Abstract
Significant gaps in knowledge remain for human-shark interaction risk in nearshore environments, with climate change adding complexity to this risk. This project aims to track bull sharks with acoustic tags to correlate movements with environmental data to elucidate fluctuations in abundance off southeast Queensland, an ocean warming hotspot. Fieldwork commenced in Sept 2023, and catch rates in highly urbanised systems have been variable to non-existent. Concurrently, less developed Sunshine Coast rivers appear to have healthy bull shark populations, with newborns detected by late October. Thirty-six C. leucas across four neighbouring river systems have been internally acoustically tagged with either a V13 or V16 tag (yielding 3 to 11 years of movement data, respectively), per individual. Preliminary detection data indicates a significant overlap of neonate and juvenile habitat use. Smaller sharks (<1m TL) initially tagged upriver were prevalent in the lower reaches after rainfall, when turbidity was higher – areas usually maintained by sub-adults (1.5-2m TL). No individuals have been recaptured in any river to date. The project will facilitate improved shark education and technological mitigation initiatives and bring together a diverse industry collaboration to advance conservation outcomes for apex predators in the UNESCO Biosphere Reserves of the Sunshine Coast.