The cross-Government LNFSWG has been working with stakeholders since 2015 to address ongoing industry and community concerns over the economic impacts of fur seals on the LCF, including depredation of catches and damage to fishing gear. Despite recent mitigation initiatives, reports from industry suggest that the seal-fisher conflict and associated economic impacts have intensified in recent years. In an effort to reduce financial pressure on licence holders, the SA Government (PIRSA Fisheries and Aquaculture) has waived cost-recovered licence fees for the net sector of the fishery, as well as implemented other more flexible management arrangements, for the 2015/16, 2016/17, 2017/18 and 2018/19 fishing seasons. Although these measures have been welcomed by industry, it is not clear whether the current level of support for fishers is adequate or how to evaluate the costs and benefits of alternative mitigation options or management interventions.

There has also been industry and community concerns about the potential impact that seals are having on waterbirds, fish populations, and on the broader Lakes and Coorong ecosystem, with some sectors advocating for seal numbers to be managed to mitigate these perceived impacts.

There is a need for reliable, quantitative information on the nature and extent of the economic and ecological impacts of seals in Lakes and Coorong region, and the factors that attract seals to the region and drive the seasonal increase in fur seal numbers. This information will support processes to identify, prioritise and develop practicable and cost-effective long-term policy/management strategies to manage long-nosed fur seal numbers and mitigate their impacts in the Lakes and Coorong region, during and after the project.

Current stock assessment of Black jewfish in the NT relies on outputs from a Stock Reduction Analysis (SRA) based on assumed stock-recruitment relationships and catch-and-effort information. Increases in Black jewfish catches in 2017/18 after several poor years were inconsistent with the SRA forecasts, demonstrating a need: 1) to better understand the drivers of fishery productivity and recruitment; and 2) for information on abundance and size-structure.

Environmental variability strongly influences abundance and recruitment in coastal fisheries of northern Australia. In contrast to Barramundi and King threadfin, anecdotal information suggests that Black jewfish catches may be negatively correlated with freshwater outflow during the wet season. However, data on external drivers of population structure and physiological responses to environmental variability are currently lacking.

Another critical knowledge gap is the abundance and size-structure of Black jewfish populations. At present, the only information available is from commercial catch data and surveys of recreational fishers. These fishery-dependent sources have important biases, particularly size selectivity. There is an urgent need for more robust, fishery-independent data on population abundance and size-structure for Black jewfish.

This project will examine a range of environmental variables and physiological parameters from sampled fish to identify the key drivers of productivity and recruitment for Black jewfish. We will also collect fishery-independent data on the abundance and size-structure of Black jewfish populations using high-resolution sonar, with a view to developing a monitoring methodology to support the CLF harvest strategy.

The overall goal is to improve the accuracy and predictive performance of Black jewfish stock assessment, thereby increasing confidence in the information used to justify management decisions and providing increased certainty to fishers across all sectors. A new, full-time post-doctoral fellow position, jointly funded by CDU and AIMS, will lead the project activities under the supervision of the project investigators. FRDC funds are requested for technical assistance, travel and operating.

The need for cumulative impact assessment (CIA) is increasingly being recognized. The development process for Australia's Harvest and Bycatch Policies, and their associated guidelines have reinforced the need for assessment of cumulative impacts, and the EPBC Act has also explicitly required consideration of cumulative impacts.

Where multiple activities occur or are planned, an understanding of their combined effects on the environment is necessary to address policy requirements and achieve sustainability. The concept of cumulative impact assessment is not new – indeed cumulative assessment has been recognized for many years, and a range of methods have been proposed around the globe. However, no methodology for undertaking cumulative assessments has been accepted nationally or globally. In addition to considering the impacts across all fishing sectors (commercial, recreational, indigenous, as required by recent changes to the Fisheries Administration Act 1991) and all fisheries, there is also an increasing need to consider other users of marine resources and coastal waters (e.g. renewable energy, shipping etc), especially where space crowding may be an issue.

Target species stock assessments typically consider the species of interest as well as other sources of fishing mortality (e.g. discards), but they do not usually consider their effects on other fisheries sectors or the effects of other sectors on the focal fishery. CIA methods therefore need to consider interactive and indirect effects. To date, interactive effects are often viewed as additive (simple linear addition of one impact to another) with little consideration given to synergistic, antagonistic or non-linear effects. While the ERAEF toolbox used for assessment of bycatch and protected species has some potential options for cumulative impacts (e.g. SAFE method), at this stage they are insufficient for moving to the scales and complexities across multiple fishing sectors and fisheries.

Thus, sustainable fisheries management requires new approaches that consider all sectors and all fisheries and how they impact the environment. Such CIAs will be challenging given that empirical data are often lacking - a dedicated research effort is needed.