Coral reefs represent one of the world's most diverse ecosystem types in terms of species and also one of the most highly productive. As the waters surrounding most coral reefs are oligotrophic (i.e., extremely depauperate in nutrients), planktonic assemblages of animals and photosynthesizers are very dilute and do not provide much in the way of food for coral reef organisms. Most of the high productivity of reefs is based ultimately on the photosynthesis of seaweeds and algal-containing corals. Thus factors that affect seaweed primary production contribute greatly to the entire organization and functioning of coral reef ecosystems. Dr. Carpenter and collaborator Dr. Susan Williams, of the University of Washington, want to look at possible mechanisms by which this high reef production is maintained in such nutrient poor environs. They hypothesize that the high numbers of reef herbivores are able to rapidly recycle nutrients bach to the seaweeds, and that nitrogen fixation may be an important, in situ nutrient-producing process. Both Drs. Carpenter and Williams are productive young researchers very familiar with the ecology of coral reefs in the Caribbean. Dr. Carpenter's background in reef herbivores and algal productivity will balance nicely with Dr. William's considerable nutrient dynamics experience. Support for this two-year investigation is recommended.
