Investigating the ecology of reef sharks in Tetiaroa - update 2026
The objective of this research is to establish a baseline understanding of how sharks use nursery habitats, specifically how that use changes across different age/size classes within a species, in a relatively undisturbed atoll.
Summary of field activities
The team returned to the lagoon to download data from the acoustic array and redeploy it for continued monitoring. Six new sharks were tagged, two blacktip reef sharks and four sicklefin lemon sharks, bringing the program's total to 195 tagged individuals (138 blacktip reef and 57 sicklefin lemon), generating over one million acoustic detections. Alongside the tagging work, long-duration cameras were deployed both above and below the waterline to capture predator-prey interactions as they unfold in real time.
Preliminary results
The data collected on this trip, in addition to previous trips, have allowed the team to examine the habitat-use and movement patterns of blacktip reef and sicklefin lemon sharks within the lagoon. Initial findings have highlighted how space-use differs among shark species, sizes, sexes, and seasons. Specifically, as sharks mature, males and females increasingly utilize different habitats.
Perspectives
The broader aim of this project is to gain a deeper insight into the dynamics of atoll shark nurseries using the relatively pristine and protected lagoon of Tetiaroa as a natural laboratory. The Ma'o team's new PhD student, Sophia Hemsi (FIU), will begin investigating the social lives of these sharks by analyzing patterns of association. In October 2026, our team will return to continue monitoring shark movements and deploy animal-borne cameras, providing a shark's-eye view of their behavior.