This study compared the spatial and temporal patterns of red hind, Epinephelus guttatus, movement and migration from annual spawning aggregations on St Thomas (STT) and St Croix (STX), United States Virgin Islands. Around STT E. guttatus migrated 6–33 km from a functional spawning migration area of 500 km2 and around STX E. guttatus migrated 5–18 km from an area of 90 km2. Similarities between sites were found in regards to timing of movement, temporal and spatial changes in sex ratios, annual and lunar predictability and were synchronized with environmental cues. E. guttatus spawning aggregations in the Virgin Islands occur between the winter solstice (i.e., after December 20) and about February 20 of any year and show a distinctive peak 20–40 days after the winter solstice. Spawning typically occurred during periods of declining seawater temperature and slacking currents within a temperature range of 26–27.5°C and current speed of 2.5–3.5 cm s−1. Males arrived early to spawning sites and stayed longer than females. These gender-based behavioral patterns are important to E. guttatus reproductive dynamics and must be factored into future studies and the design of fisheries regulations to ensure sustainability of spawning aggregation sites. The predictability of E. guttatus spawning aggregations relative to the winter solstice will be extremely beneficial for defining the temporal and spatial aspects of area closures. The consistency and synchrony of movement and migration will improve both the efficiency of planning research and monitoring programs and directing enforcement activities during critical time periods. Applying this knowledge strategically will maximize the limited resources available for research and enforcement and lead to greater protection of spawning aggregations.
US Virgin Islands