HIGHLIGHTS: Sedimentation of fine sediment particles onto seagrass leaves severely hampers the plants' performance in both light and darkness, due to inadequate internal plant aeration and intrusion of phytotoxic H2S. Anthropogenic activities leading to sediment re-suspension can have adverse effects on adjacent seagrass meadows, owing to reduced light availability and the settling of suspended...

Analysis of suspended sediment transport data for rivers in Yunnan and Tibet shows that monsoon fl ows control effective discharge. We calculate effective discharge, defi ned as the discharge that transports the most sediment, for 44 stations for which there is at least one complete year of daily suspended sediment concentration and mean daily discharge data, and fi nd that the effective discha...

An acute whole-sediment toxicity test with a benthic marine microalga was developed and optimized using flow cytometry to distinguish algae (based on their chlorophyll a autofluorescence) from sediment particles. Of seven benthic marine algae screened, the diatom Entomoneis cf punctulata was most suitable because of its tolerance of a wide range of water and sediment physicochemical parameters,...

Phosphate interacts with inorganic sediment particles through sorption reactions in streams. Collectively, this phosphorus (P) buffering mechanism can be an important determinant of soluble reactive P (SRP) concentrations. If sorption reactions control SRP concentrations in a stream, then differences in sediment characteristics may cause spatial differences in SRP concentrations. This predictio...

Forestry best management practices (BMPs) are used to reduce sedimentation from forest stream crossings. Three BMP treatments (BMP ́, BMP-std, and BMP+) were applied to three forest road stream crossings (bridge, culvert, and ford). BMP ́ did not meet existing BMP guidelines, BMP-std met standard recommendations, and BMP+ treatments exceeded recommendations. Following BMP applications, three simu...

This study evaluates sediment runoff from gas well development sites in Denton County, Texas. The magnitude of sediment runoff was investigated by intercepting sediment in traps and weirs at the periphery of each gas well site and by measuring the growth of debris lobes that formed down slope from two sites. Four debris lobes formed at one gas well site and one formed at a second site. Debris l...

Sediment and phosphorus (P) in agricultural runoff can impair water quality in streams, lakes, and rivers. We studied the factors affecting P transfer and transport in irrigated furrows in six freshly tilled fallow fields, 110 to 180 m long with 0.007 to 0.012 m m-1 slopes without the interference of raindrops or sheet flow that occur during natural or simulated rain. The soil on all fields was...

The lower Santa Maria River watershed provides important aquatic habitat on the central California coast and is influenced heavily by agricultural runoff. As part of a recently completed water quality assessment, we conducted a series of water column and sediment toxicity tests throughout this watershed. Sediment from Orcutt Creek, a tributary that drains agricultural land, consistently was tox...

rade control structures are used to control bed erosion in steep small rivers mostly in the mountains. scour downstream of this structure can lead to failure. over the past years, the effect of different variables on this phenomena have been studied, however the effect of upward seepage which is common due to head difference of the banks water table or water surface level between the upstream a...

Excess delivery of land-based sediments is an important control on the overall condition of nearshore coral reef ecosystems. Unpaved roads have been identified as a dominant sediment source on St John in the US Virgin Islands. An improved understanding of road sediment production rates is needed to guide future development and erosion control efforts. The main objectives of this study were to: ...