Standard Talk (15 mins) Australian Society for Fish Biology Conference 2022

Large-scale movements of a coastal predator (#43)

Amy Smoothey 1 , Yuri Niella 2 , Victor Peddemors 1 , Marcel Green 1 , Paul Butcher 3
  1. NSW Department of Primary Industries, Mosman, NSW, Australia
  2. Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
  3. NSW Department of Primary Industries, National Marine Science Centre, Coffs Harbour, NSW, Australia

Knowledge on the movements of marine predators is important for effective conservation and management given the increasing threats of human and climate induced changes. Bull sharks, Carcharhinus leucas, are apex predators, globally distributed throughout rivers, estuaries, near-shore areas and continental shelf waters of tropical to temperate regions. Substantial knowledge of movements and distribution have been gained through acoustic telemetry, however, detections are limited to areas of acoustic array deployments with little knowledge on how these sharks utilise the water column and depth profiles whilst travelling or foraging in coastal waters. Here we examined the horizontal movement and habitat use of seven bull sharks (185 to 283 cm total length) using MiniPAT pop-up satellite archival tags between 2021 and 2022. During their time at liberty, sharks travelled through tropical and temperate waters, where for the first time, we tracked a male bull shark (195 cm) in continental slope waters off the Lakes Entrance area, Victoria.  This is the southern-most record of a tagged bull shark and potentially new distribution range for this species, that may be associated with climate induced changes.  The findings of these large-scale latitudinal movements and the environmental drivers will be presented. Resolving environmentally driven variation in latitudinal movements of bull sharks, using data from satellite tagging, informs knowledge gaps and may support the development of future management strategies.