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A 400-year record of black carbon flux in the Xisha archipelago, South China Sea and its implication Texte intégral
2011
Liu, Xiaodong | Xu, Liqiang | Sun, Liguang | Liu, Fei | Wang, Yuhong | Yan, Hong | Liu, Yi | Luo, Yuhan | Huang, Jing
We reconstructed the first long-term (∼400years) records of black carbon (BC) deposition flux from three ornithogenic sediment profiles, which were collected from three remote, isolated islets of the Xisha archipelago, South China Sea. The significant correlations between black carbon, organic matter and excess ²¹⁰Pb suggested that black carbon was mainly derived from atmospheric deposition, and further enriched by plant-derived organic matter in sediments. During the past 400years, the BC flux remained relatively low before the onset of 20th century; it started to increase from approximately 1900 AD, and peaked around the 1970s. In the recent 30years, the BC flux seemed to display decreasing trend, very likely due to the change of energy structure and development of pollution control techniques. In comparison with marginal sea regions that are greatly impacted by anthropogenic activities, these pristine Xisha islands were not significantly influenced by black carbon of anthropogenic origin.
Afficher plus [+] Moins [-]Ingestion of marine debris by loggerhead sea turtles, Caretta caretta, in the Adriatic Sea Texte intégral
2011
Lazar, Bojan | Gračan, Romana
We examined the occurrence of marine debris in the gastrointestinal tract of 54 loggerhead sea turtles (Caretta caretta) found stranded or incidentally captured dead by fisheries in the Adriatic Sea, with a curved carapace length of 25.0–79.2cm. Marine debris was present in 35.2% of turtles and included soft plastic, ropes, Styrofoam and monofilament lines found in 68.4%, 42.1%, 15.8% and 5.3% of loggerheads that have ingested debris, respectively. The dry mass of debris per turtle was low, ranging from <0.01 to 0.71g, and the ingestion was not significantly affected by sex or body size (all p>0.05). Marine debris averaged 2.2±8.0% of dry mass of gut content, with a maximum of 35% found in a juvenile turtle that most likely died due to debris ingestion. Considering the relatively high occurrence of debris intake and possible sub-lethal effects of even small quantities of marine debris, this can be an additional factor of concern for loggerheads in the Adriatic Sea.
Afficher plus [+] Moins [-]Anthropogenic metal contamination and sapropel imprints in deep Mediterranean sediments Texte intégral
2011
Angelidis, M.O. | Radakovitch, O. | Veron, A. | Aloupi, M. | Heussner, S. | Price, B.
Anthropogenic metal contamination and sapropel imprints in deep Mediterranean sediments Texte intégral
2011
Angelidis, M.O. | Radakovitch, O. | Veron, A. | Aloupi, M. | Heussner, S. | Price, B.
Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100years represents 20–30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event S1.
Afficher plus [+] Moins [-]Anthropogenic metal contamination and sapropel imprints in deep Mediterranean sediments Texte intégral
2011
Angelidis, M. O. | Radakovitch, Olivier | Veron, Alain | Aloupi, M. | Heussner, S. | Price, B. | Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE) ; Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Sediment cores from the deep Balearic basin and the Cretan Sea provide evidence for the accumulation of Cd, Pd and Zn in the top few centimeters of the abyssal Mediterranean sea-bottom. In both cores, 206Pb/207Pb profiles confirm this anthropogenic impact with less radiogenic imprints toward surface sediments. The similarity between excess 210Pb accumulated in the top core and the 210Pb flux suggests that top core metal inventories reasonably reflect long-term atmospheric deposition to the open Mediterranean. Pb inventory in the western core for the past 100 years represents 20-30% of sediment coastal inventories, suggesting that long-term atmospheric deposition determined from coastal areas has to be used cautiously for mass balance calculations in the open Mediterranean. In the deeper section of both cores, Al normalized trace metal profiles suggest diagenetic remobilization of Fe, Mn, Cu and, to a lesser extent, Pb that likely corresponds to sapropel event Si
Afficher plus [+] Moins [-]Occurrence of Pyrodinium bahamense var. compressum along the southern coast of the Baja California Peninsula Texte intégral
2011
Gárate Lizárraga, Ismael | González-Armas, Rogelio
As part of a continuing toxic microalgae monitoring program, 22 phytoplankton samples were collected from July to November 2010 at several sampling stations along the southern coast of the Baja California Peninsula. For the first time, the toxic dinoflagellate Pyrodinium bahamense var. compressum was found along the southeastern and southwestsern coasts of the peninsula. P. bahamense var. bahamense was first observed off San José del Cabo, which is an extension of the range of this variety. Both varieties occur as solitary cells. P. bahamense var. compressum occurred at temperatures ranging between 24.5°C and 31°C, whereas var. P.bahamense occurred at 28.5°C to 29°C, indicating its tropical and subtropical nature. Occurrence of P. bahamense var. compressum along this coastline may be related to El Niño 2009–2010.
