数据收集方法: Data are collected by the following form:
"STATLANT 47A", this questionnaire covers the reporting of annual catch data, requesting a breakdown of the catches by species and statistical divisions of the FAO Major Fishing Area 47.
数据处理方法: Where officially reported national statistics are lacking or are considered unreliable, FAO/FIPS makes estimates based on the best information available. Such data are flagged with an "F".
数据核准机制: National statistics are validated through analysis, exchanges with Regional Bodies, discussions at working groups, comparative intelligence, expert advice, comparisons with trade, etc.
For major group 36 (tunas, bonito and billfishes), in order to improve coverage of world tuna catch statistics, data reported to FAO by national official sources to FAO are compared with statistics transmitted by regional bodies collecting tuna catch statistics, as there are three potential sources of tuna data discrepancies between records held by FAO/FIPS and regional bodies: 1) different sources; 2) different data coverage (e.g. exclusion of artisanal catches in the data collected by regional bodies; and 3) different dissemination timing.
Consistency and Accuracy
To facilitate the reporting of consistent and accurate world capture statistics, FAO/FIPS provides internationally agreed definitions for determining the nationality of the catch and the criteria for separating capture and aquaculture production.
The flag of the vessel performing the essential part of the operation catching the fish should be considered the paramount indication of the nationality assigned to the catch data. Aquatic organisms which are exploitable by the public as a common property resource, with or without appropriate licences, are the harvest of fisheries, while aquaculture production implies some form of intervention in the rearing process and individual or corporate ownership of the stock being cultivated.
Several countries still report their catches by large groups of species. In these circumstances the catch data presented by individual species items are likely to be underestimated. Therefore, when examining the statistics for a particular species, it should be noted that an unknown proportion of the catches for that species might have been reported by the national office under the generic, family or order name of the species, or even more roughly as 'fishes not identified'. Consequently, species item totals frequently underestimate the real catch of the individual species.
Due to the non-availability of catches by subareas for the Republics of the former USSR in the period 1988-91, and for the Russian Federation in 1992-93, the allocation of catches to the division "Not known" is abnormally high. Due consideration should be paid to the above, while using the time series data for analysis.