MFishBT: A global database of biogeochemical tags in migratory fish

Humans have long been fascinated by the mysteries surrounding fish migrations, and addressing these complex behaviors often requires large datasets. Biogeochemical tags, including trace elements and stable isotopes, are the most accessible biomarkers for tracking fish migrations. However, access to standardized biogeochemical tag data is rarely available for migratory fish, which limits our understanding of the evolutionary origins, drivers, timing, and corridors of migration. This precludes the development of conservation strategies and the implementation of management actions. Here, we present MFishBT, a global, open-access database of Migratory Fish’s Biogeochemical Tags. As of April 2023, the MFishBT contains biogeochemical records from 1,305 studies, of which 53% used element-to-calcium (E/Ca) ratios, 34% used isotopic ratios, and 13% used both techniques. The database covers 17,402 field sampling locations (inland 47% vs. marine 53%) around the globe, comprising 490 migratory fish species of four classes, 44 orders/suborders, and 137 families. Seventy-nine trace elements and 12 isotope systems were measured across various fish biomineral archives, including otoliths, scales, eye lenses, and vertebrae. E/Ca ratios were examined more frequently than isotopic ratios (59% vs. 41%), led by Sr/Ca, Mg/Ca, Ba/Ca, and 87Sr/86Sr, δ13C, and δ18O, respectively. The MFishBT compiles 26,417, 15,628, and 2,450,571 records with biogeochemical element values detected in the cores, edges, and core-to-edge transects for biomineral archives of migratory fish, respectively. This is the most globally comprehensive open-access database on biogeochemical tags in migratory fish to date, which can serve a variety of needs in scientific research, conservation, and management. We encourage researchers to add more datasets to this database in the future. This database is released for non-commercial use only. There are no copyright restrictions, and please cite this paper when using these data, or a subset of these data, for publication.

长久以来，人类始终对鱼类洄游相关的未解之谜抱有浓厚兴趣，解析这类复杂行为往往依赖大规模数据集。生物地球化学标记（biogeochemical tags）是追踪鱼类洄游最易获取的生物标志物，涵盖微量元素与稳定同位素两类指标。然而，针对洄游鱼类的标准化生物地球化学标记数据却极为稀缺，这制约了我们对洄游的演化起源、驱动因素、发生时间与洄游通道的认知，也阻碍了保护策略的制定与管理措施的落地。本研究推出MFishBT——一款全球范围的洄游鱼类生物地球化学标记开放获取数据库。截至2023年4月，MFishBT已收录来自1305项研究的生物地球化学记录，其中53%采用元素钙比（element-to-calcium, E/Ca），34%采用同位素比值，剩余13%同时使用了这两种技术。该数据库覆盖全球17402个野外采样点（内陆采样点占47%，海洋采样点占53%），涵盖4纲、44个目/亚目、137个科的490种洄游鱼类。研究团队针对多种鱼类生物矿化组织（包括耳石（otoliths）、鳞片、眼晶状体与脊椎骨）共测定了79种微量元素与12套同位素体系。相较于同位素比值（占比41%），元素钙比的分析频次更高（占比59%），其中最常用的指标依次为Sr/Ca、Mg/Ca、Ba/Ca、87Sr/86Sr、δ13C以及δ18O。MFishBT分别收录了26417条、15628条与2450571条针对洄游鱼类生物矿化组织的核心区、边缘区以及核心-边缘断面的生物地球化学元素值记录。截至目前，MFishBT是全球范围内最为全面的洄游鱼类生物地球化学标记开放获取数据库，可满足科学研究、物种保护与资源管理等多领域的多元需求。我们呼吁广大研究者未来可为该数据库贡献更多数据集。本数据库仅开放非商业用途，无版权限制，若将该数据库数据或其子集用于学术发表，请引用本论文。