IUU ? shing, the elements of which are discussed in detail further below in this Part, hinders the sustainable management of marine ? sheries world wide. Southern Ocean ? sheries and in particular the Patagonian Tooth? sh, have been targeted by IUU ? shers. The text examines the response to the persistent problem of IUU ? shing in 1 the Southern Ocean, by CCAMLR, as the appropriate RFMO, and Australia, a State with vested interests in the Southern Ocean by virtue of the Heard and McDonald Islands’ EEZ. This examination represents original work not only in the context of 2 Southern Ocean ? sheries but in the consideration of the linkages between regional and national measures to deter IUU ? shing. Faced with continued ? ag State inaction, both the CCAMLR Commission and Australia have identi? ed and applied a number of measures to deter IUU ? shing. These measures are examined in Parts 4 and 5 respectively. Indeed, the lack of ? ag State enforcement and the development and persistence of IUU ? shing are inextricably linked, a fact that will be pursued in depth in Part 2 along with the other factors identi? ed as contributing to the development of IUU ? shing.