Filtering Rate Performance of Daphnia retrocurva in Pulp Mill Effluent

Abstract

Laboratory experiments were carried out with radioactive Scenedesmus to determine the effect on filtering rate of Daphnia retrocurva of exposure to different dilutions of raw pulp mill effluent in lake water. Filtering rate decreased progressively as the exposure time in 5 and 10% effluent increased. Most animals seemed able to recover from brief exposures, but with increased time spent in effluent, larger proportions of the animals did not filter when the food was presented.