A Guide to Fisheries Stock Assessment

Fishery managers have a range of goals. They strive to maintain healthy fish populations and a healthy fishing industry while still preserving vital recreational communities. To achieve their goals, managers rely on a collection of tools, including quotas, size limits, gear restrictions, season timing and area closures. But how do decision makers determine which combinations of tools will best accomplish their objectives? To choose the best approach to managing a fish stock, managers must equip themselves with as much information as possible.

A stock assessment provides decision makers with much of the information necessary to make reasoned choices. A fishery stock assessment describes the past and current status of a fish stock. How big is the stock? Is it growing in size or shrinking? A stock assessment also attempts to make predictions about how the stock will respond to current and future management options. Will a slight increase in fishing pressure have a negative effect on the stock next year? Ten years from now? In the end, the manager must decide how to interpret the information from the stock assessment and determine which options are best overall.