The Marine Scalefish Fishery (MSF) is South Australia’s most complex fishery as it includes multiple species (including finfish, crustacea and molluscs) and multiple gears, and can be accessed by commercial, recreational and first nations fishing sectors. Over the past 30-40 years, both total commercial catch (tonnes) and fishing effort (fisher days) has declined significantly, and several fish stocks have deteriorated, with some key stocks now classified as depleted. The commercial sector has also had declining economic performance during this period with business profitability becoming an issue for many commercial fishers. As a result, the fishery has recently undergone a historic reform funded by the State Government ($24.5 million) that included licence buy-outs, tiered species management, unitisation of four key “Tier 1” stocks (namely snapper, King George whiting, garfish and southern calamari) through individual transferable quotas and the creation of four new fishing zones. The fishery’s regionalisation was a key focus of the reform and four zones of management were created based on the biological stock structures of key species, regional fishery dynamics and ecosystem boundaries. These were 1) the West Coast, 2) Spencer Gulf, 3) Gulf St Vincent/Kangaroo Island, and 4) the South-East. Fishers were consulted extensively during this process and their feedback was considered in the final decisions. While the fishery has been regionalised in terms of access to Tier 1 species, MSF licences retain state-wide access, and fishers can operate in any zone on the proviso that they own the necessary quota for Tier 1 species. Zone boundaries were determined such that the fishing grounds of most individual licence holder were not unnecessarily split between fishing zones. Each of the four zones of management selected also aligned well with the stock structure of key Tier 1 species.