Analysis of multiple enteric viral targets as sewage markers in coral reefs

Water and coral mucus samples were collected from throughout the Florida Keys National Marine Sanctuary and the Dry Tortugas for three years and were analyzed for human enteric viruses (enteroviruses, noroviruses, hepatitis A virus and adenoviruses) as conservative markers of human sewage using molecular methods. Of the 100 coral and water samples collected, 40 contained genetic material from one or more human enteric viruses. DNA-based adenoviruses were detected widely, in 37.8% of samples and at 91% of stations, including ‘pristine’ reefs in the Dry Tortugas; however, the detection rate was 12% for the RNA-based enteroviruses and noroviruses (hepatitis A virus was never detected). The disparity between the prevalence of RNA- and DNA-based viruses suggests the need for additional work to determine the utility of adenovirus as marker of human sewage.     

Understanding the textures and origin of shock melt pockets in Martian meteorites from petrographic studies,comparisons with terrestrial mantle xenoliths,and experimental studies

Abstract— We present a textural comparison of localized shock melt pockets in Martian meteorites and glass pockets in terrestrial, mantle‐derived peridotites. Specific textures such as the development of sieve texture on spinel and pyroxene, and melt migration and reaction with the host rock are identical between these two apparently disparate sample sets. Based on petrographic and compositional observations it is concluded that void collapse/variable shock impedance is able to account for the occurrence of pre‐terrestrial sulfate‐bearing secondary minerals in the melts, high gas emplacement efficiencies, and S, Al, Ca, and Na enrichments and Fe and Mg depletion of shock melt compositions compared to the host rock; previously used as arguments against such a formation mechanism. Recent experimental studies of xenoliths are also reviewed to show how these data further our understanding of texture development and can be used to shed light on the petrogenesis of shock melts in Martian meteorites.     

Bottom sediment contamination in the Bay of Naples,Italy

The nearshore sediments in the Bay of Naples show a buildup of organic carbon and increased levels of lead, copper and chromium as a result of discharge of domestic and industrial waste water. Twenty to twenty-five square kilometres of bottom area have been contaminated by the buildup of anoxic muds with elevated heavy metal concentrations.     

Heavy metals in sediments from the Athens sewage outfall area

Sediments in the upper Saronikos Gulf have been contaminated by heavy metals from the discharge of untreated industrial and domestic wastewater from the area around Athens. Neutron activation analysis indicates concentrations of antimony, arsenic, chromium, gold, mercury, silver and zinc are 8–200 times greater than in the surrounding uncontaminated sediments. The bottom area affected by increased metal concentrations is at least 13 km² and indicates a nearly radial dispersal pattern from the main outfall with higher concentrations extending to the southeast and southwest.     

Flow Adjustments Across Sea-Surface Temperature Changes

The adjustment of airflow across sea-surface temperature changes is examinedusing aircraft eddy-correlation data. Major features of the observed flow adjustmentare not included in the theory of internal boundary layers. However, the data samplesize and coverage are not sufficient to accurately quantify the additional influences.With flow from warm water over cooler water, substantial turbulence intermittentlydevelops above the newly formed surface inversion layer. The corresponding,spatially-averaged, downward momentum flux is stronger than that close to the surface.With stably stratified flow over modest increases of sea-surface temperature, areduction of stratification can trigger episodic shear generation of turbulence. Inthese cases, the primary role of increasing surface temperature in the downwinddirection is to induce shear generation of turbulence. With larger increases ofsurface temperature, upward heat flux generates turbulence, warms the air and generates a significant horizontal gradient of hydrostatic pressure. This contributionto the pressure field appears to strongly modify the flow. Major inadequacies inexisting data and future needs are noted.     

Soil erosion and management recommendations at three State Vehicular Recreation areas,California

Off-road vehicle (ORV) impact on the landscape includes the destruction of protective vegetative cover, soil compaction, and increased runoff followed by increased erosion. An investigation of three State Vehicular Recreation Areas (SVRAs) in arid regions of California have documented 10-to 25-fold increases in sediment yield relative to nearby undisturbed basins. Soil texture and slope length are the dominant factors controlling soil erodibility in these areas. Organic carbon content of the soil exposed in hillclimb gullies was comparable to C horizon values of undisturbed soil profiles demonstrating a significant (70%) loss of soil fertility due to accelerated erosion. Soil erosion can be minimized and lifespan of these recreational areas prolonged by initiating and enforcing some critical management policies, including careful control over location and length of hillclimb, rotating use areas such that rehabilitation or revegetation is feasible, and seasonal use restrictions.     

