Feeding ecology of Atlantic bluefin tuna (ABFT, Thunnus thynnus), from the Gulf of Saint Lawrence, Canada, was assessed by stomach content and stable isotope analyses. Stomachs were collected from 161 individuals averaging 249 ± 20 cm in curved fork length and 248 ± 64 in round weight. The fish were caught by commercial fishing boats using rod and reel gear during fall 2015–2017. Liver and muscle samples were taken from 133 fish for stable isotope analysis. Atlantic mackerel (Scomber scombrus) was the most abundant prey item in 2015 (%Alimentary index, %AI = 88.94), whereas in 2016 and 2017 the ABFT diet was mainly composed of Atlantic herring (Clupea harengus) (%AI = 56.73 and %AI = 77.23, respectively). PERMANOVA analysis revealed significant differences in the dietary composition between years. δ¹⁵N values varied between 12.3 and 15.4‰ for muscle and between 11.1 and 14.6‰ for liver. δ¹³C values ranged from −19.9 to −16.5‰ for muscle and from −20.7 to −17.3‰ for liver. PERMANOVA analysis also detected inter-annual isotopic differences in both muscle and liver samples (p < 0.05). Daily rations (DR) were similar in 2015 and 2016 (DR = 1.02 ± 0.32 and DR = 1.10 ± 0.21, respectively), but higher in 2017 (DR = 1.73 ± 0.54).

来自加拿大圣劳伦斯湾的大西洋蓝鳍金枪鱼（ABFT，Thunnus thynnus）的摄食生态学通过胃含量和稳定的同位素分析进行​​了评估。从161名个体收集胃，弯曲叉长平均为249±20 cm，圆形重量为248±64。在2015–2017年秋季，鱼被商业渔船使用鱼竿和渔线轮渔具捕获。从133条鱼中采集肝脏和肌肉样品，以进行稳定的同位素分析。大西洋鲭鱼（Scomber scombrus）是2015年最丰富的猎物（Alimentary index，％AI = 88.94），而在2016年和2017年，ABFT饮食主要由大西洋鲱鱼（Clupea harengus）组成）（％AI = 56.73和％AI = 77.23）。PERMANOVA分析显示不同年份之间的饮食组成存在显着差异。δ ¹⁵对肌肉和肝11.1和14.6之间‰12.3和15.4‰之间的N值变化。δ ^13个C值范围为-19.9到-16.5‰，肌肉和从-20.7至-17.3‰为肝脏。PERMANOVA分析还检测了肌肉和肝脏样品中的年际同位素差异（p <0.05）。2015年和2016年的日粮（DR）相似（分别为DR = 1.02±0.32和DR = 1.10±0.21），但在2017年则更高（DR = 1.73±0.54）。