The focus in modern fisheries management is mainly on economic control through the control of fishing capacity, fishing effort and the allocation of catch quotas and temporal/spatial access to resources. Ensuring sustainable fisheries requires precision in stock assessment and reliability in fishery modelling, both of which require the collection or access to up-to-date statistics, for example, of fish catches, broken down by species, area and gear, as well as some measure of fishing effort. Any country taking part in a multinational fishery must be able to assess such data or scientific advice pertaining to it if it is to have an independent voice in the allocation of quotas and management of stocks by fisheries bodies.

This need has not been diminished by the widespread extension of fisheries jurisdiction following the successful conclusion of the Third UN Conference on the Law of the Sea (UNCLOS) and the adoption of the Convention in 1982 that entered into force in 1994. By themselves, the new limits do not safeguard fish stocks. Even when only one country takes part in a fishery, the pressure from new entrants to the fishery and the great and ever-growing catching power of modern fishing vessels, plus the need to operate them efficiently, can soon lead to overfishing.

The value of a national capacity to assemble and analyse fisheries data goes beyond fisheries assessment and resource allocation. This capacity is needed to help determine a country's level of participation in the fisheries sector as a whole. Nowhere is this better demonstrated than in decisions related to capital investment. Over-investment is one of the greatest hazards in fisheries development, particularly when fish stocks throughout the world are approaching a state of full or over-utilization.

In addition to supporting fisheries management, reliable statistics are also required for effective policy-making and sectoral planning. For example, they are essential as a basis for describing the contribution of fisheries to national food supply and to the economy (e.g. through the system of national economic accounts) and therefore the dependence on fisheries.

Fishery statistics, including data on fishers and fishing vessels, are essential to the monitoring and management of fisheries and improving national and regional statistical systems is a continuous concern of FAO and a standing component of its programme of Work.