Surface fisheries: catch data in nominal catch weight and effort data in fishing days (purse seine, baitboat, troll, drift nets) should be provided to IOTC by 1° grid area and month strata. Purse seine fishery data should be stratified by type of school. Those data should preferably be extrapolated to the national monthly catches of each gear. The raising factors used, corresponding to the logbook coverage, should be given routinely to IOTC.

Longline fisheries: catch and effort data of the longline fisheries should be provided to the IOTC by 5° grid area and month strata, preferably in numbers and in weight. Fishing effort should be given in numbers of hooks. Those data should preferably be extrapolated to the national monthly catches. The raising factors used, corresponding to the logbook coverage, should be given routinely to IOTC.

The catches, efforts and sizes of the artisanal, small scale and sport fisheries should also be submitted on a monthly basis, but using the best geographical areas used to collect and process those data.

Considering that size data are of key importance for most tuna stock assessment, length data, including the total number of fish measured, should be routinely submitted to the IOTC on a 5° grid area and month basis, by gear and fishing mode (e.g. free/log schools for the purse seiners). Size data should be provided for all gears and for all species covered by IOTC. Size data sampling should preferably be run under strict and well described random sampling schemes which are necessary to provide unbiased figures for the sizes taken. The exact recommended level of sampling could vary between species (as a function of various parameters), but the specific level of recommended sampling needs to be established by the working party on statistics. More detailed size data, for instance size by individual samples, should also be made available to IOTC when requested by specific working groups, but under strict rules of confidentiality.

For a better understanding by IOTC of changing patterns in effective fishing effort by fleets operating in its area of competence, more information has to be obtained. Since the activities of supply vessels and the use of fish aggregating devices (FAD) are an integral part of the fishing effort of the purse seine fleet, the following information should be routinely submitted to IOTC:

Number and characteristics of supply vessels: (i) operating under their flag, (ii) assisting purse seine vessels operating under their flag, or (iii) licensed to operate in their exclusive economic zones, and that have been present in the IOTC area of competence.

Levels of activity of supply vessels: including number of days at sea, on 1° grid area and month basis.

In addition, contracting parties and cooperating non-contracting parties shall do their best to provide data on the total number and type of fish aggregating devices (FADs) operated by the fleet, on a 5° grid area and month basis.

It is essential that all fishery data be available to the IOTC Secretariat in due time to allow monitoring of stocks and analysis of the data. Thus it is recommended that the following rules be applied as standard obligations:

Surface fleets and other fleets operating in coastal zones (including supply vessels) must provide their fishery data at the earliest possible date but no later than 30 June each year (previous year's data).

Longline fleets operating on the high seas must provide the provisional fishery data at the earliest date, but no later than 30 June (previous year's data). They must provide the final estimate of their fishery data before 30 December each year (previous year's data).

The time limits presently allowed for submitting statistics could be reduced in the future as communication and data processing technologies become ever more rapid, which should reduce the present data processing delays.