Collaborative Research: Consequences of consumer adaptation for ecosystem responses to fertilization and food-web perturbations

Auburn University, Auburn AL

Investigators

Abstract

Increased nutrient input, from fertilizer and other sources, to aquatic systems (eutrophication) leads to degradation of water quality as a result of increases in algae (phytoplankton), and in particular, phytoplankton species that produce toxins. These toxins are a serious threat to human and livestock uses of surface waters in both freshwater and marine environments. One strategy for improving water quality is to manage the food web by increasing the abundance of small animals (zooplankton) that eat phytoplankton. Laboratory studies have suggested, however, that food-web manipulation may fail because of the strong negative effects of phytoplankton toxins on zooplankton growth and reproduction. Previous research has demonstrated that individuals of a common species of zooplankton (Daphnia pulicaria) vary greatly in their ability to grow on a diet of toxic phytoplankton. This project examines the consequences of adaptation to toxins for water quality in lakes in Michigan. In addition to the obvious potential impact of this research on the management of surface waters, the project focuses on two little-studied general phenomena in community ecology: how predator adaptation and trait variation within species affect species interactions. Consequently, the field experiments to be conducted will advance both basic and applied ecology. The project will also provide hands-on training in experimental ecology to graduate and undergraduate students at Michigan State University and Auburn University and provide related outreach activities to middle and high school students.