Concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs) in liver samples of different marine mammals (1984-2009)

Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus) and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20 years (1984-2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9-C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006.

Organic carbon and amino acid concentration of Karelian shungite rocks from the lake Onego area, Russia

The study of amino acids in the Precambrian shungite rocks of Karelia showed that their contents vary within 25-89 µg/g depending on proportions between shungite and mineral components. It was established that the amino acids exhibit an excess of L-enantiomers. In the shungite rocks, they form organomineral complexes with silica and aluminosilicates, being built in the globular structure of shungite matter. There are several sources of amino acids in shungites: secondary synthesis, microbial pollution, and original amino acids of organic matter in shungite rocks.

Humic acids in bottom sediments of the Western Pacific

Elemental composition, functional groups, and molecular mass distribution were determined in humic acids from the Western Pacific abyssal and coastal bottom sediments. Humic acid structure was studied by oxidative degradation with alkaline nitrobenzene and potassium permanganate, p-coumaric, guaiacilic, and syringilic structural units typical for lignin of terrestrial plants were identified in humic acids by chromatographic analysis of oxidation products. Polysubstituted and polycondensed aromatic systems with minor proportion of aliphatic structures were basic structural units of humic acids in abyssal sediments.

(Table T1) Amino acid ratios and concentrations in interstitial waters of seven ODP Leg 201 sites

Proteins and their amino acid building blocks form a major group of biomolecules in all organisms. In the sedimentary environment, proteins and amino acids have two sources: (1) soft tissues and detritus and (2) biotic skeletal structures, dominantly from calcium carbonate-secreting organisms. The focus of this report is on D/L ratios and concentrations of selected amino acids in interstitial waters collected during ODP Leg 201. The Peru margin sites are generally low in carbonates, whereas the open-ocean sites are more carbonate rich. Seifert et al. (1990, doi:10.2973/odp.proc.sr.112.152.1990) reported amino acid concentrations in interstitial waters from Site 681 (ODP Leg 112) comparable to Leg 201 Site 1229.

Geochemistry, fatty acid content and phylogenetic affiliation of soil samples from Livingston Island, South Shetland Archipelago, Antarctica

Microorganisms inhabit very different soil habitats in the ice-free areas of Antarctica, playing a major role in nutrient cycling in cold environments. We studied the soil characteristics and the dominant bacterial composition from nine different soil profiles located on Livingston Island (maritime Antarctica). The total carbon (TC) and total nitrogen (TN) values were high for the vegetated soils, decreasing with depth, whereas the values for the mineral soils were generally low. Soil pH was more acidic for moss-covered soils and neutral to alkaline for mineral soils. Numbers of culturable heterotrophic bacteria were higher at vegetated sites, but significant numbers were also detectable in carbon-depleted soils. Patterns of denaturing gradient gel electrophoresis (DGGE) revealed a highly heterogeneous picture throughout the soil profiles. Subsequent sequencing of DGGE bands revealed in total 252 sequences that could be assigned to 114 operational taxonomic units, showing the dominance of members of the Bacteroidetes and Acidobacteria. The results of phospholipid fatty acid analysis showed a lack of unsaturated fatty acids for most of the samples. Samples with a prevalence of unsaturated over saturated fatty acids were restricted to several surface samples. Statistical analysis showed that the dominant soil bacterial community composition is most affected by TC and TN contents and soil physical factors such as grain size and moisture, but not pH. Keywords

(Table 1) Organic acid analyses from Leg 135 interstitial waters

For the first time, short-chain organic acids are described in interstitial waters from sediments and lithified materials in a backarc setting. Organic acids in interstitial waters from the Tonga forearc region were also analyzed and compared with previous organic acid analyses from the Mariana and Bonin forearc interstitial waters. In the Tonga backarc setting, propionate typically dominates the organic acid assemblage, and organic acids are a consistent feature of these interstitial waters. The persistent presence of ammonia and the dominance of propionate over formate in the backarc interstitial waters suggest that the organic acids in this setting have their origin in reductive deamination of amino acids derived from sedimentary proteinaceous material. The organic acid assemblage revealed in the samples from Hole 841B in the Tonga forearc are similar to the organic acid assemblage detected in the Mariana forearc, that is, formate dominates the assemblage over acetate or propionate. These forearc organic acid assemblages may both have formed by a similar mechanism.

Bulk and amino acid parameters of core SO188-342KL from the Northern Bay of Bengal for the last 18 ka

The Northern Bay of Bengal (NBoB) is a globally important region for deep-sea organic matter (OM) deposition due to massive fluvial discharge from the Ganges-Brahmaputra-Meghna (G-B-M) rivers and moderate to high surface productivity. Previous studies have focused on carbon burial in turbiditic sediments of the Bengal Fan. However, little is known about the storage of carbon in pelagic and hemipelagic sediments of the Bay of Bengal over millennial time scales. This study presents a comprehensive history of OM origin and fate as well as a quantification of carbon sediment storage in the Eastern Bengal Slope (EBS) during the last 18 ka. Bulk organic proxies (TOC, TIC, TN, d13CTOC, d15NTN) and content and composition of total hydrolysable amino acids (THAA) in a sediment core (SO188-342KL) from the EBS were analyzed. Three periods of high OM accumulation were identified: the Late Glacial (LG), the Bölling/Alleröd (B/A), and the Early Holocene Climatic Optimum (EHCO). Lower eustatic sea level before 15 ka BP allowed a closer connection between the EBS and the fluvial debouch, favoring high terrestrial OM input to the core site. This connection was progressively lost between 15 and 7 ka BP as sea level rose to its present height and terrestrial OM input decreased considerably. Export and preservation of marine OM was stimulated during periods of summer monsoon intensification (B/A and EHCO) as a consequence of higher surface productivity enhanced by cyclonic-eddy nutrient pumping and fluvial nutrient delivery into the photic zone. Changes in the THAA composition indicate that the marine plankton community structure shifted from calcareous-dominated before 13 ka BP to siliceous-dominated afterwards. They also indicate that the relative proportion of marine versus terrestrial OM deposited at site 342KL was primarily driven by relative sea level and enlarged during the Holocene. The ballasting effect of lithogenic particles during periods of high coastal proximity and/or enhanced fluvial discharge promoted the export and preservation of OM. The high organic carbon accumulation rates in the EBS during the LG (18-17 ka BP) were 5-fold higher than at present and comparable to those of glacial upwelling areas. Despite the differences in sediment and OM transport and storage among the Western and Eastern sectors of the NBoB, this region remains important for global carbon sequestration during sea level low-stands. In addition, the summer monsoon was a key promotor of terrestrial and marine OM export to the deep-ocean, highlighting its relevance as regulator of the global carbon budget.