They use their catch per unit of effort (CpUE) as an indication for how the stocks were doing.

A very common index of is the catch per unit effort (cpue).

The most commonly used index in fisheries management is based on standardized Catch per Unit Effort (CPUE).

The thresholds are based on the catch per unit effort.

Data sometimes collected by complete enumeration and sometimes by sample surveys include catch per unit effort, price per kilogram and costs and earnings of fishing units.