Onshore transport of settlement-stage Nassau grouper Epinephelus striatus and other fishes in Exuma Sound, Bahamas

The movement of settlement-stage fishes from the pelagic environment of Exuma Sound, Bahamas, to shallow nursery areas on the Great Bahamas Bank was monitored for 75 d during winter 1990-1991 Fishes were collected with channel nets suspended in tidal passes between islands on the edge of Exuma Sound.Large-scale movement of fishes through the channels was restricted to flood tides that occurred during dark, moonless times of the night; very little movement was observed during the day, on ebb tides, or on moonlit nights.Many of the dominant taxa (e.g.leptocephali, Bothdae) recruited on dark nights throughout the study period, with peak onshore movement on nights when winds and currents had strong cross-shelf components of motion.Other taxa had very short, dscrete recruitment pulses associated with specific environmental events; 86 % of the total annual recruitment of Nassau grouper Epinephelus striatus occurred during a single 4 d storm that triggered extensive cross-shelf movement of water, while another 10 % of the recruitment occurred during a second storm event.This reliance on unpredictable storm events to drive local recruitment suggests that short-term variabihty in wind-driven currents is a possible mechanism behind the significant interannual variability of many fish species.