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Результаты 591-600 из 1,273
Actually achieving marine sustainability demands a radical re-think in approach, not ‘more of the same’
2011
Morris, Dave | O’Brien, Carl | Larcombe, Piers
The UK is committed to meeting a series of ‘high-level marine objectives’ which are required to satisfy national obligations and to meet international commitments for the marine environment. There are more than 16 such international high-level policy driven obligations and commitments, together with more than 18 European and more than 12 of national origin. In the UK, there is an assumption that the current and planned monitoring will provide evidence to demonstrate achievement against these high-level objectives.
Показать больше [+] Меньше [-]In situ biomonitoring of caged, juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Lower Duwamish Waterway
2011
Kelley, Matthew A. | Gillespie, Annika | Zhou, Guo-Dong | Zhang, Shu | Meador, James P. | Duncan, Bruce | Donnelly, K. C. | McDonald, Thomas J.
Contaminated sediments may have wide-ranging impacts on human and ecological health. A series of in situ caged exposure studies using juvenile Chinook salmon was conducted in the Lower Duwamish Waterway (LDW). Chemical analysis of sediment, water, and fish tissue were completed. Additionally, in 2004, DNA adducts in hepatic and gill tissues were measured. Gills contained significantly higher DNA adducts at stations B2 and B4, prompting further analysis of gills in 2006 and 2007. Fluorescent aromatic compounds (FACs) in bile, and CYP1A1 in hepatic tissue were also measured during 2006 and 2007, respectively. FACs in field-caged fish were comparable or significantly higher than wild-caught fish LDW fish and significantly higher than lab fish after only 8–10days, demonstrating the equivalency of exposure to that of migrating salmon. Furthermore, selected biomarkers appear to be capable of detecting spikes in contamination between sampling years, emphasizing the need for multiple year data collection.
Показать больше [+] Меньше [-]Sedimentology of a wreck: The Rainbow Warrior revisited
2011
Smith, Abigail M. | Kregting, Louise | Fern, Sophie | Fraser, Ceridwen I.
The wreck of the Rainbow Warrior, a 40-m ship sunk on 12 December 1987 in Matauri Bay (34° 59′ S, 173° 56′ E), Cavalli Islands, northeastern New Zealand, offers an opportunity to investigate the impact of artificial substrate on temperate carbonate sedimentation. Surface sediment samples showed no significant textural or compositional difference between sediments near the wreck and those far from it. The large and diverse carbonate-producing community resident on the wreck (dominated by bryozoans, corals and sponges) has not had a measurable influence on adjacent bottom sediments (dominated by bivalves and barnacles), even after 21years. It is likely that carbonate production on the Rainbow Warrior is insufficient to leave any sedimentary record over the potential lifetime of the wreck on the seafloor, which informs our understanding of the long-term impacts of shipwrecks (and other artificial substrata) on the local benthic environment in shallow temperate ecosystems.
Показать больше [+] Меньше [-]The effectiveness of double hulls in reducing vessel-accident oil spillage
2011
Yip, Tsz Leung | Talley, Wayne Kenneth | Jin, Di
While much work has been done in investigating determinants of oil spillage attributed to vessel accidents, little research has been conducted on the effectiveness of ship hull design in reducing marine pollution. This paper addresses whether the double-hull requirement reduces vessel-accident oil spillage. The volume of oil spillage due to oil-cargo vessel accidents was investigated using tobit regressions and an empirical data set of individual vessel accident pollution incidents investigated by the US Coast Guard from 2001 to 2008. The results indicate that the double hull design on average reduces the size of oil spills by 20% and 62% in tank barge and tanker ship accidents, respectively.
Показать больше [+] Меньше [-]Impacts of a fuel oil spill on seagrass meadows in a subtropical port, Gladstone, Australia – The value of long-term marine habitat monitoring in high risk areas
2011
Taylor, Helen A. | Rasheed, Michael A.
We used an established seagrass monitoring programme to examine the short and longer-term impacts of an oil spill event on intertidal seagrass meadows. Results for potentially impacted seagrass areas were compared with existing monitoring data and with control seagrass meadows located outside of the oil spill area. Seagrass meadows were not significantly affected by the oil spill. Declines in seagrass biomass and area 1month post-spill were consistent between control and impact meadows. Eight months post-spill, seagrass density and area increased to be within historical ranges. The declines in seagrass meadows were likely attributable to natural seasonal variation and a combination of climatic and anthropogenic impacts. The lack of impact from the oil spill was due to several mitigating factors rather than a lack of toxic effects to seagrasses. The study demonstrates the value of long-term monitoring of critical habitats in high risk areas to effectively assess impacts.
Показать больше [+] Меньше [-]Effects of the pharmaceuticals gemfibrozil and diclofenac on the marine mussel (Mytilus spp.) and their comparison with standardized toxicity tests
2011
Schmidt, Wiebke | O’Rourke, Kathleen | Hernan, Robert | Quinn, Brian
Human pharmaceuticals, like the lipid lowering agent gemfibrozil and the non-steroidal anti-inflammatory drug diclofenac are causing environmental concern. In this study, the marine mussel (Mytilus spp.) was exposed by injection to environmentally relevant and elevated (1μg/L and 1000μg/L) concentrations of both compounds and biomarker expression was observed. Gemfibrozil exposure induced biomarkers of stress (glutathione S-transferase and metallothionein) at both concentrations 24h and 96h after exposure, respectively. Biomarkers of damage (lipid peroxidation (LPO) and DNA damage) were significantly affected, as well as the biomarker for reproduction, alkali-labile phosphate assay, indicating the potential oxidative stress and endocrine disrupting effect of gemfibrozil. Diclofenac significantly induced LPO after 96h indicating tissue damage. Additionally standard toxicity tests using the marine species Vibrio fischeri, Skeletonema costatum and Tisbe battagliai showed differences in sensitivity to both drugs in the mg/L range. Results indicate a suite of tests should be used to give accurate information for regulation.
