Department of Marine Biology, Texas A&M University at Galveston, 1001 Texas Clipper Road, Galveston, TX 77553, USA.
Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX 77843, USA.
Biol Lett. 2020 Feb;16(2):20190878. doi: 10.1098/rsbl.2019.0878. Epub 2020 Feb 5.
Natal origin of subadult (age-1) Pacific bluefin tuna (PBT, ) from the California Current Large Marine Ecosystem (CCLME) was determined using natural tracers in ear stones (otoliths). Age-0 PBT collected from the two known spawning areas in the western Pacific Ocean (East China Sea, Sea of Japan) were used to establish baseline signatures from otolith cores over 4 years (2014-2017) based on a suite of trace elements (Li, Mg, Mn, Sr, Zn and Ba). Distinct chemical signatures existed in the otolith cores of age-0 PBT collected from the two spawning areas, with overall classification accuracy ranging 73-93% by year. Subadult PBT collected in the CCLME over the following 4 years (2015-2018) were then age-class matched to baselines using mixed-stock analysis. Natal origin of trans-Pacific migrants in the CCLME ranged 43-78% from the East China Sea and 22-57% from the Sea of Japan, highlighting the importance of both spawning areas for PBT in the CCLME. This study provides the first estimates on the natal origin of subadult PBT in this ecosystem using otolith chemistry and expands upon the application of these natural tracers for population connectivity studies for this species.
利用耳石（耳石）中的天然示踪剂确定了来自加利福尼亚海流大海洋生态系统（CCLME）的未成年（1 龄）太平洋蓝鳍金枪鱼（PBT）的出生地。从西太平洋（东海、日本海）两个已知产卵区采集的 0 龄 PBT 用于在 4 年内（2014-2017 年）根据一系列微量元素（Li、Mg、Mn、Sr、Zn 和 Ba）建立耳石核心的基线特征。来自两个产卵区的 0 龄 PBT 的耳石核心存在明显的化学特征，每年的总体分类准确率为 73-93%。接下来的 4 年（2015-2018 年）在 CCLME 中收集的亚成年 PBT 然后使用混合种群分析根据基线进行年龄匹配。CCLME 中跨太平洋洄游幼鱼的出生地范围从东海的 43-78%到日本海的 22-57%不等，这突出了这两个产卵区对 CCLME 中 PBT 的重要性。本研究使用耳石化学首次估算了该生态系统中亚成年 PBT 的出生地，并扩展了这些天然示踪剂在该物种种群连通性研究中的应用。
