خيارات البحث
النتائج 641 - 650 من 1,301
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.
اظهر المزيد [+] اقل [-]Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): Sources and depositional history
2011
Martins, César C. | Bícego, Márcia C. | Mahiques, Michel M. | Figueira, Rubens C.L. | Tessler, Moyses G. | Montone, Rosalinda C.
Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950’s, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatão industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.
اظهر المزيد [+] اقل [-]Seasonal variations of imposex indices and butyltin concentrations in the rock shell Thais clavigera collected from Hong Kong waters
2011
Qiu, Jian-Wen | Chan, Ka Ming | Leung, Kenneth Mei Yee
This study investigated butyltin contamination in Hong Kong waters using the rock shell Thais clavigera as a biomonitor. We collected rock shells from nine coastal sites in both winter 2005 and summer 2006 to examine the spatial and seasonal patterns. The relative penis size index (RPSI) and vas deferens sequence index (VDSI) were determined following a standard protocol, while the tissue concentrations of butyltins (i.e., mono-, di- and tri-butyltin) were measured using gas chromatography. The results showed that imposex was particularly severe in T. clavigera collected from Victoria Harbour, Pak Sha Wan and Sai Kung Pier where shipping activities were frequent. Both imposex indices had a positive correlation with tissue concentration of tributyltin in T. clavigera. While VDSI exhibited little seasonal variation, RPSI of winter specimens was significantly higher than that of summer specimens. Thus, sampling season should be standardised when using RPSI as a biomarker.
اظهر المزيد [+] اقل [-]Vessel traffic patterns in the Port of Kaohsiung and the management implications for preventing the introduction of non-indigenous aquatic species
2011
Liu, Dagang | Tsai, Tzung-Kuen
Data on shipping traffic in one of the busiest seaports in the world, the Port of Kaohsiung, were analyzed to evaluate the implications for ballast water management. Results show that 67% of the arriving vessels were registered to a flag of convenience, which typically have a lower degree of environmental records. The top five donor countries historically suffer from harmful algal bloom problems. The short journey and busy trading between these countries and Taiwan lead to a higher risk of inoculation. In addition, only 1.4% of all vessels visited more than once every year during the 9-year span, indicating that the port authority encounters many new vessels each year. These findings could influence the design and application of ballast water management strategies as well as highlight the challenges in their implementation. We suggest that an analysis of vessel traffic patterns should be coupled with other useful vessel information to make risk assessment successful.
اظهر المزيد [+] اقل [-]Anthropogenic organic contaminants in water, sediments and benthic organisms of the mangrove-fringed Segara Anakan Lagoon, Java, Indonesia
2011
Dsikowitzky, Larissa | Nordhaus, Inga | Jennerjahn, Tim C. | Khrycheva, Polina | Sivatharshan, Yoganathan | Yuwono, Edy | Schwarzbauer, Jan
Segara Anakan, a mangrove-fringed coastal lagoon in Indonesia, has a high diversity of macrobenthic invertebrates and is increasingly affected by human activities. We found >50 organic contaminants in water, sediment and macrobenthic invertebrates from the lagoon most of which were polycyclic aromatic compounds (PACs). Composition of PACs pointed to petrogenic contamination in the eastern lagoon. PACs mainly consisted of alkylated PAHs, which are more abundant in crude oil than parent PAHs. Highest total PAC concentration in sediment was above reported toxicity thresholds for aquatic invertebrates. Other identified compounds derived from municipal sewage and also included novel contaminants like triphenylphosphine oxide. Numbers of stored contaminants varied between species which is probably related to differences in microhabitat and feeding mode. Most contaminants were detected in Telescopium telescopium and Polymesoda erosa. Our findings suggest that more attention should be paid to the risk potential of alkylated PAHs, which has hardly been addressed previously.
اظهر المزيد [+] اقل [-]DDT in endangered Galapagos sea lions (Zalophus wollebaeki)
2011
Alava, Juan José | Ross, Peter S. | Ikonomou, Michael G. | Cruz, Marilyn | Jimenez-Uzcátegui, Gustavo | Dubetz, Cory | Salazar, Sandie | Costa, Daniel P. | Villegas-Amtmann, Stella | Howorth, Peter | Gobas, Frank A.P.C.
We characterize for the first time the presence of DDT and its metabolites in tropical Galapagos sea lions (Zalophus wolleabeki). ∑DDT concentrations in Galapagos sea lion pups sampled in 2005 and 2008 ranged from 16 to 3070μg/kg lipid. Concentrations of ∑DDT in pups in 2008 averaged 525μg/kg lipid and were 1.9 times higher than that (281μg/kg lipid) detected in pups in 2005. These concentrations are lower than those reported in many pinnipeds elsewhere, comparable to those in Hawaiian monk seals, and higher than those in southern elephant seals. The health risk characterization showed that 1% of the male pups exceeded the p,p′-DDE toxic effect concentration associated with anti-androgenic effects reported in rats. The findings provide preliminary guidance on the relationship between DDT use and ecological impacts, serving as a reference point against which possible future impact of tropical DDT use can be assessed.
