WILLIAM S. JOHNSON

Research Interests: Marine and Estuarine Ecology

Research In Progress:

Structure and Organization of Coral Reef Fish Communities. Tropical regions support an unusually rich fauna and flora, yet we are largely ignorant of the underlying mechanisms that promote or maintain high levels of species diversity. Coral reef fishes offer a unique opportunity to document patterns of food and habitat utilization because they may be readily observed in situ using scuba. The challenge is to relate this observed structure to overall community dynamics. I have also studied the behavior and ecology of cleaning symbiosis where certain species of fish shrimp remove parasites from fishes who come to “cleaning stations” just for this service.

Predator-Prey Interactions of Planktivorous Fishes. Planktivorous fishes form a key link between planktonic food webs and the larger predatory fishes, including the primary food and sport fishes. I am particularly interested in the feeding dynamics of plankton-feeding fishes and the nature of prey selection. In our studies of the saltmarsh ecosystem in South Carolina we are trying to quantify the impact of planktivorous on the system both in terms of population dynamics and energy transfer. These zooplanktivores also constitute an important connection in transferring marsh based productivity to oceanic systems.

Representative Student Independent Research Projects:

Drzewianowski, Andrea Seasonal patterns of photosynthesis in mountain laurel, an understory evergreen in the deciduous forest.

Gasparine, John and The Relationship between respiration and osmoregulation in

Winters, Lynette the fiddler crab Uca pugilator at decreasing salinities and hypoxia

Dickens, Virginia Effects of lead on the reproduction and natural rate of increase of Daphnia magna.

Christensen, Karen Acute toxicity and bioaccumulation of cadmium in juvenile and adult frogs.

Silveri, Ann Resource partitioning within a Fall/Winter bird

community.

(Winner Phi Beta Kappa Award of Excellence)

Rango, Jessamy Degradation of leaf litterfall in Donnybrook Stream by resident aquatic insects: Possible effects of global warming on leaf pack decomposition rates.

WILLIAM S. JOHNSON (cont.)

Selected Publications:

Gladfelter, W.B. and W.S. Johnson (1983) Feeding niche separation in a guild of tropical reef fishes (Holocentridae). Ecology 64: 552-563.

Johnson, W.S. and P. Ruben (1988) Behavior and cleaning activity of Bodianus rufus, Thalassoma bifasciatum and Gobiosoma evelynae along a depth gradient at Salt River Canyon, St. Croix. Environmental Biology of Fishes. 23: 225-232.

Johnson, W.S., D.M. Allen, M.V. Ogburn and S.E. Stancyk (1990) Short-term predation responses of adult bay anchovies Anchoa mitchilli to estuarine zooplankton

availability. Marine Ecology Progress Series 64: 55-68.

Allen, D.M., W.S. Johnson, and M.V. Ogburn (1995) Trophic relationships and seasonal utilization of salt marsh creeks by zooplanktivorous fishes. Environmental Biology of Fishes 42: 37-50.

Johnson, W. S., E. Stevens, and L. Watling (2000/2001) Reproduction and development in marine peracaridans. Advances in Marine Biology 39: 107-261. (Review article)

Johnson, W. S. and D.M. Allen Zooplankton of the Atlantic and Gulf Coasts: A Guide

to Their Identification and Ecology. Johns Hopkins University Press. (Projected

publication in 2004; circa 500 pages.)