This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Every oceanic whitetip shark has a fin pattern as unique as a human fingerprint. In a new study published in Marine Biology, FIU researchers identified more than 50 oceanic whitetip sharks by their fins alone using pelagic baited remote underwater video stations, pBRUVS, off the coast of Cat Island, the Bahamas.
The use of BRUVS is nothing new in the field of marine biology, according to the team, but the strategic use of pelagic BRUVS, or those not connected to the seafloor or a reef, was unique in this location due to the relative abundance of the critically endangered oceanic whitetip shark in the area and the depth of water. "One of the key aspects of managing and conserving an endangered species—or any species—is being able to track trends in the population over time," said Yannis Papastamatiou, an FIU marine biologist and researcher in the FIU Institute of Environment. Is the population declining, stable or starting to increase?
"When you're talking about marine predators in the ocean, that's very difficult to answer—much harder than with terrestrial predators," Papastamatiou continued. "If you want an idea of the abundance of lions, you can do airplane surveys and count them. But in the marine environment, you can't see things, so that's very difficult to do." Previously, FIU researchers used BRUVS to survey a different species of shark over a 10-year period at an atoll.
Through this study they were able to show that the relative abundance of this other species was declining even though the atoll was a protected area. But at Cat Island, the water was too deep to anchor cameras to the bottom of the ocean. So, for this research, FIU alumna Candace Fields, who earned her Ph.D. in marine biology in 2025, tested two techniques of pelagic BRUVS: free-drifting and boat-tethered.
According to Fields, free-drifting BRUVS were initially the main method of collection, but boat-tethered BRUVS let the team increase their sample size and test the influence of boat noise on shark behavior—which they found had no effect. Similar to examining spot patterns on a whale shark, oceanic whitetip identification can be done by looking at their distinctive fin pigmentation as well as the shape of the tips of the fins, according to Fields. "That's been done before, but using underwater photography, where you can position yourself or wait until the shark passes to get the right angle," she said.
"In a video survey, obviously, you have no means to control how the shark approaches the camera. So, one big question was: Is this even viable? Are the sharks even going to give us enough of the correct angle to do this kind of identification?" The method came with challenges.
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