Skipjack tuna | European Tracking Network

Skipjack tuna

Katsuwonus pelamis

Image: planettuna.com ©

 

Species description and statusSkipjack tuna (Katsuwonus pelamis) is the world’s most widely caught tuna species and the one that is most common in canned tuna. It is a mid-sized tuna that can weigh up to 35 kg as an adult. Katsuwonus pelamis lives in the Atlantic Ocean, reaching in the last decades Mediterranean waters. This species reaches sexual maturity at just one year of age and in tropical waters it can be continuously spawning. Skipjack tuna is distributed throughout the tropics in every ocean, both as adults and as larvae. There are also populations that inhabit temperate and tropical waters all around the world with its northernmost distribution usually around 40ºN (Fig. 1). The International Union for Conservation of Nature (IUCN) Red list of Threatened Species classifies skipjack tuna as Least Concern (IUCN downloaded on 29 November 2019 \www.iucnredlist. org. The International Commission for the Conservation of Atlantic Tuna (ICCAT), in charge of the management of skipjack tuna in the Atlantic Ocean and adjacent seas, identifies an Eastern and a Western Atlantic stock (ICCAT 2019). Skipjack tuna abundances are rising in the Western Mediterranean where they breed from May through August.

Figure 1. Distribution of skipjack tuna with blue representing adult habitat and green representing spawning areas.

 

Regions of interest: The Meditarrenean Sea, the Atlantic Ocean and all oceans in general.

Knowledge gaps: Knowledge gaps exist in their migration patterns. The range of distribution of this species is generally expanding (Worm and Tittensor 2011). However, the migration routes of skipjack tuna remain unknown. In recent decades, skipjack tuna has been breeding in the Western Mediterranean although there is no knowledge on the origin of the adults. This species is found in schools and can aggregate to Fish Aggregation Devices (FADs) that are deployed in most oceans.

Telemetry tools: There are still many challenges regarding tagging for this species. Pop-up satellite archival tags (PSAT) are not suitable for small fish sizes. Acoustic telemetry offers possibilities to characterize movement patterns for this species. 

Benefits within the ETN: This species is a large migratory species that performs migrations across boundaries. Collaborations across countries including joint research efforts and international collaboration and sharing infrastructures is key to understand migration patterns, stock mixing, environmental thresholds, ontogenetic changes in species distributions as well as to improve the current biased life-history traits caused by the recapture of tagged individuals in a short time frame in neighboring areas while estimating these key management parameters on a long time scale.

Contacts: Patricia Reglero (patricia.reglero@ieo.es), Miguel Cabanellas Reboredo (miguel.cabanellas@ieo.es) and Francisco Abascal (francisco.abascal@ieo.es)

References:

Reglero, P., Tittensor, D. P., Álvarez-Berastegui, D., Aparicio-González, A., & Worm, B. (2014). Worldwide distributions of tuna larvae: revisiting hypotheses on environmental requirements for spawning habitats. Marine Ecology Progress Series, 501, 207-224.

Worm, B., & Tittensor, D. P. (2011). Range contraction in large pelagic predators. Proceedings of the National Academy of Sciences, 108(29), 11942-11947.