Dr. Karla Heidelberg
Research Associate, Department of Biology
University of Maryland
College Park, MD 20742
karla@hpl.umces.edu

BA, Liberal Arts, Maryville College, TN, 1988 Ph.D. Oceanography, Marine-Estuarine Environmental Science Program 1999.

I first started diving in 1988. It was not until this experience that I realized the vast realm of life underwater. From these experiences, I decided to return to graduate school in the field of marine science.

In graduate school, I worked with co-advisors Jenny Purcell and Kenneth Sebens at the University of Maryland's Horn Point Laboratory. Initially, I focused my studies on the predatory impact of jellyfish and ctenophores in Chesapeake Bay. Later, I became interested in the small-scale mechanisms of zooplankton feeding by jellyfish. However, it was difficult to study (videotape) predator and prey behaviors with a moving predator. Corals, a cnidarian related to the jellyfish with similar dietary habitats, seemed like a logical alternative.

Interestingly, zooplankton contents in coral guts rarely matched the proportions of zooplankton prey types available in the water. I wanted to determine why this discrepancy occurred. Did the corals reject prey, was the coral unable to capture certain prey types because of their size, or was it the behavior of the prey that determined which types are caught? A series of laboratory flume studies using high magnification video tape, infrared light, and enhanced concentrations of zooplankton prey showed that the selective feeding patterns were controlled by both the prey behavior and the flow speed of the surrounding water.

This Aquarius mission will allow us for the first time to fully evaluate all aspects of coral feeding in their natural habitat. In addition to filming coral feeding throughout the night, we will evaluate zooplankton abundances at multiple heights off the reef bottom to determine available prey, and we will characterize the fine scale water flow patterns around coral colonies.

Coral reefs are unique systems that we know relatively little about. Ironically, scientists and legislatures are being asked to develop management guidelines to preserve these rapidly changing ecosystems before we fully understand the basic biology of reef ecosystems. As we learn more about the biology of the reefs, we will be better able to develop management guidelines that will protect our reefs.