Researchers from Florida Atlantic University (FAU) mapped where rock bass spawn by listening to their courtship and mating sounds. The study, published in Fisheries Research, adds a new layer to our understanding of how these fish coordinate reproduction in their natural environment. By focusing on the acoustic signatures of rock bass, scientists were able to identify key behaviors that mark the start of the spawning season and reveal how these fish communicate in the open water. This work helps explain the timing and locations that are critical for successful mating in rocky habitats near shorelines.
Across several months each year, large groups of grouper relatives gather to breed. This seasonal gathering—comprising hundreds and thousands of individuals from the grouper family—creates opportunities for both reproduction and exploitation. In a contemporary study, researchers recorded courtship and mating sounds from fish in three marine zones off Puerto Rico’s west coast, concentrating on two species: Nassau groupers (Epinephelus striatus) and blackfin groupers (Epinephelus guttatus). The goal was to map vocal activity and link it to specific reef areas that function as spawning hotspots. This acoustic approach helps scientists pinpoint where populations concentrate their reproductive efforts and how environmental factors might influence these gatherings.
Instruments placed underwater captured four minutes of ocean sound per hour, providing a comprehensive audio map of the reef system’s reproductive period. The findings show that vocalizations linked to courtship peak roughly 500 meters from known spawning sites, a pattern that helps delineate safe zones for egg and larval dispersal. The study also uncovered previously unrecognized congregating sites, which could become focal points for conservation measures. In the future, these newly identified areas may be considered for temporary fishing closures during spawning windows to safeguard grouper populations from overharvest and potential extinctions, aligning management actions with natural reproductive timelines.
Ultimately, the research emphasizes how acoustic monitoring can inform habitat protection. By revealing where and when groupers vocalize during courtship, managers gain practical targets for protection efforts, supporting healthier reef ecosystems and more stable fish populations across the Caribbean region. These insights contribute to a broader understanding of reef connectivity and the role of soundscapes in guiding migratory and spawning behaviors among large-bodied coral reef fishes.