Jm. Shenker et al., ONSHORE TRANSPORT OF SETTLEMENT-STAGE NASSAU GROUPER EPINEPHELUS-STRIATUS AND OTHER FISHES IN EXUMA SOUND, BAHAMAS, Marine ecology. Progress series, 98(1-2), 1993, pp. 31-43
The movement of settlement-stage fishes from the pelagic environment o
f Exuma Sound, Bahamas, to shallow nursery areas on the Great Bahamas
Bank was monitored for 75 d during winter 1990-1991. Fishes were colle
cted with channel nets suspended in tidal passes between islands on th
e edge of Exuma Sound. Large-scale movement of fishes through the chan
nels 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. l
eptocephali, Bothidae) recruited on dark nights throughout the study p
eriod, with peak onshore movement on nights when winds and currents ha
d strong cross-shelf components of motion. Other taxa had very short,
discrete recruitment pulses associated with specific environmental eve
nts; 86 % of the total annual recruitment of Nassau grouper Epinephelu
s 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 s
torm events to drive local recruitment suggests that short-term variab
ility in wind-driven currents is a possible mechanism behind the signi
ficant interannual variability of many fish species.