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Accumulation features of trace elements in mass-stranded harbor seals (Phoca vitulina) in the North Sea coast in 2002: The body distribution and association with growth and nutrition status Полный текст
2011
Agusa, Tetsuro | Yasugi, Shin-ya | Iida, Asami | Ikemoto, Tokutaka | Anan, Yasumi | Kuiken, Thijs | Osterhaus, Albert D.M.E. | Tanabe, Shinsuke | Iwata, Hisato
Body distribution and growth- and nutritional status-dependent accumulation of 21 trace elements were investigated in harbor seals (Phoca vitulina) stranded in the North Sea coast in 2002. Higher concentrations and burdens of Mn, Se, Mo, Ag, Sn, Hg, and Bi in the liver, Cd in the kidney, As in the blubber, and Co, Sr, and Ba in the bone were observed. Significant positive correlations of hepatic Se, Mo, Ag, Cd, Sn, Hg, Tl, and Bi with standard body length were found, while significant negative relationships were detected for Mn, As, Rb, Sr, and Sb in the liver. Concentrations of Co, Se, Sr, Sn, Hg, and Bi in the liver, V, Sr, Ag, Sn, and Hg in the kidney, V, Mn, Co, Rb, Sr, Sn, Ba, and Pb in the blubber increased with decreasing blubber thickness of harbor seals, indicating enrichment of these elements in the target tissue by emaciation.
Показать больше [+] Меньше [-]Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico Полный текст
2011
Ley-Quiñónez, C. | Zavala-Norzagaray, A.A. | Espinosa-Carreón, T.L. | Peckham, H. | Marquez-Herrera, C. | Campos-Villegas, L. | Aguirre, A.A.
Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89μgg⁻¹), followed by Selenium (10.92μgg⁻¹). The mean concentration of toxic metal Cadmium was 6.12μgg⁻¹ and 1.01μgg⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn>Se>Ni>Cu>Mn>Cd>Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.
Показать больше [+] Меньше [-]Sediment concentrations of heavy metals in the Homa Lagoon (Eastern Aegean Sea): Assessment of contamination and ecological risks Полный текст
2011
Uluturhan, Esin | Kontas, Aynur | Can, Elif
The concentrations of heavy metals and organic carbon in sediment of the Homa Lagoon which is one of the most productive lagoons and commercial important active fish trap in the Eastern Aegean Sea, were investigated in order to describe the temporal and spatial distributions of metals. These results were used to evaluate possible ecological risks that could be a problem for the environment of the lagoon in the future. Sediments were enriched with Cr, Ni and considered as heavily polluted per the SQG. The Cf of Ni and Cr were presented moderate level of contamination in this area. The Cd levels indicated moderate degree of contamination at station B, C, D and E due to agricultural drainage water, industrial and domestic wastewater, are transported by the Gediz River. Sediments from Homa Lagoon were most toxic for Ni due to exceedances of the TEL and PEL values.
Показать больше [+] Меньше [-]Hypoxia in Manila Bay, Philippines during the northeast monsoon Полный текст
2011
Jacinto, Gil S. | Sotto, Lara Patricia A. | Senal, Maria Isabel S. | Diego-McGlone, Maria Lourdes San | Escobar, Ma. Teresa L. | Amano, Atsuko | Miller, Todd W.
Herein we present results from one of the first extensive bay-wide oceanographic surveys of Manila Bay, wherein 31 stations were sampled during the northeast monsoon (cold and dry season). A band of hypoxic bottom water (dissolved oxygen <2.8mg/L) spanned the midsection of the bay from east to west. Bottom nitrate concentrations (5.7–16.8μM; avg. 11.1μM) and total organic carbon values in sediments (1.7–3.1%; avg. 2.4%) were high in the midsection, which coincided with the band of hypoxic bottom water. Physical processes and site-specific accumulation of organic material likely lead to hypoxic conditions in Manila Bay, even during the northeast monsoon period when the water column is relatively well mixed. The results of this study complement the previously reported widespread hypoxia that occurs during the rainy season. Thus, hypoxia may be pervasive in the bay throughout the year, although it varies in intensity and spatial extent.
