Turcotte François, Hanke Alex, McDermid Jenni L
Fisheries and Oceans Canada, Gulf Fisheries Centre, 343 Université Avenue, Moncton, New Brunswick, E1C 9B6, Canada.
Fisheries and Oceans Canada, St. Andrews Biological Station, 125 Marine Science Drive, St. Andrews, New Brunswick, E5B 0E4, Canada.
Mar Environ Res. 2023 May;187:105949. doi: 10.1016/j.marenvres.2023.105949. Epub 2023 Mar 14.
The abundance of top predators in the southern Gulf of St. Lawrence, Canada, has fluctuated dramatically in recent decades. The associated increase in predation and its effect on the lack of recovery of many fish stocks in the system generates the need for a better understanding of predator-prey relationships and the implementation of an ecosystem approach to fisheries management. This study used stomach content analysis to further describe the diet of Atlantic bluefin tuna in the southern Gulf of St. Lawrence. Teleost fish largely dominated the stomach contents in all years. Previous studies established that Atlantic herring was the main component of the diet by weight, whereas herring was almost absent from the diet in this study. A shift in the diet of Atlantic bluefin tuna has been observed, as it now feeds almost exclusively on Atlantic mackerel. The estimated daily meal varied between years, ranging from 1026 g per day in 2019 to 2360 g per day in 2018. Daily meals and daily rations were calculated and showed substantial year-to-year variation.
加拿大圣劳伦斯湾南部顶级捕食者的数量在最近几十年中波动剧烈。捕食行为的相应增加及其对该系统中许多鱼类种群缺乏恢复的影响，使得有必要更好地了解捕食者与猎物的关系，并实施生态系统方法进行渔业管理。本研究采用胃内容物分析来进一步描述圣劳伦斯湾南部大西洋蓝鳍金枪鱼的食性。在所有年份中，硬骨鱼在胃内容物中占主导地位。先前的研究表明，按重量计算，大西洋鲱鱼是主要食物成分，而在本研究中鲱鱼几乎未出现在食物中。已观察到大西洋蓝鳍金枪鱼的食性发生了转变，因为它现在几乎只以大西洋鲭鱼为食。估计的每日食量在不同年份有所不同，从2019年的每天1026克到2018年的每天2360克不等。计算了每日食量和每日定量，结果显示年际变化很大。
