Extracting daily isotopic records on fish otolith Trachurus japonicus by combining micro‐milling and micro‐scale isotopic analysis (MICAL‐CF‐IRMS)
Extracting daily isotopic records on fish otolith Trachurus japonicus by combining micro‐milling and micro‐scale isotopic analysis (MICAL‐CF‐IRMS)
复制标题
通过结合微研磨和微尺度同位素分析（MICAL-CF-IRMS）提取鱼耳石 Trachurus japonicus 的日常同位素记录
DOI：
10.1002/rcm.9366
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发表时间：
2022
影响因子：
2
通讯作者：
Nishida Kozue
中科院分区：
文献类型：
--
作者：
Muto Daichi;Ishimura Toyoho;Takahashi Motomitsu;Nishida Kozue
近年来，微尺度耳石同位素分析技术的发展，使得利用耳石的稳定氧同位素比值（δ 18 O）可以重建鱼类经历的每几天分辨率的水温历史。本研究旨在改进这些技术，提取幼鱼期耳石的δ 18 O日记录。利用高空间分辨率的微细研磨系统（Geomill 326），对竹荚鱼耳石中的日年轮进行了精确的区分，并将其沿着日年轮进行了研磨。然后，我们确定了稳定的碳和氧使用高精度微量同位素分析系统测定（δ 13 C，δ 18 O）同位素组成结果我们成功地研磨了每个日环，宽度范围为14.0 - 62.9 μm（平均27.0 μm）在高生长期（孵化后30-70天），结论本方法首次应用于鱼类耳石δ 18 O的测定，并对耳石文石的δ 18 O同位素组成进行了分析。结合δ ~（18）O-水温方程，可以解释经历水温的日变化历史。我们的高分辨率研磨和分析技术也可应用于钟乳石、蛤蜊和珊瑚的高分辨率同位素分析。
RationaleThe recent progress in micro‐scale isotopic analytical techniques for otoliths has enabled the reconstruction of the experienced water temperature history of fish in every few days resolution using the stable oxygen isotope ratio (δ18O) of otoliths. We aimed to improve those techniques and extract the dailyδ18O records of otoliths formed during the juvenile period.MethodsGrowth rings were formed daily in fish otoliths. We precisely distinguished the daily rings in otoliths of Japanese jack mackerelTrachurus japonicus, and milled them along daily growth rings using a high‐spatial resolution micromilling system (Geomill326). Then, we determined the stable carbon and oxygen (δ13C,δ18O) isotopic compositions using a high‐precision micro‐scale isotopic analytical system (MICAL3c with IsoPrime 100).ResultsWe successfully milled each daily ring with width ranging from 14.0 to 62.9 μm (average 27.0 μm) during the high growth period (30–70 days after hatching), and determined the isotopic compositions of otolith aragonite.ConclusionsOur improved micro‐scale analytical method is the first to determine the dailyδ18O history of fish otoliths. By using our method together with theδ18O – water temperature equation, the daily history of experienced water temperature can be elucidated. Our high‐resolution milling and analytical technique can also be applied to high‐resolution isotope analysis for stalactites, clams, and corals.