Effective management of fishing capacity requires reliable estimates of current capacity, and to this end most countries have developed a form of capacity measure usually based on some physical characteristics of the fleet. In the United Kingdom, the “capacity” measurement system currently in place is used as the basis of existing capacity reduction programmes. Each vessel has a number of Vessel Capacity Units (VCUs) defined by its size and engine power. An assumption is made that this measure is related to the ability of the fleet to catch fish. More recently, techniques have been developed...

Effective management of fishing capacity requires reliable estimates of current capacity, and to this end most countries have developed a form of capacity measure usually based on some physical characteristics of the fleet. In the United Kingdom, the “capacity” measurement system currently in place is used as the basis of existing capacity reduction programmes. Each vessel has a number of Vessel Capacity Units (VCUs) defined by its size and engine power. An assumption is made that this measure is related to the ability of the fleet to catch fish. More recently, techniques have been developed to measure capacity directly in terms of potential output. In this paper, the fishing capacity of a sample of UK otter trawlers and a set of boats that primarily use static gear (i.e. nets and lines) is estimated using data envelopment analysis (DEA). Estimates are made on a species-by-species basis for the key species harvested. These are compared to the existing measures of physical capacity. The results suggest that VCUs may provide a reasonable approximation of fishing capacity for fleets using mobile gear, but may be inappropriate for fleets using static gear. Implications for capacity management based on the physical measures, given the results, are drawn.