Long-term ecological and economic assessment of COVID-19 travel restrictions on Australia's only white shark cage-diving industry

The reduction and cessation of human activities due to the COVID-19 pandemic impacted animal populations globally, often with ecological and economic repercussions on sectors such as wildlife tourism. Restrictions in human mobility led Australia's only white shark (Carcharodon carcharias) cage-diving industry in South Australia to stop for 50 days between March and May 2020 — the longest period of industry inactivity for over 12 years. More than 10 years of monitoring and research on the sustainability of the industry was leveraged to investigate the immediate and long-term impacts of this 50-day closure on white sharks and the supporting ecosystem using a before, during, and after design based on ecological and economic metrics. We found limited impacts on the residency, activity, and diet of white sharks but a 10-fold reduction in the economic value of the industry in April – May 2020. Only silver trevally (Pseudocaranx georgianus), a species that commonly associates with cage-diving activities, showed behavioural modification, shifting its diet from provisioned to natural sources of food and reducing its residency at operator sites; however, these changes were short-term and reverted once operations resumed. Overall, there was no evidence of lasting impacts of COVID-19 restrictions on white sharks or other fish that closely associate with cage-diving activities. The prompt resumption of tourism and continued implementation of and adherence to management regulations that restrict the amount of bait/berley and operational capacity likely moderated any behavioural changes of white sharks both during and after COVID-19.