The statistical population is the set of countries participating in the work of the COFI, i.e. OECD members, excluding landlocked countries, with some exceptions (Czech Republic and Slovakia are included, Israel is not).

The group includes also the following partner countries: Argentina, China, Chinese Taipei, Colombia, Costa Rica, Indonesia, Peru, Philippines, Russian Federation and Thailand.

In order to facilitate analysis and comparisons over time, historical data for OECD members have been provided over as long a period as possible, often even before a country became a member of the Organisation.

Information on the membership dates of all OECD countries can be found at OECD Ratification Dates.

The 'fishing population' includes all commercial, industrial and subsistence fishers, operating in freshwater, brackish water, and marine waters in economically inspired efforts to catch and land any of the great variety of aquatic animals and plants, should be included. People working on fish farms, hatcheries, and employed in shell fish culture operations, should also be included. The term 'fisher' should include not only those operating from fishing vessels of all types, but also those operating land-based fishing gears and installations from the banks of rivers, lakes, canals, dams etc., and from beaches and shores which do not require the use of auxilliary boats. Where possible a breakdown by the type of activity should be included. The crews on fish factory ships, mother ships to fishing fleets, and on auxilliary craft such as, fish carriers, and fish transport craft should be included.

The data collected nationally should include nationals, and others employed on nationally registered vessels landing their catches in foreign ports.

Foreign fishers working on foreign vessels landing in national ports should be excluded from the data. However the data should show, preferably separately, the national fishers working on foreign vessels chartered to national companies.

Fishers on whaling vessels should be recorded separately.

The crews of state-operated fishery patrol vessels, fishery protection vessels, hospital ships, etc. should be excluded from the fishers statistics.

The methodological reference document for fisheries and aquaculture statistics is the CWP Handbook of Fishery Statistics.

The CWP noted a number of problems in identifying and enumerating separately 'fishers' as primary producers among the economically active population. These problems arise largely from the seasonal availability of the various fishery resources compounded by the seasonal availability of more lucrative occupations. In many countries the number of people whose only source of income is from a year-round activity in fishing is small compared with the number of people entering the industry at peaks of activity in that industry, or slack periods in a more lucrative industry. For example, fishing is often of major importance in 'under-developed' regions where the other major industry may be tourism. (See FAO Fisheries Circular 929, Revision2). The fishing 'season' may be adapted so that it does not coincide with the peak tourist period from which earnings might well be higher.

Another problem is associated with subsistence fishing which is undertaken on a full-time, part-time, or occasional basis in many developed or developing communities as part of the occupation of the economically-active populations. However, people who are too young, too old to be normally included in the economically active population may be involved in subsistence fishing. These issues are further complicated where subsistence fishing merges with recreational fishing. For example, sports fishers and people owning and operating pleasure craft might try to offset their capital expenditure and running costs through the sale of fish caught during trips of such recreational craft.