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A comparison of integrated and discrete depth sampling for monitoring toxic species of Dinophysis 全文
2012
Escalera, Laura | Pazos, Yolanda | Dolores Doval, María | Reguera, Beatriz
A comparison of integrated and discrete depth sampling for monitoring toxic species of Dinophysis 全文
2012
Escalera, Laura | Pazos, Yolanda | Dolores Doval, María | Reguera, Beatriz
Dinophysis acuminata and Dinophysis acuta produce lipophilic toxins that cause most shellfish harvesting closures in the Atlantic coastal waters of Europe. Dinophysis often exhibit patchy distributions and sampling with conventional methods may fail to detect them. A 6-month calibration study in 2006, plus an additional sampling in 2010 were carried out in Galicia to compare Dinophysis counts obtained from weekly high vertical resolution bottle samples with depth-integrated hose samples. Counts with these two methods were comparable at some depth-ranges, but hose maxima were over one order of magnitude lower under thin-layer scenarios. Estimates from hose samplers should be used with caution in programmes using a “Dinophysis index”, either to trigger shellfish sampling or to establish precautionary harvesting closures. In general, hose samplers provide reliable information on the occurrence of Dinophysis except under extreme site-specific hydrodynamic conditions. This study adds new information about the heterogeneous, specific vertical distributions of two Dinophysis spp.
显示更多 [+] 显示较少 [-]A comparison of integrated and discrete depth sampling for monitoring Dinophysis. 全文
2012
Escalera-Moura, Laura | Pazos, Yolanda | Doval, M. Dolores | Reguera Ramírez, Beatriz
Dinophysis acuminata and Dinophysis acuta produce lipophilic toxins that cause most shellfish harvesting closures in the Atlantic coastal waters of Europe. Dinophysis often exhibit patchy distributions and sampling with conventional methods may fail to detect them. A 6-month calibration study in 2006, plus an additional sampling in 2010 were carried out in Galicia to compare Dinophysis counts obtained from weekly high vertical resolution bottle samples with depth-integrated hose samples. Counts with these two methods were comparable at some depth-ranges, but hose maxima were over one order of magnitude lower under thin-layer scenarios. Estimates from hose samplers should be used with caution in programmes using a “Dinophysis index”, either to trigger shellfish sampling or to establish precautionary harvesting closures. In general, hose samplers provide reliable information on the occurrence of Dinophysis except under extreme site-specific hydrodynamic conditions. This study adds new information about the heterogeneous, specific vertical distributions of two Dinophysis spp. | Sí
显示更多 [+] 显示较少 [-]Radionuclides in resident and migratory fishes of a wedge bank region: Estimation of dose to human beings, South India 全文
2012
Khan, M Feroz | Wesley, S Godwin
Baseline activity concentration of ¹³⁷Cs, ²¹⁰Po and ²¹⁰Pb was determined for 25 resident and 22 migratory fish species collected in a so-called wedge bank region in the extreme south of India. A nuclear power station is now under construction at Kudankulam near the target region and the data provide background information on the radionuclide activity concentration in the region. Three-way ANOVA revealed no significant variation in the concentrations of ¹³⁷Cs, ²¹⁰Po and ²¹⁰Pb between species based on feeding habit, habitat and migratory pattern except the effect of feeding habit on ²¹⁰Po concentration (p<0.05). The annual dose due to radionuclide ingestion through the fishes was calculated based on the survey results of fish consumption rates for the local population. The dose due to ¹³⁷Cs was negligibly small while those due to ²¹⁰Po and ²¹⁰Pb varied from 1.2 to 36.9 and 0.2 to 2.9μSvyr⁻¹, respectively.
显示更多 [+] 显示较少 [-]Severe pollution of PCDD/Fs and dioxin-like PCBs in sediments from Lake Shihwa, Korea: Tracking the source 全文
2012
Moon, Hyo-Bang | Choi, Minkyu | Choi, Hee-Gu | Kannan, Kurunthachalam
Concentrations of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were determined in surface sediments from Lake Shihwa and from creeks that discharge into this artificial lake. The toxic equivalents (TEQs) in sediments ranged from 1.0 to 1770pg/g dry weight, which were some of the highest values ever reported so far for coastal sediments on a global basis. The concentrations of PCDD/Fs and DL-PCBs decreased with increasing distance from the creeks to offshore regions of the lake. Based on a multivariate statistical analysis and congener profiles, it was found that high contamination by PCDD/Fs in creek sediments collected around Lake Shihwa was associated with releases from chlor-alkali processes. Significant correlations were found for total organic carbon content and the concentrations of highly chlorinated PCDD/F congeners. This is the first report to document chlor-alkali processes as a significant source of PCDD/F contamination in Korean coastal waters.
显示更多 [+] 显示较少 [-]Petroleum hydrocarbon contamination in Nelson Lagoon, Alaska, sampling three different matrices 全文
2012
Lance, Ellen W. | Matz, Angela C. | Reeves, Mari K. | Verbrugge, Lori A.
