Best scientific estimates of retained catches by year, main IOTC area, fleet, and gear for IOTC species

Revision on 22 October 2025: incorporation of Indonesia’s re-submitted 2024 official catch data (submitted on 19 October 2025)

This dataset corresponds to the latest version of the best scientific estimates of annual catches in live-weight equivalent for the 16 IOTC species, aggregated by year, IOTC statistical area and fishing fleet, and fully disaggregated by species and fishing gear. Data are reported by calendar year and extend back to the 1950s, when industrial longlining started in the Indian Ocean.

The data originate from the IOTC Contracting Parties and Cooperating Non-Contracting Parties (CPCs) as per the IOTC data requirements (Resolution 15/02). They are submitted annually, mostly using IOTC Form 1RC, and curated by the Secretariat for dissemination prior to IOTC Working Parties and other scientific data users.

The breakdown by species or gear is performed using additional sources of information available to the Secretariat, such as statistical publications, fishery bulletins, and other historical or proxy data. In some cases, the Secretariat may re-estimate the species or gear composition for strata affected by known data collection or reporting issues. These re-estimations are made in agreement with the IOTC Scientific Committee and may be revised in future updates.

Previous update (2025-10-16) : Catches for Indonesia in 2024 were repeated from 2023, following feedback from Indonesia that additional checks and data processing were ongoing to improve their data

Global attributes

• Title: Best scientific estimates of retained catch by IOTC species, gear and vessel flag reporting country for 1950-2024
• Summary: Curated dataset providing detailed information on the tuna catches in the Indian Ocean
• Context of development: Management of tuna and tuna-like species under IOTC mandate
• Data origin: Retained catch data collected on land or at sea by national institutions and the fishing industry, with some data having been previously extrapolated to represent the broader fishery
• Lineage: Formatting, filtering
• Keywords: Bigeye tuna, IOTC species, catch, tuna fisheries
• Type: Tabular file
• Format: CSV
• Size: 1,067 KB for compressed dataset and 18,476 KB for original dataset
• Structures: 56,255 rows x 27 columns
• Taxonomic standard: ASFIS
• Geographic description: Fishing areas within the Indian Ocean
• Date standard: ISO 8601
• Update frequency: According to data revisions and updates
• Metadata production date: 22 October 2025
• Source: IOTC
• Contact: [email protected]
• Credit: IOTC Secretariat
• Associated rights: Public-domain data requiring source acknowledgement

Data processing

Dataset fields