Poster Australian Marine Sciences Association 2022

Using 'Flic' Buttons to Map False Killer Whale Depredation Events in a Longline Fishery (#468)

Erin Monaghan 1 , David Schoeman 1 2 , Jessica Bolin 1 3 , Kylie Scales 1
  1. University of the Sunshine Coast, Sippy Downs, QLD, Australia
  2. Nelson Mandela University, Port Elizabeth, South Africa
  3. CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia

Depredation is a relatively understudied but well-known occurrence within the fishing industry. Marine mammals and sharks take fish from fishing gear, causing damage to gear, loss of catch and the potential for entanglement and mortality of non-target species. Depredation therefore presents an issue for the economic and ecological sustainability of the fishery. The Eastern Tuna and Billfish Fishery (ETBF) is a significant contributor to Australia’s economy. Anecdotal reports from fishers suggest false killer whales (Pseudorca crassidens) are a depredation problem within the ETBF, hindering productivity. Whilst some mitigation strategies have been developed, such as acoustic deterrents and alterations to fishing gear, the reported effectiveness of these interventions are variable. In collaboration with fishers and industry, we are trialling the use of 'Flic' buttons to record the location and time of depredation events by false killer whales. This technology provides a simple, affordable approach to investigate influencing factors associated with depredation events, and model where and when these events are more likely to occur throughout the ETBF. By understanding the oceanographic and fishery conditions associated with depredation, we aim to guide avoidance tactics for fishers, and minimise the likelihood of bycatch, depredation and economic losses for the ETBF.