Sediment cores collected from eight lakes along the western coast of Svalbard as part of a project investigating atmospheric pollution and environmental change in Arctic regions were dated radiometrically using natural (Pb) and artificial (Cs and Am) fallout radionuclides. At four sites the sedimentation rates were relatively uniform, and in consequence the Pb dates were relatively unambiguous....

This is a preliminary report on total mercury (THg) in core sediments (\63 lm particle size) of Sunderban mangrove wetland, northeastern part of the Bay of Bengal, India. Cold vapor atomic absorption spectrometry (CVAAS) was used for THg determination. The concentration varies from 9.8 to 535.1 ppb (ngg). Results revealed variations over premonsoon and postmonsoon month at different core depth,...

In order to determine the contribution of aquatic macrophyte communities on nutrition to sustain the high primary productivity of an estuary aquatic community, we analyzed the process of phosphorus release from sediments in aquatic macrophyte community in the estuary of the Chikugogawa River, South-Western Japan. Vertical profile of 4 PO  concentration and redox potential (Eh) of pore water in...

[1] There is increasing evidence indicating that syndepositional redistribution of sediment on the seafloor by bottom currents is common and can significantly affect sediment mass accumulation rates. Notwithstanding its common incidence, this process (generally referred to as sediment focusing) is often difficult to recognize. If redistribution is near synchronous to deposition, the stratigraph...

This paper reports the metals content in water, sediment, macroalgae, aquatic plant, and fish of Batang Ai Hydroelectric Reservoir in Sarawak, Malaysia. The samples were acid digested and subjected to atomic absorption spectrometry analysis for Na, K, Mn, Cr, Ni, Zn, Mg, Fe, Sn, Al, Ca, As, Se, and Hg. The total Hg content was analysed on the mercury analyser. Results showed that metals in wate...

Reduced streamflow via flow diversion has the potential to limit the sediment-transport capacity of downstream channels and lead to accumulation of fine sediments and habitat degradation. To investigate, we examined the effects of variable levels of flow diversion on fine-sediment deposition, hydraulic conditions and geomorphic alteration. Our study consisted of a detailed field analysis pairin...

Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered the initial morphology of the basin. As part of the Deschutes River Estuary Restoration Feasibility Study, the United States Geological Survey (USGS) is modeling how tidal and storm processes will influence the river, lake and lower Budd Inlet should estuary restoration occur. Understand...

OBJECTIVES The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. METHODS Metals like cadmium (Cd), copper (Cu),...

this study reports the concentrations of important tracers of the marine environment, 210po and210pb, in different matrices from field samples collected at central adriatic sea (italy), a non-contaminatedmarine ecosystem. 210po concentration appears to decrease with increasing distance from the coast and asignificant difference in 210po concentrations in seawater samples at two different depths...

Hiatuses pervade the stratigraphic record at all scales from grain boundaries to inter-regional unconformities. Every attempt to measure a rate of accumulation must average together sediment increments and surfaces of hiatus. As the time span of measurement lengthens, longer hiatuses tend to be incorporated into the estimated rate. Consequently, short term rates are systematically faster than l...