Показать больше [+] Меньше [-]Using existing data and focused surveys to highlight Cuvier’s beaked whales favourable areas: A case study in the central Tyrrhenian Sea Полный текст
2011
Gannier, Alexandre
This study focuses on the necessary elements to implement strategic mitigation in order to avoid Cuvier’s beaked whale (CBW) strandings linked to intense sound sources, such as military active sonars, in the Mediterranean Sea. A careful review of stranding data and the analysis of existing survey results are required to highlight the main characters of the species regional distribution. Focused and repeated surveys are needed to confirm that possible favourable areas, such as the Balearic, Tyrrhenian or Aegean Seas, are really favourable CBW habitats. These surveys should be carried out with sea states 0 to 1 in order to minimize the risk of false absence data. Among the regions of interest, the central Tyrrhenian Sea was surveyed with a 12m sailboat in 2007 and 2008. With 907km of effective effort, a mean sighting rate of 1.9 CBW school/100km was obtained, which is amongst the highest densities recorded in the Mediterranean.
Показать больше [+] Меньше [-]Temporal changes of polyphenols and enzyme activities in seedlings of Kandelia obovata under lead and manganese stresses Полный текст
2011
Yan, Zhong Zheng | Tam, Nora Fung Yee
The temporal responses of peroxidase (POD), superoxide dismutase (SOD), total polyphenols (TP), extractable condensed tannins (ECT) to different levels of lead (Pb) or manganese (Mn) stress, as well as the metal accumulation, in seedlings of Kandelia obovata were investigated. Both stress time and stress intensity had significant effects with significant accumulation of Pb and Mn in roots at Day 1. Pb and Mn showed no significant effects on root or leaf TP and ECT at Day 1. Prolonged exposure to metals caused significant drops of root TP and ECT but increased in leaves at Days 7 and 49. POD activities decreased in both roots and leaves at Day 1, while POD and SOD both increased under moderate levels of Pb and Mn at Day 7. The present study showed that antioxidative enzyme activities were more sensitive indicators to Pb or Mn stresses than phenolic compounds.
Показать больше [+] Меньше [-]Environmental toxicology: Population modeling of cod larvae shows high sensitivity to loss of zooplankton prey Полный текст
2011
Stige, Leif Christian | Ottersen, Geir | Hjermann, Dag Ø | Dalpadado, Padmini | Jensen, Louise K. | Stenseth, Nils Chr
Two factors determine whether pollution is likely to affect a population indirectly through loss of prey: firstly, the sensitivity of the prey to the pollutants, and secondly, the sensitivity of the predator population to loss of prey at the given life stage. We here apply a statistical recruitment model for Northeast Arctic cod to evaluate the sensitivity of cod cohorts to loss of zooplankton prey, for example following an oil spill. The calculations show that cod cohorts are highly sensitive to possible zooplankton biomass reductions in the distribution area of the cod larvae, and point to a need for more knowledge about oil-effects on zooplankton. Our study illustrates how knowledge about population dynamics may guide which indirect effects to consider in environmental impact studies.
Показать больше [+] Меньше [-]Risk acceptance criterion for tanker oil spill risk reduction measures Полный текст
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.
Показать больше [+] Меньше [-]Differential concentration of Technetium-99 (⁹⁹Tc) in common intertidal molluscs with different food habits Полный текст
2011
Sjøtun, K. | Heldal, H.E. | Brakstad, D.S.
Concentration of ⁹⁹Tc has been measured in fucoids and molluscs, sampled in a sheltered intertidal at the southwest coast of Norway from February to November 2006. The concentrations of ⁹⁹Tc in molluscs differed significantly between species. The filtering bivalve Mytilus edulis had the lowest concentrations with averages of 2.3–5.9Bqkg⁻¹d.w., while the herbivorous gastropods Littorinalittorina, Littorina obtusata and Patella vulgata had higher concentrations. P. vulgata and L. obtusata had the highest concentrations, 40–47 and 26–30Bqkg⁻¹d.w., respectively. L. obtusata has a specialized habit of living, and prefers to feed on fucoids. P. vulgata can graze extensively on the fucoid Ascophyllum nodosum when available. Fucoids are known to have very high uptake of ⁹⁹Tc, and this was also found in the present study. The high ⁹⁹Tc-concentrations of L. obtusata and P. vulgata are most likely due to their habit of feeding on fucoids.
Показать больше [+] Меньше [-]Trace metal contamination of Beaufort’s Dyke, North Channel, Irish Sea: A legacy of ordnance disposal Полный текст
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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