Thermal sensitivity of field metabolic rate predicts differential futures for bluefin tuna juveniles across the Atlantic Ocean

• Published in: Nature communications Vol. 14; no. 1; p. 7379
• Main Authors: Trueman, Clive N., Artetxe-Arrate, Iraide, Kerr, Lisa A., Meijers, Andrew J. S., Rooker, Jay R., Sivankutty, Rahul, Arrizabalaga, Haritz, Belmonte, Antonio, Deguara, Simeon, Goñi, Nicolas, Rodriguez-Marin, Enrique, Dettman, David L., Santos, Miguel Neves, Karakulak, F. Saadet, Tinti, Fausto, Tsukahara, Yohei, Fraile, Igaratza
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 27.11.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 101/58; 631/158/2455; 631/158/2466; 631/158/672; 704/829/826; Climate change; Constraining; Environmental changes; Global warming; Humanities and Social Sciences; Intergovernmental Panel on Climate Change; Metabolic rate; Metabolism; multidisciplinary; Natural environment; Nursery grounds; Otoliths; Physiology; Science; Science (multidisciplinary); Sensitivity; Spawning; Spawning grounds; Stable isotopes; Thunnus thynnus; Trajectory analysis; Tuna; Mediterranean Sea
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-41930-2

Changing environmental temperatures impact the physiological performance of fishes, and consequently their distributions. A mechanistic understanding of the linkages between experienced temperature and the physiological response expressed within complex natural environments is often lacking, hampering efforts to project impacts especially when future conditions exceed previous experience. In this study, we use natural chemical tracers to determine the individual experienced temperatures and expressed field metabolic rates of Atlantic bluefin tuna ( Thunnus thynnus ) during their first year of life. Our findings reveal that the tuna exhibit a preference for temperatures 2–4 °C lower than those that maximise field metabolic rates, thereby avoiding temperatures warm enough to limit metabolic performance. Based on current IPCC projections, our results indicate that historically-important spawning and nursery grounds for bluefin tuna will become thermally limiting due to warming within the next 50 years. However, limiting global warming to below 2 °C would preserve habitat conditions in the Mediterranean Sea for this species. Our approach, which is based on field observations, provides predictions of animal performance and behaviour that are not constrained by laboratory conditions, and can be extended to any marine teleost species for which otoliths are available. In this study, the authors use a dataset of stable isotope compositions of otoliths from Atlantic bluefin tuna to infer the thermal sensitivity of metabolic performance in their first year of life. They then assess the likely trajectories of tuna production until end century under differing emission scenarios in their two main spawning grounds, the western Atlantic and Mediterranean Sea.