Management strategy evaluation for line fishing in the Great Barrier Reef: balancing conservation and multi-sector fishery objectives

Modern fisheries operate in circumstances of contested demands on resources from multiple stakeholders and management under different legislative jurisdictions. Formal management strategy evaluation (MSE) facilitates quantitative assessment of strengths and weaknesses of alternative management strategies designed to meet multiple agenda. The reef line fishery on the Great Barrier Reef (GBR, Australia) operates under multiple jurisdictions in a World Heritage Area with diverse stakeholder agenda for conservation and commercial and recreational harvest. We worked with stakeholders to identify: (i) specific objectives; (ii) alternative management strategies; and (iii) performance indicators to compare likelihoods of meeting economic, recreational and stock objectives for the fishery and conservation objectives for the effects of line fishing on the GBR. Stakeholders identified objectives and associated performance indicators in four categories, for: (1) conservation of unfished populations; (2) the harvestable stock; (3) economic performance of the fishery; (4) satisfaction of recreational fishers. We used a metapopulation and fishing simulation model (ELFSim) to assess the effects of three effort regimes in combination with three area closure regimes on the primary target species, common coral trout (Plectropomus leopardus). The nine management strategieswere also compared with a zero fishing scenario for reference. Controlling fishing effort most improved prospects of meeting economic, stock and recreational satisfaction objectives for the fishery. Nine of ten performance indicators across all stakeholder objectives were maximised when fishing effort was at the lowest non-zero level tested. Maximising the area closed to fishing with reduced fishing effort was most likely to achieve the conservation objectives. This research provides a case study of productive engagement with stakeholders to address fisheries and conservation management needs in a multi-sectoral spatial management context. Together, we provided a common currency (the prospect of meeting quantified objectives) for impartial evaluation of performance of alternative management options against diverse and often competing stakeholder agenda