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Tracing decadal environmental change in ombrotrophic bogs using diatoms from herbarium collections and transfer functions Full text
2013
Poulíčková, Aloisie | Hájková, Petra | Kintrová, Kateřina | Bat'ková, Romana | Czudková, Markéta | Hájek, Michal
Central European mountain bogs, among the most valuable and threatened of habitats, were exposed to intensive human impact during the 20th century. We reconstructed the subrecent water chemistry and water-table depths using diatom based transfer functions calibrated from modern sampling. Herbarium Sphagnum specimens collected during the period 1918–1998 were used as a source of historic diatom samples. We classified samples into hummocks and hollows according to the identity of dominant Sphagnum species, to reduce bias caused by uneven sampling of particular microhabitats. Our results provide clear evidence for bog pollution by grazing during the period 1918–1947 and by undocumented aerial liming in the early 90-ies. We advocate use of herbarized epibryon as a source of information on subrecent conditions in recently polluted mires.
Show more [+] Less [-]Titanium determination by multisyringe flow injection analysis system and a liquid waveguide capillary cell in solid and liquid environmental samples Full text
2013
Sánchez-Quiles, David | Tovar-Sánchez, Antonio | Horstkotte, Burkhard
Titanium determination by multisyringe flow injection analysis system and a liquid waveguide capillary cell in solid and liquid environmental samples Full text
2013
Sánchez-Quiles, David | Tovar-Sánchez, Antonio | Horstkotte, Burkhard
A multisyringe flow injection analysis system using a liquid waveguide capillary cell (MSFIA-LWCC) has been used for the spectrophotometric determination of titanium (Ti) in marine environmental samples. Samples were previous digested using potassium peroxodisulfate (K2S2O8). The method showed to be linear over a range up to 1μM with a detection limit of 9.2nM. The analysis consumes little reagent (250μL) and sample (600μL). It had an adequate accuracy with high repeatability (RSD of 1.8%) for all marine samples. The proposed method was used to evaluate the concentration of Ti in natural samples collected in the coastal area of the Majorca Island (Western Mediterranean Sea). We report average concentrations of Ti in coastal surface microlayer of 510.7±267.2nM, in surface sediments of 2.72±1.84μmol/g, and in rhizomes and leaves of Posidonia oceanica of 310±295nmol/g and 157±132nmol/g, respectively.
Show more [+] Less [-]Titanium determination by multisyringe flow injection analysis system and a liquid waveguide capillary cell in solid and liquid environmental samples Full text
2013
Sánchez-Quiles, David | Tovar-Sánchez, Antonio | Horstkotte, Burkhard
A multisyringe flow injection analysis system using a liquid waveguide capillary cell (MSFIA-LWCC) has been used for the spectrophotometric determination of titanium (Ti) in marine environmental samples. Samples were previous digested using potassium peroxodisulfate (K2S2O8). The method showed to be linear over a range up to 1μM with a detection limit of 9.2nM. The analysis consumes little reagent (250μL) and sample (600μL). It had an adequate accuracy with high repeatability (RSD of 1.8%) for all marine samples. The proposed method was used to evaluate the concentration of Ti in natural samples collected in the coastal area of the Majorca Island (Western Mediterranean Sea). We report average concentrations of Ti in coastal surface microlayer of 510.7±267.2nM, in surface sediments of 2.72±1.84μmol/g, and in rhizomes and leaves of Posidonia oceanica of 310±295nmol/g and 157±132nmol/g, respectively. © 2013 Elsevier Ltd. | This work was supported by the ISUMAR project (CTM2011-22645) funded by the Spanish Ministry of Economy and Competitiveness. We thank M. Makhani for assistance and J.F. González (SCT – UIB) for technical assistance. D.S.-Q. was supported by the JAE-predoc program of the Spanish National Research Council (CSIC). B.H. was supported by JAEDOC 2008 program (CSIC). | Peer reviewed
Show more [+] Less [-]Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques Full text
2013
Deposition of tar balls along the coast of Goa, India is a common phenomenon during the southwest monsoon. Representative tar ball samples collected from various beaches of Goa and one Bombay High (BH) crude oil sample were subjected to fingerprint analysis based on diagnostic ratios of n-alkane, biomarkers of pentacyclic tri-terpanes and compound specific stable carbon isotope (δ13C) analysis to confirm the source. The results were compared with the published data of Middle East Crude Oil (MECO) and South East Asian Crude Oil (SEACO). The results revealed that the tar balls were from tanker-wash derived spills. The study also confirmed that the source is not the BH, but SEACO. The present study suggests that the biomarkers of alkanes and hopanes coupled with stable carbon isotope analysis act as a powerful tool for tracing the source of tar balls, particularly when the source specific biomarkers fail to distinguish the source.
