Do keystone species structure aquatic communities

Do keystone species structure aquatic communities?

Donald J. Hall

Professor Emeritus, Zoology

Aquatic Population and Community Ecology

I pursue an experimental approach to ecology by first exploring currently exciting conceptual issues in population and community ecology. After posing testable hypotheses that are suggested by a theoretical framework, I attempt to evaluate these hypotheses experimentally largely under near-natural conditions by means of controlled field experiments. Freshwater systems are particularly approachable in this regard because of their distinct physical boundaries and ease of mimicking the state of natural systems.

I am particularly interested in elucidating if and how certain "key" species interactions can release a series of cascading changes in community and even trophic level dynamics and structure. I study fish-zooplankton interactions under both disturbed and benign conditions. By exploring how these systems shift from one configuration to another I hope to elucidate both the underlying biological mechanisms and the basis of ecological stability.

My current research projects include: 1) Deepwater ecology of the benthic/fish community of Lake Michigan and Superior using submarines and remotely operated vehicles (ROV’s); and 2) Fish/zooplankton community dynamics in winterkill perturbed lakes.

Selected Publications

Hall, D.J. and T.J. Ehlinger. 1989. Perturbation, planktivory and pelagic community structure: The consequences of winterkill in a small lake. Can. J. Fish. Aquat. Sci. 46:2203-2209.

Mittelbach, G.G., A.M. Turner, D.J. Hall, J.E. Rettig and C.W. Osenberg. 1995. Perturbation and resilience in an aquatic community: A long-term study of the extinction and reintroduction of a top predator. Ecology 76:2347-2360.

Hall, D.J., E.E. Werner, J. Gilliam, G. Mittelbach, C. Doner, D. Howard, J. Dickerman and A. Stewart. 1979. Diel activity and foraging patterns of the golden shiner. J. Fish. Res. Bd. Can. 3:1029-39.

Werner, E.E., J.G. Gilliam, D.J. Hall and G.G. Mittelbach. 1983. An experimental test of the effects of predation risk on habitat use in fish. Ecology 64:1540-48.

Werner, E.E. and D.J. Hall. 1988. Ontogenetic habitat shifts in the bluegill sunfish (Lepomis macrochirus): The foraging rate-predation risk tradeoff. Ecology 69(5):1352-1366.