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Seasonal variations of imposex indices and butyltin concentrations in the rock shell Thais clavigera collected from Hong Kong waters 全文
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.
显示更多 [+] 显示较少 [-]Using aerial photography and in situ measurements to estimate the quantity of macro-litter on beaches 全文
2011
Nakashima, Etsuko | Isobe, Atsuhiko | Magome, Shinya | Kako, Shin’ichiro | Deki, Noriko
This study has demonstrated a reliable method of quantifying the total mass of litter on a beach. It was conducted on Ookushi beach, Goto-Islands, Japan, and uses a combination of balloon-assisted aerial photography and in situ mass measurements. The total mass of litter over the beach was calculated to be 716±259kg. This figure was derived by multiplying the litter-covered area (calculated using balloon-assisted aerial photography) by the mass of litter per unit area. Light plastics such as polyethylene made up 55% of all plastic litter on the beach, although more work is needed to determine whether lighter plastics are transported to beaches more readily by winds and ocean currents compared with heavier plastics, or whether lighter plastics comprise a greater percentage of marine litter. Finally, the above estimates were used to calculate the total mass of metals released into coastal ecosystems via plastic litter on beaches.
显示更多 [+] 显示较少 [-]Differential presence of anthropogenic compounds dissolved in the marine waters of Puget Sound, WA and Barkley Sound, BC 全文
2011
Keil, Richard | Salemme, Keri | Forrest, Brittany | Neibauer, Jaqui | Logsdon, Miles
Organic compounds were evaluated in March 2010 at 22 stations in Barkley Sound, Vancouver Island Canada and at 66 locations in Puget Sound. Of 37 compounds, 15 were xenobiotics, 8 were determined to have an anthropogenic imprint over natural sources, and 13 were presumed to be of natural or mixed origin. The three most frequently detected compounds were salicyclic acid, vanillin and thymol. The three most abundant compounds were diethylhexyl phthalate (DEHP), ethyl vanillin and benzaldehyde (∼600ngL⁻¹ on average). Concentrations of xenobiotics were 10–100 times higher in Puget Sound relative to Barkley Sound. Three compound couplets are used to illustrate the influence of human activity on marine waters; vanillin and ethyl vanillin, salicylic acid and acetylsalicylic acid, and cinnamaldehyde and cinnamic acid. Ratios indicate that anthropogenic activities are the predominant source of these chemicals in Puget Sound.
显示更多 [+] 显示较少 [-]Organic and inorganic matter in Louisiana coastal waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi regions 全文
2011
Schaeffer, Blake A. | Conmy, Robyn N. | Aukamp, Jessica | Craven, George | Ferer, Erin J.
Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi River locations, in 2007–2008. The range of CDOM was 0.092m⁻¹ at Barataria in June 2008 to 11.225m⁻¹ at Mississippi in February 2008. An indicator of organic matter quality was predicted by the spectral slope of absorption coefficients from 350 to 412nm which was between 0.0087m⁻¹ at Mississippi in May 2008 and 0.0261m⁻¹ at Barataria in June 2008. CDOM was the dominant component of light attenuation at Terrebonne and Barataria. Detritus and CDOM were the primary components of light attenuation at Vermilion, Atchafalaya, and Mississippi. DOC ranged between 65 and 1235μM. PIM ranged between 1.1 and 426.3mgL⁻¹ and POM was between 0.3 and 49.6mgL⁻¹.
显示更多 [+] 显示较少 [-]Polybrominated diphenyl ethers and their hydroxylated/methoxylated analogs: Environmental sources, metabolic relationships, and relative toxicities 全文
2011
Wiseman, Steve B. | Wan, Yi | Chang, Hong | Zhang, Xiaowei | Hecker, Markus | Jones, Paul D. | Giesy, John P.
Brominated compounds are ubiquitous in the aquatic environment. The polybrominated diphenyl ether (PBDE) flame retardants are anthropogenic compounds of concern. Studies suggest that PBDEs can be biotransformed to hydroxylated brominated diphenyl ethers (OH-BDE). However, the rate of OH-BDE formation observed has been extremely small. OH-BDEs have also been identified as natural compounds produced by some marine invertebrates. Another class of compounds, the methoxylated BDEs (MeO-BDEs), has also been identified as natural compounds in the marine environment. Both the OH-BDEs and MeO-BDEs bioaccumulate in higher marine organisms. Recent studies have demonstrated that MeO-BDEs can be biotransformed to OH-BDEs and this generates greater amounts of OH-BDEs than could be generated from PBDEs. Consequently, MeO-BDEs likely represent the primary source of metabolically derived OH-BDEs. Given that for some endpoints OH-BDEs often exhibit greater toxicity compared to PBDEs, it is prudent to consider OH-BDEs as chemicals of concern, despite their seemingly “natural” origins.
