South Australia’s aquaculture industry generates 50% of the State’s seafood economic output, and was worth $200.1m (farm gate) in 2020/21. The Aquaculture Act 2001 provides the State government regulatory agency, the Department of Primary Industries and Regions, with the capacity to regulate aquaculture development under a single dedicated legislative framework. A fundamental feature of this legislative framework is the capacity to establish dedicated statutory aquaculture zone policies in State waters. These zone policies represent a unique marine spatial planning approach for aquaculture industry access to a shared resource; providing certainty to all user groups, including fisheries, marine parks, tourism, shipping, other marine industries and Indigenous communities. The aquaculture zone policy process illustrates how dedicated legislation can effectively support strengthening growth of this industry sector in an ecologically sustainable manner.
Twelve aquaculture zone policies are prescribed in South Australia. These zone policies occupy approximately 7% of State waters. More than half (52%) of the zone policy area is allocated to aquaculture exclusion zones, where no aquaculture activity is permitted. The remaining 48% is set aside to allow aquaculture to occur, with generally only 5-10% permitted to be allocated at any one time.
The current review process for the Aquaculture (Zones—Lower Eyre Peninsula) Policy 2013 will be detailed as a case study. This Zone Policy covers one of the most diverse and in-demand aquaculture areas in South Australia, in addition to coexisting with other marine user groups. All established aquaculture sectors (e.g. southern bluefin tuna, yellowtail kingfish, and bivalve molluscs) and emerging aquaculture sectors (e.g. algae or seaweed) are permitted within the Zone Policy. The review considered the latest science and industry developments to ensure the Zone Policy stayed relevant and appropriate, and maximised benefits to the community from the State’s aquaculture resources in a sustainable manner. This included use of an updated and innovative nitrogen based carrying capacity model. The model incorporated estimates of dissolved ammonium released from supplementary fed classes of aquaculture, such as southern bluefin tuna and yellowtail kingfish, and its diffusion considering ocean flushing timescales against specific conservative water quality guideline values for the first time. Results from the modelling were used to determine maximum biomass limits for this class of aquaculture in the Zone Policy, to promote sustainable growth while allowing legislative flexibility to update biomass limits in the future. For example, robust nitrogen offset data (e.g. seaweed,) can be considered within an integrated multi-trophic aquaculture context. Policy flexibility also provides adaptability for climate change mitigation strategies (e.g. lease movement, species).
The effective and efficient process to design, consult with stakeholders, finalise and implement an aquaculture zone policy, and the opportunities for aquaculture growth will be described.