Show more [+] Less [-]Macrobenthos habitat potential mapping using GIS-based artificial neural network models Full text
2013
Lee, Saro | Park, Inhye | Koo, Bon Joo | Ryu, Joo-Hyung | Choi, Jong-Kuk | Woo, Han Jun
This paper proposes and tests a method of producing macrobenthos habitat potential maps in Hwangdo tidal flat, Korea based on an artificial neural network. Samples of macrobenthos were collected during field work, and eight control factors were compiled as a spatial database from remotely sensed data and GIS analysis. The macrobenthos habitat potential maps were produced using an artificial neural network model. Macrobenthos habitat potential maps were made for Macrophthalmus dilatatus, Cerithideopsilla cingulata, and Armandia lanceolata. The maps were validated by compared with the surveyed habitat locations. A strong correlation between the potential maps and species locations was revealed. The validation result showed average accuracies of 74.9%, 78.32%, and 73.27% for M. dilatatus, C. cingulata, and A. lanceolata, respectively. A GIS-based artificial neural network model combined with remote sensing techniques is an effective tool for mapping the areas of macrobenthos habitat potential in tidal flats.
Show more [+] Less [-]Detection of verotoxin producing Escherichia coli in marine environments of the Caribbean Full text
2013
Walker, Trisha J. | Bachoon, D.S. | Otero, Ernesto | Ramsubhag, Adesh
The goal of this study was to determine the potential for Enterohemorrhagic Escherichia coli O157:H7 (EHEC) contamination in tropical marine waters. Samples were collected from urban, suburban, and rural sites around the islands of Puerto Rico and The Republic of Trinidad and Tobago. Quantification of E. coli and EHEC was evaluated using MI plates and qPCR. EHEC was detected in six sites in Puerto Rico: West of La Parguera Town, Boquilla, Oro Creek, Fishers Association, Joyuda Lagoon, and Boqueron Wetland Creek and in two rural sites in Trinidad: Balandra Bay and Quinam Bay. Plate count enumeration of E. coli was not a reliable indicator for the presence of EHEC. The sites where EHEC was detected on both islands are used for recreational bathing, water sports and recreational/commercial fisheries and therefore pose a public potential health risk.
Show more [+] Less [-]Bioavailability of heavy metals in water and sediments from a typical Mediterranean Bay (Málaga Bay, Region of Andalucía, Southern Spain) Full text
2013
Alonso Castillo, M.L. | Sánchez Trujillo, I. | Vereda Alonso, E. | García de Torres, A. | Cano Pavón, J.M.
Concentrations of heavy metals were measured in sediment and water from Málaga Bay (South Spain). In the later twentieth century, cities such as Málaga, have suffered the impact of mass summer tourism. The ancient industrial activities, and the actual urbanization and coastal development, recreation and tourism, wastewaters treatment facilities, have been sources of marine pollution. In sediments, Ni was the most disturbing metal because Ni concentrations exceeded the effects range low (ERL), concentration at which toxicity could start to be observed in 85% of the samples analyzed. The metal bioavailability decreased in the order: Cd>Ni>Pb>Cu>Cr. In the sea water samples, Cd and Pb were the most disturbing metals because they exceeded the continuous criteria concentration (CCC) of US EPA in a 22.5% and 10.0% of the samples, respectively. Statistical analyses (ANOVA, PCA, CA) were performed.
