Hayami Kana, Sakata Masayuki K, Inagawa Takashi, Okitsu Jiro, Katano Izumi, Doi Hideyuki, Nakai Katsuki, Ichiyanagi Hidetaka, Gotoh Ryo O, Miya Masaki, Sato Hirotoshi, Yamanaka Hiroki, Minamoto Toshifumi
Graduate School of Human Development and Environment Kobe University Kobe Japan.
OYO Corporation Miharu-machi Japan.
Ecol Evol. 2020 May 6;10(12):5354-5367. doi: 10.1002/ece3.6279. eCollection 2020 Jun.
Environmental DNA (eDNA) analysis has seen rapid development in the last decade, as a novel biodiversity monitoring method. Previous studies have evaluated optimal strategies, at several experimental steps of eDNA metabarcoding, for the simultaneous detection of fish species. However, optimal sampling strategies, especially the season and the location of water sampling, have not been evaluated thoroughly. To identify optimal sampling seasons and locations, we performed sampling monthly or at two-monthly intervals throughout the year in three dam reservoirs. Water samples were collected from 15 and nine locations in the Miharu and Okawa dam reservoirs in Fukushima Prefecture, respectively, and five locations in the Sugo dam reservoir in Hyogo Prefecture, Japan. One liter of water was filtered with glass-fiber filters, and eDNA was extracted. By performing MiFish metabarcoding, we successfully detected a total of 21, 24, and 22 fish species in Miharu, Okawa, and Sugo reservoirs, respectively. From these results, the eDNA metabarcoding method had a similar level of performance compared to conventional long-term data. Furthermore, it was found to be effective in evaluating entire fish communities. The number of species detected by eDNA survey peaked in May in Miharu and Okawa reservoirs, and in March and June in Sugo reservoir, which corresponds with the breeding seasons of many of fish species inhabiting the reservoirs. In addition, the number of detected species was significantly higher in shore, compared to offshore samples in the Miharu reservoir, and a similar tendency was found in the other two reservoirs. Based on these results, we can conclude that the efficiency of species detection by eDNA metabarcoding could be maximized by collecting water from shore locations during the breeding seasons of the inhabiting fish. These results will contribute in the determination of sampling seasons and locations for fish fauna survey via eDNA metabarcoding, in the future.
环境DNA（eDNA）分析作为一种新型生物多样性监测方法，在过去十年中得到了迅速发展。以往的研究在eDNA宏条形码分析的几个实验步骤中评估了同时检测鱼类物种的最佳策略。然而，最佳采样策略，尤其是水采样的季节和位置，尚未得到充分评估。为了确定最佳采样季节和位置，我们在三个大坝水库全年每月或每两个月进行一次采样。分别从日本福岛县三春和小川大坝水库的15个和9个地点以及兵库县须古大坝水库的5个地点采集水样。用玻璃纤维滤膜过滤1升水，并提取eDNA。通过进行MiFish宏条形码分析，我们分别在三春、小川和须古水库成功检测到了21种、24种和22种鱼类。从这些结果来看，eDNA宏条形码分析方法与传统长期数据的性能水平相似。此外，它被发现对评估整个鱼类群落有效。通过eDNA调查检测到的物种数量在三春和小川水库于5月达到峰值，在须古水库于3月和6月达到峰值，这与栖息在水库中的许多鱼类物种的繁殖季节相对应。此外，与三春水库的离岸样本相比，岸边检测到的物种数量明显更多，其他两个水库也发现了类似趋势。基于这些结果，我们可以得出结论，通过在栖息鱼类的繁殖季节从岸边采集水样，可以最大限度地提高eDNA宏条形码分析检测物种的效率。这些结果将有助于未来通过eDNA宏条形码分析确定鱼类区系调查的采样季节和位置。
