Researchers have harnessed more than a decade of underwater recordings to unlock new approaches for monitoring and managing vulnerable reef fish.
The team from Florida Atlantic University’s Oceanographic Institute and College of Engineering and Computer Science, with partners, focused their work on the red hind (Epinephelus guttatus), a Caribbean grouper prized by fisheries.
Like many fish species, the red hind changes genders during its life cycle, being born female and later transforming into males. However, each winter as they travel to offshore spawning sites during this ritual, males emit two distinct low-frequency sounds: one to court females and another to defend territory. The team tracked these sounds over several years and was able to gain a better understanding of population dynamics in different locations.
According to Laurent Chérubin, the lead author and a research professor at FAU Harbor Branch:
“This shift could indicate changes in the population, such as an increase in the number of older or more dominant males, changes in sex ratios, or even a shift in the core spawning area. What’s remarkable is that even a single underwater microphone can reveal so much about fish populations. With consistent long-term monitoring, we can pick up early warning signs – like shifts in spawning behavior or population stress – and give resource managers the information they need to adapt conservation strategies before it’s too late…
“This study shows how much we can learn simply by listening. Thanks to FADAR, we processed 12 years of acoustic data in weeks – uncovering patterns that would have taken years to find. It’s a game changer for monitoring and managing reef fish like red hind. As passive acoustics advances, it’s transforming our understanding of the ocean. By tuning in to underwater soundscapes, we’re discovering not just when and where fish spawn, but how those patterns change over time – offering vital insights into the health of marine ecosystems.”
You can find the original research here, or check out a video of the team in action below.
