramteke, Darwin | Ingole, Baban S.
The objectives of the present study were to evaluate the ecological status of tropical coastal waters using the temperate benthic indices and examine the effect of seasonal variability on the performance of benthic indices. Macrobenthic samples were collected from northwest to southeast coast of India during 2003–2012 and we tested different univariate indices, ecological strategies, indicator species and multimetric indices. AMBI and multimetric indices performed satisfactorily in evaluating the ecological status. Seasonal variability on the biotic indices was observed during the southwest monsoon and fall intermonsoon period due to recruitment. Therefore, we recommended the non-monsoon period (January–May) as a suitable time of the year to use the indices for effective assessment of the Indian coastal waters. Results show that, the temperate benthic indices are efficient in assessing the tropical environmental status. However, complementary use of different indices is suggested for accurate assessment of the environmental status.
显示更多 [+] 显示较少 [-]Distribution of 137Cs in the Mediterranean mussel (Mytilus galloprovincialis) in Eastern Black Sea Coast of Turkey
2016
Baltas, H. | Kiris, E. | Dalgic, G. | Cevik, U.
This study presents the results of 137Cs and 40K radionuclide concentrations in mussel (Mytilus galloprovincialis) samples collected during the period of February–November 2014 from twelve different stations within the border of the eastern Black Sea region of Turkey. Also, these radionuclide concentrations were determined in sea water and sediment samples. The activity concentrations in seawater, sediment and mussel tissue samples were between 1.12–1.69mBqL−1, 3.26–30.74 and 1.61–3.16Bqkg−1 for 137Cs and 231.41–399.49mBqL−1, 215.71–450.07 and 286.84–382.16Bqkg−1 for 40K, respectively. These values are also in accordance with the concentrations reported for similar regions. Additionally, radiological impact parameters such as daily intake of 137Cs and 40K, annual committed effective dose and carcinogenic risk due to the consumption of mussel were calculated and compared with the international data. Lifetime cancer risk values are lower than the limit of 10−3.
显示更多 [+] 显示较少 [-]Analysis of the TSP, PM10 concentrations and water-soluble ionic species in airborne samples over Sistan, Iran during the summer dusty period
2016
Dahmardeh Behrooz, Reza | Esmaili-Sari, Abbas | Bahramifar, Nader | Kaskaoutis, D.G.
The present study analyzes the total suspended particulates (TSP) and particulate matter less than 10 μm (PM10) concentrations along with the water-soluble ionic species (WSIS) in airborne dust samples collected in Zabol, located in the Sistan basin of southeast Iran. Rather extreme TSP and PM10 mean concentrations of 1867.0 μg m−3 and 433.4 μg m−3 are found, while the WSIS contribute only 8.9% and 19.3% to the TSP and PM10 mass, respectively indicating large fraction of water-insoluble crustal elements, carbonaceous aerosols and heavy metals that remained unexplored. Ca2+ is the most abundant ionic species contributing ∼25–26% to the total WSIS mass, followed by NH4+, K+, and SO42−. Important fractions of Cl− and Na+ (7–9% of the total WSIS mass) indicate the presence of saline dust storms over Sistan due to desiccation of the Hamoun lakes and uplift of evaporated minerals by the strong Levar (120-days) wind. High correlations between the WSIS suggest large possibility for formation of NaCl, (NH4)2SO4, MgSO4, K2SO4, CaSO4 and NH4NO3. The dusty days (visibility < 2 km) are associated with intense winds (11.7 ms−1 on average) and large increase (∼80–100%) in the concentrations of the crustal elements (e.g., Ca2+, Mg2+ and Cl−) compared to the normal days, while the TSP and PM10 concentrations reach to 4496 μgm−3 and 1010.6 μgm−3, respectively.
显示更多 [+] 显示较少 [-]Trends and drivers of debris accumulation on Maui shorelines: Implications for local mitigation strategies
2016
Blickley, Lauren C. | Currie, Jens J. | Kaufman, Gregory D.
Marine debris, particularly plastic, is an identified concern for coastal areas and is known to accumulate in large quantities in the North Pacific. Here we present results from the first study to quantify and compare the types and amounts of marine debris on Maui shorelines. Surveys were conducted monthly between May 2013 and December 2014, with additional daily surveys conducted on Maui's north shore during January 2015. Debris accumulation rates, loads, and sources varied between sites, with plastics being the most prevalent type of debris at all sites. Large debris loads on windward shores were attributed to the influence of the North Pacific Subtropical Gyre and northerly trade winds. Daily surveys resulted in a significantly higher rate of debris deposition than monthly surveys. The efficacy of local policy in debris mitigation showed promise, but was dependent upon the level of enforcement and consumer responsibility.
