细化搜索
结果 651-660 的 1,273
Hazardous and Noxious Substances (HNS) in the marine environment: Prioritizing HNS that pose major risk in a European context
2011
Neuparth, T. | Moreira, S. | Santos, M.M. | Reis-Henriques, M.A.
Increases in the maritime transportation of Hazardous and Noxious Substances (HNS), alongside the need for an effective response to HNS spills have led environmental managers and the scientific community to focus attention on HNS spill preparedness and responsiveness. In the context of the ARCOPOL project, a weight-of-evidence approach was developed aimed at prioritizing HNS that pose major environmental risks to European waters. This approach takes into consideration the occurrence probability of HNS spills in European Atlantic waters and the severity of exposure associated with their physico-chemical properties and toxicity to marine organisms. Additionally, a screening analysis of the toxicological information available for the prioritization of HNS was performed. Here we discuss the need for a prioritization methodology to select HNS that are likely to cause severe marine environmental effects as an essential step towards the establishment of a more effective preparedness and response to HNS incidents.
显示更多 [+] 显示较少 [-]Phytoplankton distribution and productivity in a highly turbid, tropical coastal system (Bach Dang Estuary, Vietnam)
2011
Rochelle-Newall, E.J. | Chu, V.T. | Pringault, O. | Amouroux, D. | Arfi, R. | Bettarel, Y. | Bouvier, T. | Bouvier, C. | Got, P. | Nguyen, T.M.H. | Mari, X. | Navarro, P. | Duong, T.N. | Cao, T.T.T. | Pham, T.T. | Ouillon, S. | Torréton, J.-P.
Phytoplankton diversity, primary and bacterial production, nutrients and metallic contaminants were measured during the wet season (July) and dry season (March) in the Bach Dang Estuary, a sub-estuary of the Red River system, Northern Vietnam. Using canonical correspondence analysis we show that phytoplankton community structure is potentially influenced by both organometallic species (Hg and Sn) and inorganic metal (Hg) concentrations. During March, dissolved methylmercury and inorganic mercury were important factors for determining phytoplankton community composition at most of the stations. In contrast, during July, low salinity phytoplankton community composition was associated with particulate methylmercury concentrations, whereas phytoplankton community composition in the higher salinity stations was more related to dissolved inorganic mercury and dissolved mono and tributyltin concentrations. These results highlight the importance of taking into account factors other than light and nutrients, such as eco-toxic heavy metals, in understanding phytoplankton diversity and activity in estuarine ecosystems.
显示更多 [+] 显示较少 [-]Plastic debris ingestion by marine catfish: An unexpected fisheries impact
2011
Possatto, Fernanda E. | Barletta, Mario | Costa, Monica F. | Ivar do Sul, Juliana A. | Dantas, David V.
Plastic marine debris is a pervasive type of pollution. River basins and estuaries are a source of plastics pollution for coastal waters and oceans. Estuarine fauna is therefore exposed to chronic plastic pollution. Three important catfish species [Cathorops spixii (N=60), Cathorops agassizii (N=60) and Sciades herzbergii (N=62)] from South Western Atlantic estuaries were investigated in a tropical estuary of the Brazilian Northeast in relation to their accidental ingestion of plastic marine debris. Individuals from all three species had ingested plastics. In C. spixii and C. agassizii, 18% and 33% of individuals had plastic debris in their stomachs, respectively. S. herzbergii showed 18% of individuals were contaminated. All ontogenetic phases (juveniles, sub-adults and adults) were contaminated. Nylon fragments from cables used in fishery activities (subsistence, artisanal and commercial) played a major role in this contamination. These catfish spend their entire life cycles within the estuary and are an important feeding resource for larger, economically important, species. It is not yet possible to quantify the scale and depth of the consequences of this type of pollution. However, plastics are well known threat to living resources in this and other estuaries. Conservation actions will need to from now onto take plastics pollution into consideration.
