Twenty-eight sediment samples collected from Osaka Bay, Japan, were analyzed for phospholipid ester-linked fatty acids (PLFA) to determine regional differences in microbial community structure of the bay. The abundance of three major groups of C(10) to C(19) PLFA (saturated, branched, and monounsaturated PLFA), which accounted for 84 to 97% of the total PLFA, indicated the predominance of proka...

Twenty-eight coupled observations of flow, transport, and bed surface grain size distribution were made in a laboratory flume using a wide range of flows and a sediment with a very poorly sorted, bimodal grain size distribution. These observations permit the transport rates of individual size fractions to be scaled by the proportion of each size immediately available for transport on the bed su...

Although environmental DNA (eDNA) has been used to infer the presence of rare aquatic species, many facets of this technique remain unresolved. In particular, the relationship between eDNA and fish distribution is not known. We examined the relationship between the distribution of fish and their eDNA (detection rate and concentration) in a lake. A quantitative PCR (qPCR) assay for a region with...

Parts of the sandy littoral sediment of a Precambrian shield lake (Lake 302s) were intermittently covered with a layer of flocculent organic-rich material l-20 mm thick. Sandy sediments with flocculent surface sediment had higher rates of respiration (31-105%) and photosynthesis (37224%) than those without. Densities of invertebrate macrofauna were 10 times higher in the flocculent surface sedi...

The Baltic Sea is vulnerable to environmental changes. With the increasing shipping activities, the risk of oil spills remains high. Archaea are widely distributed in many environments. However, the distribution and the response of archaeal communities to oil contamination have rarely been investigated in brackish habitats. Hence, we conducted a survey to investigate the distribution, diversity...

A sensitivity analysis was performed on a sediment-phosphate transport model by determining the phosphate sorption characteristics of separated size fractions and prepared size distributions of fine-grained ( < 64 jum) river sediment typically transported in two southern Ontario streams. The Langmuir equation was used to quantify phosphate release from the sediment. Results of the study indicat...

Nitrification was studied with microsensors and fluorescence in situ hybridization (FISH) in sandy sediment of a small lowland stream. Comparative measurements were performed in both intact field sediment (‘natural sediment’) and sediment from the same site after processing for a laboratory incubation experiment (‘manipulated sediment’). In natural sediment, the nitrification activity and abund...

This contribution presents sediment classification results derived from different sources of data collected at the Dordtse Kil river, the Netherlands. The first source is a multi-beam echo-sounder (MBES). The second source is measurements taken with a gamma-ray scintillation detector, i.e., the Multi-Element Detection System for Underwater Sediment Activity (Medusa), towed over the sediments an...

Design of vegetative filter strips for trapping sediment and sediment-borne chemicals can be done on a storm event basis using VFSMOD. This approach requires confidence in a number of input parameters such as soil infiltration characteristics, surface topography, vegetative composition and roughness, and incoming sediment load and particle size distribution. We have developed a simple program, ...

This work presents the formulation of the pickup probability for sediment entrainment under the log-normally distributed instantaneous velocity. Herein two mathematical approaches, namely the analytical method and the first-order approximation method, are employed in the theoretical derivation. The results are compared with the published experimental data and the previous pickup probability der...