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Derelict fishing gear in Chesapeake Bay, Virginia: Spatial patterns and implications for marine fauna 全文
2014
Bilkovic, Donna Marie | Havens, Kirk | Stanhope, David | Angstadt, Kory
Derelict fishing gear is a source of mortality for target and non-target marine species. A program employing commercial watermen to remove marine debris provided a novel opportunity to collect extensive spatially-explicit information for four consecutive winters (2008–2012) on the type, distribution, and abundance of derelict fishing gear and bycatch in Virginia waters of Chesapeake Bay. The most abundant form of derelict gear recovered was blue crab pots with almost 32,000 recovered. Derelict pots were widely distributed, but with notable hotspot areas, capturing 40 species and over 31,000 marine organisms. The target species, blue crab, experienced the highest mortality from lost pots with an estimated 900,000 animals killed each year, a potential annual economic loss to the fishery of $300,000. Important fishery species were captured and killed in derelict pots including Atlantic croaker and black sea bass. While some causes of gear loss are unavoidable, others can be managed to minimize loss.
显示更多 [+] 显示较少 [-]Tracking anthropogenic influences on the continental shelf of China with sedimentary linear alkylbenzenes (LABs) 全文
2014
Wei, Gao-Ling | Liu, Liang-Ying | Bao, Lian-Jun | Zeng, E. Y. (Eddy Y.)
Surface sediments collected along the entire continental shelf of China, including Yellow Sea, the East China Sea (ECS) inner shelf and the South China Sea (SCS), were analyzed for linear alkylbenzenes (LABs), from which regional anthropogenic influences on the marine environment were assessed. The occurrence of LABs (5.6–77ng/g; mean: 25ng/g; median: 20ng/g) implied light sewage contamination in coast sediment off China. Specifically, the SCS had higher sedimentary LAB levels than Yellow Sea and the ECS inner shelf, which was mainly related to the intensity of domestic wastewater discharge and marine fishing activities. Values of L/S and C13/C12 (defined in the main text) suggested certain degradation while I/E indicated limited degradation of LABs. Also, additional input sources and congener inter-conversions may have contributed to the inconsistent results for degradation of LABs in offshore sediments. Atmospheric inputs and wastewater discharge from marine fishing vessels predominantly contributed to sedimentary LABs in Yellow Sea and the SCS, while riverine input was mainly responsible for LABs along the ECS inner shelf.
显示更多 [+] 显示较少 [-]Disutility analysis of oil spills: Graphs and trends 全文
2014
Ventikos, Nikolaos P. | Sotiropoulos, Foivos S.
This paper reports the results of an analysis of oil spill cost data assembled from a worldwide pollution database that mainly includes data from the International Oil Pollution Compensation Fund. The purpose of the study is to analyze the conditions of marine pollution accidents and the factors that impact the costs of oil spills worldwide. The accidents are classified into categories based on their characteristics, and the cases are compared using charts to show how the costs are affected under all conditions. This study can be used as a helpful reference for developing a detailed statistical model that is capable of reliably and realistically estimating the total costs of oil spills. To illustrate the differences identified by this statistical analysis, the results are compared with the results of previous studies, and the findings are discussed.
显示更多 [+] 显示较少 [-]Changes in the concentration and relative abundance of alkanes and PAHs from the Deepwater Horizon oiling of coastal marshes 全文
2014
Turner, R.E. | Overton, E.B. | Meyer, B.M. | Miles, M.S. | Hooper-Bui, L.
We determined changes of 28 alkanes and 43 different PAHs in 418 wetland soil samples collected on ten sampling trips to three Louisiana estuaries before and after they were oiled from the 2010 Deepwater Horizon disaster. There was a significant decline in 22 of the 28 alkane analytes (0.42%day−1), no change in 6, over 2.5years. The concentration of five aromatic petroleum hydrocarbons (PAHs) increased (range 0.25–0.70%day−1), whereas the total PAH pool did not change. Of these five, naphthalene and C-1-naphthalenes are suggested to be of higher toxicity than the other three because of their relatively higher volatility or solubility. The relative proportions of alkane analytes, but not PAHs, does not yet resemble that in the pre-oiled marshes after 3years, The trajectories of nine indicators for degradation/weathering were either inconclusive or misleading (alkanes) or confirmed the relatively meager degradation of PAHs.
显示更多 [+] 显示较少 [-]Spatial patterns of metals, PCDDs/Fs, PCBs, PBDEs and chemical status of sediments from a coastal lagoon (Pialassa Baiona, NW Adriatic, Italy) 全文
2014
Guerra, Roberta | Pasteris, Andrea | Lee, Seok-hyung | Park, No-jin | Ok, Gon
The European Water Framework Directive (WFD) establishes a framework for the protection and improvement of all water bodies including transitional waters; its final objective is to achieve at least ‘good status’ by 2015. In the present work, a hierarchical sampling design was applied to analyze the influence of anthropogenic inputs on the spatial distribution of metals, polychlorinated dibenzo-p-dioxins (PCDDs) dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in sediment at four areas in Pialassa Baiona coastal lagoon. In order to assess the chemical status, levels of priority substances and other pollutants were compared with the recently developed national Environmental Quality Standards (EQS) and site specific background levels for metals. Levels of mercury and PCBs were particularly high and exceeded their national EQS values at all sampled areas, thus not contributing to the achievement of a good chemical status of this transitional water body according to the WFD classification.
