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Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments of the Hormuz strait, Persian Gulf
2014
Rahmanpoor, Shirin | Ghafourian, Hosein | Hashtroudi, Seyed Mehri | Bastami, Kazem Darvish
The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the sediment from the Hormuz strait, Persian Gulf. The sum of 16 PAHs (ΣPAH) concentrations varied from 72.17 to 277.77ngg−1 dry weight, with an average value of 131.20±59.29ngg−1 dry weight. An ecological risk assessment of PAHs, indicated that adverse biological effects caused by acenaphthene and acenaphthylene occasionally may take place in the sediment of Hormuz strait. PAH source identification showed that the PAHs in the sediments come from pyrogenic and mixed origin. Based on classification of pollution levels, sediments from Hormuz strait could be considered as low to moderately polluted with PAHs.
显示更多 [+] 显示较少 [-]Factors contributing to elevated concentrations of PM2.5 during wintertime near Boise, Idaho
2014
Mwaniki, George Ruchathi | Rosenkrance, Chelsea | Will Wallace, H. | Tom Jobson, B. | Erickson, Mathew H. | Lamb, Brian K. | Hardy, Rick J. | Zalakeviciute, Rasa | VanReken, Timothy M.
Wintertime chemical composition of water–soluble particulate matter with aerodynamic diameter less than 2.5μm (PM2.5) was monitored in the Treasure Valley region near Boise, Idaho. Aerosol was sampled using a Particle Into Liquid Sampler (PILS) and subsequently analyzed using ion exchange chromatography and a total organic carbon analyzer. During the two–month sampling campaign, the region experienced varying meteorological regimes, with an extended atmospheric stagnation event towards the end of the study. For all of the weather regimes, water–soluble PM2.5 was dominated by organic material, but particulate nitrate showed the greatest variation over time. These variations in particulate nitrate concentration were found to be dependent on the time of day, nitrogen oxides (NOX) concentrations, and relative humidity. The increases in particulate nitrate did not correlate with an equivalent molar increase of ammonium concentration, ruling out solid ammonium nitrate formation as the dominant source. Instead, our analysis using an online aerosol thermodynamic model suggests that the condensation of gas phase nitric acid was possible within the meteorological conditions experienced during the study. In running this model, atmospheric chemical and physical parameters close to those observed during the study were used as model input. The simulation was run for three different scenarios, representing the different meteorological regimes experienced during the study. From the simulation particulate nitrate concentration was highest during cold and humid nights. Currently this region is in attainment with the National Ambient Air Quality Standards (NAAQS) for PM2.5; however, with the projected increase in population and economic growth, and the subsequent increase in NOX emissions, these episodic increases in particulate nitrate have the potential of pushing the area to non–attainment status.
显示更多 [+] 显示较少 [-]Organotin contamination in seafood and its implication for human health risk in Hong Kong
2014
Ho, Kevin K.Y. | Leung, Kenneth M.Y.
Organotins (OTs) have caused widespread adverse effects on marine organisms, while they can also induce health problems to humans via consumption of contaminated seafood. This study aimed to quantify the tissue concentrations of OTs in 11 seafood species in Hong Kong, and assess the human health risk for consuming these species. The tongue sole Paraplagusia blochii had the highest concentration of total OTs. Triphenyltin (TPT) accounted for 56–97% of total OTs. The highest hazard quotient (HQ) for TPT was 1.41 in P. blochii, while the HQs for butyltins were much less than 1. The results indicated that it is likely to have certain health risks for consuming P. blochii due to its high TPT contamination. Therefore, TPT should be a priority pollutant of concern. Appropriate management actions should be taken to control its use and release in the region in order to safeguard the marine ecosystem and human health.
显示更多 [+] 显示较少 [-]Validation trials of a shipboard filter skid (p3SFS) demonstrate its utility for collecting living zooplankton
2014
Drake, Lisa A. | Moser, Cameron S. | Robbins-Wamsley, Stephanie H. | Riley, Scott C. | Wier, Timothy P. | Grant, Jonathan F. | Herring, Penny R. | First, Matthew R.
Relatively large volumes of water—on the order of cubic meters—must be sampled and analyzed to generate statistically valid estimates of sparsely concentrated organisms, such as in treated ballast water. To this end, a third prototype of a shipboard filter skid (p3SFS) was designed and constructed. It consisted of two housings (each containing a 35μm mesh filter bag) and its own pump and computer controller. Additionally, the skid had a drip sampler, which collected a small volume (∼10L) of whole (unfiltered) water immediately upstream of the housings. Validation of the p3SFS occurred in two segments: (1) land-based trials, in which the collection of organisms ⩾50μm (nominally zooplankton) by the p3SFS was compared to a plankton net, and (2) shipboard trials, in which ballast water was sampled aboard a ship. In both types of trials, the data collected showed the filter skid to be an appropriate flow-through sampling device.
显示更多 [+] 显示较少 [-]Australia’s pesticide environmental risk assessment failure: The case of diuron and sugarcane
2014
Holmes, Glen
In November 2012, the Australian Pesticide and Veterinary Medicines Authority (APVMA) concluded a 12year review of the PSII herbicide diuron. One of the primary concerns raised during the review was the potential impact on aquatic ecosystems, particularly in the catchments draining to the Great Barrier Reef. The environmental risk assessment process used by the APVMA utilised a runoff risk model developed and validated under European farming conditions. However, the farming conditions in the sugarcane regions of the Great Barrier Reef catchments have environmental parameters beyond the currently validated bounds of the model. The use of the model to assess environmental risk in these regions is therefore highly inappropriate, demonstrating the pitfalls of a one size fits all approach.
