Distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea

Summary Data were collected in 1988 and 1989 on the distribution and activity of petroleum hydrocarbon degrading bacteria in the North Sea and Baltic Sea. Crude oil degrading bacteria and the number of bacteria which in particular degrade naphthalene were quantified using a modified dilution method (MPN). Crude oil degrading bacteria were present in all of about 100 water samples, with as many as 10³ ml^–1 in some samples. Numbers of naphthalene degrading bacteria were at least tenfold lower. There is obviously a greater connection between this bacteria group and petroleum hydrocarbon (PHC) contamination than between the more nonspecific group of crude oil degrading bacteria and PHC contamination. Data from the North Sea show an extremely high abundance of hydrocarbon degrading bacteria, even in winter, while in the southern Baltic Sea low numbers of bacteria were found and slower crude oil degradation was observed.

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Verteilung und Aktivität von erdölkohlenwasserstoffabbauenden Bakterien in Nord- und Ostsee

Zusammenfassung 1988 und 1989 wurden Daten über Verteilung und Aktivität von erdölkohlenwasserstoffabbauenden Bakterien in Nord- und Ostsee gesammelt. Rohölabbauende Bakterien und die Zahl von Bakterien, die insbesondere Naphthalen abbauen, wurden mit einer modifizierten Lösungsmethode (MPN) bestimmt. Rohölabbauende Bakterien wurden in allen ca. 100 Wasserproben nachgewiesen; in einigen Proben mit nicht weniger als 10³/ml. Die Zahl der naphthalenabbauenden Bakterien war mindestens um den Faktor 10 kleiner. Ein stärkerer Zusammenhang zwischen dieser Bakteriengruppe und der Belastung des Meerwassers durch Erdöl-Kohlenwasserstoffe als zwischen der eher unspezifischen Gruppe der rohölabbauenden Bakterien und dieser Belastung ist wahrscheinlich. Daten aus der Nordsee zeigen, selbst im Winter, eine sehr hohe Zahl von kohlenwasserstoffabbauenden Bakterien, während in der südlichen Ostsee eine niedrigere Anzahl von Bakterien bestimmt und ein langsamerer Rohölabbau beobachtet wurde.

     

Cytochrome P4501A expression,chemical contaminants and histopathology in roach,goby and sturgeon and chemical contaminants in sediments from the Caspian Sea,Lake Balkhash and the Ily River Delta,Kazakhstan

Roach, goby and sturgeon were examined for cytochrome P4501A (CYP1A) expression and histopathology, in relation to contaminant burdens in fish and sediment. Gradients of induction of CYP1A were observed. Roach from the Ural and Ily River Deltas and roach and goby from the two stations nearest the Caspian Sea oil fields displayed higher levels of CYP1A expression in several organs than was observed in fish from further offshore. Great sturgeon and Russian sturgeon showed higher levels of CYP1A expression than was seen in starred sturgeon and gobies in the Ural delta. No fish showed evidence of contaminant-related histopathologies in the organs examined, despite the elevated CYP1A levels. Low levels of polychlorinated biphenyls and elevated levels of inshore and riverine petroleum hydrocarbons from these habitats suggest that this ongoing hydrocarbon exposure, and that from natural sources and long-term oil exploration on the Northeastern Caspian shore, contributed to the CYP1A induction observed.     

Hydrogeochemical characteristics of spring water in the Harz Mountains,Germany

Spring water samples of the Harz Mountains were taken in several seasons of 2010, 2011, and 2012. The samples have been analysed for main components (Na⁺, K⁺, Ca²⁺, Mg²⁺, SO₄²⁻, Cl⁻, HCO₃⁻ and NO₃⁻), trace elements (Fe, Cu, Pb, Zn, Y and REE), DOC, δ¹⁸O and δ²H of water. Meteoric water is indicated as the main source of the springs sampled. High precipitation rates lead to a dilution of the measured elemental concentrations. Furthermore, regional differences of rock and water interactions were found. REE concentrations and patterns of the spring waters vary between the distinct geological units and reflect the geochemical characteristics of the surrounding rocks. The actual data compared to measured data from the seventies and nineties of the last century indicate a decrease of the sulphate concentrations in the spring waters which is typical of many European mountain catchments.     