Show more [+] Less [-]Human impact on a small barrier reef meadow of Posidonia oceanica (L.) Delile on the north Tyrrhenian coast (Italy) Full text
2013
Mauro, Lenzi | Paola, Gennaro | Margherita, Volterrani | Rugiada, Roffilli | Francesca, Birardi | Primo, Micarelli | Duccio, Solari | Enrica, Franchi
The health status of an emerging Posidonia oceanica meadow, subject to high human impact, was studied. Biometric variables, heavy metals, PAHs and C, N, P contents were determined in sediment and seagrass samples. The meadow was found to grow under oligotrophic conditions and an increase in nutrient content was only recorded in autumn. In sediment, Hg exceeded its ERL (effects range low) and sometimes also its ERM (effects range medium), and Cu was close to its ERL. In leaves, Hg and Cu were relatively high but below their respective ERLs. Sediments close to the meadow were heavily contaminated with pyrolytic PAHs, some of which exceeded their ERLs. P. oceanica did not show major accumulation of PAHs, lighter molecules predominating. Despite 40years of intense human activity, meadow growth dynamics and contaminant accumulation did not suggest that the meadow was regressing.
Show more [+] Less [-]Sources and preservation of organic matter in soils of the wetlands in the Liaohe (Liao River) Delta, North China Full text
2013
Lin, Tian | Ye, Siyuan | Ma, Chuanliang | Ding, Xigui | Brix, Hans | Yuan, Hongming | Chen, Yingjun | Guo, Zhigang
Total organic carbon, total nitrogen, δ13Corg, δ15N, and aliphatic and polyaromatic hydrocarbons of fifty-five soil samples collected from the coastal wetlands of the Liaohe Delta were measured, in order to determine the sources and possible preservation of organic matter (OM). The δ15N and δ13Corg values in the samples ranged from 3.0‰ to 9.4‰ and from −30.4‰ to −20.3‰, respectively, implying that the OM in the soils is predominantly derived from C3 plant. The long-chain n-alkanes had a strong odd-over-even carbon number predominance, suggesting a significant contribution from waxes of higher plants. The ubiquitous presence of unresolved complex mixture, alkylated polycylic aromatic hydrocarbons and typical biomarkers of petroleum hydrocarbons (pristane, phytane, hopanes and steranes) indicates that there is a contribution of petroleum hydrocarbons to the organic carbon pool in the wetland soils. P. australis-vegetated wetlands have strong potentials for the preservation of organic carbon in the wetlands.
Show more [+] Less [-]Distribution and sources of polycyclic aromatic hydrocarbons in Cilician Basin shelf sediments (NE Mediterranean) Full text
2013
This study corresponds to preliminary work representing an initial assessment for spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in the Cilician Basin coastal sediments. The concentrations of PAHs in shelf sediments were determined from the three different regions of Cilician Basin (Eastern Mediterranean) in 2011. Concentrations of PAHs were low 5.43–271ngg−1 with respect to other coastal sediments in the Mediterranean and these results could be compared with concentrations found in open sea areas. PAH composed mainly of pyrolytic four and five-ring compounds. An abundance of high molecular weight PAHs indicated that atmospheric particles and urban aerosols are the major input route of hydrocarbons in the Cilician and Lattakia Basins. PAH levels were assessed in accordance with numerical Sediment Quality Guideline (SQG) of the USEPA. The results showed that no samples exceeded biological thresholds to pose biological impairments.
Show more [+] Less [-]Bacteria associated with sabellids (Polychaeta: Annelida) as a novel source of surface active compounds Full text
2013
(Emilio),
A total of 69 bacteria were isolated from crude oil enrichments of the polychaetes Megalomma claparedei, Sabella spallanzanii and Branchiomma luctuosum, and screened for biosurfactant (BS) production by conventional methods. Potential BS-producers (30 isolates) were primarily selected due to the production of both interesting spots on thin layer chromatography (TLC) plates and highly stable emulsions (E24⩾50%). Only few strains grew on cetyltrimethylammonium bromide and blood agar plates, indicating the probable production of anionic surfactants. The 16S rRNA gene sequencing revealed that selected isolates mainly belonged to the CFB group of Bacteroidetes, followed by Gammaproteobacteria and Alphaproteobacteria.A number of BS-producers belonged to genera (i.e., Cellulophaga, Cobetia, Cohaesibacter, Idiomarina, Pseudovibrio and Thalassospira) that have been never reported as able to produce BSs, even if they have been previously detected in hydrocarbon-enriched samples. Our results suggest that filter-feeding Polychaetes could represent a novel and yet unexplored source of biosurfactant-producing bacteria.
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