Zooplankton, Species Composition, Reservoir Flushing
The effects of nutrient renewal, conservation pool water level, and the average weekly discharge rate on the species composition, relative abundance, and population fluctuations of the Copepoda and Cladocera of Red Rock Reservoir were determined. The average retention time (flushing rate) was 11.2 days. Twenty-one species were identified with the dominants being Cyclops spp., Diaptomus spp., Daphnia spp., Bosmina longirostris, Moina micrura, Ceriodaphnia quadrangula, and Diaphano-soma spp. Three distinct seasonal peaks in population growth were noted. Population fluctuations showed slight correlation with temperature, transparency, discharge rate, nutrient levels and no relationship was seen with water level. A time interval of 18 to 32 days occurred between high nitrate and phosphate levels and population abundance peaks. Species composition showed distinct seasonal changes. Population numbers began increasing at the dam area and continued upstream with declines following the reverse pattern.
Proceedings of the Iowa Academy of Science
©1972 Iowa Academy of Science, Inc.
Asch, Ronald L. and Kingsbury, Phyllis J.
"Copepoda and Cladocera Populations of Red Rock Reservoir, Iowa from April to November, 1970,"
Proceedings of the Iowa Academy of Science, 78(3-4), 73-75.
Available at: https://scholarworks.uni.edu/pias/vol78/iss3/13