1. In general, and mainly for trawling, the fishing effort exerted per unit of areas (e.g. in hours of trawling per 100 square miles). In stock assessment theory, the effective (or standard) fishing effort per unit area must be proportional to fishing mortality through the relation F = q(f/A) where (f/A) is the fishing intensity, and q is the catchability coefficient; 2. Effective fishing effort; 3. Fishing effort per unit area; 4. Effectiveness of fishing.