海洋堆積物に残存する環境dnaを用いた魚類相把握の試み

Abstract

The environmental DNA (eDNA) derived from fish in marine sediments is preserved for long periods and could be used as successive proxy data for fish assemblages. However, metabarcoding analysis for fish eDNA has never been applied to marine sediments. In this study, metabarcoding analysis for fish eDNA was applied to the Tohoku Earthquake sediment samples collected from Otsuchi Bay after the tsunami induced by the 2011 Earthquake off the Pacific Coast of Tohoku to track the past fish species composition. We successfully detected 17 fish eDNA from sediment samples throughout the study period. The number of sequence reads of migratory fish species was relatively high in the samples of the first two years, whereas that of demersal fish species increased in the samples of the latter two years. Temporal changes in fish species identified by eDNA metabarcoding are consistent with those in fish species identified by visual censuses in the Pacific coast of northeastern Japan. Thus, eDNA in marine sediments could be used to track the past fish species composition.

Detection of fish sedimentary DNA in aquatic systems: A review of methodological challenges and future opportunities

“…Similarly, Sakata et al (2021) established an effective sampling technique for contemporary fish sedDNA metabarcoding. Other attempts to analyze aquatic sediments using universal fish primers for DNA metabarcoding have also been performed (Cheang et al, 2020; Naro‐Maciel et al, 2022; Sakata et al, 2020; Sales et al, 2021; Shiragaki et al, 2021) with varying degrees of success, and many unsuccessful attempts remain unreported or unpublished (Table 1). Promising results have also been obtained by metagenomic analyses (e.g., shotgun sequencing) of sedDNA in freshwater (Hebda et al, 2022; Pedersen et al, 2016) and marine systems (Armbrecht, 2020).…”