Polycyclic aromatic hydrocarbon (PAH) levels were measured in sediments, bivalves and semi-permeable membrane devices (SPMDs) in the relatively pristine marine environment of Nelson Lagoon, Alaska. Most PAH levels in Nelson Lagoon were low, and similar to global background concentrations. Sampling media type can significantly influence conclusions of PAH contamination in the environment. Concentration of a broad size range of PAHs was observed in the tissues of blue mussels (Mytilus edulis). SPMDs collected some two- to three-ring PAHs from the dissolved water phase, while sediments collected five- to six-ring PAHs that were likely adsorbed onto particulate matter. Benzo(a)pyrene, a potent carcinogen, was found in mussels at levels similar to more industrialized harbors in Alaska.
显示更多 [+] 显示较少 [-]Phenolic endocrine disrupting chemicals (EDCs) in Anzali Wetland, Iran: Elevated concentrations of 4-nonylphenol, octhylphenol and bisphenol A 全文
2012
Mortazavi, Samar | Riyahi Bakhtiari, Alireza | Sari, Abbas Esmaili | Bahramifar, Nader | Rahbarizade, Fatemeh
We have studied the distribution and value of phenolic endocrine disrupting chemicals (EDCs) in surface sediment samples taken from Anzali Wetland, Iran. These samples were collected from 22 stations during the time span of June–May 2010. In each of the sampling stations, we detected 4-nonylphenol (4-NP), octylphenol (OP), and bisphenol A (BPA) with maximal concentrations of 29, 4.3, and 7μgg⁻¹ dry weight (dw), respectively. High levels of alkylphenols (APs) and BPA were also found near urban areas. Furthermore there were no significant differences between those stations in terms of the detected levels. One of the important factors in controlling the fate of these compounds in the aquatic environment appeared to be Total Organic Carbon (TOC). Hierarchical cluster analysis showed differences in the biomarker characteristics of EDCs and TOC between the stations. Our findings indicate that EDCs are ubiquitous in sediments from northeast Wetlands of Iran, contaminating the aquatic habitats in this area.
显示更多 [+] 显示较少 [-]Chesapeake Bay nutrient pollution: Contribution from the land application of sewage sludge in Virginia 全文
2012
Land, Lynton S.
Human health concerns and the dissemination of anthropogenic substances with unknown consequences are the reasons most often given why disposal of municipal sewage sludge in landfills or using the organic waste as biofuel is preferable to land application. But no “fertilizer” causes more nitrogen pollution than sludge when applied according to Virginia law. Poultry litter is the only other “fertilizer” that causes more phosphorus pollution than sludge. Cost savings by the few farmers in Virginia who use sludge are far less than the costs of the nitrogen pollution they cause. A ban on the land application of all forms of animal waste is very cost-effective and would reduce Chesapeake Bay nutrient pollution by 25%.
显示更多 [+] 显示较少 [-]Satellite imaging coral reef resilience at regional scale. A case-study from Saudi Arabia 全文
2012
Rowlands, Gwilym | Purkis, Samuel J. | Riegl, Bernhard | Metsamaa, Liisa | Bruckner, Andrew | Renaud, Philip
We propose a framework for spatially estimating a proxy for coral reef resilience using remote sensing. Data spanning large areas of coral reef habitat were obtained using the commercial QuickBird satellite, and freely available imagery (NASA, Google Earth). Principles of coral reef ecology, field observation, and remote observations, were combined to devise mapped indices. These capture important and accessible components of coral reef resilience. Indices are divided between factors known to stress corals, and factors incorporating properties of the reef landscape that resist stress or promote coral growth. The first-basis for a remote sensed resilience index (RSRI), an estimate of expected reef resilience, is proposed. Developed for the Red Sea, the framework of our analysis is flexible and with minimal adaptation, could be extended to other reef regions. We aim to stimulate discussion as to use of remote sensing to do more than simply deliver habitat maps of coral reefs.
显示更多 [+] 显示较少 [-]Evaluation of the partial renewal of in situ phytoplankton microcosms and application to the impact assessment of bentazon and dimethenamid 全文
2012
de la Broise, Denis | Stachowski-Haberkorn, Sabine
Evaluation of the partial renewal of in situ phytoplankton microcosms and application to the impact assessment of bentazon and dimethenamid 全文
2012
de la Broise, Denis | Stachowski-Haberkorn, Sabine
Microcosms, each consisting of 2L natural surface seawater maintained in 2.3-L glass bottles, were immersed at a depth of 6m. The renewal of 10% of microcosm volumes was carried out every other day. Phytoplankton-containing seawater was used for renewal (previously filtered through 25-, 50- or 200-μm cut-off). Phytoplankton community pigment analysis (by HPLC) and flow cytometry analysis were performed. After 13days, data exhibited phytoplankton characteristics in microcosms in the same range as that of the natural surrounding sea water over the same period. Furthermore, in these microcosms, a negative correlation was observed between the filtration cut-off used for renewal water, and the total cell count. Herbicides were tested as commercial mixtures at 1, 10 and 100μgL⁻¹ active substance. Both Frontier® (dimethenamid) and Basamais® (bentazon) induced significant modifications of the phytoplankton populations at every concentration tested. Such results suggest a possible disturbance in polluted coastal areas.
