Given AFMA’s need to satisfy its ESD objective, there is a need to consider uncertainty explicitly and identify performance indicators and harvest strategies that are as robust as possible to incorrect assumptions and misinformed interpretations of data. Use of these indicators and harvest strategies will improve the chances of achieving a reasonable balance between the conflicting objectives of long-term resource sustainability and the maximisation of economic gains.

The project also addresses to some extent two key research areas in subprogram (B) of the Wild Stock Program of the SCFA Research Committee: “Biological and socio-economic evaluation of alternative management scenarios for different species and categories of fishery to provide a framework for management planning” and “The evaluation and provision of harvest strategy models through comparison of management strategies using theory and case studies, establishing objective performance indicators for different jurisdictions and identifying options which are appropriate to the nature of the fishery”.

FRDC project 98/102 has already identified several areas where there is considerable uncertainty. However, that project has focussed on ‘generic’ data-poor species (although tailored to some extent to the actual situation for jackass morwong, pink ling, tiger flathead and spotted warehou, species that have been identified as ‘high' and 'medium' priority by SEFAG). Ideally, harvest strategy calculations should be tailored to particular species to achieve optimal outcomes. This project will evaluate harvest strategies for the four species that received initial focus in FRDC 98/102. FRDC 98/102 also focused on situations in which the fishery is based on a single gear-type only. However, it is increasingly being realised within SEFAG that even within the trawl sector there are sub-fleets, each of which differ substantially in terms of their selectivity. For example, for blue warehou, the trawl fleet off New South Wales has a selectivity pattern closer to that of the non-trawl fleet based at Lakes Entrance than that of the trawl fleet based in Portland.

One of AFMAs legislative objectives relates to providing cost-effective management. Increasingly industry is being expected to bear some of the costs associated with the monitoring on which stock assessments and hence TACs are based. There is therefore a need for an objective process for determining the trade-off between monitoring costs and the ability to which AFMAs management objectives are satisfied. The aim of this study is to examine this question within the scope of the trade-off between catch and risk.

Finally, there is a major need for stock assessment on more species in the SEF. However, although data for many species is poor, there are nevertheless fewer assessments than there could be due to a lack of software for conducting the increasingly complicated assessments demanded by stakeholders. FRDC 98/102 has developed software modules for implementing several commonly applied stock assessment methods (including “Integrated Analysis” – the basis for the current assessments for blue grenadier, school whiting, eastern gemfish, and blue warehou). If the detailed output from the software that implements these assessment methods could be available in an easily useable and visual form, this software could provide a better basis for conducting routine stock assessments.

1) Legal obligation.

In Australia, sea snakes are a protected species group under Schedule 1 of the National Parks and Wildlife Regulations 1994, but despite their protected status, tens of thousands of snakes are caught incidentally in the Queensland trawl fishery each year. In the Northern Prawn Fishery (NPF) it has been estimated that between 81,000 and 120,000 were caught annually in the early 1990s (see Wassenberg et al. 1994 and Ward 1996). Wassenberg et al. (2001) reported that 48.5% of sea snakes caught from research and commercial prawn trawling die as a result of being trawled. The Queensland Government and the Queensland commercial trawl fishers are legally obliged to address the problem and minimise sea snake – trawl interactions.

2) Recommendations by the Department of Environment and Heritage (DEH)

The impact of prawn trawling on the sustainability of sea snake populations on the Queensland east coast is a major concern to DEH. In their review of the strategic assessment of the Queensland east coast trawl fishery, DEH recommended to the Queensland Government that research into the impact of trawling on sea snakes be promoted, and that all reasonable steps should be undertaken to reduce interactions between protected species and the Queensland trawl fishery.

In summary there is a strong legal case in support of research that reduces the impacts of trawling on sea snake populations. In addition, addressing the DEH recommendations will help to ensure that that the Queensland east coast trawl fishery remains on the list of fisheries that are accredited for export, thus securing the continuation of the export of seafood produced from the fishery.

References

Ward TM (1996) Sea snake by-catch of prawn trawlers on the northern Australian continental shelf. Marine and Freshwater Research 47, 631-635.

Wassenberg TJ, Milton DA, Burridge CY (2001) Survival rates of sea snakes caught by demersal trawlers in northern and eastern Australia. Biological Conservation 100, 271-280.

Wassenberg TJ, Salini JP, Heatwole H, Kerr JD (1994) Incidental capture of sea-snakes (Hydrophiidae) by prawn trawlers in the Gulf of Carpentaria, Australia. Australian Journal of Marine and Freshwater Research 45, 429-443.

The current Harvest Strategy Framework has no formal process for deciding whether the Tier harvest strategy applied to a stock is appropriate or not, there is thus no formal process for deciding when to use a lower Tier. Even worse, when a Tier4 assessment is deemed inappropriate in the SESSF there is no lower Tier available for use. There is thus a need to establish guidelines for identifying when a Tier method is inappropriate for a stock, and also a need to develop an array of alternative harvest strategies for use as a Tier5 when Tier4 is deemed inappropriate. As there is such a wide range of potential Tier 5 procedures, many with the same data requirements, testing is required to allow an informed decision about which are best to implement - particularly in the SESSF context.

Section 6 of the DAFF public discussion paper for the review of the Commonwealth fisheries Harvest Strategy Policy (see FRDC project 2012/225) investigates questions of uncertainty about assessment approaches, the level of data required to maintain species within a given Tier and when to switch between Tiers. The proposed project directly addresses known issues in the SESSF that relate to this question, and timing of the review allows this project to tailor analyses to specifically address review recommendations and advice.

A parallel and complementary project (FRDC 2012/202) provides a study of the trade-off among ecological and economic risks associated with harvesting, the benefits of harvesting and the costs associated with management. This is concerned with strategic considerations over all Tiers, whereas the current project looks more specifically at data requirements within SESSF Tiers, and alternative Tier procedures for data poor species in the SESSF.