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Liebezeit G.,Institute for Chemistry and Biology of the Marine Environment | Liebezeit E.,MarChemConsult
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment | Year: 2013

A total of 19 honey samples, mostly from Germany but also from France, Italy, Spain and Mexico, were analysed for non-pollen particulates. Only coloured fibres and fragments were quantified. Transparent fibres, considered to be cellulosic because they could be stained with fuchsin, were not quantified. Coloured material was found in all the samples investigated. Fibre counts ranged from 40/kg to 660/kg of honey, with a mean value of 166 ± 147/kg of honey, whereas fragments were considerably less abundant (0-38/kg of honey; mean 9 ± 9/kg of honey). Sources are tentatively identified as environmental, that is particles having been transported by the bees into the hive, or having been introduced during honey processing or both. In addition, five commercial sugars were analysed. In all the refined samples, transparent and coloured fibres (mean 217 ± 123/kg of sugar) and fragments (32 ± 7/kg of sugar) were found. Unrefined cane sugar had 560 fibres and 540 fragments per kilogram of honey. In addition, in both honey and sugar samples, granular non-pollen material was observed. © 2013 Taylor & Francis.

Williams T.,Lamont Doherty Earth Observatory | Morin R.H.,U.S. Geological Survey | Jarrard R.D.,University of Utah | Jackolski C.L.,Northern Illinois University | And 6 more authors.
Geosphere | Year: 2012

The ANDRILL (Antarctic Drilling Project) McMurdo Ice Shelf (MIS) project drilled 1285 m of sediment in Hole AND-1B, representing the past 12 m.y. of glacial history. Downhole geophysical logs were acquired to a depth of 1018 mbsf (meters below seafl oor), and are complementary to data acquired from the core. The natural gamma radiation (NGR) and magnetic susceptibility logs are particularly useful for understanding lithological and paleoenvironmental change at ANDRILL McMurdo Ice Shelf Hole AND-1B. NGR logs cover the entire interval from the seafl oor to 1018 mbsf, and magnetic susceptibility and other logs covered the open hole intervals between 692 and 1018 and 237-342 mbsf. In the upper part of AND-1B, clear alternations between low and high NGR values distinguish between diatomite (lacking minerals containing naturally radioactive K, U, and Th) and diamictite (containing K-bearing clays, K-feldspar, mica, and heavy minerals). In the lower open hole logged section, NGR and magnetic susceptibility can also distinguish claystones (rich in K-bearing clay minerals, relatively low in magnetite) and diamictites (relatively high in magnetite). Sandstones can be distinguished by their high resistivity values in AND-1B. On the basis of these three downhole logs, diamictite, claystones, and sandstones can be predicted correctly for 74% of the 692-1018 mbsf interval. The logs were then used to predict facies for the 6% of this interval that was unrecovered by coring. Given the understanding of the physical property characteristics of different facies, it is also possible to identify subtle changes in lithology from the physical properties and help refi ne parts of the lithostratigraphy, for example, the varying terrigenous content of diatomites and the transitions from subice diamictite to openwater diatomite. © 2012 Geological Society of America.

Nomura D.,Norwegian Polar Institute | Nomura D.,Japan Society for the Promotion of Science | Nomura D.,Hokkaido University | Assmy P.,Norwegian Polar Institute | And 7 more authors.
Annals of Glaciology | Year: 2013

We identified ikaite crystals (CaCO3·6H2O) and examined their shape and size distribution in first-year Arctic pack ice, overlying snow and slush layers during the spring melt onset north of Svalbard. Additional measurements of total alkalinity (TA) were made for melted snow and sea-ice samples. Ikaite crystals were mainly found in the bottom of the snowpack, in slush and the surface layers of the sea ice where the temperature was generally lower and salinity higher than in the ice below. Image analysis showed that ikaite crystals were characterized by a roughly elliptical shape and a maximum caliper diameter of 201.0±115.9 μm (n = 918). Since the ice-melting season had already started, ikaite crystals may already have begun to dissolve, which might explain the lack of a relationship between ikaite crystal size and sea-ice parameters (temperature, salinity, and thickness of snow and ice). Comparisons of salinity and TA profiles for melted ice samples suggest that the precipitation/dissolution of ikaite crystals occurred at the top of the sea ice and the bottom of the snowpack during ice formation/ melting processes.

