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Resultados 901-910 de 3,243
Proteomic analysis of the European flounder Platichthys flesus response to experimental PAH–PCB contamination
2015
Galland, Claire | Dupuy, Célie | Loizeau, Véronique | Danion, Morgane | Auffret, Michel | Quiniou, Louis | Laroche, Jean | Pichereau, Vianney
Platichthys flesus is often used as a sentinel species to monitor the estuarine water quality. In this study, we carried out an experimental contamination of fish using a PAHs/PCBs mixture, which was designed to mimic the concentrations found in the Seine estuary (C1) and 10 times these concentrations (C2). We used a proteomic approach to understand the molecular mechanisms implied in the response of P. flesus to these xenobiotics. We showed that 54 proteins were differentially accumulated in one or several conditions, which 34 displayed accumulation factors higher than two. 18 of these proteins were identified by MALDI TOF–TOF mass spectrometry. The results indicated the deregulation of oxidative stress- and glutathione metabolism-(GST, GPx) proteins as well as of several proteins belonging to the betaine demethylation pathway and the methionine cycle (BHMT, SHMT, SAHH), suggesting a role for these different pathways in the P. flesus response to chemical contamination.
Mostrar más [+] Menos [-]Trace elements and ingested plastic debris in wintering dovekies (Alle alle)
2015
Fife, Danielle T. | Robertson, Gregory J. | Shutler, Dave | Braune, Birgit M. | Mallory, Mark L.
We provide the first report on winter concentrations of 32 trace metals from dovekies (Alle alle), a small, Arctic seabird that has a seasonal shift in diet from small zooplankton in the breeding season to larger zooplankton and small fish in the non-breeding season. Concentrations of selected trace elements, as well as stable carbon (δ13C) and nitrogen (δ15N) isotope concentrations for a sample of 25 dovekies, were similar between adult males and females, and there was evidence that dovekies feeding at higher trophic levels had higher hepatic Hg. We also found plastic debris in nine of 65 (14%) gizzards examined. Our study helps provide a more complete picture of the foraging ecology and contaminant profile of dovekies, an important species in Arctic marine food webs.
Mostrar más [+] Menos [-]Piling underwater noise impact on migrating salmon fish during Lithuanian LNG terminal construction (Curonian Lagoon, Eastern Baltic Sea Coast)
2015
Bagočius, Donatas
Development of human activities in the Klaipėda strait generates a wide spectrum of underwater noise. In the fall of 2013, at the liquid natural gas terminal construction site in the shallow Curonian Lagoon area, an assessment of possible negative impacts on migrating salmon fish caused by pile driving noise was made. It is well known that impact hammer pile driving generates pulses with extremely high underwater noise levels. The obtained results proved that the pile hammering into the lagoon bottom generated pulses with a sound exposure level of 218dB re 1μPa2s @1m thus posing a risk to the migrating fish.
Mostrar más [+] Menos [-]Suitability of the ALien Biotic IndEX (ALEX) for assessing invasion of macroalgae across different Mediterranean habitats
2015
Piazzi, Luigi | Gennaro, Paola | Ceccherelli, Giulia
The ALien Biotic IndEX (ALEX) has been recently proposed to evaluate biological invasions in soft-bottom macro-invertebrate assemblages. The present paper proposes the use of ALEX in sessile assemblages of Mediterranean hard bottom habitats and tests it along gradients of invasion. For five invasive macroalgae a variable number of case studies per each of four habitats were examined from the available data sets. For each case study samples were attributed to four levels of invasion depending on the abundance of the invading macroalgae. Results showed that the application of ALEX to sessile assemblages of hard bottoms allows to qualify the level of invasion along the considered gradients. Moreover, the decline of index values matched the impact of invasion on species number of the assemblages. Results also suggest that the concurrent use of ALEX and indices of benthic quality status can be a valuable tool to assess biopollution in hard bottom habitats.
Mostrar más [+] Menos [-]Mapping elements distribution in carapace of Caretta caretta: A strategy for biomonitoring contamination in sea turtles?
2015
Mattei, D. | Veschetti, E. | D’Ilio, S. | Blasi, M.F.
This study analyzed the carapace distribution of Ca, Cd, Cr, Cu, Mg, Mn, Pb, Sb, U, V and Zn by GF-AAS and ICP-AES in one specimen of Caretta caretta from Mediterranean Sea. Calcium, Mg, Mn, Pb, U, Zn were mainly distributed in the central area while Cd, Cr, Cu, Sb, V in lateral areas. Cadmium, Cr, Mg, Mn, Sb, U and V were different between lateral areas.The different distribution may be related to several exposures during lifetime and/or the shell ossification during growth. Carapace may be a suitable matrix for metal biomonitoring, however, further studies are required to confirm these findings.
