Poster Presentation Australian Society for Fish Biology Conference 2022

Accelerometers and animal-borne cameras reveal behavioural plasticity in white shark predatory strategy (#208)

Adrienne Gooden 1 2 , Tom Clarke 1 2 3 , Lauren Meyer 1 2 4 , Charlie Huveneers 1 2
  1. Flinders University, Adelaide, SA, Australia
  2. Southern Shark Ecology Group, Flinders University, Adelaide, SA, Australia
  3. Department for Environment and Water, South Australian Government, Adelaide, South Australia, Australia
  4. Georgia Aquarium, Atlanta, Georgia, USA

Predation is one of the key forces driving animal evolution, with predator-prey interactions being fundamental to the survivorship of both participants. Animal-borne cameras and accelerometer loggers are increasingly used to study marine predators in-situ to record behaviours that would otherwise remain largely unseen. White sharks, Carcharodon carcharias are assumed to aggregate at the Neptune Islands Group Marine Park to prey on seals and sea lions. We deployed animal-borne cameras and accelerometers on 18 white sharks and used 17 observed burst events and a random forest machine learning model to characterise predatory behaviour of white sharks. Overall, we identified 33 bursting events primarily taking place in midwater (20 – 40 m) and had an ascent phase smaller than starting depth, suggesting that the burst events did not finish at the surface and that sharks did not breach. Burst events mostly took place during the day or at night (12 and 17 events respectively), with the fastest swim speed during burst event being 6 ms-1. Our study suggests that white sharks might be using different predatory strategy at the Neptune Islands compared to other locations where predatory behaviours are frequently observed (i.e. False Bay, South Africa). These sub-surface night-time predatory tactics might explain the low number of natural predations observed at the Neptune Islands and highlights the plasticity in predatory strategy across white shark populations or aggregation sites.