Total Hg distributions have been measured for seven sediment cores collected from the major basins of the Arctic Ocean during the Arctic Ocean Section in 1994. Hg determinations were perfomed on the top 10 cm of the sectioned cores using gold amalgamation atomic fluorescence spectroscopy. In five cores, Hg concentrations decrease downward from 34 to 116 ng g-1 at the sediment surface to 10-65 n...

To better understand the past and present impact of contaminants of emerging concern (CECs) in coastal and marine ecosystems, archived samples were analyzed for a broad suite of analytes, including pharmaceuticals and personal care products (PPCPs), flame retardants (including PBDEs), perfluorinated compounds (PFCs), and current-use pesticides. Surface sediment, mussels (Mytilus spp.) and sedim...

the caspian sea as the biggest surrounded water body (lake) in the world is bordered by the states of azerbaijan, russia, iran, kazakhstan and turkmenistan. urban development in addition to the increase of industrial and oil production activities (oil refinery and petrochemical plants) in the northern and eastern regions of caspian sea in recent years have caused entrance of high amount of oily...

A microbiological study was conducted in the area north and northeast of Svalbard, Arctic Ocean. Samples were taken in surface microlayers, ice, water column (down to 300 m) and sediment (maximum depth 3920 m). ATP-content in the upper 100 m was between 8 and 80 ng I-'; total bacterial numbers varied between 0.4 and 4.4 105 ml-l. Ice-samples contained high amounts of ATP (max. 120 ng I-'). Bact...

Sedimentary phosphorus sPd composition was investigated in Effingham Inlet, a fjord located on the west coast of Vancouver Island in Barkley Sound. Solid-state P nuclear magnetic resonance sNMRd spectroscopy was applied to demineralized sediment samples from sites overlain by oxic and anoxic bottom waters. The two sites were similar in terms of key diagenetic parameters, including the mass accu...

Marine surface sediments, which are replete with sulfate, are typically considered to be devoid of endogenous methanogenesis. Yet, methanogenic archaea are present in those sediments, suggesting a potential for methanogenesis. We used an isotope dilution method based on sediment bag incubation and spiking with 13C-CH4 to quantify CH4 turnover rates in sediment from Aarhus Bay, Denmark. In two i...

Sedimentary rocks are the archives of environmental conditions and ancient planetary surface processes that led to their formation. Reconstructions of Earth's past surface behaviour from the physical sedimentary record remain controversial, however, in part because we lack a quantitative framework to deconvolve internal dynamics of sediment-transport systems from environmental signal preservati...

A suite of 36 surface sediment samples, taken between 10 and 100 m water depth in Mejillones Bay (Northern Chile), were analyzed for mineralogy, grain size, total organic carbon, Al, and heavy metal content (Cd, Zn, Ni, Mn, V, Mo). Quartz and feldspars were the main lithogenic minerals and carbonate the predominant biogenic mineral. Sediments were fine sands in the shallow zone and organic silt...

Spawning synchrony represents a common reproductive strategy in sessile marine organisms and for broadcast spawning corals, buoyancy of egg-sperm bundles is critical to maximise fertilisation at the ocean surface. Here we demonstrate a novel threat to coral reproduction whereby buoyant egg-sperm bundles intercept and are "ballasted" by sediment grains on their journey to the ocean surface, prev...

In mangrove ecosystems, litter fall accumulates as refractory organic carbon on the sediment surface and creates anoxic sediment layers. Fiddler crabs, through their burrowing activity, translocate oxygen into the anoxic layers and promote aerobic respiration, iron reduction and nitrification. In this study, the effects of four species of fiddler crabs (Uca triangularis, Uca rosea, Uca forcipat...