Thunnus albacares | UAE National Red List of Marine Species: Reef-building corals, cartilaginous fishes and select bony fishes

Thunnus albacares | (Bonnaterre, 1788)
Countries in Assessment
United Arab Emirates
Country ISO code(s)
Does the assessment cover a marine EEZ area(s)?
Scope (Assessment)
Taxonomic Group
Taxonomic Group Level 2
Assessed taxon level
Taxonomic Notes
Although several geographic populations have been named as species, morphological and genetic data show there is one world-wide panmictic species (Gibbs and Collette 1967, Scoles and Graves 1993).
Taxon distribution as listed in assessment
In UAE waters, this species occurs only in the Sea of Oman, and is excluded from the Arabian Gulf. Elsewhere, it is circumglobally distributed in tropical and subtropical waters.
Habitats and Ecology
Ecological system type
Terrestrial system
Freshwater system
Marine system
Habitat details as listed in assessment
This open-water pelagic and oceanic species inhabits waters between 18-“31'°C and occurs above and below the thermocline to at least 400 m depth. It schools primarily by size, either in monospecific or multi-species groups. Larger fish frequently school with porpoises and are also associated with floating debris and other objects. It feeds on fishes, crustaceans and squids. Maximum fork length is 240 cm. In the Indian Ocean, longevity is 9 years, length at 50% maturity for males and females is 100 cm and age at first maturity is 3-5 years (IOTC 2018). When applying an age at first reproduction of 4 years and longevity of 9 years, its estimated generation length is 6.5 years based on the following equation recommended by the IUCN Red List methods: Age at first reproduction + (Age at last reproduction -“ age at first reproduction)/2.
Is there a map available in assessment?
Assessed status
Asessment status in full
Assessment status abreviation
Assessment status criteria
Assessment rationale/justification
In the UAE, this pelagic species occurs only in the Sea of Oman where it is taken in both commercial and recreational fisheries. It is heavily targeted by commercial fisheries that operate throughout the Indian Ocean, including the Sea of Oman. Due in part to its highly migratory behavior, the Indian Ocean is considered a single stock by the Indian Ocean Tuna Commission (IOTC). According to the 2018 IOTC stock assessment, this species is overfished with overfishing occurring. Catch has been increasing since 2009, and is currently at an unsustainable level, but effort data are largely lacking, and the 2017 spawning stock biomass (SSB) was at 30% of unfished levels. As of 2009, SSB had declined by 45% over the previous decade (1999-“2008). Assuming this decline continued to the present due to increasing catch levels since 2009, a linear regression of estimated adult biomass indicates that the Indian Ocean stock is suspected to have declined by 61% over the past three generation lengths (1999-2019 or 20 years); therefore, it is listed as Endangered A2bd.
About the assessment
Assessment year
Assessors/contributors/reviewers listed
UAE National Red List Workshop
Affliation of assessor(s)/contributors/reviewers listed on assessment
Assessor affiliation specific
Criteria system
Criteria system specifics
IUCN v3.1 + Regional Guidelines v4.0
Criteria system used
Criteria Citation
IUCN. 2012. IUCN Red List Categories and Criteria: Version 3.1, Second edition. IUCN, Gland, Switzerland and Cambridge, UK. iv + 32pp pp. And IUCN. 2012. Guidelines for Application of IUCN Red List Criteria at Regional and National Levels: Version 4.0. Gland, Switzerland and Cambridge, UK: IUCN. iii + 41pp.
Endemic to region
Endemism Notes
Is an endemic?: Not_assigned
Threats listed in assessment
Overfishing is a major threat to this species in the UAE in part due to its overfished status across the Indian Ocean stock, in which the Sea of Oman is included (IOTC 2018).
Conservation Measures

Conservation measures:
Conservation measures notes:
Required conservation measures:

Scientific Name Kingdom Phylum Class Order Family Genus
Thunnus albacares Animalia Chordata Actinopterygii Perciformes Scombridae Thunnus