| This dissertation explores the physical and biological factors that control zooplankton population growth rates in the Ohio River (USA). I employed both observational studies and a mesocosm experiment to ascertain zooplankton population and community dynamics in response to biotic and abiotic variables. This dissertation is separated into three chapters. In chapter 1, I introduce the reader to life history traits of zooplankton and characteristics of large rivers. In chapter 2, I present the results of an observational study of zooplankton population growth rates in two navigation pools of the Ohio River and use multiple regression analysis to determine the significance of environmental variables on zooplankton taxa densities and population growth rates. In addition, I use ordination analysis to assess zooplankton community similarity and spatial positioning among sites in the Ohio River and two tributaries, the Wabash and Kentucky Rivers. In the final chapter I test the effect of velocity on zooplankton communities and their impact on chlorophyll alpha and particulate organic carbon. My results provide a mechanistic explanation for the observed patterns of zooplankton in the Ohio River and how river management may affect these important members of riverine food webs. |
