Yamamoto Satoshi, Minami Kenji, Fukaya Keiichi, Takahashi Kohji, Sawada Hideki, Murakami Hiroaki, Tsuji Satsuki, Hashizume Hiroki, Kubonaga Shou, Horiuchi Tomoya, Hongo Masamichi, Nishida Jo, Okugawa Yuta, Fujiwara Ayaka, Fukuda Miho, Hidaka Shunsuke, Suzuki Keita W, Miya Masaki, Araki Hitoshi, Yamanaka Hiroki, Maruyama Atsushi, Miyashita Kazushi, Masuda Reiji, Minamoto Toshifumi, Kondoh Michio
Graduate School of Human Development and Environment, Kobe University, Hyogo, Japan.
Faculty of Fisheries Sciences, Hokkaido University, Hokkaido, Japan.
PLoS One. 2016 Mar 2;11(3):e0149786. doi: 10.1371/journal.pone.0149786. eCollection 2016.
Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R(2) value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10-150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a 'snapshot' of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.
近期针对溪流和池塘的研究表明，通过检测和量化环境DNA（eDNA），可以估算水生生物的分布和生物量。在诸如海洋等更开放的系统中，由于各种环境因素（如水流）预计会影响eDNA的分布和浓度，因此eDNA是否能够代表水生生物的分布和生物量尚不明晰。为了测试鱼类分布与eDNA之间的关系，我们在日本海的舞鹤湾进行了网格调查，采集了表层水和底层水样本，同时使用回声测深技术监测日本竹荚鱼（Trachurus japonicus）的生物量。一个线性模型在没有异常数据点的情况下显示出较高的R²值（0.665），并且表层水样本中估计的eDNA浓度与回声强度之间的关联呈显著正相关，这表明估计的eDNA浓度空间变化能够反映竹荚鱼的局部生物量。我们还发现，最佳拟合模型包括在距离水样采集点10 - 150米范围内获得的回声强度，这表明估计的eDNA浓度最有可能反映该海湾150米范围内的鱼类生物量。尽管来自一个批发鱼市场的eDNA对eDNA浓度有部分影响，但我们得出结论，eDNA总体上提供了大面积鱼类分布和生物量的“快照”。进一步考虑野外条件下eDNA动态（例如eDNA的释放、降解和扩散模式）的研究，将基于eDNA对鱼类分布和生物量做出更好的估计。