Показать больше [+] Меньше [-]Monitoring persistent organic pollutants in leatherback turtles (Dermochelys coriacea) confirms maternal transfer
2011
Stewart, Kelly R. | Keller, Jennifer M. | Templeton, Ryan | Kucklick, John R. | Johnson, Chris
To assess threats to endangered species, it is critical to establish baselines for contaminant concentrations that may have detrimental consequences to individuals or populations. We measured contaminants in blubber and fat from dead leatherback turtles and established baselines in blood and eggs in nesting turtles. In fat, blubber, blood and eggs, the predominant PCBs were 153+132, 187+182, 138+163, 118, and 180+193. Total PCBs, 4,4′-DDE, total PBDEs and total chlordanes were significantly and positively correlated between blood and eggs, suggesting maternal transfer. Significant positive relationships also existed between fat and blubber in stranded leatherbacks. Less lipophilic PCBs appeared to more readily transfer from females to their eggs. PBDE profiles in the four tissues were similar to other wildlife populations but different from some turtle studies. Concentrations were lower than those shown to have acute toxic effects in other aquatic reptiles, but may have sub-lethal effects on hatchling body condition and health.
Показать больше [+] Меньше [-]Public awareness and attitudes towards naval sonar mitigation for cetacean conservation: A preliminary case study in Fairfax County, Virginia (the DC Metro area)
2011
Zirbel, K. | Balint, P. | Parsons, E.C.M.
The potential impacts of naval sonar on cetaceans has led to a series of court cases and statements of concern by international organizations. However, there has been no research conducted on attitudes of the general public with respect to this issue. To investigate this, a preliminary public survey was conducted in Fairfax, Virginia (the Washington, DC Metro region). The majority of the public sampled believed that naval sonar impacted marine mammals (51.3%), that the US Navy should not be exempt from environmental regulations in time of peace (75.2%), and that sonar use should be moderated if it impacts cetaceans (75.8%). Individuals who were conservative, Republican, and have served in the military were more likely to believe the Navy should be exempt from marine mammal protection regulations. In addition, expert interviews were conducted to gain opinions on the potential ramifications of the recent US Supreme Court case on naval sonar mitigation.
Показать больше [+] Меньше [-]Modelling temporal trends of ¹³⁷Cs and ⁹⁹Tc concentrations in Fucus vesiculosus from the eastern Irish coastline
2011
Cournane, S. | León Vintró, L. | Mitchell, P.I. | McMahon, C.A. | Smith, K. | Long, S.
Time series of ¹³⁷Cs and ⁹⁹Tc activity concentrations in the brown seaweed Fucus vesiculosus and seawater, gathered at three locations on the eastern Irish coastline during the period 1988–2008, have been modelled using a novel approach incorporating a variable uptake rate in the seaweed. Seasonal variations in the time series, identified using spectral analysis, were incorporated into the model which was used to determine transfer kinetic parameters and to predict ¹³⁷Cs and ⁹⁹Tc concentrations in seaweed, as influenced by levels in ambient seawater. An optimisation method combining evolutionary and grid search minimisation techniques was adopted to determine the best values for the model parameters, from which concentration factors (CF) and biological half-lives (tb₁/₂) for ¹³⁷Cs and ⁹⁹Tc in F. vesiculosus were calculated. CF values of 170–179 and 1.1×105lkg⁻¹ (dry weight) were obtained for ¹³⁷Cs and ⁹⁹Tc, respectively, while the corresponding tb₁/₂ values were 39–47 and 32days, respectively.
Показать больше [+] Меньше [-]Persistent halogenated compounds in two typical marine aquaculture zones of South China
2011
Yu, Huan-Yun | Guo, Ying | Bao, Lian-Jun | Qiu, Yao-Wen | Zeng, E. Y. (Eddy Y.)
Samples of two seawater farmed fish (crimson snapper (Lutjanus erythopterus) and snubnose pompano (Trachinotus blochii)), water, air, sediment, fish feed, macroalgae and phytoplankton were collected from two estuarine bays (Daya Bay and Hailing Bay) in South China. The concentrations of persistent halogenated compounds (PHCs) including polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and polychlorinated biphenyls (PCBs) varied widely with the different sample matrices under investigation. The compositional patterns in fish, fish feed, macroalgae and phytoplankton, as well as the good correlations between the abundances of p,p′-DDT and BDE-209 and their metabolites (i.e., p,p′-DDD and p,p′-DDE for p,p′-DDT and BDE-47 for BDE-209) in fish indicated the occurrence of DDT and PBDE biotransformation in fish body. Finally, the marine aquaculture environment in South China is somewhat biologically impaired by DDT-contaminated water, sediment and fish feed, and there may be some cancer risk associated with fish consumption for humans, especially for urban residents.
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