Document Type

Technical Report

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Biomonitoring, Reservoir management, Water quality, Ceriodaphnia


The objective of this research was to determine if ambient toxicity exists in the receiving stream below a reservoir in which water from the hypolimnion is released. The Ceriodaphnia 7-day test was utilized to determine if toxicity existed. This test is routinely used in the monitoring of municipal and industrial effluent. It has also been utilized in determining if ambient toxicity exists within receiving streams. Nimrod Lake is a flood control impoundment on the Fourche LaFave River in west central Arkansas. The literature suggest that during stratification the hypolimnetic release contains high levels of iron, manganese, ammonia and sulfide during the period of stratification. Patterns of decreased mean productivity and percent survival of Ceriodaphnia were found in the tailwater of the lake during the time the lake was stratified.

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