Afficher plus [+] Moins [-]Accumulation of butyltin compounds in cetaceans from Korean coastal waters Texte intégral
2011
Choi, Minkyu | Moon, Hyo-Bang | An, Yong-Rock | Choi, Seok-Gwan | Choi, Hee-Gu
Data on the occurrence and accumulation profiles of butyltins (BTs), including tributyltin (TBT), in marine mammals are scarce. This is the first study to investigate residue levels and accumulation patterns of BTs in cetaceans from Korean coastal waters. The total concentrations of BTs (sum of mono- to tri-butyltins) in minke whales (Balaenoptera acutorostrata) and long-beaked common dolphins (Delphinus capensis) ranged from 15.7 to 297ng/g wet weight (mean: 100ng/g wet weight) and from 59.0 to 412ng/g wet weight (mean: 228ng/g wet weight), respectively. Dibutyltin (DBT) accounted for 63% of the total BTs in all cetacean samples. Significant species-specific differences in BT concentrations, possibly due to the differences in their habitat and diet, were found between the two cetacean species. The concentrations of DBT and TBT in most cetacean samples exceeded the threshold value for cytotoxic effects in cetaceans, implying potentially adverse health risks from exposure to BTs.
Afficher plus [+] Moins [-]Metal distribution in sediment cores from São Paulo State Coast, Brazil Texte intégral
2011
Silva, Paulo S.C. | Damatto, Sandra R. | Maldonado, Caio | Fávaro, Deboráh I.T. | Mazzilli, Barbara P.
Ten sediment core samples with lengths ranging from 35 to 100cm were collected in the Baixada Santista region and analyzed to determine As, Br, Co, Cr, Cs, Fe, Rb, Sb, Ta, Th, U, Zn and rare earths (Sc, Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) level concentrations using instrumental neutron activation analysis (INAA). The studied region is located in the southeastern coast of São Paulo State and is comprised of a densely urbanized area, the largest industrial complex of the country, with a predominance of petrochemical and fertilizer plants. It is also home to Brazil’s most important and busiest port. The conclusions found that the As, La, Sm, Ne, Ce, Eu, Hf, Ta, Th, and U elements have a high background level in the region and that Fe and Zn were the main indicators of anthropogenic contribution in the sediments.
Afficher plus [+] Moins [-]Risk mapping for sensitive species to underwater anthropogenic sound emissions: Model development and validation in two Mediterranean areas Texte intégral
2011
Azzellino, A. | Lanfredi, C. | D’Amico, A. | Pavan, G. | Podestà, M. | Haun, J.
Recent observations of cetacean mass strandings, coincident with anthropogenic sounds emissions, have raised concerns on the potential environmental impact of underwater noise. Cuvier’s beaked whale (Ziphius cavirostris) was reported in all the cited stranding events. Within the NATO Marine Mammal Risk Mitigation project (MMRM), multiple interdisciplinary sea trials have been conducted in the Mediterranean Sea with the objective of developing tools and procedures to mitigate the impact of underwater sound emissions. During these cruises, visual observations, passive acoustic detections and environmental data were collected. The aim of this study was to evaluate “a priori” predictions of Cuvier’s beaked whale presence in the Alboran Sea, using models developed in the Ligurian Sea that employ bathymetric and chlorophyll features as predictors. The accuracy of these predictions was found adequate and elements are given to account for the uncertainties associated to the use of models developed in areas different from their calibration site.
