Harvest Strategies Toolkit

Traditionally, fisheries management has relied on advice from scientists making educated assessments to predict the present and future size of a fish population.

Harvest strategies are emerging as a critical innovation in fisheries management. Understanding the terms used to describe the many steps in the process will help fisheries managers and other stakeholders effectively apply the practices described in this toolkit. Consistent definitions provide a universal frame of reference for discussing harvest strategies and the concepts involved.

Traditional fisheries management is a two-step process: First, scientists conduct stock assessments, and then fishery managers negotiate measures, such as quotas or time-area closures, to make sure that the resource—the targeted fish—is being used optimally and sustainably. While this seems simple enough, the current approach is anything but.

In recent years, managers of tuna fisheries around the world have begun to shift to using harvest strategies, or management procedures, because they offer a more predictable and stable approach than the traditional use of stock assessments followed by often contentious quota negotiations. The effectiveness of harvest strategies depends, in large part, on managers first agreeing to a set of management objectives for the fishery and the stock, and then using a process called management strategy evaluation (MSE) to select a harvest control rule that is most likely to achieve these goals.

Fisheries managers are responsible for ensuring the health of both fisheries and fish populations. How is health defined, and how can success be measured? Through biological reference points, such as the biomass needed to provide maximum sustainable yield (BMSY). Scientists have used reference points for over 50 years to evaluate stock status and now are applying them more broadly; in fact, reference points are emerging as one of the most widespread and effective bases for modern fisheries management.

Harvest control rules (HCRs) are the operational component of a harvest strategy, essentially pre-agreed guidelines that determine how much fishing can take place, based on indicators of the targeted stock’s status. These indicators can be based on either monitoring data or models.

Management strategy evaluation (MSE) is a tool that scientists and managers can use to simulate the workings of a fisheries system and allow them to test whether potential harvest strategies—or management procedures— can achieve pre-agreed management objectives. In so doing, MSE helps to determine the harvest strategy likely to perform best. That means the strategy would perform well, regardless of uncertainty, and balance trade-offs amid competing management objectives. Around the world, fisheries are moving toward management based on harvest strategies to increase long-term sustainability, stability and profitability. MSE must be an integral component of the process to ensure that the chosen strategy can achieve its objectives.

An examination of existing harvest strategies showcases the range of approaches and what success can look like. As management bodies, including the regional fisheries management organizations (RFMOs) focused on tunas, develop these strategies, policymakers, scientists and stakeholders can gain insight from reviewing the designs and implementation processes for the harvest strategies already in use.