This dataset lists the monthly-spatially aggregated catch of tuna and tuna-like species (i.e. billfish,bonitos,and mackerel) by purse seiners and pole-and-liners from 1950-01-01 to 2019-12-31 in the Indian,Atlantic and Eastern Pacific Oceans.

This dataset was computed using public domain georeferenced catch-and-effort datasets released by the five tuna Regional Fisheries Management Organizations:the Commission for the Conservation of Southern Bluefin Tuna (CCSBT),the Inter-American Tropical Tuna Commission (IATTC),the International Commission for the Conservation of Atlantic Tunas (ICCAT),the Indian Ocean Tuna Commission (IOTC) and the Western and Central Pacific Fisheries Commission (WCPFC).

Species-specific catches expressed in weight or number are stratified by year,month,reporting / fishing fleet,fishing gear,fishing mode (i.e. type of school association) and area (statistical squares of 1° longitude and latitude).

Data from the Western Pacific ocean were not included because WCPFC only provides purse seine and pole-and-line catch at a spatial resolution of statistical squares of 5° longitude and latitude.

“FIRMS level 0” identifies the processes applied to the primary datasets by the FIsheries and Resources Monitoring System (FIRMS)to generate the dataset.

t-RFMO specific descriptions of the original input data sets can be found at the following links:- CCSBT:https://www.ccsbt.org/en/content/sbt-data - IATTC:https://www.iattc.org/ - ICCAT:https://www.iccat.int/en/accesingdb.html - IOTC:https://iotc.org/data/datasets/latest/CESurface - WCPFC:https://www.wcpfc.int/public-domain

The processes applied to produce this FIRMS level 0 dataset at global scale consist of a series of steps:Original catch-and-effort data are disseminated in such a way that redundancy may exist between the various datasets released,or that dimensions may be split over the datasets for some strata. To cope with these issues and collate a unique and (possibly)complete value of catch per stratum (i.e. with all the available dimensions),the original datasets had to be merged and post-processed by removing the duplicated strata or reassembling those strata with all available dimensions split over multiple datasets; Overlapping zone between RFMO lead to providing redundant data,which is removed from the dataset. (See details in Markdown). Errors in CTOI's cwp code reulsts in modifying data from the provided dataset by renaming the grid.

Removal Southern Bluefin Tuna data provided by t-RFMOs other than the Commission for the Conservation of Southern Bluefin Tuna (CCSBT),which is considered the only authoritative source of information for the species. The years in which no data is provided by CCSBT but it is by other RFMOS,this data is kept. Mapping of the original code lists (t-RFMO specific) to standard FAO / CWP code lists (e.g.,for gears and species) or to ad-hoc classifications as in the case of reporting / fishing fleets. These mappings have been done in collaboration with the t-RFMOs Secretariats and might be subject to future revisions

More details on the processes are provided in the lineage section. - Units for the measures were harmonized. - Values of catch were expressed in weight converting numbers using matrices of average weights varying with species,fishing gear,year and large geographical areas,i.e. equatorial or tropical (A. Fonteneau,pers.com). Average weights were computed from the Japanese and Taiwanese size-frequency data as well as from the Japanese total catches and catch-and-effort data. Some data might not be converted at all because no conversion factor exists for the stratum:those data were kept and the unit of catch was set to Number of fishes harvested. - Values of catch were expressed in weight converting numbers using matrices of average weights varying with species,fishing gear,year and large geographical areas,i.e. equatorial or tropical (A. Fonteneau,pers.com). Average weights were computed from the Japanese and Taiwanese size-frequency data as well as from the Japanese total catches and catch-and-effort data. Some data might not be converted at all because no conversion factor exists for the stratum:those data were kept and the unit of catch was set to Number of fishes harvested.