Proposal for applying a component-based mixture approach for ecotoxicological assessment of fracturing fluids

Hydraulic fracturing is increasingly being used to produce gas from unconventional resource sites for energy supply. Therefore, concerns about risks of this technology related to human health and the environment have to be addressed. Among the major issues is the potential contamination of surrounding water systems by chemical additives used in fracturing fluids. In this study, the ecotoxicological hazards of fracturing fluids, both, their individual components (chemicals) as well as their mixtures (product) were assessed using a component-based mixture approach. For five exemplary fracturing fluids, 40–90 wt% of the contained substances could unambiguously be defined in their chemical identity. The concentrations used in the applied fluid mixture were considered as (maximum) exposure concentrations. For components with mass fractions between 10 and 74 wt%, the effect concentrations for acute and chronic toxicity of fish, daphnia and algae were retrieved from experimental databases and through predictive modeling. The hazard indices calculated from the ratio of exposure to effect concentration were >1 for all fracturing fluids, using different scenarios. This indicated a hazard from the undiluted fracturing fluids. The assessment framework presented in this study allows for dealing with data gaps and uncertainties in a tiered fashion and in particular accommodates for combined effects resulting from chemical mixtures. It might be employed for ecotoxicological risk assessment of products containing chemical mixtures and optimization of their environmental performance.     

Volatile (S,Cl and F) and fluid mobile trace element compositions in melt inclusions: implications for variable fluid sources across the Kamchatka arc

Volatile element, major and trace element compositions were measured in glass inclusions in olivine from samples across the Kamchatka arc. Glasses were analyzed in reheated melt inclusions by electron microprobe for major elements, S and Cl, trace elements and F were determined by SIMS. Volatile element–trace element ratios correlated with fluid-mobile elements (B, Li) suggesting successive changes and three distinct fluid compositions with increasing slab depth. The Eastern Volcanic arc Front (EVF) was dominated by fluid highly enriched in B, Cl and chalcophile elements and also LILE (U, Th, Ba, Pb), F, S and LREE (La, Ce). This arc-front fluid contributed less to magmas from the central volcanic zone and was not involved in back arc magmatism. The Central Kamchatka Depression (CKD) was dominated by a second fluid enriched in S and U, showing the highest S/K₂O and U/Th ratios. Additionally this fluid was unusually enriched in ⁸⁷Sr and ¹⁸O. In the back arc Sredinny Ridge (SR) a third fluid was observed, highly enriched in F, Li, and Be as well as LILE and LREE. We argue from the decoupling of B and Li that dehydration of different water-rich minerals at different depths explains the presence of different fluids across the Kamchatka arc. In the arc front, fluids were derived from amphibole and serpentine dehydration and probably were water-rich, low in silica and high in B, LILE, sulfur and chlorine. Large amounts of water produced high degrees of melting below the EVF and CKD. Fluids below the CKD were released at a depth between 100 and 200 km due to dehydration of lawsonite and phengite and probably were poorer in water and richer in silica. Fluids released at high pressure conditions below the back arc (SR) probably were much denser and dissolved significant amounts of silicate minerals, and potentially carried high amounts of LILE and HFSE. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Die Zustandswerte in der freien Atmosphäre bei Schauerniederschlägen

Zusammenfassung Radiosondenergebnisse von 1664 Aufstiegen der Monate Mai bis September 1949 bis 1953 in München-Riem werden hinsichtlich der Bildung von Gewittern und Schauern untersucht. Die Kondensationsfeuchtadiabate liegt an Gewittertagen höher als an Tagen ohne Gewitter; auch die 0°C-Grenze erscheint angehoben. Die Zahl der Tage ohne Niederschlag und die Zahl der Gewittertage steigt mit wachsender Mitteltemperatur in der freien Atmosphäre. Während die Zahl der Tage mit Hagelfällen in Bayern von der Temperatur kaum abhängig erscheint, nimmt das vom Hagel betroffene Gebiet mit zunehmender Temperatur bedeutend zu. Niederschläge und Gewittertätigkeit werden von der Verteilung des vertikalen Temperaturgradienten mit der Feuchtigkeit stark abhängig gefunden. Aus dieser Abhängigkeit wird eine als Labilitätsmaß geeignete Regel abgeleitet.

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Summary Results obtained by 1664 ascents of radiosondes during the months may till september 1949 to 1953 at Munich-Riem are evaluated with regard to the formation of thunderstorms and showers. On days with thunderstorms the moistadiabatic lies at a higher level than on days without; the 0°C-level appears to be lifted as well. The number of days without precipitation and the number of thunderstorm days increase with growing mean temperature in the free atmosphere. Whereas, in Bavaria, there is hardly any relation between the number of days with hail and temperature, the region covered by hail grows considerably in extent with increasing tmmperature. Precipitation and thunderstorm activity are found to be strongly dependent on the distribution of the vertical temperature gradient and humidity. From this dependence a rule is derived which may be used as a measure for instability.

