Dynamics and impacts of changing reference points with a focus on recruitment productivity

Abstract

Managing fish stocks in the context of changing ecosystems and productivity is an ongoing challenge for fisheries science. Reference points are key tools for enabling effective management, defining management goals, guiding management actions and providing advice on sustainable catches. Measuring productivity is crucial for estimating reference points. For many fish stocks, there is evidence that productivity has changed over time in a non-stationary manner. While understanding why these changes have occurred is important, in the more immediate term, understanding how productivity is changing and accounting for those changes is crucial for tactical management. The objectives of this thesis were to (i) explore reference point estimation and retrospective changes, (ii) highlight a method developed by Randall Peterman and colleagues (Peterman’s Productivity Method) as a method to track temporal changes in recruitment productivity of fish stocks, and (iii) apply this method to the Celtic Seas ecoregion.