显示更多 [+] 显示较少 [-]Risk acceptance criterion for tanker oil spill risk reduction measures
2011
Psarros, George | Skjong, Rolf | Vanem, Erik
This paper is aimed at investigating whether there is ample support for the view that the acceptance criterion for evaluating measures for prevention of oil spills from tankers should be based on cost-effectiveness considerations. One such criterion can be reflected by the Cost of Averting a Tonne of oil Spilt (CATS) whereas its target value is updated by elaborating the inherent uncertainties of oil spill costs and establishing a value for the criterion’s assurance factor. To this end, a value of $80,000/t is proposed as a sensible CATS criterion and the proposed value for the assurance factor F=1.5 is supported by the retrieved Protection and Indemnity (P&I) Clubs’ Annual Reports. It is envisaged that this criterion would allow the conversion of direct and indirect costs into a non-market value for the optimal allocation of resources between the various parties investing in shipping. A review of previous cost estimation models on oil spills is presented and a probability distribution (log-normal) is fitted on the available oil spill cost data, where it should be made abundantly clear that the mean value of the distribution is used for deriving the updated CATS criterion value. However, the difference between the initial and the updated CATS criterion in the percentiles of the distribution is small. It is found through the current analysis that results are partly lower than the predicted values from the published estimation models. The costs are also found to depend on the type of accident, which is in agreement with the results of previous studies. Other proposals on acceptance criteria are reviewed and it is asserted that the CATS criterion can be considered as the best candidate. Evidence is provided that the CATS approach is practical and meaningful by including examples of successful applications in actual risk assessments. Finally, it is suggested that the criterion may be refined subject to more readily available cost data and experience gained from future decisions.
显示更多 [+] 显示较少 [-]Disruption of Sema3A expression causes abnormal neural projection in heavy oil exposed Japanese flounder larvae
2011
Kawaguchi, Masahumi | Song, Jun-Young | Irie, Kouta | Murakami, Yasunori | Nakayama, Kei | Kitamura, Shin-Ichi
It has been well known that oil spills cause serious problems in the aquatic organisms. In particular, some species of teleosts, which develop on the sea surface thought to be affected by heavy oil (HO). During the embryogenesis, the nervous system is constructed. Therefore, it is important to study the toxicological effects of HO on the developing neurons. We exposed HO to eggs of Japanese flounder (Paralichthys olivaceus) and investigated the neural disorder. In larvae exposed by HO at the concentration of 8.75mg/L, the facial and lateral line nerves partially entered into the incorrect region and the bundle was defasciculated. Furthermore, in the HO-exposed larvae, Sema3A, a kind of axon guidance molecule, was broadly expressed in second pharyngeal arch, a target region of facial nerve. Taken together, we suggested the possibility that the abnormal expression of Sema3A affected by HO exposure causes disruption of facial nerve scaffolding.
显示更多 [+] 显示较少 [-]Effects of polychlorinated biphenyls on liver function and sexual characteristics in Japanese medaka (Oryzias latipes)
2011
Nakayama, Kei | Sei, Naomi | Handoh, Itsuki C. | Shimasaki, Yohei | Honjo, Tsuneo | Ōshima, Yūji
The effects of polychlorinated biphenyls (PCBs) on liver function and their differences between sexes were analyzed in Japanese medaka (Oryzias latipes) exposed to PCB126 or Kanechlor-400 (KC-400) using microarray. PCB exposure induced vitellogenin 1 expression in female medaka while suppressing choriogenin genes, which suggests that the effects of PCBs on estrogen-responsive genes do not occur directly through an estrogen receptor-mediated pathway. Reduction of androgen receptor alpha expression was also observed, and the gene expression pattern in PCB-exposed males changed to become more similar to that of females. Furthermore, changes in glycolysis-related genes indicate that PCB exposure might enhance glucose production via gluconeogenesis in the liver of medaka. Taken together, our results suggest that PCBs disrupt the endocrine system, especially androgen function, and may have the potential to cause demasculinizing effects. Additionally, induction of gluconeogenesis might be a response to maintain glucose levels consumed as a result of PCB exposures.
