Fine-scale positioning of wobbegong sharks within an Aquatic Reserve
Since June 2008, wobbegong sharks have been tagged and monitored through acoustic receivers part of the AATAMS network. A total of 20 sharks are currently being tracked in Cabbage Tree Bay Aquatic Reserve south of Manly, in Sydney, NSW. The project partly funded by the Department of Environment and Climate Change (DECC), Sydney Aquarium Conservation Fund, and Passions of Paradise through the Oceania Chondrichthyan Society aims to determine the preferred habitat, seasonality, and residence times of wobbegongs within a protected area.
We have already obtained over 330,000 detections showing strong site fidelity to the Reserve with some individuals nearly continuously remaining inside the Bay. On the other hand, other sharks left the area for up to six months prior to returning to Cabbage Tree Bay. This project also uses a new technology that can estimate the actual position of the tagged shark within 2 m accuracy instead of only providing presence/absence information. In the last 6 months, nearly 1000 positions were obtained showing very small site occupancy with wobbegongs remaining within on side of the Aquatic Reserve rather than utilising the entire area.