Concentration of total Hg, methyl Hg, and other heavy metals were determined in sediment collected along a salinity gradient in a Louisiana Gulf Coast estuary. Surface sediment was collected at established coordinates (n = 292) along a salinity gradient covering Lake Maurepas, Lake Pontchartrain, Lake Borgne and the Chandeleur Sound located in the 12,170 km(2) Pontchartrain basin estuary southe...

The origin of the microbial community in a coastal marine sediment was investigated by examining the physical, chemical, and microbial characteristics of the sedimenting particles in Halifax Harbor, Canada. Particles were collected using particle interceptor traps placed on the sediment surface. The measured rate of particle accumulation compared to the sediment accumulation rate indicates that...

Sediment is a major nonpoint-source pollutant, and the exchange of materials between water and sediment is an important component of the lake eutrophication process. Suspended sediment increases water surface reflectivity and light attenuation in the water column. Nutrients can be absorbed to sediment particles and desorb from sediment to the water. In addition, nutrients can also be released f...

Data describing long-term sediment yield rates on semiarid rangeland watersheds are relatively rare. To augment existing data and gain a better understanding of the controlling variables, sediment yields from 8 subwatersheds within the US Department of Agriculture–Agricultural Research Service Walnut Gulch Experimental Watershed in southeastern Arizona were computed from stock pond sediment acc...

For certain database tasks that require great exibility, some people are turning to a new kind of data representation in which the database is not constrained by a schema. Instead, each component of the database carries its own description, which is independent of other components. Systems like ACeDB, which has become very popular with biologists, and the recent Tsimmis proposal for data integr...

GOAL, SCOPE AND BACKGROUND Lumbriculus variegatus Miller (Oligochaeta), a common freshwater sediment-dweller, has frequently been used in toxicokinetic studies, although has been less used in ecotoxicity tests. METHODS For the first time the Multispecies Freshwater Biomonitor (MFB) was applied in a short-term whole-sediment toxicity test. The MFB automatically and quantitatively recorded the ...

estimate of sediment load is required in a wide spectrum of water resources engineering problems. the nonlinear nature of suspended sediment load series necessitates the utilization of nonlinear methods to simulate the suspended sediment load. in this study artificial neural networks (anns) are employed to estimate daily suspended sediment load. two different ann algorithms, multi layer percept...

The aim of our study was to investigate how exposure to heavy metal-rich waters from gypsum mining affects the morphology and levels of primary DNA damage in Gammarus balcanicus. Chemical analysis revealed increased concentrations of metals in water and sediment collected at a site impacted by gypsum mine wastewaters. The specimens also showed elevated total tissue metal levels when compared wi...

Sesarmid crabs are important ecosystem engineers in mangroves because they remove a large proportion of mangrove leaf litter. However, the effects on mangrove sediments of sesarmid crab foraging on mangrove leaves has been poorly quantified. Through a laboratory experiment, the present study aimed to quantify changes in nutrient concentrations and enzyme activities in mangrove sediment due to f...

Cop Abstract: Event sediment transport and yield were studied for 45 events in the upstream part of the 260 km agricultural Koga catchment that drains to an irrigation reservoir. Discharge and turbidity data were collected over a period of more than a year, accompanied by grab sampling. Turbidity was very well correlated with the sediment concentrations from the samples (r = 0.99), which allowe...