TY - JOUR
AU - Vanni, Michael J.
AB -  The feasibility of using the zooplankton species Daphnia pulex as a biological control agent of nuisance algal blooms was investigated experimentally in two Illinois lakes. Two questions were posed: (1) Can grazing by Daphnia pulex buffer the effects of increased nutrient loading to an initially low-nutrient lake? and (2) Can D. pulex significantly reduce algal biomass when introduced into a lake that already exhibits excessive phytoplankton growth? These questions were answered by introducing D. pulex individuals into large enclosures (1,000 liters) suspended in the lakes, which do not naturally contain D. pulex . The first question was addressed in Dynamite Lake, an oligo-mesotrophic quarry lake that does not normally exhibit algal blooms. Four treatments were employed within the enclosures: (1) a control, (2) D. pulex added, (3) nutrients (nitrogen and phosphorus) added, and (4) D. pulex and nutrients added. Nutrients were not added until the D. pulex populations became established and were added at weekly intervals after initial addition. In an experiment performed in 1982 D. pulex displayed the ability to substantially buffer the effects of increased nutrient loading. Although addition of nutrients increased phytoplankton biomass in all enclosures to which they were added, by the end of the experiment enclosures without D. pulex had phytoplankton densities (measured as chlorophyll a concentration) greater than those with D. pulex . The second question was addressed in Larimore Pond, a highly eutrophic farm pond with a dense summer surface bloom of phytoplankton. One experiment in the summer of 1982 was performed with a control and with D. pulex added. The results were quite striking: by the end of the experiment (roughly 6 weeks) enclosures without D. pulex exhibited phytoplankton densities an order of magnitude greater than those with D. pulex . These results demonstrate that D. pulex can effectively control phytoplankton biomass even in lakes in which D. pulex is not a natural inhabitant. Therefore, management strategies designed to facilitate introduction and survival of D. pulex or other large grazers should be encouraged as a viable within-lake technique for mitigating the symptoms of eutrophication. 
TI - BIOLOGICAL CONTROL OF NUISANCE ALGAE BY DAPHNIA PULEX: EXPERIMENTAL STUDIES
JF - Lake and Reservoir Management
DO - 10.1080/07438148409354502
DA - 1984-01-01
UR - https://www.deepdyve.com/lp/taylor-francis/biological-control-of-nuisance-algae-by-daphnia-pulex-experimental-UFO6vWfPF0
SP - 151
EP - 156
VL - 1
IS - 1
DP - DeepDyve
ER -