Illegal, unreported and unregulated (IUU) fishing is the term given to particular kinds of fishing activity that in some way contravene national or international laws (DAFF, 2019). This activity has numerous environmental impacts, such as depleting fish stocks (especially of vulnerable species) and causing damage to ecosystems. It also impacts both socially and economically, such as through disrupting the livelihood of lawful fishers, removing a source of protein for those who rely on fish for consumption, and diminishing amenity and activity for tourism and recreation. Left unchecked, IUU fishing can create irreversible harms. IUU is largely concealed, with illegal catches easily intermingled with lawful catches, making prevention, detection and thus penalisation difficult. Nevertheless, various laws, treaties and monitoring programmes combined with technological and other surveillance tactics seek to offer some level of traceability and deterrence.