Jin H.,Institute for Chemistry and Biology of the Marine Environment | Liebezeit G.,Institute for Chemistry and Biology of the Marine Environment | Ziehe D.,Johann Heinrich Von Thunen Institute
Bulletin of Environmental Contamination and Toxicology | Year: 2012

A total of 114 surface sediment samples was equidistantly collected in the western part of the Jade Bay, southern North Sea, to analyse total mercury contents as well as grain size distribution and total organic carbon (TOC) contents. Total mercury was determined by oxygen combustion-gold amalgamation. Validation, precision and accuracy of the method were evaluated and controlled with two certified reference materials (HISS-1 and MESS-3). Total mercury contents varied between 8 and 243 ng/g dry sediment with a mean value of 103 ng/g dw. The mercury levels in surface sediments showed an inhomogeneous spatial distribution with higher contents in near-dike areas. The values are mostly in the range of natural background values (50-100 ng/g dw) and positively related to TOC and clay/silt contents (\63 lm). The present total mercury contents are compared to those of previous studies, in order to estimate possible temporal trends of mercury contents in the study area over the last decades. Moreover, the comparison to sediment quality guidelines indicated that the surface sediments of the Jade Bay are not mercury contaminated. These results also suggested that the current mercury contents of Jade Bay surficial sediments are mostly affected by atmospheric deposition and re-emission. © Springer Science+Business Media, LLC 2012.

PubMed | Lawrence Berkeley National Laboratory, Los Alamos National Laboratory, U.S. Department of Energy, Leibniz Institute DSMZ German Collection of Microorganisms and Cell Cultures and 2 more.
Type: Journal Article | Journal: Standards in genomic sciences | Year: 2014

Phaeobacter arcticus Zhang et al. 2008 belongs to the marine Roseobacter clade whose members are phylogenetically and physiologically diverse. In contrast to the type species of this genus, Phaeobacter gallaeciensis, which is well characterized, relatively little is known about the characteristics of P. arcticus. Here, we describe the features of this organism including the annotated high-quality draft genome sequence and highlight some particular traits. The 5,049,232 bp long genome with its 4,828 protein-coding and 81 RNA genes consists of one chromosome and five extrachromosomal elements. Prophage sequences identified via PHAST constitute nearly 5% of the bacterial chromosome and included a potential Mu-like phage as well as a gene-transfer agent (GTA). In addition, the genome of strain DSM 23566(T) encodes all of the genes necessary for assimilatory nitrate reduction. Phylogenetic analysis and intergenomic distances indicate that the classification of the species might need to be reconsidered.

Hieronymi M.,Leibniz Institute of Marine Science | Hieronymi M.,Leibniz Institute for Tropospheric Research | MacKe A.,Leibniz Institute for Tropospheric Research | Zielinski O.,Institute for Chemistry and Biology of the Marine Environment
Ocean Science | Year: 2012

A Monte Carlo based radiative transfer model has been developed for calculating the availability of solar radiation within the top 100 m of the ocean. The model is optimized for simulations of spatial high resolution downwelling irradiance i E d fluctuations that arise from the lensing effect of waves at the water surface. In a first step the accuracy of simulation results has been verified by measurements of the oceanic underwater light field and through intercomparison with an established radiative transfer model. Secondly the potential depth-impact of nonlinear shaped single waves, from capillary to swell waves, is assessed by considering the most favorable conditions for light focusing, i.e. monochromatic light at 490 nm, very clear oceanic water with a low chlorophyll i a content of 0.1 mg m-3 and high sun elevation. Finally light fields below irregular wave profiles accounting for realistic sea states were simulated. Our simulation results suggest that under open ocean conditions light flashes with 50% irradiance enhancements can appear down to 35 m depth, and light variability in the range of ±10% compared to the mean i E d is still possible in 100 m depth. © 2013 Author(s).

Liebezeit G.,Institute for Chemistry and Biology of the Marine Environment | Wostmann R.,Institute for Chemistry and Biology of the Marine Environment | Ziehe D.,Institute for Chemistry and Biology of the Marine Environment
Asian Journal of Water, Environment and Pollution | Year: 2014

A total of 33 plant species and 122 surface sediments were obtained from March 2004 to November 2008 in the Siak River system including its major tributaries and coastal areas. Grain size distribution shows the sediments to be sands to silt with a general trend of coarser sediments in the upper reaches and fi ner ones in the estuary. The expected linear relationship between the content of organic carbon and the mud fraction of the sediments (<63 μm) is distorted by input of (a) clay-sized, organic-poor material from river bank erosion and (b) input of coarse plant detritus. All samples were analysed for n-alkanes and steroids. For all plant samples and a limited number of sediment samples, fatty acids were also determined. The data indicate a variety of organic carbon sources, the dominant one being river bank vegetation. Urban and industrial discharges, peat erosion and atmospheric deposition of black carbon and biomarkers might also play a role in controlling the lipid composition of the sedimentary organic carbon pool.

