Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon (14C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14C dispersal and uptake dynamics. All east basin biota exhibited 14C enrichments above ambient background while most west basin biota had 14C activities close to background, although four organisms includ...

The sulfur cycle of Ebro Delta microbial mats was studied in order to determine sulfide production and sulfide consumption. Vertical distribution of two major functional groups involved in the sulfur cycle, anoxygenic phototrophic bacteria and dissimilatory sulfate-reducing bacteria (SRB), was also studied. The former reached up to 2.2x10(8) cfu cm(-3) sediment in the purple layer, and the latt...

The fluvial system is a major concern in modeling landform evolution in response to tectonic deformation. Three stream bed types (bedrock, coarse-bed alluvial, and fine-bed alluvial) differ in factors controlling their occurrence and evolution and in appropriate modeling approaches. Spatial and temporal transitions among bed types occur in response to changes in sediment characteristics and tec...

Polycyclic aromatic hydrocarbons (PAHs) were quantified in sediment, soil, and plant material from Hanoi, Vietnam, and an aquatic production system in peri-urban Hanoi. The sum of the concentration of 16 US-EPA priority PAHs ( summation PAH16) ranged between 0.44 and 6.21 mg kg(-1) dw in sediment and between 0.26 and 1.35 mg kg(-1) dw in soil, with decreasing concentrations from the urban area ...

A thorough knowledge of sedimentary processes that cause the production, transportation and deposition in varied hydrodynamic conditions, is most important in environmental reconstruction. Size analysis of sediment is an essential requirement to understand their mechanism of transportion and deposition. Textural parameters are primarily related to made of transportation and energy condition of ...

Wide spread damage due to floods is one of the very common water induced natural disasters in Nepal that account for heavy losses during the monsoon period every year. Perennial rivers that flow through Siwalik area transport heavy sediments loads than rivers located in other areas during rainy season due to very fragile geology of the Siwaliks. Investigating the sediment production and transpo...

The incomplete understanding of the processes which control aquatic nitrous oxide (N2O) production is partially due to a lack of onsite data with which to describe the temporal resolution of N2O production. To help resolve this, we directly measured the N2O saturation (relative to atmospheric partial pressure) on an hourly basis over two survey periods (July and September 2003) in Lake Taihu, a...