10.2190/UM0K-Q9QQ-L8BL-QW4N UM0KQ9QQL8BLQW4N 281 Effect of Predation and Zooplankton-Mortality on the Overall Ecosystem-Health of Udaipur Lakes in India: A Case Study Application of Five Compartment Ecological Food-Web Interaction Model 281 297 20020509 20020509 20020509 20020509 UM0KQ9QQL8BLQW4N.pdf http://baywood.metapress.com/link.asp?target=contribution&id=UM0KQ9QQL8BLQW4N 4 J.S. Pandey, S. Khan, R. Shanker, P. R. Chaudhary, P. Padmanabhan, and T. K. Ghosh Pichola and Fatehsagar lakes of Udaipur city in India are presently experiencing very high levels of algal eutrophication due mainly to instability in the relevant ecological food-webs that resulted from interspecies predation and mortality at various trophic levels. In both lakes, very low zooplankton levels were observed, indicating high mortality and associated predation rates. We studied the impacts of varying zooplankton-mortality-coefficients on the dynamics of other ecological state variables phytoplankton, pelagic fish, benthic fauna, and demersal fish using a five-compartment aquatic ecosystem computer simulation model. The software (UDAIPUR.C) quantified the most and least perturbed state variables. Analysis reveals, <em>inter alia</em>, that phytoplankton levels show a strongly rising trend, especially in the case of Pichola lake, while most of the other variables exhibit a declining trend. Ecological dynamics of the two lakes were found to be quite dissimilar. The most perturbed compartments were pelagic fish and demersal fish.