Current rectification in a tropical coral reef system

Acoustic Doppler current profiles (ADCP) and conductivity-temperature-depth (CTD) profiles were recorded in the Veracruz Reef System (VRS) to elucidate the effect of topography on current circulation and zoo-plankton distribution. Measurements showed the baroclinic behavior of the tropical coral reef system with vertical temperature and salinity gradients of 0.4 degrees C m(-1) and 0.5 psu m(-1), respectively. Under sustained southerly wind conditions, a cyclonic eddy generated by subtidal and tidal current rectification was observed between the two groups of coral colonies studied. Current rectification was attributed to the shallowness of the coral colonies and to a small cape close to Anton Lizardo Village. The cyclonic eddy, with low surface temperature, produced an increment in the vertically integrated acoustic scattering volume (biovolume), suggesting that this is a high-productivity area.