Acoustic tracking detects nine white sharks at Flower Garden Banks reefs

Biologists have recorded the presence of white sharks (Carcharodon carcharias) within the Flower Garden Banks National Marine Sanctuary (FGBNMS) in the northwestern Gulf of Mexico. According to a study published in Frontiers in Marine Science, acoustic receivers documented nine individuals in the outer continental shelf ecosystem between 2022 and 2025 doi.orgFrontiers in Marine Sciencedoi.orgOpen source ↗. Previously, over 35 years of visual surveys and remotely operated vehicle operations at the sanctuary had yielded no confirmed observations of the species.

Acoustic tracking and migration routes

The sharks were fitted with acoustic transmitters in the western North Atlantic Ocean off the coasts of the eastern United States and Canada between 2014 and 2024. The receiver network, deployed from July 2022, included 32 listening stations across 17 coral banks and adjacent artificial structures. Signals revealed that individuals traveled substantial distances to reach the region, with some specimens covering nearly 3,800 km from their tagging locations doi.orgFrontiers in Marine Sciencedoi.orgOpen source ↗.

Specific transit paths included an individual tagged off Cape Cod, Massachusetts, in October 2021 that arrived at Alderdice Bank after covering 3,600 km in 280 days. Another tracked shark traveled 3,631 km in 261 days to reach Sidner Bank doi.orgFrontiers in Marine Sciencedoi.orgOpen source ↗.

Habitat use and seasonal patterns

Detections occurred between January and August, with activity concentrated in seven natural reef banks within the sanctuary as well as nearby natural and artificial reefs. The data showed evidence of site fidelity (philopatry), as two individuals—one male and one female—returned to the Flower Garden Banks area across multiple years doi.orgFrontiers in Marine Sciencedoi.orgOpen source ↗.

These findings indicate that the outer continental shelf reefs of the Gulf of Mexico provide winter and spring habitats for migratory apex predators. The authors stated that continuous acoustic telemetry offers an effective method for monitoring oceanic marine protected areas without relying on direct visual encounters doi.orgFrontiers in Marine Sciencedoi.orgOpen source ↗.