Satellite tagging a tiger shark.
Photo by Erica Heller.

By Adam Barnett, Richard Fitzpatrick, Michael Bradley, Ingo Miller, Marcus Sheaves, Andrew Chin, Bethany Smith, Amy Diedrich, Jonah Yick, Nicolas Lubitz, Kevin Crook, Carlo Mattone, Michael Bennett, Leah Wojitach, and Katya Abrantes.

Read the full paper here.

In 2018, three people suffered shark bites in Cid Harbour, the Whitsundays (Queensland, Australia). The region had no history of negative shark interactions, and little was known about the shark community. The context of the three incidents was extremely unusual: the first two bites occurred within 24 hours of each other. The third, a fatal bite, followed six weeks later. Particularly unusual was that all bites occurred within a very small area (estimated to be the size of a football field), and people were bitten almost instantly upon entering the water. Following the third bite, the Queensland Government implemented a plan to improve safety. The plan included commissioning research into shark prevalence and behaviour in Cid Harbour, including a social science study to understand human behaviours, awareness and perceptions in relation to ‘Shark Smart’ practices.

In our study, we describe and evaluate the research conducted in response to the Cid Harbour shark bite incidents. We used fishing, satellite and acoustic tracking, camera and side-scan sonar methods to identify the shark species using Cid Harbour, describe habitat use and residency, and assess prey availability.

Overall, we did not find anything unusual about the shark community that could have contributed to the shark bite cluster. However, information from the social science study, which included surveys and discussions with various local stakeholders (fishers, community groups, management agencies, and the tourism industry) suggested that the regular dumping of food/fish scraps overboard while at anchorages could have could have contributed to the shark bites. This means that any species capable of biting humans (or even multiple species) could have been responsible. In addition, stakeholders voiced concerns about the overlap in activities in the harbour. For example, people swam and snorkelled in areas also used for fishing and where food/fish scraps were regularly dumped from liveaboard boats. Together, these two human-related factors could have contributed to the Cid Harbour shark bite incidents. The eradication of activities that attract sharks in areas used for in-water activities such as swimming and snorkelling may therefore reduce the risk of future shark bites.