MEPS 558:129-142 (2016)  -  DOI: https://doi.org/10.3354/meps11846

ABSTRACT: Spawning aggregations of reef fish tend to be predictable in time and space. The extent of movement, residence time and seasonality of the aggregation can be difficult to determine, but are important for effective management. We utilized acoustic transmitters and a receiver array to track dog snapper Lutjanus jocu and Cubera snapper Lutjanus cyanopterus within a multi-species spawning aggregation site at the Grammanik Bank in the US Virgin Islands from June 2014 to September 2015. Acoustic detections showed that both species utilized spawning areas of 1.4 to 1.5 km², centered at the shelf promontory. The aggregation area of L. cyanopterus was situated along the shelf edge; the L. jocu aggregation may have been displaced by L. cyanopterus as it occupied some of the inner shelf as well. Receivers along the shelf edge recorded the longest residence times during the hours of spawning (16:45 to 20:00 h), suggesting this is likely a spawning site for both species. L. cyanopterus aggregated monthly from May through November, with residence time peaking in August. L. jocu aggregated monthly throughout the year and residence time did not vary significantly by month. Each month, detections increased in the week before and the first week after the full moon, but then decreased to zero by the third week after the full moon. This study outlines the spatial and temporal dimensions of the spawning aggregation, which can be applied to the management and development of protected areas.

KEY WORDS: Acoustic telemetry · Reproduction · US Virgin Islands · Dog snapper · Cubera snapper