Datasets

The IOTC Secretariat maintains a range of fisheries datasets submitted by Contracting Parties and Cooperating Non-Contracting Parties (CPCs), in accordance with the Commission’s data reporting obligations established under Resolutions 15/01 and 15/02. These datasets include retained catches by species and gear, geo-referenced catch-and-effort data, size-frequency measurements, and information on fishing vessels. Additional datasets cover time series on fishing fleet characteristics and fish and crude oil prices. The dissemination of these data is governed by the rules set out in Resolution 12/02, ensuring both transparency and appropriate safeguards. The data underpin scientific stock assessments, compliance monitoring, and the formulation of management advice within the IOTC framework.

Most Recent Datasets Released by the IOTC Secretariat

Global Tuna Atlas

The Global Tuna Atlas (GTA) brings together global experience and earlier tuna fishery atlases, which were consolidated in 2019 into a coordinated initiative under the governance of the Fisheries and Resources Monitoring System Partnership (FIRMS).

The GTA disseminates catch data on tuna and tuna-like species made available by the IOTC and four other tuna Regional Fisheries Management Organisations (tRFMOs): 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), and the Western & Central Pacific Fisheries Commission (WCPFC), in collaboration with the Secretariat of the Pacific Community (SPC).

GTA datasets are available through the FAO Fisheries and Aquaculture metadata catalogue catalogue and can be explored via an interactive map viewer. The viewer displays the global distribution of catches at multiple spatial and temporal resolutions for several species groups, including tropical and temperate tunas (both principal oceanic market species and more coastal/neritic species), billfishes, tuna-like species such as bonitos and mackerels, and selected bycatch species, including several pelagic sharks.

Datasets and their accompanying metadata from the GTA are publicly available through the open-access repository:

Other datasets available at the IOTC Secretariat

Tagging Data

Some earlier tagging experiments focusing on skipjack and yellowfin tuna were conducted in the Indian Ocean around the Maldives in 1990–1991 and 1993–1995, with support from the Indo-Pacific Tuna Tagging Programme. Between 2005 and 2009, a large mark–recapture dataset for the principal tropical tuna species of commercial interest -- bigeye tuna, skipjack tuna, and yellowfin tuna -- was collected through the implementation of an EU-funded Regional Tuna Tagging Programme (IO-RTTP), together with several smaller tagging projects. An overview of the tagging programme and its scientific results supporting the management of tropical tunas in the Indian Ocean is available in a special issue of the journal Fisheries Research (Murua et al. 2015).

The policy governing the release of tagging data is established under IOTC Resolution 12/02 on Data Confidentiality Policy and Procedures. Annex 1 of the Resolution provides a Tagging Data Users Application Form, which must be submitted to the IOTC Secretariat to request access to the dataset.

Biological and Morphometric Data

The IOTC Secretariat holds datasets and information on morphometric relationships and selected biological characteristics of IOTC stocks and related species. These include:

• Morphometric relationships and conversion factors used to convert non-standard measurements into standard measurements
• Data on the proportion of specimens by sex (sex ratio)
• Data on maturity and fecundity of IOTC and related species
• Additional datasets, such as those used to derive growth functions for IOTC stocks based on otolith readings.

Stock Assessment Data

Please refer to the meeting pages of each Working Party to consult and download the datasets that were used for stock assessment:

• WP on Billfish (WPB)
• WP on Neritic Tunas (WPNT)
• WP on Temperate Tunas (WPTmT)
• WP on Tropical Tunas (WPTT)
• WP on Ecosystems and Bycatch (WPEB)

For further information on the datasets available and the procedures for obtaining access, please contact the IOTC Secretariat.