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Результаты 621-630 из 1,540
On the biological connectivity of oil and gas platforms in the North Sea
2012
Thorpe, S.A.
Tests are made of the conjecture that the platforms in the North Sea are biologically connected, with organisms originating from some platforms reaching and substantially augmenting those at others so that, together, the platforms effectively form a sort of artificial reef. The M₂ tide results in a relatively rapid transfer of organisms between neighbouring platforms. Some 60% of platforms in the southern UK Sector are directly connected by tidal flows. Such connection in the northern Sector is relatively rare, about 23% of platforms being connected. Mean flows connect platforms in ‘strings’ sharing a common streamline spread by turbulent dispersion. Metrics are devised to indicate how well a particular platform is connected to others. Strings are broken when contributions to the concentration of organisms from platforms fall below detection limits. Many platforms are likely to be connected in strings in the southern UK Sector, but relatively few in the northern Sector.
Показать больше [+] Меньше [-]PCBs, PBDEs and organochlorine pesticides in crabs Hepatus pudibundus and Callinectes danae from Santos Bay, State of São Paulo, Brazil
2012
Magalhães, C.A. | Taniguchi, S. | Cascaes, M.J. | Montone, R.C.
The occurrence of persistent organic pollutants (POPs) as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDE) in crabs Hepatus pudibundus and Callinectesdanae was assessed from two different places inside of the Santos Bay and Moela Island near one of the most economically important metropolitan areas in Southern Brazil. Among POPs analyzed, ∑PCBs (222–923ngg⁻¹lipid weight) and ∑DDTs (154–410ngg⁻¹lw) exhibited the highest concentrations in the crabs. ∑HCHs ranged from 10.3 to 30.9ngg⁻¹lw and were found in all individuals. Other OCPs found in lower concentration was Mirex (7.6–41.6ngg⁻¹lw) and HCB (5.83–16.9ngg⁻¹lw). ∑PBDEs (24.1ngg⁻¹lw) were only found in one male individual from the species C. danae collected near to the submarine sewage of Santos. Male crabs showed higher POP concentrations than female crabs for those two species.
Показать больше [+] Меньше [-]Ecosystem under pressure: Ballast water discharge into Galveston Bay, Texas (USA) from 2005 to 2010
2012
Steichen, Jamie L. | Windham, Rachel | Brinkmeyer, Robin | Quigg, Antonietta
Ballast water exchange processes facilitate the dispersal and unnatural geographic expansion of phytoplankton, including harmful algal bloom species. From 2005 to 2010, over 45,000 vessels (∼8000 annually) travelled across Galveston Bay (Texas, USA) to the deep-water ports of Houston (10th largest in the world), Texas City and Galveston. These vessels (primarily tankers and bulkers) discharged ∼1.2×10⁸metrictons of ballast water; equivalent to ∼3.4% of the total volume of the Bay. Over half of the ballast water discharged had a coastwise origin, 96% being from US waters. Galveston Bay has fewer non-indigenous species but receives a higher volume of ballast water discharge, relative to the highly invaded Chesapeake and San Francisco Bays. Given the magnitude of shipping traffic, the role of Galveston Bay, both as a recipient and donor region of non-indigenous phytoplankton species is discussed here in terms of the invasibility risk to this system by way of ballast water.
Показать больше [+] Меньше [-]Antibiotic resistant pathogens versus human impacts: A study from three eco-regions of the Chennai coast, southern India
2012
Vignesh, Sivanandham | Muthukumar, Krishnan | Arthur James, Rathinam
We assessed the occurrence of pollution indicators and antibiotic resistant bacterial isolates from water and sediment samples of three different eco-regions of the Chennai coast between March – May of 2010. Total of 960 bacterial strains belonging to four genera were isolated which show the highest frequencies of resistance to vancomycin (53.6%) and penicillin (52.6%) (except Enterococcus sp., which is highly resistant to erythromycin) and lowest frequencies of resistance to chloramphenicol (3.43%), ciprofloxacin (3.95%), gentamicin (4.68%), and tetracycline (6.97%). The E. coli, Vibrio sp., Salmonella sp. and Enterococcus sp. show high frequency of resistance to 2–5 antibacterials of 60.4%, 45.83%, 69.16% and 46.6%, respectively. High pollution indices (PI – 6.66–14.06) and antibiotic resistance indices (ARI – 0.29–0.343) indicate that the coastal environment is highly exposed to antibiotic sources that suggesting to avoid direct contact.
Показать больше [+] Меньше [-]Papuan Bird’s Head Seascape: Emerging threats and challenges in the global center of marine biodiversity
2012
Mangubhai, Sangeeta | Erdmann, Mark V. | Wilson, Joanne R. | Huffard, Christine L. | Ballamu, Ferdiel | Hidayat, Nur Ismu | Hitipeuw, Creusa | Lazuardi, Muhammad E. | Muhadjir, | Pada, Defy | Purba, Gandi | Rotinsulu, Christovel | Rumetna, Lukas | Sumolang, Kartika | Wen, Wen
The Bird’s Head Seascape located in eastern Indonesia is the global epicenter of tropical shallow water marine biodiversity with over 600 species of corals and 1,638 species of coral reef fishes. The Seascape also includes critical habitats for globally threatened marine species, including sea turtles and cetaceans. Since 2001, the region has undergone rapid development in fisheries, oil and gas extraction, mining and logging. The expansion of these sectors, combined with illegal activities and poorly planned coastal development, is accelerating deterioration of coastal and marine environments. At the same time, regency governments have expanded their marine protected area networks to cover 3,594,702ha of islands and coastal waters. Low population numbers, relatively healthy natural resources and a strong tenure system in eastern Indonesia provide an opportunity for government and local communities to collaboratively manage their resources sustainably to ensure long-term food security, while meeting their development aspirations.
