[M-TT38] Frontiers in Geochemistry

[MTT38-P03] Ecological history analysis of fish using the otolith step dissolution method

*Yosuke Miyairi¹, Yusuke Yokoyama¹, Kozue Ando¹, Keito Aonuma¹, Toshi Nagata¹ (1.Atmosphere and Ocean Research Institute, The University of Tokyo)

Keywords:Radiocarbon, AMS, otolith

Isotopes and trace elements extracted from fish otoliths have been widely used to understand different fish habitats. Otoliths can track the life-long histories of fish habitats and can supplement the information that is often difficult to reconstruct using tagging methods. Due to the advancement of radiocarbon measurement techniques, small quantities can be prepared for this purpose, and radiocarbon can be used to understand the migration history by referring to the variations of radiocarbon in the surface ocean. One major drawback of otolith isotope methods is the length of time it takes to collect samples by milling before each sample can be measured by accelerator mass spectrometry. Sequential acid digestion systems can potentially offer a solution whereby each dissolution step can provide information of otolith growth. Here we designed a glass apparatus that can be used for this purpose. This technique has been applied to otoliths of the western Pacific roughy, walleye pollack, and cod. Stepwise dissolution using a newly designed glass apparatus, proposed here, can aid marine fish ecological studies using otoliths.