显示更多 [+] 显示较少 [-]DDT in endangered Galapagos sea lions (Zalophus wollebaeki) 全文
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.
显示更多 [+] 显示较少 [-]Microplastics in the marine environment 全文
2011
Andrady, A. L. (Anthony L.)
This review discusses the mechanisms of generation and potential impacts of microplastics in the ocean environment. Weathering degradation of plastics on the beaches results in their surface embrittlement and microcracking, yielding microparticles that are carried into water by wind or wave action. Unlike inorganic fines present in sea water, microplastics concentrate persistent organic pollutants (POPs) by partition. The relevant distribution coefficients for common POPs are several orders of magnitude in favour of the plastic medium. Consequently, the microparticles laden with high levels of POPs can be ingested by marine biota. Bioavailability and the efficiency of transfer of the ingested POPs across trophic levels are not known and the potential damage posed by these to the marine ecosystem has yet to be quantified and modelled. Given the increasing levels of plastic pollution of the oceans it is important to better understand the impact of microplastics in the ocean food web.
显示更多 [+] 显示较少 [-]Who, when, and how? Marine planning stakeholder involvement preferences – A case study of the Solent, United Kingdom 全文
2011
Maguire, Bernadine | Potts, Jonathan | Fletcher, Stephen
The introduction of a marine planning system throughout English territorial waters over the next decade provides an opportunity for stakeholder input to the management of the marine environment. Stakeholder involvement has been identified as an important component of successful development and subsequent implementation of marine planning but it has to be recognised that the views and interest of stakeholders can vary greatly, thus the desire for involvement with the process is unlikely to be uniform. This paper presents the views of stakeholders within the Solent, United Kingdom on their potential involvement with the marine planning process. Interestingly, it highlights a strong variability of views within and across sectors. Assuming the situation in the Solent is typical of groups of stakeholders throughout the country, the lack of uniformity in the potential involvement from different stakeholders may present a challenge in achieving a representative and truly collaborative marine planning process.
显示更多 [+] 显示较少 [-]Persistence profile of polyaromatic hydrocarbons in shallow and deep Gulf waters and sediments: Effect of water temperature and sediment–water partitioning characteristics 全文
2011
Tansel, B. | Fuentes, C. | Sánchez, M. | Predoi, K. | Acevedo, M.
Persistence profiles of selected polyaromatic hydrocarbons (PAHs) were analyzed depending on temperature variations in the water column and water–sediment interactions in the Gulf of Mexico. The PAHs studied include anthracene, fluoranthene, pyrene, and chrysene. The half-lives of PAHs in the deep waters (over 1000m) are about twice as long as those in the shallow areas (100–150m), and almost 2.5 times as long as those in the top layer (0–10m) of the water column. The half-lives of the PAHs in the sediments are significantly longer. Among the PAHs studied, chrysene is the most persistent in the water column, and pyrene is the most persistent in the sediments. The half-life of chrysene in the shallow and deep waters is over 2.5 and about 5years, respectively. For pyrene, the half-life in the shallow and deep sediments is about 9 and 16years, respectively.
显示更多 [+] 显示较少 [-]Identification of genes expressed in juvenile Haliotis rufescens in response to different copper concentrations in the north of Chile under controlled conditions 全文
2011
Silva-Aciares, Fernando | Zapata, Manuel | Tournois, Jennifer | Moraga, Dario | Riquelme, Carlos
This study reports molecular markers potentially associated with resistance or sensitivity to the impact of copper in juvenile red abalone, Haliotis rufescens, in the north of Chile under experimental conditions. Genomic analysis was made applying subtractive hybridization libraries (SSH) to identify genes up-and down regulated during cooper exposure in abalone over periods of 12 and 168h exposed to 2.5 and 10μg/L of Cu⁺². Results obtained from the SSH library revealed 368 different sequences regulated by copper, that correspond to eight major physiological functions. The validation of these sequences obtained by SSH as well as their expression kinetics were made by PCR in real time on 14 potential genes regulated by metal stress. This study provides information for the characterization of potential genomic markers that may be used in future environmental monitoring and to investigate new mechanisms of stress to copper in this commercially important marine species.
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