اظهر المزيد [+] اقل [-]Organochlorine pesticides in sediments of Laizhou Bay and its adjacent rivers, North China
2011
Zhong, Guangcai | Tang, Jianhui | Zhao, Zhen | Pan, Xiaohui | Chen, Yingjun | Li, Jun | Zhang, Gan
Organochlorine pesticides (HCHs, DDTs and HCB) have been investigated in sediments of Laizhou Bay and its adjacent rivers. The average concentrations of HCHs, DDTs and HCBs are 0.09ng/gdw, 0.59 and 0.05 for marine sediments and 0.55, 8.6 and 1.1 for riverine sediments, respectively. Laizhou Bay is less contaminated by HCHs and DDTs in comparison with other coastal regions around the world, including the other two biggest bays in Bohai Sea. Fresh input of lindane and dicofol-type DDT were found in several riverine sites. Relatively strong TOC-dependence of HCB distribution in the entire studied area suggested no point source existed and/or water–sediment equilibrium achieved. No significant difference of α/γ-HCH ratios have been observed between marine and riverine sediments. However, o,p′-DDT/p,p′-DDT ratios varied largely between the two regions.
اظهر المزيد [+] اقل [-]Arsenic, cadmium, lead and mercury in canned sardines commercially available in eastern Kentucky, USA
2011
Shiber, John G.
Seventeen samples of canned sardines, originating from six countries and sold in eastern Kentucky, USA, were analyzed in composites of 3–4 fish each for total arsenic (As), cadmium (Cd) and lead (Pb) by graphite furnace atomic absorption spectrophotometry (AAS) and for mercury (Hg) by thermal decomposition amalgamation and AAS. Results in μg/g wet: As 0.49–1.87 (mean: 1.06), Cd<0.01–0.07 (0.03), Pb<0.06–0.27 (0.11), Hg ND <0.09. Values fall generally within readings reported by others, but no internationally agreed upon guidelines have yet been set for As or Cd in canned or fresh fish. The incidence of cancers and cardiovascular diseases associated with As ingestion is extraordinarily high here. With the role of food-borne As in human illness presently under scrutiny and its maximum allowable limits in fish being reviewed, more studies of this nature are recommended, especially considering the potential importance of small pelagic fishes as future seafood of choice.
اظهر المزيد [+] اقل [-]Regime shifts in the marine environment: The scientific basis and political context
2011
Kraberg, Alexandra C. | Wasmund, Norbert | Vanaverbeke, Jan | Schiedek, Doris | Wiltshire, Karen H. | Mieszkowska, Nova
Regime shifts in the marine environment have recently received much attention. To date, however, few large-scale meta-analyses have been carried out due to insufficient data coverage and integration between sustained observational datasets because of diverse methodologies used in data collection, recording and archival. Here we review the available data on regime shifts globally, followed by a review of current and planned policies with relevance to regime shifts. We then focus on the North and Baltic Seas, providing examples of existing efforts for data integration in the MarBEF Network of Excellence. Existing gaps in data coverage are identified, and the added value from meta-analyses of multiple datasets demonstrated using examples from the MarBEF integrated data project LargeNet. We discuss whether these efforts are addressing current policy needs and close with recommendations for future integrated data networks to increase our ability to understand, identify and predict recent and future regime shifts.
اظهر المزيد [+] اقل [-]Trace metal contamination of Beaufort’s Dyke, North Channel, Irish Sea: A legacy of ordnance disposal
2011
Callaway, Alexander | Quinn, Rory | Brown, Craig J. | Service, Matthew | Benetti, Sara
Beaufort’s Dyke is a disused ordnance disposal ground within the North Channel of the Irish Sea. Over 1 million tonnes of ordnance were disposed of in the dyke over a 40year period representing a substantial volume of trace metal pollutants introduced to the seabed. Utilising particle transport modelling software we simulated the potential transport of metal particles from Beaufort’s Dyke over a 3month period. This demonstrated that Beaufort’s Dyke has the potential to act as a source for trace metal contamination to areas beyond the submarine valley. Trace metal analysis of sediments from the Dyke and surrounding National Marine Monitoring Programme areas demonstrate that the Dyke is not the most contaminated site in the region. Particle transport modelling enables the transport pathways of trace metal contaminants to be predicted. Implementation of the technique in other munitions disposal grounds will provide valuable information for the selection of monitoring stations.
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