作者：Li, Z., Ramon, C.L., Bogdanowicz, S., et al.

Natural environmental DNA (eDNA) offers a powerful tool for aquatic ecosystem monitoring. However, its transport in large lakes remains poorly understood due to its instability, scarcity, and heterogeneity, as well as the complex hydrodynamics of lakes. We developed biodegradable synthetic DNA particles (sDNAp) that encapsulate DNA fragments with unique sequences to serve as quantitative tracers for investigating eDNA transport. This sDNAp tracer was deployed in Cayuga Lake (NY, USA; 172 km2 surface area) and its dispersion was monitored for 33 h over similar to 11 km2 through depth-integrated water sampling followed by quantitative PCR analysis. Despite gram-scale release quantities, sDNAp were detected over 7 km from the source after more than a day, at concentrations as low as similar to 3-5 particles mL-1, demonstrating high sensitivity and durability. A 3D hydrodynamic model incorporating wind-driven circulation and stratification reproduced key dispersion patterns observed in the field. Forward particle-tracking simulations captured both horizontal advection and vertical displacement, while backward simulations revealed that vertical position sensitivity limited the accuracy of source attribution. This approach provides one of the first lake-scale demonstrations that time-resolved, probabilistic attribution of natural eDNA sources is feasible under favorable conditions. Using sDNAp tracers, it also establishes a robust benchmark for future studies on eDNA transport in large waterbodies.

自然环境DNA（eDNA）为水生生态系统监测提供了一种强大的工具。然而，由于其不稳定性、稀缺性、异质性以及湖泊复杂的流体动力学特性，其在大型湖泊中的迁移情况仍知之甚少。我们研发了可生物降解的合成DNA颗粒（sDNAp），这种颗粒包裹着具有独特序列的DNA片段，可作为定量示踪剂用于研究eDNA的迁移。该sDNAp示踪剂在卡尤加湖（美国纽约州，表面积 172 平方公里）中投放，并通过深度整合水样采集以及随后的定量 PCR 分析，在约11平方公里的范围内对其扩散情况进行了33小时的监测。尽管释放量仅为克级，但一天多后，在距离源头7公里以上的地方仍检测到了sDNAp，浓度低至约3-5个颗粒/毫升，这表明其具有较高的灵敏度和耐久性。一个包含风生环流和分层现象的三维流体动力学模型再现了野外观察到的关键扩散模式。正向粒子追踪模拟捕捉到了水平平流和垂直位移，而反向模拟则显示，垂直位置的敏感性限制了源头溯源的准确性。这种方法首次在湖泊尺度上证明，在有利条件下，对自然eDNA来源进行时间分辨的概率性溯源是可行的。此外，利用sDNAp示踪剂，还为未来研究大型水体中eDNA的迁移建立了一个可靠的基准。

(来源：Environmental Science & Technology   2026  DOI: 10.1021/acs.est.5c11071）