# Researchers Use Fin Identification to Track Oceanic Whitetip Sharks New camera-based survey method improves accuracy in counting endangered oceanic whitetip shark populations. - **Source:** [Earth.com](https://www.earth.com) - **Published:** 2026-11-06 - **Topic:** [science](https://brifing.si/c/science) - **Original article:** - **On Brifing:** https://brifing.si/s/59bb06e5-22e8-4afa-8562-952ca68b9896 ## Innovative Shark Survey Method Researchers from Florida International University deployed baited GoPro cameras off Cat Island in The Bahamas during 2023 and 2024. By using bonito as bait, the team successfully filmed oceanic whitetip sharks at depths of 43 feet. This method allowed scientists to identify 50 individual sharks based on unique dorsal fin markings. ## Overcoming Marine Observation Challenges Counting marine predators is notoriously difficult compared to terrestrial species like lions, which can be tracked via aerial surveys. Because oceanic whitetips inhabit deep, open waters, traditional visual counting methods often fail. The new fin-based identification technique provides a more precise alternative to the standard MaxN count used in previous studies. ## Technical Rig Setup Details The team utilized two types of rigs to capture footage: a drifting frame made of 3/4-inch galvanized steel pipe and a tethered wire bait cage. These were deployed from a sportfishing yacht across 99 sets between Columbus Point and Tartar Bank. The equipment successfully attracted sharks despite the deep, non-anchorable water conditions. ## Fin Identification Mechanism Researchers identified individual sharks by analyzing the notches, shape, and pigmentation patterns on their first dorsal fins. Each shark was assigned a specific code, such as OWT1, only after both sides of the fin were captured on video. This process is similar to identifying whale sharks by their unique spot patterns. ## Comparison With Standard Metrics The study compared fin identification results with MaxN, the traditional count of the largest number of a species in a single frame. While both methods agreed on 87 percent of sets, the fin-based count was significantly more accurate when multiple sharks appeared simultaneously, revealing up to three times more individuals than standard tallies. ## Status of the Whitetip The oceanic whitetip is currently listed as Critically Endangered by the IUCN and threatened under the U.S. Endangered Species Act. Populations across the Pacific have declined by 80 to 95 percent since the mid-1990s. Threats include commercial fishery bycatch and the global demand for shark fins, which remains a major conservation concern. ## Fieldwork and Local Impact Led by Candace Fields, the survey highlights the importance of Bahamian researchers in local shark conservation. While The Bahamas is a shark sanctuary, these predators frequently travel into fished waters where they face higher risks. The study provides a foundational dataset for future monitoring efforts across the wider Bahamian archipelago and beyond. ## Future Research Directions The team plans to expand camera deployments to additional points along the archipelago to determine if sharks remain stationary or migrate between islands. They also aim to incorporate photos from citizen scientists into the existing fin catalog. Two sharks, OWT8 and OWT15, were confirmed to have returned to the site annually. ## Sources covering this story - https://www.earth.com/animals/bahamian-scientist-oceanic-whitetip-sharks-fins-cat-island/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._