显示更多 [+] 显示较少 [-]Assessment of organotin (butyltin species) contamination in marine biota from the Eastern Aegean Sea, Turkey
2011
Kucuksezgin, F. | Aydin-Onen, S. | Gonul, L.T. | Pazi, I. | Kocak, F.
The marine environment continues to be adversely affected by tributyltin (TBT) release from maritime traffic. Therefore the concentrations of TBT, dibutyltin (DBT) and monobutyltin (MBT) were measured in barnacles, mussels and fish along the Eastern Aegean coastline. The average concentrations of TBT ngSng⁻¹ were found to be 235 in fish, 116 in mussels and 635 in barnacles. The highest concentrations of TBT, DBT and MBT were observed in the barnacles which had been sampled in marinas and harbors. All mussels sampled showed values of TBT+DBT, which were below the “tolerable average residue level (TARL)” as currently accepted. This indicates a lack of risk to the consumer. However, 7 out of the 15 fish sampled displayed TBT+DBT levels above the TARL, which indicates that a fish consumer group may be at risk. Barnacles have high potential as biomonitors for the presence of organotin in the Aegean Sea.
显示更多 [+] 显示较少 [-]Eutrophication and hypoxia in four streams discharging in Guanabara Bay, RJ, Brazil, a case study
2011
Aguiar, Valquiria Maria de Carvalho | Neto, José Antônio Baptista | Rangel, Carlos Marclei
Four streams in the city of São Gonçalo, were sampled to evaluate their potential as sources of nutrients to Guanabara Bay aiming to contribute with the government program to decrease the levels of pollution in this area. Imbuaçu, Guaxindiba, Marimbondo and Brandoas streams were sampled in 2007, 2008 and 2009. The streams revealed to be hipereutrophic with severe limitation of primary production by nitrogen, as shown by the N/P molar ratio. Phosphate levels were abnormally high varying between 4.35 and 130.82μM, whereas nitrate and nitrite ranged from 0.06 to 54.05μM and from 0.28 to 19.23μM, respectively. The streams also presented severe hypoxia and anoxia, with oxygen values varying from non-detected to 3.72mll⁻¹. Heavy loads of particulate suspended material were recorded in the studied streams, ranging between 6.00 and 400.00mgl⁻¹. The streams were considered inexorable sources of nutrients, enhancing the severe eutrophication process in Guanabara Bay.
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
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 [-]Ostreopsis cf. ovata bloom in the northern Adriatic Sea during summer 2009: Ecology, molecular characterization and toxin profile
2011
Accoroni, Stefano | Romagnoli, Tiziana | Colombo, Federica | Pennesi, Chiara | Di Camillo, Cristina Gioia | Marini, Mauro | Battocchi, Cecilia | Ciminiello, Patrizia | Dell’Aversano, Carmela | Dello Iacovo, Emma | Fattorusso, Ernesto | Tartaglione, Luciana | Penna, Antonella | Totti, Cecilia
Intense blooms of the benthic dinoflagellate Ostreopsis cf. ovata have occurred in the northern Adriatic Sea since 2006. These blooms are associated with noxious effects on human health and with the mortality of benthic organisms because of the production of palytoxin-like compounds. The O. cf. ovata bloom and its relationships with nutrient concentrations at two stations on the Conero Riviera (northern Adriatic Sea) were investigated in the summer of 2009. O. cf. ovata developed from August to November, with the highest abundances in September (1.3×10⁶cellsg⁻¹ fw corresponding to 63.8×10³cellscm⁻²). The presence of the single O. cf. ovata genotype was confirmed by a PCR assay. Bloom developed when the seawater temperature was decreasing. Nutrient concentrations did not seem to affect bloom dynamics. Toxin analysis performed by high resolution liquid chromatography–mass spectrometry revealed a high total toxin content (up to 75pgcell⁻¹), including putative palytoxin and all the ovatoxins known so far.
显示更多 [+] 显示较少 [-]