Organic and inorganic matter in Louisiana coastal waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi regions

Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi River locations, in 2007-2008. The range of CDOM was 0.092 m⁻¹ at Barataria in June 2008 to 11.225 m⁻¹ at Mississippi in February 2008. An indicator of organic matter quality was predicted by the spectral slope of absorption coefficients from 350 to 412 nm which was between 0.0087 m⁻¹ at Mississippi in May 2008 and 0.0261 m⁻¹ at Barataria in June 2008. CDOM was the dominant component of light attenuation at Terrebonne and Barataria. Detritus and CDOM were the primary components of light attenuation at Vermilion, Atchafalaya, and Mississippi. DOC ranged between 65 and 1235 μM. PIM ranged between 1.1 and 426.3 mg L⁻¹ and POM was between 0.3 and 49.6 mg L⁻¹.     

Archaeol as a methanogen biomarker in ombrotrophic bogs

In order to develop new tools in the reconstruction of microbiological processes in ancient continental settings, we determined the concentration of archaeol and sn-2-hydroxyarchaeol in four Holocene ombrotrophic peatlands, spanning a range of European climate zones. Neither ether lipid was present in the aerobic acrotelm peat, consistent with an origin from anaerobic archaea, presumably methanogens. At the depth of the maximum seasonal water table, archaeol and sn-2-hydroxyarchaeol concentration markedly increased at all four sites, again consistent with an anaerobic source, but differed strongly among sites. The differences apparently reflect a combination of vegetation - ericaceous and graminoid plants as opposed to Sphagnum spp. and other mosses lacking root systems - and temperature influence on methanogenesis. In particular, low ether lipid concentrations in Finland probably reflect the lack of vascular vegetation possessing well-developed root systems, together with low mean annual temperature. Similarly low concentrations of archaeol and sn-2-hydroxyarchaeol in a German bog likely result from winter temperatures below 0 °C and a relatively shorter growing season. The occurrence of sn-2-hydroxyarchaeol is limited to a narrow and shallow depth range, indicating that it is poorly preserved, but archaeol persists throughout the cores. Decoupling the concentration of archaeol and the more labile sn-2-hydroxyarchaeol below ca. 50 cm suggests that the former records fossil biomass rather than living biomass. If so, then downcore variation in archaeol concentration likely reflects past changes in methane cycling, and archaeol, pending further developmental research, could serve as a new tool for reconstruction of past peatland biogeochemistry.     

Pyrolysis GC-MS as a rapid screening tool for determination of peat-forming plant composition in cores from ombrotrophic peat

Peat cores provide decadal to centennial records of climatic and environmental change, including evidence for human/environment interaction. Existing palaeoenvironmental proxies (macrofossils, pollen, humification, testate amoebae, lipid composition) require multiple laboratory preparation steps and may be subject to differential preservation that can limit production of a continuous time series. The potential for pyrolysis gas-chromatography-mass-spectrometry (Py-GC-MS) to be applied to bulk peat samples is investigated here. The only preparatory step required was freeze drying. Analysis of a range of important peat-forming plants demonstrates that Sphagnum moss species are unique in containing the pyrolysis product of sphagnum acid, 4-isopropenylphenol. In contrast, non-Sphagnum species are rich in lignin pyrolysis products, which are absent from Sphagnum. The presence of these pyrolysis markers is reflected in bulk peat composition and tested here using archives from Bolton Fell Moss and Butterburn Flow (UK), Kontolanrahka (Finland) and Bissendorfer Moor (Germany). A ratio between 4-isopropenylphenol and two lignin pyrolysis products is proposed as a proxy for total Sphagnum input to peat archives and shows potential for use as a rapid screening tool for characterising bulk peat composition before more intensive analysis.     

Mineralogy,microtexture, and composition of shock‐induced melt pockets in thi Los Angeles basaltic shergottite

Abstract— Analytical electron microscopy of shock features in the basaltic shergottite Los Angeles (stone 1) reveals: 1) shock recorded in the bulk sample; and 2) localized pressure and temperature excursions that have generated melt pockets up to 4 mm in diameter. Bulk shock effects include microfaulting (offsets 1–200 μm), mosaicism, deformed exsolution lamellae and planar fracturing in pyroxene, undulose extinction in whitlockite, mechanical twinning in titanomagnetite and ilmenite, and the transformation of plagioclase to maskelynite (≤4% remnant reduced birefringence). The pressure estimates for bulk shock are 35–40 GPa. Localized shock excursions have generated three types of discrete melt zones (0.07 times 1.3 mm to 3.0 times 3.5 mm apparent diameter) possessing glassy to microcrystalline groundmasses. These melt pockets are differentiated on the basis of size, clast volume, and degree of crystallization and vesiculation. Melt veins and melt dikelets emanate from the melt pockets up to 3 mm into the host rock but do not necessarily connect with other melt pockets. The melt pockets were generated by pressure‐temperature excursions of 60–80 GPa and 1600–2000°C, resulting in discrete melting of adjacent host rock minerals at grain boundary margins. Concentric zoning in the margins of clinopyroxenes coincides with a progressive reduction in birefringence as melt pockets are approached. This suggests that the shock excursions were focused as point sources in the wake of the shock front that induced bulk damage.