Показать больше [+] Меньше [-]Use of species sensitivity distributions to predict no-effect concentrations of an antifouling biocide, pyridine triphenylborane, for marine organisms
2012
Mochida, Kazuhiko | Onduka, Toshimitsu | Amano, Haruna | Ito, Mana | Ito, Katsutoshi | Tanaka, Hiroyuki | Fujii, Kazunori
We used species sensitivity distributions (SSDs) and a Bayesian statistical model to carry out a primary risk assessment for pyridine triphenylborane (PTPB) in Hiroshima Bay, Japan. We used SSDs derived from toxicity values, such as EC₅₀ and LC₅₀, obtained from this study and previous work to calculate hazardous concentrations that should protect 95% and 99% of species (HC₅ and HC₁) and demonstrated that the medians of the HC₅ and HC₁ were 0.78 and 0.17μg/L, respectively. We also used liquid chromatography/mass spectrometry to investigate the occurrence of PTPB in seawater from several coastal sites of Hiroshima Bay and detected PTPB at concentrations of 4.8–21pg/L. Comparison of environmental concentrations to the HC values suggests that the current ecological risk posed by PTPB in Hiroshima Bay is low. This is the first report of the detection of PTPB in the natural marine environment.
Показать больше [+] Меньше [-]A historical review and bibliometric analysis of research on estuary pollution
2012
Sun, Jinshui | Wang, Ming-Huang | Ho, Yuh-Shan
A bibliometric method based on Science Citation Index-Expanded published by the Thomson Reuters was used to quantitatively assess the global estuary pollution research from 1991 to 2010. The main results were as follows: there had been a notable growth trend in publication outputs. Marine Pollution Bulletin was the most active journal. Environmental sciences were top popular subject categories. USA produced the most single, internationally collaborative, first authored and corresponding authored articles. The Chinese Academy of Sciences was the most productive institute for the total articles. Sediment was the most active research topic, which ranked 1st in article title, article abstract, author keyword, and KeyWords Plus analysis, respectively. Heavy metals received stable focus on a high degree in the field of estuary pollution research. Mostly refractory organic compounds (e.g. PAHs) became more active. Biomarkers and bioaccumulation both were active issues. Eutrophication of estuarine waters receives increasing concern in estuary pollution research.
Показать больше [+] Меньше [-]Island shadow effects and the wave climate of the Western Tuamotu Archipelago (French Polynesia) inferred from altimetry and numerical model data
2012
Andréfouët, Serge | Ardhuin, Fabrice | Queffeulou, Pierre | Le Gendre, Romain
To implement a numerical model of atoll lagoon circulation, we characterized first the significant wave height (Hs) regime of the Western Tuamotu Archipelago and the local attenuation due to the protection offered by large atolls in the south Tuamotu. Altimetry satellite data and a WAVEWATCH III two-way nested wave model at 5km resolution from 2000 to 2010 were used. Correlation between altimetry and model was high (0.88) over the period. According to the wave model, the archipelago inner seas experienced attenuated Hs year-long with a yearly average Hs around 1.3m vs a minimum of 1.6m elsewhere. The island shadow effect is especially significant in the austral winter. In contrast with southern atolls, Western Tuamotu experienced only few days per year of Hs larger than 2.5m generated by very high Hs southern swell, transient western local storms, strong easterly winds, and during the passage of distant hurricanes.
Показать больше [+] Меньше [-]Seasonal variation of polycyclic aromatic hydrocarbons concentrations in urban streams at Niterói City, RJ, Brazil
2012
Ribeiro, Angelo Morgado | da Rocha, Camila Coimbra Martins | Franco, Caroline Fernandes Jaegger | Fontana, Luiz Francisco | Pereira Netto, Annibal D.
Polycyclic aromatic hydrocarbons (PAHs) were determined in water samples collected in two streams and a lake located at Niteroi City, Rio de Janeiro State, Brazil between October 2008 and September 2009. Samples were extracted using liquid–liquid extraction and analyzed using high performance liquid chromatography with fluorescence detection. The limits of quantification were sufficiently low to accomplish PAH determination below the maximum concentration levels established by the Brazilian (50ng/L) and USEPA legislations, with recoveries larger than 81.6%. Phenanthrene, fluoranthene, pyrene and benz[a]anthracene predominated among PAHs. Total concentrations of PAHs were well correlated with rainfall indicating a possible role of runoff to local pollution of water by PAHs and showed a seasonal variation in wet and dry seasons. Our results highlight the contribution of the widespread streams located around Guanabara Bay to the PAH burden found in its waters.
Показать больше [+] Меньше [-]Trace elements in two marine fish species during estuarine residency: Non-essential versus essential
2012
Mieiro, C.L. | Coelho, J.P. | Pacheco, M. | Duarte, A.C. | Pereira, M.E.
Trace element levels in fish are of particular interest, owing the potential risk to human health. In accordance, juveniles of Dicentrarchus labrax and of Liza aurata were sampled and arsenic, cadmium, chromium, selenium and zinc were determined in the muscle. The levels of trace elements in muscle demonstrated to be similar for both species and sites, with the exception of selenium levels at reference, which seemed to be higher in D. labrax. Moreover, apart from arsenic levels in muscle, all elements were in conformity with the existent regulatory guidelines for fish consumption. The dietary intake of each element was also calculated, with arsenic and selenium showing intakes above the recommended dietary allowances. Nevertheless, no arsenic speciation was carried out and thus no accurate risk evaluation could be established. Additionally, selenium levels never exceeded the dietary allowances more than five times, which are considered safe.
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