Fish have been making sounds for thousands of years, but we've barely been listening. Now a new underwater camera system is changing that — capturing individual fish calls from the wild for the first time at scale, offering conservation scientists a tool they've desperately needed.
The breakthrough comes from combining audio and visual recording in a single device called UPAC-360°. It works by isolating individual fish sounds from the acoustic chaos of a reef or riverbed, then matching those calls to the specific fish making them. The result: researchers at Cornell University and their collaborators recorded and identified 46 fish species in their natural habitat — the largest wild fish sound collection ever assembled.
"We were shocked about how many fish we could record and identify in a relatively short amount of time," said Aaron Rice, an ecologist at Cornell who led the study, published recently in Methods in Ecology and Evolution.
We're a new kind of news feed.
Regular news is designed to drain you. We're a non-profit built to restore you. Every story we publish is scored for impact, progress, and hope.
Start Your News DetoxWhy this matters becomes clear when you consider the alternative methods scientists used before. Studying fish acoustics traditionally meant sending divers into habitats to disturb them, or worse — bringing fish into labs and stressing them with electric shocks or handling to force vocalizations. The data you got was real, but it came from fish in distress, not fish being themselves.
The new approach lets researchers listen in without interference. And that listening is urgent. More than 4,000 fish species are now listed by the IUCN as vulnerable, endangered, or critically endangered. Sound offers a window into their lives that other monitoring methods can't match: where populations congregate, how their numbers shift across seasons, when they're most active, and which behaviors — spawning, feeding, territorial displays — make them vulnerable to overfishing or habitat loss.
For threatened species living in murky water or deep habitats where visual surveys fail, acoustic monitoring could be the difference between extinction and recovery. A fish's call is a kind of census, a heartbeat that tells you the population is still there.
The technology is still new, and researchers are working to expand the library of identified species and refine how the system works across different ecosystems. But the foundation is set: we can finally hear what the underwater world has been trying to tell us.