显示更多 [+] 显示较少 [-]Polychlorinated biphenyls and organochlorine pesticides as intrinsic tracer tags of foraging grounds of bluefin tuna in the northwest Atlantic Ocean
2016
Deshpande, Ashok D. | Dickhut, Rebecca M. | Dockum, Bruce W. | Brill, Richard W. | Farrington, Cameron
Researchers have utilized chemical fingerprints in the determination of habitat utilization and movements of the aquatic animals. In the present effort, we analyzed polychlorinated biphenyl (PCB) congeners and organochlorine pesticides in the samples of juvenile bluefin tuna caught offshore of Virginia, and in larger bluefin tuna from the Gulf of Maine and near Nova Scotia. For a given specimen, or a given location, PCB concentrations were highest, followed by DDTs, and chlordanes. Average contaminant concentrations from fish captured from the three locations were not significantly different; and PCBs, DDTs, and chlordanes correlated well with each other. Trans-nonachlor/PCB 153 ratios in bluefin tuna of eastern Atlantic (i.e., Mediterranean) origin are low compared to the corresponding ratios in fish in the western Atlantic. As the former migrate to the western Atlantic, these ratios gradually turnover due to the accumulation of biomass from forage contaminated with higher trans-nonachlor/PCB 153 ratio reflecting dissimilar use of chlordane pesticides on two sides of the Atlantic Ocean. The trans-nonachlor/PCB 153 ratio indicated that one juvenile bluefin tuna from offshore of Virginia and one large bluefin tuna from Gulf of Maine in the present study originated from foraging grounds in the Mediterranean Sea, and that they have made the trans-Atlantic migrations. The remaining individuals were determined to be either spawned in the Gulf of Mexico or the trans-nonachlor/PCB 153 ratio for the putative Mediterranean bluefin tuna was completely turned over to resemble the ratio characteristic to the western Atlantic. Based on the turnover time for trans-nonachlor/PCB 153 ratio previously determined, the residence time of juvenile bluefin tuna offshore Virginia was estimated to be at least 0.8 to 1.6years. A discriminant function analysis (DFA) plot of total PCB normalized signatures of PCB congeners showed three separate clusters, which suggested that bluefin tuna from offshore Virginia, Gulf of Maine, and Nova Scotia could have had extended residences and foraging within the areas of capture to be able to sustain the stable signatures of PCB congeners. The DFA cluster results supported the concept of metapopulation theory of spatial ecology comprising discrete aggregates of local populations of bluefin tuna where the desired prey species are likely to be abundant. Despite their highly migratory trait and endothermic advantage of foraging in broader and colder habitats, the movements and mixing across the aggregation ranges related to feeding did not appear to be extensive. Advancement in the understanding of bluefin tuna population dynamics beyond the coarse concept of trans-Atlantic migrations to the metapopulation hypothesis provides a novel exploratory tool in the stock assessment and resource management. As the chemical tracer tags are fortified naturally and document the time- and space-integrated foraging history, they promise to serve as the low-cost alternatives to the high-cost electronic data recording tags employed for addressing the migratory movements of bluefin tuna. Between the different potential chemical tracer tags, a distinct advantage of PCB/pesticide analysis over the otolith micro-constituent analysis is that the muscle tissue of a given individual bluefin tuna can be sampled repeatedly for PCB/pesticide analysis over different spatial and temporal scales in a non-lethal manner.
显示更多 [+] 显示较少 [-]Organic matter quantity and quality, metals availability and foraminiferal assemblages as environmental proxy applied to the Bizerte Lagoon (Tunisia)
2016
Martins, Maria Virgínia Alves | Helali, Mohamed Amine | Zaaboub, Noureddine | Boukef-BenOmrane, Imen | Frontalini, Fabrizio | Reis, Darlly | Portela, Helena | Clemente, Iara Martins Matos Moreira | Nogueira, Leandro | Pereira, Egberto | Miranda, Paulo | El Bour, Monia | Aleya, Lotfi
This study analyzes the benthic trophic state of Bizerte Lagoon (Tunisia) based on the total organic matter and the bioavailability of biopolymeric carbon including proteins (PTN), carbohydrates (CHO), lipids (LIP), chlorophyll a, as well as bacteria counts. The overall simultaneously extracted metals (SEM), and acid volatile sulfides (AVS) as well as the SEM/AVS ratio indicative of the toxicity of the sediments also were analyzed aiming to study their impact in the dimension, composition and structure of both dead and living benthic foraminiferal assemblages.In the studied sites TOC content is relatively high and the PTN/CHO values indicate that they can be considered as meso-eutrophic environments. The CHO/TOC and C/N values suggest that the OM which accumulated on the sediments surface has mainly natural origin despite the introduction of municipal and industrial effluents in the lagoon and the large bacterial pool.The living assemblages of benthic foraminifera of Bizerte Lagoon are quite different to other Mediterranean transitional systems studied until now. They are composed of typical lagoonal species but also include several marine and opportunistic species including significant numbers of bolivinids, buliminids, Nonionella/Nonionoides spp. and Cassidulina/Globocassidulina spp. These assemblages seem to benefitfrom the physicochemical parameters and the sediment stability. They may however face environmental stress in the lagoon related to the AVS production as a result of the organic matter degradation and toxicity in some areas due to the available concentrations of metals. Nonetheless statistical results evidence that the structure and dimension of assemblages are being controlled mostly by OM quantity and quality related mainly to the availability of PTN, CHO and chlorophyll a. Results of this work support the importance of considering OM quantity and quality in studies of environmental impact in coastal systems.
显示更多 [+] 显示较少 [-]