Harvest Strategy Evaluation for School and Gummy Shark

Abstract

The Management Strategy Evaluation (MSE) approach is used to assess the benefits of alternative harvest strategies to set annual Total Allowable Catches (TACs) for school shark (Galeorhinus galeus) and gummy shark (Mustelus antarcticus). The harvest strategies are based on a stock assessment method that includes consideration of the gear-types employed in the fishery and the nature of the shark pupping process. The harvest strategies are compared in terms of performance measures that relate to average catches, catch variability and resource conservation. The uncertainties that impact performance to the greatest extent are the technical interaction between fishing for school shark and for gummy shark, the productivity of the overexploited school shark resource, and the extent to which tagged animals lose tags (or die) immediately after tagging.