Abstract

Red hind (Epinephelus guttatus) in the Caribbean form annual spawning aggregations during full moon periods between the months of December through February. Few studies have attempted to investigate what factors influence timing of spawning or selection of aggregation sites. From December 2005 through February 2006 three separate red hind spawning aggregations sites located in St. Thomas and St. Croix USVI and in Saba, NA. were investigated. At each site an acoustic doppler current profiler (ADCP) was deployed in early December and retrieved in late February to measure current speed and direction and temperature during the spawning season. Divers at each site conducted visual counts on scuba to estimate red hind density and collected at least six females per site per day to determine gonado-somatic index. Relatively few fish were observed or collected in December or February in Saba and St. Croix but higher densities were seen in St. Thomas in February. GSI increased to a maximum one day before the full moon at all sites. Temperature was remarkably similar among sites. Average daily water temperature declined from 27.5 ºC in December to 26.2 ºC in February at all sites with water temperature at 26.5ºC to 26.7ºC during the week of the January full moon when fish were spawning. Current speeds ranged from 0.10 to 0.14 cm/s in Saba and from 0.13 to 0.20 in the USVI. During the week of spawning in January the average current speed on the bottom slowed to 0.105 cm/s in Saba and 0.145 in the USVI. This study suggests that red hind select sites based on certain oceanographic features and that timing of spawning is may be synchronized through a variety of factors on a relatively large spatial scale

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