April 22, 2026 — An international team of scientists deployed electronic tags on bluefin tunas across three decades to investigate stock movement between the eastern and western Atlantic. They also examined catch data dating back to 1950 to better understand the proportion of removals among regions.
The study was published in the Proceedings of the National Academy of Sciences.
Dr. Barbara Block, lead author from Stanford University summarized, “Our research demonstrates that lower fishing mortality in the West and North Atlantic has provided a refuge for eastern-origin Atlantic bluefin tuna, and highlights the importance of Atlantic waters to bolster the bluefin tuna population as a whole.”
Atlantic bluefin tuna is a highly coveted species, managed as two stocks by the International Commission for the Conservation of Atlantic Tunas. The western stock is harvested by the United States, Mexico, Japan, and Canada. The eastern stock is targeted by many countries across the Mediterranean basin and eastern Atlantic. ICCAT divides management of these two stocks at the 45oW meridian, setting separate catch limits and management measures for each stock.
Eugenio Piñeiro Soler, NOAA’s Assistant Administrator of Fisheries stated, “Management of this internationally shared resource requires high quality scientific information—and this work provides one example of that. This research addresses one of the primary sources of uncertainty surrounding the amount of mixing and movement occurring between these two stocks. This is a critical piece of information needed to inform sustainable yield advice.”