Crossing the line: migratory and homing behaviors of Atlantic bluefin tuna

• Published in: Marine Ecology Progress Series
• Main Authors: Dettman, David L., DEGUARA, Simeon, ADDIS, Piero, Karakulak, Firdes Saadet, Santos, Miguel Neves, ARRIZABALAGA, Haritz, SECOR, David H., ABID, Noureddine, Macias, David, SAKAI, Osamu, Kimoto, Ai, ROOKER, Jay R., Fraile, Igaratza
• Other Authors: ,, 62145
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Tarımsal Bilimler; Çevre / Ekoloji; Tarım ve Çevre Bilimleri (AGE); DENİZ VE TATLISU BİYOLOJİSİ; Bitki ve Hayvan Bilimleri; OŞİNOGRAFİ; Yerbilimleri; Temel Bilimler (SCI); Ziraat; Toprak ve Bitki Besleme; Toprak ve Su Muhafazası ve Amenajmanı; Su Hasadı; Çevre Mühendisliği; Çevre Teknolojisi; Ekoloji ve Kirlenme; Deniz Bilimleri ve Teknolojisi; Oşinografi; Fiziksel Oşinografi; Mühendislik ve Teknoloji; EKOLOJİ; North Atlantic
• Online Access: https://hdl.handle.net/20.500.12627/95334; https://doi.org/10.3354/meps10781

Assessment and management of Atlantic bluefin tuna Thunnus thynnus populations is hindered by our lack of knowledge regarding trans-Atlantic movement and connectivity of eastern and western populations. Here, we evaluated migratory and homing behaviors of bluefin tuna in several regions of the North Atlantic Ocean and Mediterranean Sea using chemical tags (delta C-13 and delta O-18) in otoliths. Significant emigration of bluefin tuna from their place of origin was inferred from otolith delta C-13 and delta O-18, with both eastern and western bluefin tuna commonly 'crossing the line' (45 degrees W management boundary) in the Central North Atlantic Ocean and mixing with the other population. Several western migrants were also detected in Moroccan traps off the coast of Africa, indicating that trans-Atlantic movement occurs for members of the western population; however, the degree of mixing declined with proximity to the eastern spawning area (Mediterranean Sea). The origin of bluefin tuna collected at the entrance to the Strait of Gibraltar and from several regions within the Mediterranean Sea (Balearic Islands, Malta, and Sardinia) was essentially 100% eastern fish, demonstrating that natal homing is well developed by the eastern population, with western migrants rarely entering the Mediterranean Sea.