Jin H.,Institute for Chemistry and Biology of the Marine Environment | Liebezeit G.,Institute for Chemistry and Biology of the Marine Environment
Journal of Soils and Sediments | Year: 2013

Purpose: Sediment cores provide a reliable record of mercury (Hg) contamination and can be used to study long-term Hg pollution and relevant environmental change. In the last hundred years, there were several events which may have contributed to the accumulation of Hg in Jade Bay and its catchment. This work was undertaken to assess the record in total Hg (THg) content in sediments of cores from Jade Bay and its catchment. Materials and methods: A 5-m sediment core from Jade Bay, Lower Saxonian Wadden Sea, southern North Sea and a 12-m core from its catchment area (Wangerland, coastal zone of the Jade Bay) were used to study Hg contents in sediments. Total Hg, grain size distribution, aluminium (Al) and total organic carbon (TOC) were analysed on subsamples of both sediment cores. Total Hg was determined by oxygen combustion-gold amalgamation using DMA-80. Results and discussion: As THg contents of the Jade Bay core were positively correlated to the sum of TOC and Al contents (r2 = 0. 86, p & 0. 001), the Hg data were interpreted using a regional normalisation function with the sum of Al and TOC as the normalisation parameters. Total Hg contents of the Wangerland core were correlated better to Al contents (r2 = 0. 70, p & 0. 001) than to the sum of TOC and Al contents (r2 = 0. 63, p & 0. 05). Therefore, Hg contents in sediments of the Wangerland core were normalised to Al contents. Comparison between enrichment factors and the background range of the sediment cores suggested that Jade Bay was contaminated about 50 years ago, and that Wangerland, or the catchment area of Jade Bay, was contaminated about 300 years ago, if no diagenetic remobilization occurred. Conclusions: Total Hg contents of both cores were low and of no concern to the aquatic environment of Jade Bay. The Hg record was in good agreement with the history of industrial development in the region; thus, Hg deposition could have occurred through atmospheric input, ammunition residues of the Second World War and volcanic emanations, as well as through diagenetic remobilization. © 2012 Springer-Verlag Berlin Heidelberg.

Jin H.,Institute for Chemistry and Biology of the Marine Environment | Liebezeit G.,Institute for Chemistry and Biology of the Marine Environment
Bulletin of Environmental Contamination and Toxicology | Year: 2013

In this study, we evaluate the nature of the relationship between particulate matter and total mercury concentrations. For this purpose, we estimate both of the two values in water column over 12-h tidal cycles of the Jade Bay, southern North Sea. Total particulate mercury in 250 mL water samples was determined by oxygen combustion-gold amalgamation. Mercury contents varied from 63 to 259 ng/g suspended particulate matter (SPM) or 3.5-52.8 ng/L in surface waters. Total particulate mercury content (THgp) was positively correlated with (SPM), indicating that mercury in tidal waters is mostly associated with (SPM), and that tidal variations of total particulate mercury are mainly due to changes in (SPM) content throughout the tidal cycle. Maximum values for THgp were observed during mid-flood and mid-ebb, while the lowest values were determined at low tide and high tide. These data suggest that there are no mercury point sources in the Jade Bay. Moreover, the THgp content at low tide and high tide were significantly lower than the values recorded in the bottom sediment of the sampling site (>200 ng/g DW), while THgp content during the mid-flood and mid-ebb were comparable to the THg content in the surface bottom sediments. Therefore, changes in THgp content in the water column due to tidal forcing may have resulted from re-suspension of underlying surface sediments with relatively high mercury content. © 2012 Springer Science+Business Media New York.

Scholz B.,Institute for Chemistry and Biology of the Marine Environment | Liebezeit G.,Institute for Chemistry and Biology of the Marine Environment
Harmful Algae | Year: 2012

Several monitoring events in different freshwater, brackish water and marine habitats were conducted in the years 2004-2011. In some cases, mass occurrences of potential toxic species were accompanied by other species. While the antibacterial toxicity tests (LUMIStox) of samples showed the highest values, the producing taxa were not identified, although the bloom-forming species were in the majority. Under the acceptance that the accompanying taxa could be the source of the observed toxicity, we have tested 21 freshwater, 25 marine and 17 brackish water isolates for potential allelochemical production (e.g. alkaloids, flavonoids) and allelopathic activities (e.g. algicidal, antimicrobial). Most isolates accumulated potential phytochemical compounds in their biomass. Only polyunsaturated fatty acids, terpenes and sterols were found in supernatant extracts, but aldehydes, flavonoids, alkaloids and phenols were detected in biomass extracts. Of the bioassays employed in this study, the acetylcholinesterase inhibition test was the most responsive to the extracts, whereas the invertebrate lethality assay using Artemia salina was least sensitive. Standard tests for alkaloids, flavonoids, phenols including tannins and saponins indicate that bioactivities were not necessarily related to the presence of these compound classes. This indicates that other compound classes such as peptides/proteins or polysaccharides need also to be taken into consideration. These findings may have important consequences not only for ecological research but also for biotechnological applications. © 2012 Elsevier B.V.

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