There has never been a concurrent study of prey capture success and water flow over reef corals. This project will investigate the effect of water movement on several aspects of the feeding biology of corals. The first portion of the project will measure field rates of feeding of three species of coral, Montastrea annularis, Eusmilia fastigiata and Porites porites with prey sampling by an automated pump/sampler array that allows concurrent measurement of water flow (thermistor flowmeter, video), irradiance (Licor quantum irradiance meter) and prey availability (DO pump sampler). Feeding experiments on expansion and contraction behavior and feeding during several diel cycles. A self-contained underwater thermistor flowmeter with a 2 mm spatial resolution has been constructed and tested for this research based on the design of LaBarbera and Vogel (1976). The data collected will be used to characterize the general flow regime at the site (mainstream flow at several points along depth transects using the Interocean S4 recording current meter), providing new information about the flow environment on coral reefs in St. Croix at the NOAA National Undersea Research Program's AQUARIUS habitat.