The NPF tiger prawn stock assessment uses a bio-economic model to maximise economic yield (MEY) by determining fleet-specific optimal effort pathways over a seven-year projection period. The projected effort output determines the Total Allowable Effort (TAE) for the following two years, managing the fishery toward its MEY-based Target Reference Point (TRP).
MEY has been the operative TRP in the NPF for over a decade, yet questions persist about whether other targets from different harvest control rules (HCR), particularly Maximum Sustainable Yield (MSY)-based or “hockey-stick” biomass/economic targets, would have delivered better economic and operational outcomes across the fishery’s inherently variable recruitment and multi-species dynamics.
To evaluate alternative TRPs, a retrospective analysis of the NPF tiger prawn assessments from 2016 onward is applied. We quantify and compare how alternative TRPs would have changed recommended fishing efforts, their relevant biological catches, realized stock trajectories, revenues and costs, and the stability of fishing opportunities.
The finding from the analysis suggests the current NPF HCR with dynamic MEY performs best in terms of biomass status, economic benefit and the fishery stability.