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Résumé Etude de 1664 radiosondages des mois de mai à septembre 1949 à 1953 à München-Riem du point de vue de la formation des orages et des averses. L'adiabatique humide est plus élevée lors des jours d'orage qu'en l'absence de ceux-ci; l'isotherme de zéro degré semble aussi plus élevée. Le nombre de jours sans précipitations et celui des jours d'orage croissent avec la température moyenne dans l'atmosphère libre. Tandis qu'en Bavière le nombre de jours de grêle semble indépendant de la température, la surface des régions grêlées augmente nettement avec elle. Les précipitations et l'activité orageuse dêpendent fortement de la distribution du gradient vertical de température selon l'humidité; de cette dépendance on peut tirer une règle servant de critère de labilité.

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Mit 4 Textabbildungen.     

Basis for a streamflow forecasting system to Rincón del Bonete and Salto Grande (Uruguay)

This paper presents the basis for the design of streamflow prediction systems for the hydroelectric dams of Rincón del Bonete (Uruguay) and Salto Grande (Uruguay–Argentina). The prediction is made, independently, for each reservoir and each month of the year with two methodologies: data-driven statistical models and hybrid downscaling that includes atmospheric predictors. We determine a set of potential predictors and then fit linear models coupled with variable selection techniques, under the hypothesis of perfectly known predictors. The predictive skill of the schemes outperforms the climatological forecast throughout the year in both reservoirs (except August in Rincón del Bonete). This remains the case even when the forecast lead does not allow for the use of preceding flows as predictors. While in Rincón del Bonete it is not possible to distinguish a period of high predictability, in Salto Grande, there is a robust signal in March–May and October–December.     

Vodyanitskii mud volcano,Sorokin trough,Black Sea: Geological characterization and quantification of gas bubble streams

Vodyanitskii mud volcano is located at a depth of about 2070 m in the Sorokin Trough, Black sea. It is a 500-m wide and 20-m high cone surrounded by a depression, which is typical of many mud volcanoes in the Black Sea. 75 kHz sidescan sonar show different generations of mud flows that include mud breccia, authigenic carbonates, and gas hydrates that were sampled by gravity coring. The fluids that flow through or erupt with the mud are enriched in chloride (up to ∼650 mmol L⁻¹ at ∼150-cm sediment depth) suggesting a deep source, which is similar to the fluids of the close-by Dvurechenskii mud volcano. Direct observation with the remotely operated vehicle Quest revealed gas bubbles emanating at two distinct sites at the crest of the mud volcano, which confirms earlier observations of bubble-induced hydroacoustic anomalies in echosounder records. The sediments at the main bubble emission site show a thermal anomaly with temperatures at ∼60 cm sediment depth that were 0.9 °C warmer than the bottom water. Chemical and isotopic analyses of the emanated gas revealed that it consisted primarily of methane (99.8%) and was of microbial origin (δD-CH₄ = −170.8‰ (SMOW), δ¹³C-CH₄ = −61.0‰ (V-PDB), δ¹³C-C₂H₆ = −44.0‰ (V-PDB)). The gas flux was estimated using the video observations of the ROV. Assuming that the flux is constant with time, about 0.9 ± 0.5 × 10⁶ mol of methane is released every year. This value is of the same order-of-magnitude as reported fluxes of dissolved methane released with pore water at other mud volcanoes. This suggests that bubble emanation is a significant pathway transporting methane from the sediments into the water column.     

High resolution profiles of vertical particulate organic matter export off Cape Blanc,Mauritania: Degradation processes and ballasting effects

Vertical carbon fluxes between the surface and 2500 m depth were estimated from in situ profiles of particle size distributions and abundances me/asured off Cape Blanc (Mauritania) related to deep ocean sediment traps. Vertical mass fluxes off Cape Blanc were significantly higher than recent global estimates in the open ocean. The aggregates off Cape Blanc contained high amounts of ballast material due to the presence of coccoliths and fine-grained dust from the Sahara desert, leading to a dominance of small and fast-settling aggregates. The largest changes in vertical fluxes were observed in the surface waters (<250 m), and, thus, showing this site to be the most important zone for aggregate formation and degradation. The degradation length scale (L), i.e. the fractional degradation of aggregates per meter settled, was estimated from vertical fluxes derived from the particle size distribution through the water column. This was compared with fractional remineralization rate of aggregates per meter settled derived from direct ship-board measurements of sinking velocity and small-scale O₂ fluxes to aggregates measured by micro-sensors. Microbial respiration by attached bacteria alone could not explain the degradation of organic matter in the upper ocean. Instead, flux feeding from zooplankton organisms was indicated as the dominant degradation process of aggregated carbon in the surface ocean. Below the surface ocean, microbes became more important for the degradation as zooplankton was rare at these depths.