显示更多 [+] 显示较少 [-]Simulation of the potential effects of CO2 leakage from carbon capture and storage activities on the mobilization and speciation of metals 全文
2014
de Orte, Manoela Romanó | Sarmiento, Aguasanta M. | DelValls, T Ángel | Riba, Inmaculada
One of the main risks associated with carbon capture and storage (CCS) activities is the leakage of the stored CO2, which can result in several effects on the ecosystem. Laboratory-scale experiments were performed to provide data on the possible effects of CO2 leakage from CCS on the mobility of metals previously trapped in sediments. Metal-contaminated sediments were collected and submitted to acidification by means of CO2 injection using different pH treatments. The test lasted 10days, and samples were collected at the beginning and at the end of the experiment for metal analysis. The results revealed increases in the mobility of metals such as Co, Cu, Fe, Pb and Zn due to pH decreases. Geochemical modeling demonstrated that acidification influenced the speciation of the metals, increasing the concentrations of their free forms. These data suggest the possible sediment contamination consequences of accidental CO2 leakage during CCS activities.
显示更多 [+] 显示较少 [-]Diffusion of microcystins (cyanobacteria hepatotoxins) from the reservoir of Isahaya Bay, Japan, into the marine and surrounding ecosystems as a result of large-scale drainage 全文
2014
Takahashi, Tohru | Umehara, Akira | Tsutsumi, Hiroaki
In the artificial reservoir of the Isahaya reclaimed land, Nagasaki, Japan, algal blooms have become an annual event, dominated primarily by the microcystin (MC) producing cyanobacteria Microcystis aeruginosa. Although the majority of MCs are either degraded by bacteria or washed out to sea, some remain in the sediment of the reservoir and bay throughout the year. As a result, they also accumulate in aquatic organisms (mullet, oyster, etc.) that inhabit the reservoir and surrounding areas, as well as midge flies that spend their larval period in the bottom of the reservoir. Accordingly, MCs also accumulate in the predators of these organisms, allowing the toxin to spread from the hydrosphere to terrestrial ecosystems. The most effective method for resolving this potentially dangerous condition is to introduce seawater into the reservoir by opening the drainage gates at high tide.
显示更多 [+] 显示较少 [-]Bioremediation potential of microorganisms derived from petroleum reservoirs 全文
2014
Dellagnezze, Bruna Martins | de Sousa, Gabriel Vasconcelos | Martins, Laercio Lopes | Domingos, Daniela Ferreira | Limache, Elmer E.G. | de Vasconcellos, Suzan Pantaroto | da Cruz, Georgiana Feitosa | de Oliveira, Valéria Maia
Bacterial strains and metagenomic clones, both obtained from petroleum reservoirs, were evaluated for petroleum degradation abilities either individually or in pools using seawater microcosms for 21days. Gas Chromatography–Flame Ionization Detector (GC–FID) and Gas Chromatography-Mass Spectrometry (GC–MS) analyses were carried out to evaluate crude oil degradation. The results showed that metagenomic clones 1A and 2B were able to biodegrade n-alkanes (C14 to C33) and isoprenoids (phytane and pristane), with rates ranging from 31% to 47%, respectively. The bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 showed higher rates reaching 99% after 21days. The metagenomic clone pool biodegraded these compounds at rates ranging from 11% to 45%. Regarding aromatic compound biodegradation, metagenomic clones 2B and 10A were able to biodegrade up to 94% of phenanthrene and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 55% to 70% after 21days, while the bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 were able to biodegrade 63% and up to 99% of phenanthrene, respectively, and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 23% to 99% after 21days. In this work, isolated strains as well as metagenomic clones were capable of degrading several petroleum compounds, revealing an innovative strategy and a great potential for further biotechnological and bioremediation applications.
显示更多 [+] 显示较少 [-]The distribution of heavy metals including Pb, Cd and Cr in Kendari Bay surficial sediments 全文
2014
Armid, Alrum | Shinjo, Ryuichi | Zaeni, Ahmad | Sani, Asrul | Ruslan, Ruslan
The surficial coastal sediments in Kendari Bay are sampled in the field to determine the concentration and pollution level of three heavy metals (Pb, Cd and Cr). Twenty-five sampling points ranging from the inner (Wanggu River) to the outer area of the bay have been chosen. The physicochemical properties, such as temperature, pH, salinity and TDS of the overlying water, as well as the sediment type and TOC of the surficial sediments, are also measured. The total concentrations of the Pb, Cd and Cr in the sediment samples are quantified using inductively-coupled plasma mass spectrometry (ICP-MS). The concentrations of the heavy metals (Pb, Cd and Cr) ranged from 0.84 to 17.02μg/g, 0.02 to 0.17μg/g and 1.92 to 40.11μg/g (dry weight), respectively, following the Cr>Pb>Cd sequence. To assess the degree of contamination, a geoaccumulation index (Igeo) is measured. Kendari Bay is not a contaminated area regarding Pb, Cd and Cr.
显示更多 [+] 显示较少 [-]Fishing down the largest coral reef fish species 全文
2014
Fenner, Douglas
Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism.
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