It has been hypothesized that pelagically-spawning coral reef fishes select spawning sites and times that lead to eggs being rapidly removed from reefs. This hypothesis is currently being tested by determining the fate of eggs spawned by a reef fish. One program component of this research is the dynamical modelling of current flow, which is necessary to understand forces affecting dispersal and to which fish may be responding in their selection of spawning sites and times, and for developing predictions of egg transport and potential predation. Data collected during simulated-spawning experiments has not been sufficient for this task. This award will support this research program through the acquistion of a WeatherPak 100 weather recording system with sensors for water temperature and solar radiation. Wind stress is the major component affecting water transport. Strong winds will drive surface waters but are also thought to set up a cross-shelf pressure gradient due to the curl of the bottom stress. The latter is believed to be responsible for observed current reversals. Wind stress effects will be determined by monitoring water pressure and current flow at an inshore and offshore station in response to changes in wind speed and direction. Measurements will be taken hourly over the course of a year to account for high-frequency (tidal) and low-frequency (seasonal) components. Results will test the theory of current reversal, and be used to complete the dynamic model of current flow.
