Difficulties with current legislation in Australia at State and Federal level make it challenging for marine farms to protect themselves, but equally for the community to have faith that aquaculture development is not harming the marine environment. An example from Tasmania is the recent contamination of Macquarie Harbour, whereby tailings from Copper Mines Tasmania (CMT) dam in Queenstown entered the harbour and undoubtedly caused environmental harm to salmon and other species. Because CMT and salmon farmers operate under different Acts CMT was not responsible for the incident but rather the government. Consequently, no investigation or clean-up ensued.

Additionally, the scope of statutory tools, such as EIS under the Tasmanian Marine Farm Planning Act 1995, is not regional and does not consider the compound interactions of and on production activities. A good example is the recent Storm Bay salmon farming expansion; while the EPBC listed handfish species in Tasmania were listed in the marine farming development plan, with a brief context, management of these species was not considered in the EIS because that process only includes direct impact of the lease position. Arguably, cumulative impacts from all development in the area will have varying impacts on the species, impacts which are not being considered under current government legislation, but are potentially the source of public ire.

For aquaculture to pursue sustainable efforts environmentally, economically and socially in the increasingly crowded near shore space requires proactive planning and transparency that is not currently possible given existing assessment tools. In particular, assessment of cumulative impacts must be addressed. Cumulative impact assessments (CIA) are gaining momentum across multiple industries due to a recognised need to apply them in the pursuit of sustainable management. CIAs are being undertaken with the protection of marines resources at front of mind, but so far there has been little consideration of aquaculture. An approach to CIA that makes aquaculture the centre point is required if we are to consider its impacts or conversely, its effectiveness.

The north west of Western Australia has productive commercial and recreational fisheries and extensive offshore oil and gas (O&G) infrastructure. These man-made structures support a range of demersal and pelagic fishes which are targeted by recreational and commercial fishers. As this O&G infrastructure reaches the end of its productive life, decisions on the best practice option for decommissioning must be made. The current policy for decommissioning requires complete removal. Regulators may support alternative strategies, such as leaving infrastructure in place, if risks and impacts are minimised and there are clear environmental, social and economic benefits to do so. It is thought that removal of infrastructure will decrease catch rates and have negative ecological, economic (direct and downstream) and social consequences.

At the same time as the discussion is occurring about removing O&G infrastructure, there have been large investments in constructing and installing purpose built man-made aquatic structures on the seafloor for the express purpose of enhancing the experience of recreational fishers and SCUBA divers.

There is a need to deliver critical information on: 1) the ecological, economic and social value of these man-made structures to recreational and commercial fishers and other stakeholders; 2) the attitudes of stakeholders to man-made structures; and 3) the opportunities and risks of decommissioning strategies to fishers and other groups (e.g. tourism).

Policy regarding the removal of decommissioned structures will benefit from the increased clarity that this project will provide in regards to data requirements for socio-economic models and stakeholder consultation methods. Comparative assessments of decommissioning options rely on the existence of appropriate socio-economic data, a knowledge gap this project aims to fill. An understanding of the impact of man-made aquatic structures on recreational and commercial fisheries is a global priority, and as such this project has strong international importance and relevance.