Synthetic particles as contaminants in German beers.

A total of 24 German beer brands was analysed for the contents of microplastic fibres, fragments and granular material. In all cases contamination was found. Counts ranged from 2 to 79 fibres L(-1), from 12 to 109 fragments L(-1) and from 2 to 66 granules L(-1). The results show a high variability between individual samples and samples from different production dates. Possible sources of this contamination with foreign materials are discussed.

Non-pollen particulates in honey and sugar.

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.

Tidal cycles of total particulate mercury in the Jade Bay, lower Saxonian Wadden Sea, southern North Sea.

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 (THg(p)) 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 THg(p) 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 THg(p) 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 THg(p) content during the mid-flood and mid-ebb were comparable to the THg content in the surface bottom sediments. Therefore, changes in THg(p) content in the water column due to tidal forcing may have resulted from re-suspension of underlying surface sediments with relatively high mercury content.

Microplastics in beaches of the East Frisian islands Spiekeroog and Kachelotplate.

Microplastic particles were quantified in beach transects of the East Frisian islands Spiekeroog and Kachelotplate and in two samples from a tidal flat. Both granules and fibres were present while fragments and polystyrene pellets were completely absent. On the Kachelotplate the highest number of granules (496/10 g sediment) was observed at the high water line while on Spiekeroog a sample from the dune area had the highest value (38/10 g sediment). The tidal flat samples hat 36 and 136 granules/10 g sediment with the higher number being associated with a blue mussel bank. Fibres were more homogeneously distributed and did not show any particular enrichment. In comparison with data from the Belgian coast the total numbers are higher which might be related to the exposure situation of the island beaches.

Distribution of total mercury in surface sediments of the western Jade Bay, Lower Saxonian Wadden Sea, southern North Sea.

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 (50­100 ng/g dw) and positively related to TOC and clay/silt contents (<63 µm). 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.

Coprostanol in Siak River sediments, E Sumatra, Indonesia.

To follow faecal pollution steroid compounds have been analysed in 106 sediment samples from the Siak River, E Sumatra, Indonesia. Coprostanol was detected in 40 of these. Contents ranged from 50 to 10,530 ng/g d.w. with a mean of 878 (TOC-normalised: range 7.4-393.0, mean 44.1 µg/g TOC). Total contents and the coprostanol/cholesterol ratio argue for a major contribution from untreated sewage which is also evident from field observations. The distribution along the river indicates the quantitatively dominant source to be the city of Pekanbaru with an estimated population of 1.5 million. Coprostanol contents decrease downstream indicating ongoing degradation either during transport or in the surface sediment. However, additional sources of coprostanol become evident further downstream. On the other hand, the 5ß/(5ß + 5α)-cholestan-3ß-ol ratio versus cholesterol and a ternary plot using C27 sterols suggest that plant sources also contribute to the sedimentary coprostanol due to its formation by bacteria in suboxic/anoxic sediments.

Organochlorine compounds in blue mussels, Mytilus edulis, and Pacific oysters, Crassostrea gigas, from seven sites in the Lower Saxonian Wadden Sea, Southern North Sea.

Blue mussels (Mytilus edulis) and Pacific oysters (Crassostrea gigas) collected at seven locations in the Lower Saxonian Wadden Sea in January and February 2007 were analysed for organochlorine compounds. Contaminants were present in all samples, albeit with variable amounts and composition. The highest values were found in the Jade Bay. Congener PCB 153 was the contaminant which had the highest content of all organochlorines tested (475.75-937.39 ng/g lipid). DDT was detected in one sample only while DDD and DDE were found in all samples, the latter with contents up to 351.34 ng/g lipid. No clear differentiation could be made in terms of accumulation of organochlorines for M. edulis and C. gigas. Comparison with data from 2001 to 2006 showed an increase in 2007, which may be due to the different season the samples were taken.

n-alkanes as indicators of natural and anthropogenic organic matter sources in the Siak River and its estuary, E Sumatra, Indonesia.

Along the Siak River and its estuary a total of 100 sediment and 57 plant samples were taken for the analysis of n-alkanes from 2003 to 2005. Sediment n-alkanes exhibit in the majority of samples a pronounced odd over even predominance with maxima at C29 and C31 indicative of a plant origin. Plant n-alkanes analysed have chain lengths up to C39. These compounds are also present in the river sediments. In some plants the Carbon Preference Index (CPI) has extremely low values normally only found in petroleum-contaminated samples. A distinction between vegetation- and petroleum-derived n-alkanes is therefore only possible by a combination of CPI and and the absence/presence of a prominent unresolved complex mixture. Based on these criteria only a limited number of the 100 sediments analysed exhibit clear indications of a petroleum contamination.

Aquaculture of "non-food organisms" for natural substance production.

Marine invertebrates are already sources of commercially important secondary metabolites and may become even more so as knowledge on marine natural products and chemical ecology develops. Among the producers of these compounds predominantly sponges, bryozoa and molluscs have received the attention of academic and industrial research and development. For all these invertebrate groups culture techniques have been developed encompassing in situ, laboratory and cell culture approaches for the production of natural products. Potential applications of these are not restricted to pharmaceuticals but include marine cements, biominerals and antifouling compounds. In addition, markets exist for ornamental species. All culture approaches require sound ecological knowledge about the organisms to be cultured and possible symbiotic interactions between host invertebrates and microheterotrophs.

Chemical characterisation of three haemolytic compounds from the microalgal species Fibrocapsa japonica (Raphidophyceae).

The molecular structures of the three main haemolytic compounds (Fj1, Fj2 and Fj3) isolated from the ichthyotoxic microalgal species Fibrocapsa japonica have been investigated by NMR, LC-ESI-MS, ESI-MS-MS, IR, GC-MS and GC-HRMS methods. They are polyunsaturated fatty acids which we identified as: 6,9,12,15-octadecatetraenoic acid (OTA, C18:4omega3), 5,8,11,14,17-eicosapentaenoic acid (EPA, C20:5omega3) and 5,8,11,14-eicosatetraenoic acid (arachidonic acid AA, C20:4omega6). The identity of the latter two was confirmed on the basis of commercial standards (C20:5omega3 and C20:4omega6). Both displayed the same spectroscopic and chromatographic characteristics as Fj2 and Fj3 and had a similar strong haemolytic effect. We propose that when F. japonica cells accumulate in fish gills during blooms these compounds could be the cause of icthyotoxicity.

Efficiency of blue mussel (Mytilus edulis) spat collectors in highly dynamic tidal environments of the Lower Saxonian coast (southern North Sea).

Traditional mussel culture in the Wadden Sea, southern North Sea, is carried out by taking seed mussels of about 1-4 cm shell length from natural beds and transplanting them to permanently water covered sites. Besides the damage done to the natural beds, the ratio of seeded to harvested mussels is only about 1:1-1.3, i.e. about the same tonnage of mussels seeded is recovered. In addition, this technique relies exclusively on natural spat falls, which do not occur regularly. In order to overcome these difficulties spat collectors have been deployed in the Jade Bay, southern North Sea. These provided suitable settlement grounds for mussel larvae. Blue mussel weights reached weights of about 8-9 kg/m collector rope with maximum shell lengths of 4-5 cm within one growing season.