Making the waves safe
For over 30 years, Taronga has housed the Australian Shark-Incident Database (formally known as the Australian Shark Attack File) and has an established reputation for research in shark biology. In response to multiple human fatalities from shark attacks in recent years, the NSW DPI Fisheries, commissioned a review of current and emerging shark deterrent technologies and in 2015 convened a Scientific Shark Summit to address the issue of shark attacks. The NSW State Government has now developed a $16 million Shark Management Strategy to better protect bathers, but it has become evident that options to protect the highest risk group of water users, surfers, are limited.
This project aims to see the world through the eyes of a shark and, in doing so, develop new visual deterrents based on the principle of counter-illumination that will protect surfers from shark attack. This approach is based on our team’s discovery that white sharks do not attack light emitting seal-shaped decoys. A successful method will not only save lives of surfers, but will also protect sharks and other marine animals by reducing the need for costly and indiscriminate shark meshing/culling programs.
Trials were recently conducted to investigate the plausibility of the theory of mistaken identity, whereby sharks are thought to mistake humans for their usual prey (which are pinnipeds in the case of white sharks). Data from the pilot program analysing visual motion cues of Australian sea lions, a New Zealand fur seal and surfboards/surfers looking upwards from the deep pools of the Marine Mammal habitat at Taronga provided the first quantitative evidence of the visual similarity of surfers and pinnipeds. Our next trials will test the effectiveness of various counter-illumination strategies in reducing that visual similarity to sharks and the team will ultimately field test various options on white sharks in South Africa.