Introduction to the IOTC tuna factory purchases data flow and database

Tuna factory purchases data constitute a complementary source of independent information in support of IOTC tuna fisheries analyses. This novel data source is aimed to be used routinely for future assessment and to cross-verify and reduce uncertainties in the currently available statistical data (in particular for what concerns species composition). A total of 45 companies have been submitting tuna quarterly reports to IOTC secretariat since 2010. Here, we present the IOTC tuna factory purchases data flow and database, including the different steps of data harmonization, compilation and preliminary curation undertaken on the quarterly reports to improve the overall data quality and traceability to the original information source. Between 2010 and 2020, 72% of the total number of purchases records received at the Secretariat came from the Indian Ocean, and the rest from the Atlantic and Pacific Oceans. The Indian Ocean 2010-2020 reports revealed that purse-seine and pole-and-line represented the majority of the total number of records (63% and 21%, respectively), and were dominated by skipjack (37%), followed by yellowfin (31%), bigeye (15%), and albacore (14%) tunas. Moreover, around 75% of purchases data from the Indian Ocean reports were harmonized into four species-specific commercial weight categories for each of the four major tuna species. Next project steps aim to finalize data curation and conduct analyses including comparisons of the tuna purchases data against the IOTC fisheries statistics by species and gear.