Spanish study shows how ocean currents shape tuna populations

The Balearic Oceanographic Centre of the Spanish Institute of Oceanography (IEO-CSIC) and the Coastal Ocean Observing and Forecasting System of the Balearic Islands (SOCIB) have presented a study examining the role of ocean currents in the reproduction of Atlantic bluefin tuna.

It is well known that highly migratory species such as Atlantic bluefin tuna, albacore tuna, and swordfish travel thousands of kilometers to spawn in specific regions of the ocean.

The areas where larvae are transported by these currents provide suitable food availability and temperatures that increase their chances of survival. For example, particularly low dispersal rates have been observed in the Balearic region, suggesting that larvae tend to remain in favorable habitats.

This study investigates the mechanisms behind this behavior, providing valuable insights into the ecology of these species and supporting the development of effective conservation and management measures.

Also, these findings will help improve fisheries assessment and management by including oceanographic information to better understand how populations of commercially and ecologically important species change and move over time.

The analyses were based on Lagrangian simulations covering the period from 2009 to 2019, allowing researchers to assess the persistence of these patterns over time.

"This knowledge is essential for improving the conservation of ecologically valuable species such as Atlantic bluefin tuna, swordfish, and albacore tuna in the Mediterranean," concludes Andrea Casaucao, the study's lead author.

The project also involved the Mediterranean Institute for Advanced Studies (IMEDEA) and the Institute of Marine Sciences of Andalusia (ICMAN). Funding was provided by the Government of the Balearic Islands through the Sustainable Tourism Tax, as well as by the European Union's European Maritime, Fisheries and Aquaculture Fund (EMFAF) programme.