Cumulative Impact Risk Assessment Tool for Aquaculture in Australia
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.
Biological parameters for stock assessments in South Eastern Australia – an information and capacity uplift
South-east Australian waters are recognised as ocean warming hotspots and overall, Australian waters have warmed faster than the global average (Hobday and Pecl 2013, IPCC 2019). Key components of the productivity of marine fish (growth, maturity, and recruitment) are expected to be changing in response to shifts in climate and it is entirely possible that there have been changes in fundamental productivity parameters for Australian stocks.
The regularity with which the biological parameters that are used in stock assessments are evaluated and updated varies considerably among the species that are targeted in Commonwealth Fisheries. Assessment of changes in these parameters is limited largely to sensitivity analyses consisting of exploring alternate time-invariant values of natural mortality, maturity and stock recruitment steepness at values close to those used in the base-case assessment and generally agreed upon as within acceptable ranges of values. Recently an evaluation of the provenance of the biological parameters used in stock assessments found that species from the SESSF contained the largest number of parameters where provenance could not be ascertained from the literature and that SESSF species comprised over 50% of those species where biological parameters were determined to be more than 20 years old (FRDC project 2019-010, Evans et al. 2022). When plausible changes to biological parameters (such as those that might occur under environmental change) were explored quite substantial changes in biomass estimates for key target species occurs. This means that parameter mis-specification, such as due to relying on older parameter estimates that encode predator-prey and other ecosystem processes from a system state that has since changed, could be a real issue for assessments in the SESSF.
The reliance of current assessments on what is likely to be out-of-date information leads to considerable uncertainty, which cannot be easily quantified that then propagates into management decisions. Without an understanding of changes in biological parameters and how these changes might impact assessments, it is difficult (if not impossible) to evaluate whether current management measures are ensuring sustainability. Overall, the project recommended that updating parameters in stock assessments, modifying base cases, or more heavily drawing on results from sensitivity analysis in discussion of stock assessment results would be strongly advisable, especially in regions where large environmental shifts are known to be occurring, such as the SESSF.
The RV Investigator voyages to be conducted in 2023 and 2024 under the CSIRO led SEA-MES project provide a unique opportunity to access relevant biological samples that could be used to update the biological parameters identified in FRDC Project 2019-010 as a high priority (age, growth, reproduction, stock structure and although not directly used in stock assessments themselves but having significant influence on parameters that are used in assessments (such as growth and mortality), diet and food webs). These voyages have a focus on the marine ecosystem that supports the SESSF and a number of the hypotheses being posed by the study are focused on target species within the SESSF and their food webs. This will result in significant sampling of those species , with the co-benefit that there will be new samples available for the contemporary estimation of key biological parameters and evaluation of the representativeness of parameters being used in stock assessments (and with sufficient sample numbers to ensure robust updated estimates). These voyages also provide a unique opportunity to build capacity in at sea sampling, exposure to ecosystem level sampling design and post-voyage biological analyses. By linking post voyage analyses with the direct needs of both stock assessments and ecosystem models used in the SESSF, the project provides opportunities for building deeper understanding of the use of biological parameters in stock assessments, and direct application of fisheries biology.
Role of marine reserves in sustainable management of Australia's ocean estate - review of the Heard Island and McDonald Islands bioregion
The HIMI bioregion supports significant marine conservation values as well as a highly sustainable, and valuable commercial fishing industry. Typically, marine parks/reserve development processes are tasked with developing marine spatial planning arrangements that achieve a balance between preserving conservation values of the area and maintaining/promoting human activities through the principles of Ecologically Sustainable Development (ESD). However, key uncertainties remain regarding the policy priorities and how the final design of marine parks are objectively determined.
This project will provide an independent assessment of the framework used for original design of the HIMI Marine Reserve in 2002, the review in 2014, and the current review to provide recommendations for future development. The project will also explore how/if the policy objectives have been achieved since inception . Furthermore, this project will explore the potential of a quantitative risk-based approach to provide for minimising the uncertainties in the Marine Protected Area (MPA) development processes and deliver an objective framework.
In addition, the project will explore the current HIMI marine reserve framework, the associated commercial fishing industry arrangements and how they intersect with regard to:
Regulation
• Regulatory processes to minimise impacts of commercial fishing
• Legislative framework currently in place for Ecological Risk Assessment/ESD, Ecosystem-Based Fisheries Management, bycatch policy strategic research plans
• Marine Protected Areas review processes
• Statutory Fishing Rights (SFRs)
Economic impacts
• Commercial fishing viability
• Statutory fishing rights
• Permitted fishing gear types – (e.g. potential removal of MSC certified trawl fisheries with additional implications on research activity)
Biological impacts
• Impact on juvenile toothfish index of abundance and icefish estimates – accuracy of tracking stock will be significantly reduced if ability to trawl is removed (i.e. random stratified trawl survey impacted)
• Stock assessment model ability to consider toothfish population structure if longline fishery further constrained
• Climate change and effects of population shift
• Increasing policy position of MPAs as fisheries management tools
• Increased localised depletion and constrained ability to distribute commercial fishing effort
Social Impacts
• Market access
• Community sentiment