From input to output controls in a short-lived species: the case of Australia's Northern Prawn Fishery

Abstract

A management strategy evaluation (MSE) framework is developed to evaluate strategies that provide total allowable catches (TACs) when the target biomass corresponds to maximum economic yield (MEY). The framework is applied to Australia’s Northern Prawn Fishery (NPF), which has been actively managed using a tradable input-control system, but is to move to output controls based on individual transferable quotas (ITQs), with a consequence that the current management strategy needs to be replaced. Because the fleet is small, it is possible to set a TAC that cannot be taken entirely. Whereas input controls tend to self-adjust if recruitment is not accurately predicted, and consequently catch variability tends to be low, this is not the case for the reasonably variable species caught in the NPF when they are managed using TACs. The management strategy recovered the simulated stock to the target reference point when it was initially depleted, and avoided dropping the stock below the limit reference point (LRP) for five scenarios based on the current best understanding of resource status; however, in some cases, the stock was left above the target biomass because of biases in the assessment. A scenario in which the stock was forced to be initially depleted to below the limit reference point showed that the management strategy allows recovery.