Accumulations of sediment beneath the Antarctic Ice Sheet contain a range of physical and chemical proxies with the potential to document changes in ice sheet history and to identify and characterize life in subglacial settings. Retrieving subglacial sediments and sediment cores presents several unique challenges to existing technologies. This paper briefly reviews the history of sediment sampl...

Bacterial abundance, production, and extracellular enzyme activity were determined in the shallow water column, in the epiphytic community of Thalassia testudinum, and at the sediment surface along with total carbon, nitrogen, and phosphorus in Florida Bay, a subtropical seagrass estuary. Data were statistically reduced by principle components analysis (PCA) and multidimensional scaling and rel...

Heavy metal contamination of aquatic environment has attracted global attention owing to its abundance, persistence, and environmental toxicity, especially in developing countries like Bangladesh. Five heavy metals, namely chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) were investigated in surface and core sediments of the Karnaphuli River (KR) estuary in Chittagong, Banglades...

A study was carried out on the occurrence of chitinolytic bacteria inhabiting surface water, water above the sediment and bottom sediments of lakes: Jeziorak, Jeziorak Maty and Tynwald. The greatest amounts of them were found in demersal water and in bottom sediment surface stratum. However, the percentage share of chitinolytic bacteria proved greater in deep water (9.35%) than in bottom sedime...

Coarse-textured surface horizons are common in highly weathered southeastern US coastal plain soils. These soils have historically been managed under conventional tillage practices, but conservation tillage management practices are increasing. Although clay (<2 �m) contents are low in these surface horizons (typically <100 g kg−1), the reactive nature of this fraction tends to play a dominant r...

The New Zealand cockle Austrovenus stutchburyi is often found stranded on the sediment surface due to infections by echinostome trematodes. High densities of heavily-infected cockles on the sediment surface a¡ect near-seabed hydrodynamics and sedimentation and, in turn, benthic animal community structure and diversity. In a six-month ¢eld experiment on an intertidal sand£at we manipulated the d...

Quantification of river bedform variability and complexity is important for sediment transport modeling as well as for characterization of river morphology. Alluvial bedforms are shown to exhibit highly nonlinear dynamics across a range of scales, affect local bed roughness, and vary with local hydraulic, hydrologic, and geomorphic properties. This paper examines sediment sorting on the crest a...

The transfer of Cryptosporidium oocysts from the surface water to the sediment beds of streams and rivers influences their migration in surface waters. We used controlled laboratory flume experiments to investigate the deposition of suspended Cryptosporidium parvum oocysts in streambeds. The experimental results demonstrate that hydrodynamic interactions between an overlying flow and a sediment...

Surface runoff and sediment transport in ̄uence soil quality and the quality of receiving waters. Simulation models are useful tools to describe drainage behavior and sediment yield to develop management strategies for agricultural waters. The objective of this study was to investigate the performance of the Agricultural Non-Point Source Pollution Model (AGNPS) and modi®ed versions comparing mea...

Using enriched stable (201)Hg injections into intact sediment cores, we provide the first reported Hg methylation potential rate constants (km) in prairie wetland ponds (0.016-0.17 d(-1)). Our km values were similar to other freshwater wetlands and did not differ in ponds categorized with high compared to low surface water concentrations of sulphate. Sites with high sulphate had higher proporti...