Afficher plus [+] Moins [-]Seabirds and chronic oil pollution: Self-cleaning properties of gulls, Laridae, as revealed from colour-ring sightings Texte intégral
2011
(C.J.) Camphuysen, Kees
Mystery oil spills off the Dutch coast affected colonial, adult Lesser Black-backed Gulls prior to and within the breeding season. From colour-ringed individuals, it was demonstrated that most oiled birds survived and were clean within a few weeks and often bred successfully. Further evidence of self-cleaning properties of Larus-gulls is provided from a long-term colour-ringing project (1984–2009). In total 46 birds were reported ‘oiled’, two died, but the majority cleaned itself and survived for up to 20years after being oiled. From colour-ring data and 30years of beached bird surveys (1980–2010) it is demonstrated that the effects of chronic oil pollution is larger in winter than in summer; a reflection of seasonal differences in exposure and environmental conditions. The self-cleaning properties of gulls are such that long-term survival is not necessarily jeopardised and even in a breeding season, not all is lost in case of a spill.
Afficher plus [+] Moins [-]Content and distribution of trace metals in surface sediments from the northern Bering Sea, Chukchi Sea and adjacent Arctic areas Texte intégral
2011
Cai, M.H. | Lin, J. | Hong, Q.Q. | Wang, Y. | Cai, M.G.
Concentrations of trace metals (Zn, Cr, Cu, V, Cd and Pb), total organic carbon (TOC), black carbon (BC) and their granulometry were examined in 25 surface sediment samples from the northern Bering Sea, Chukchi Sea and adjacent areas. Trace metal concentrations in the sediments varied from 21.06–168.21mgkg⁻¹ for Zn, 8.91–46.94mgkg⁻¹ for Cr, 2.69–49.39mgkg⁻¹ for Cu, 32.46–185.54mgkg⁻¹ for V, 0.09–0.92mgkg⁻¹ for Cd, and 0.95–15.25mgkg⁻¹ for Pb. The geoaccumulation index (Igₑₒ) indicated that trace metal contamination (Zn and Cd) existed in some stations of the study area. The distribution of grain size plays an important role in influencing the distribution of trace metals (Zn, Cr, Cu, V, and Pb) in sediments from the Chukchi Sea and adjacent areas.
Afficher plus [+] Moins [-]Contamination status and spatial distribution of organochlorine compounds in fishes from Nansei Islands, Japan Texte intégral
2011
Malarvannan, Govindan | Takahashi, Shin | Ikemoto, Tokutaka | Isobe, Tomohiko | Kunisue, Tatsuya | Sudaryanto, Agus | Miyagi, Toshihiko | Nakamura, Masaru | Yasumura, Shigeki | Tanabe, Shinsuke
Two species of fishes (n=52; tilapia and mullet) from industrialized and urbanized areas of Okinawa Island (Manko-Noha river, Hija river and Shikaza river) and from a remote area of Ishigaki Island (Anparu mudflat), Japan were collected between August 2005 and July 2006, and analyzed for five organochlorine compounds (OCs), viz., DDTs, PCBs, CHLs, HCHs and HCB. Concentrations and the contamination patterns of OCs in fishes varied between locations. Considerable residue levels of OCs, especially CHLs and DDTs were found in both fishes from the main Okinawa Island. These levels were relatively higher than the reported values for seafood from Japanese coasts, indicating that even now pollution sources of these contaminants still exist in this region. On the other hand, lower concentrations of OCs were detected in fishes from Ishigaki Island waters than those of other Japanese coastal waters, suggesting that this region is less contaminated by OC contaminants.
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