This dataset lists the global monthly-spatially aggregated catch of tuna and tuna-like species (i.e. billfish,bonitos,and mackerel) from 1950-01-01 to 2019-12-31. 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 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.htmlIOTC:https://iotc.org/data/datasets/latest/CEAllWCPFC:https://www.wcpfc.int/public-domainThe 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;Removal of WCPFC data within the overlapping zone between the IATTC and the WCPFC areas of competence,as information on reporting / fishing fleet is available from IATTC only;Removal of all 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;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;In addition,data that were provided at spatial resolutions inferior to 5° x 5°were aggregated to the corresponding 5° x 5°quadrant. Data that were provided at lower spatial resolutions than 5° x 5° grids were not disaggregated. More details on the processes are provided in the lineage section.