显示更多 [+] 显示较少 [-]Modeling the distribution of illicit oily discharges detected by aerial surveillance in western Canadian marine waters
2014
Serra-Sogas, Norma | O’Hara, Patrick D. | Canessa, Rosaline
Oily discharges from vessel operations have been documented in Canada’s Pacific region by the National Aerial Surveillance Program (NASP) since the early 1990s. We explored a number of regression methods to explain the distribution and counts per grid cell of oily discharges detected from 1998 to 2007 using independent predictor variables, while trying to address the large number of zeros present in the data. Best-fit models indicate that discharges are generally concentrated close to shore typically in association with small harbours, and with major commercial and tourist centers. Oily discharges were also concentrated in Barkley Sound and at the entrance of Juan de Fuca Strait. The identification of important factors associated with discharge patterns, and predicting discharge rates in areas with surveillance effort can be used to inform future surveillance. Model output can also be used as inputs for risk models for existing conditions and as baseline for future scenarios.
显示更多 [+] 显示较少 [-]Similar diversity-disturbance responses to different physical impacts: Three cases of small-scale biodiversity increase in the Belgian part of the North Sea
2014
De Backer, Annelies | Van Hoey, Gert | Coates, Delphine | Vanaverbeke, Jan | Hostens, Kris
Human activities at sea are still increasing. As biodiversity is a central topic in the management of our seas, it is important to understand how diversity responds to different disturbances related with physical impacts. We investigated the effects of three impacts, i.e. sand extraction, dredge disposal and offshore wind energy exploitation, on the soft-bottom macrobenthic assemblages in the Belgian part of the North Sea. We found similar diversity-disturbance responses, mainly related to the fact that different impacts caused similar environmental changes. We observed a sediment refinement which triggered a shift towards a heterogenic, dynamic (transitional) soft-bottom macrobenthic assemblage, with several species typically associated with muddy sands. This led to a local unexpected biodiversity increase in the impacted area. On a wider regional scale, the ever increasing human impacts might lead to a homogenization of the sediment, resulting in a more uniform, yet less diverse benthic ecosystem.
显示更多 [+] 显示较少 [-]Prevalence of marine debris in marine birds from the North Atlantic
2014
Provencher, Jennifer F. | Bond, Alexander L. | Hedd, April | Montevecchi, William A. | Muzaffar, Sabir Bin | Courchesne, Sarah J. | Gilchrist, H Grant | Jamieson, Sarah E. | Merkel, Flemming R. | Falk, Knud | Durinck, Jan | Mallory, Mark L.
Marine birds have been found to ingest plastic debris in many of the world’s oceans. Plastic accumulation data from necropsies findings and regurgitation studies are presented on 13 species of marine birds in the North Atlantic, from Georgia, USA to Nunavut, Canada and east to southwest Greenland and the Norwegian Sea. Of the species examined, the two surface plungers (great shearwaters Puffinus gravis; northern fulmars Fulmarus glacialis) had the highest prevalence of ingested plastic (71% and 51%, respectively). Great shearwaters also had the most pieces of plastics in their stomachs, with some individuals containing as many of 36 items. Seven species contained no evidence of plastic debris. Reporting of baseline data as done here is needed to ensure that data are available for marine birds over time and space scales in which we see changes in historical debris patterns in marine environments (i.e. decades) and among oceanographic regions.
显示更多 [+] 显示较少 [-]Plastic in the Thames: A river runs through it
2014
Morritt, David | Stefanoudis, Paris V. | Pearce, Dave | Crimmen, Oliver A. | Clark, Paul F.
Although contamination of the marine ecosystems by plastics is becoming recognised as a serious pollution problem, there are few studies that demonstrate the contribution made by freshwater catchments. Over a three month period from September to December 2012, at seven localities in the upper Thames estuary, 8490 submerged plastic items were intercepted in eel fyke nets anchored to the river bed. Whilst there were significant differences in the numbers of items at these locations, the majority were some type of plastic. Additionally in excess of 20% of the litter items were components of sanitary products. The most contaminated sites were in the vicinity of sewage treatment works. While floating litter is visible, this study also demonstrates that a large unseen volume of submerged plastic is flowing into the marine environment. It is therefore important that this sub-surface component is considered when assessing plastic pollution input into the sea.
显示更多 [+] 显示较少 [-]Heavy metal concentration in mangrove surface sediments from the north-west coast of South America
2014
Fernández-Cadena, J.C. | Andrade, S. | Silva-Coello, C.L. | De la Iglesia, R.
Mangrove ecosystems are coastal estuarine systems confined to the tropical and subtropical regions. The Estero Salado mangrove located in Guayaquil, Ecuador, has suffered constant disturbances during the past 20years, due to industrial wastewater release. However, there are no published data for heavy metals present in its sediments and the relationship with anthropogenic disturbance. In the present study, metal concentrations were evaluated in surface sediment samples of the mangrove, showing that B, Cd, Cu, Pb, Se, V, and Zn levels exceeded those declared in international environmental quality standards. Moreover, several metals (Pb, Sn, Cd, Ag, Mo, Zn and Ni) could be linked to the industrial wastewater present in the studied area. In addition, heavy metal levels detected in this mangrove are higher than previous reports on mangrove sediments worldwide, indicating that this mangrove ecosystem is one of the most disrupted on earth.
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