显示更多 [+] 显示较少 [-]Evaluation of the partial renewal of in situ phytoplankton microcosms and application to the impact assessment of bentazon and dimethenamid 全文
2012
De La Broise, Denis | Stachowski-haberkorn, Sabine
Microcosms, each consisting of 2 L natural surface seawater maintained in 2.3-L glass bottles, were immersed at a depth of 6 metres. The renewal of ten percent of microcosm volumes was carried out every other day. Phytoplankton-containing seawater was used for renewal (previously filtered through 25-, 50- or 200-μm cut-off). Phytoplankton community pigment analysis (by HPLC) and flow cytometry analysis were performed. After 13 days, data exhibited phytoplankton characteristics in microcosms in the same range as that of the natural surrounding sea water over the same period. Furthermore, in these microcosms, a negative correlation was observed between the filtration cut-off used for renewal water, and the eukaryote cell count. Herbicides were tested as commercial mixtures at 1, 10 and 100 μg.L-1 active principal. Both Frontier® (dimethenamid) and Basamais® (bentazon) induced significant modifications of the phytoplankton populations at every concentration tested. Such results suggest a possible disturbance in polluted coastal areas.
显示更多 [+] 显示较少 [-]Hair sampling location in harbor seals (Phoca vitulina) affects selenium and mercury concentrations: Implications for study design of trace element determination in pinnipeds 全文
2012
McHuron, Elizabeth A. | Harvey, James T. | Castellini, J Margaret | O’Hara, Todd M.
Hair is used to determine trace elements exposure and status of pinnipeds because it is an excretory route for many elements and can be collected non-lethally. Despite increased use, there have been few studies on how sampling designs and procedures (e.g., hair type, collection site) affect results. The objective of this study was to determine whether concentrations of an essential (selenium; Se) and non-essential element (mercury; Hg) differed between hair samples collected from two body locations on harbor seals (Phoca vitulina). Concentrations of Se and total Hg (THg) differed between mid-dorsal midline and neck samples, and although the absolute differences were relatively small (Δₐbₛₒₗᵤₜₑ Se=0.69μgg⁻¹, Δₐbₛₒₗᵤₜₑ THg=2.86μgg⁻¹), the relative differences were large (Δᵣₑₗₐₜᵢᵥₑ Se=49%, Δᵣₑₗₐₜᵢᵥₑ THg=17%). These differences highlight the need to standardize the collection site for trace element determination in pinnipeds.
显示更多 [+] 显示较少 [-]Water column characterisation on the Azores platform and at the sea mounts south of the archipelago 全文
2012
Palma, Carla | Lillebø, Ana I. | Borges, Carlos | Souto, Miguel | Pereira, Eduarda | Duarte, Armando C. | Abreu, Manuel Pinto de
Water column characterisation on the Azores platform and at the sea mounts south of the archipelago 全文
2012
Palma, Carla | Lillebø, Ana I. | Borges, Carlos | Souto, Miguel | Pereira, Eduarda | Duarte, Armando C. | Abreu, Manuel Pinto de
This study provides data concerning the hydrography and water chemistry of the Atlantic region between 29–38° N and 27–31° W, and establishes background values for dissolved Cu, Cd, Pb and As. Three water masses were identified: the Eastern North Atlantic Central Water (ENACW), the Mediterranean Water (MW) and the North Atlantic Deep Water (NADW). The ENACW exhibits a clear meridional gradient of temperature and salinity, with comparatively high values at the southern sites and lower values on the Azores platform. The ENACW, which includes the euphotic zone, also had comparatively high concentrations of oxygen and lower concentrations of nutrients and metals. The Cu, Cd and Pb results suggest that new background concentrations for OSPAR Region V (the Wider Atlantic) should be established as follows: 0.15–13nM for Cu, 0.05–1.4nM for Cd and 0.03–5nM for Pb. The background concentrations of As for OSPAR Region V should be 7–28nM.
显示更多 [+] 显示较少 [-]Water column characterisation on the Azores platform and at the sea mounts south of the archipelago 全文
2012
Palma, Carla | Lillebø, Ana I. | Borges, Carlos | Souto, Miguel | Pereira, Eduarda | Duarte, Armando C. | Abreu, Manuel Pinto de
This study provides data concerning the hydrography and water chemistry of the Atlantic region between 29-38° N and 27-31° W, and establishes background values for dissolved Cu, Cd, Pb and As. Three water masses were identified: the Eastern North Atlantic Central Water (ENACW), the Mediterranean Water (MW) and the North Atlantic Deep Water (NADW). The ENACW exhibits a clear meridional gradient of temperature and salinity, with comparatively high values at the southern sites and lower values on the Azores platform. The ENACW, which includes the euphotic zone, also had comparatively high concentrations of oxygen and lower concentrations of nutrients and metals. The Cu, Cd and Pb results suggest that new background concentrations for OSPAR Region V (the Wider Atlantic) should be established as follows: 0.15-13 nM for Cu, 0.05-1.4 nM for Cd and 0.03-5 nM for Pb. The background concentrations of As for OSPAR Region V should be 7-28 nM. | published
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