Mostrar más [+] Menos [-]Distributions and sources of petroleum, aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from Bohai Bay and its adjacent river, China
2015
Wang, Min | Wang, Chuanyuan | Hu, Xiaoke | Zhang, Haijiang | He, Shijie | Lv, Shuangyan
Surface sediment samples from Bohai Bay and its adjacent river, China, were analyzed for aliphatic hydrocarbon, PAHs and biomarkers in order to determine the distribution, composition and source of organic matter in a coastal environment. Results suggested that the input of organic matter from anthropogenic activities has a more significant influence on its distribution than that from natural processes. Petroleum contamination, mainly from offshore oil exploration and discharge of pollutants from rivers, was the main source of n-alkanes. PAHs were mostly of pyrogenic origin; while some sites in Yellow River Estuary were derived mainly from the petrogenic sources. The toxic assessment suggested that the PAHs in surface sediments will not cause immediately adverse biological effects in sediments from Bohai Bay and its adjacent river, China.
Mostrar más [+] Menos [-]Major hydrogeochemical processes in an Acid Mine Drainage affected estuary
2015
Asta, Maria P. | Calleja, Maria Ll | Pérez López, Rafael | Auqué, Luis F.
This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion–ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn).
Mostrar más [+] Menos [-]Synthetic ultraviolet light filtering chemical contamination of coastal waters of Virgin Islands national park, St. John, U.S. Virgin Islands
2015
Bargar, Timothy A. | Alvarez, David A. | Garrison, Virginia H.
Contamination of surface waters by synthetic ultraviolet light (UV) filtering chemicals is a concern for the Virgin Islands National Park (VINP). Discrete water samples were collected from VINP bays to determine UV filter chemical presence in the coastal waters. Spatial distribution and the potential for partitioning between subsurface waters and the sea surface microlayer (SML) were also examined. The UV filter chemicals 4-methylbenzylidene camphor, benzophenone-3, octinoxate, homosalate, and octocrylene were detected at concentrations up to 6073ng/L (benzophenone-3). Concentrations for benzophenone-3 and homosalate declined exponentially (r2=0.86 to 0.98) with distance from the beach. Limited data indicate that some UV filter chemicals may partition to the SML relative to the subsurface waters. Contamination of VINP coastal waters by UV filter chemicals may be a significant issue, but an improved understanding of the temporal and spatial variability of their concentrations would be necessary to better understand the risk they present.
Mostrar más [+] Menos [-]The Mediterranean non-indigenous ascidian Polyandrocarpa zorritensis: Microbiological accumulation capability and environmental implications
2015
Stabili, Loredana | Licciano, Margherita | Longo, Caterina | Lezzi, Marco | Giangrande, Adriana
We investigated the bacterial accumulation and digestion capability of Polyandrocarpa zorritensis, a non-indigenous colonial ascidian originally described in Peru and later found in the Mediterranean. Microbiological analyses were carried out on homogenates from “unstarved” and “starved” ascidians and seawater from the same sampling site (Adriatic Sea, Italy). Culturable heterotrophic bacteria (22°C), total culturable bacteria (37°C) and vibrios abundances were determined on Marine Agar 2216, Plate Count Agar and TCBS Agar, respectively. Microbial pollution indicators were measured by the most probable number method. All the examined microbiological groups were accumulated by ascidians but differently digested. An interesting outcome is the capability of P. zorritensis to digest allochthonous microorganisms such as coliforms as well as culturable bacteria at 37°C, counteracting the effects of microbial pollution. Thus, the potential exploitation of these filter feeders to restore polluted seawater should be taken into consideration in the management of this alien species.
Mostrar más [+] Menos [-]Developmental toxicity of three hexabromocyclododecane diastereoisomers in embryos of the marine medaka Oryzias melastigma
2015
Hong, Haizheng | Shen, Rong | Liu, Wanxin | Li, Dongmei | Huang, Lingming | Shi, Dalin
The composition of major hexabromocyclododecane (HBCD) diastereoisomers, i.e. α-, β-, and γ-HBCDs, in marine biota is different from that of the commercially available form (technical HBCD), which is used extensively for toxicological studies. To properly evaluate the impact of HBCDs, the embryos of Oryzias melastigma were used to examine the developmental toxicity of the individual diastereoisomers. Results showed that HBCD diastereoisomers at the environmentally realistic concentrations in the embryos induced malformation rate and heartbeat, and caused the appearance of apoptotic heart. In addition, α-, β-, and γ-HBCDs had similar potency to stimulate the generation of reactive oxygen species, consequently leading to apoptosis in O. melastigma embryos. The order of the developmental toxicity of α-, β-, and γ-HBCDs in O. melastigma embryos was different from that in zebrafish embryos studied previously, which highlighted the importance of using species from both fresh and salt water for toxicity assessment.
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