Oral Presentation Australian Society for Fish Biology Conference 2024

Shifts in habitat suitability and seasonal movements of a top marine predator (111405)

Adrienne Gooden 1 , Brendan Kelaher 1 , Curtis Champion 2 , Charlie Huveneers 3 , Paul Butcher 2
  1. National Marine Science Centre, Coffs Harbour, NSW, Australia
  2. New South Wales Department of Primary Industries and Regional Development, Coffs Harbour, NSW, Australia
  3. Southern Shark Ecology Group, Flinders University, Adelaide, SA, Australia

Ocean warming is driving shifts in seasonal animal movements and long-term range extensions across marine taxa. Such changes are altering predator-prey interactions with consequences for large marine predators. To better understand how ocean warming may impact white sharks (Carcharodon carcharias), we generated habitat suitability models for white sharks and made spatial predictions under current and future climate scenarios to assess for changes in the timing and distribution of white shark seasonal movements along the southeast and east coasts of Australia. We built these models using location data from 4 white sharks (172 – 367 cm total length) tracked over a 5-year period (2015–2020) and a suite of remotely-sensed environmental covariates including sea surface temperature, chlorophyll a, sea level anomaly, depth, distance to land, and eddy kinetic energy. White sharks showed a negative response to increasing distance to land and ocean depth indicating a preference for shallower coastal areas. Further, sharks were more likely to occur in low to moderate currents and temperatures between 18 – 23 °C. Temperature is likely triggering the shark's seasonal movements northward during austral winter and spring. While analysis is ongoing, our study will utilise habitat suitability models to infer likely future changes in seasonal migration patterns of a top marine predator in the face of climate change.