Data from: An environmental DNA-based method for monitoring spawning activity: a case study, using the endangered Macquarie perch (Macquaria australasica)

Determining the timing and location of reproductive events is critical for efficient management of species. However, methods currently used for aquatic species are costly, time intensive, biased and often require destructive or injurious sampling. Hence, developing a non-invasive sampling method to accurately determine the timing and location of reproduction for aquatic species would be extremely valuable.
We conducted an experimental and field study to determine the influence of spawning, and the mass release of spermatozoa in particular, on environmental DNA (eDNA) concentrations. Using a quantitative PCR approach we monitored changes in nuclear and mitochondrial eDNA concentrations over time.
The data from the experimental study and the field survey supported our hypothesis that spawning events are characterized by higher concentrations of nuclear relative to mitochondrial eDNA. Outside of the reproductive period, we find that nuclear and mitochondrial DNA fragments are equally abundant in environmental water samples.
We have shown that changes in the relative abundance of nuclear and mitochondrial eDNA can be used to monitor spawning activity of the endangered Macquarie perch. Our method is likely to be transferrable to other aquatic species and can be particularly useful to increase our understanding of the spawning biology of cryptic, rare or threatened species as well as design and evaluate environmental management actions and determine species establishment.

确定繁殖事件的时间与地点，对于物种种群的高效管理至关重要。然而，当前用于水生生物的监测方法存在成本高昂、耗时漫长、结果偏倚等缺陷，且往往需要开展破坏性或损伤性采样。因此，开发一种无创采样方法，以精准测定水生生物的繁殖时间与地点，将具有极高的应用价值。
本研究通过实验与野外调查相结合的方式，探究了产卵行为——尤其是精子的大规模释放——对环境DNA（environmental DNA, eDNA）浓度的影响。我们采用定量聚合酶链式反应（quantitative PCR, qPCR）技术，实时追踪了核eDNA与线粒体eDNA浓度随时间的变化动态。
实验与野外调查的数据均验证了本研究的假设：产卵事件会导致环境样本中核eDNA浓度显著高于线粒体eDNA。在非繁殖期，环境水样中的核DNA与线粒体DNA片段丰度并无显著差异。
本研究证实，通过监测核eDNA与线粒体eDNA的相对丰度变化，可用于监测濒危物种麦夸里鲈（Macquarie perch）的产卵活动。该方法有望推广应用于其他水生生物，尤其有助于深化我们对隐秘、珍稀或受威胁物种产卵生物学的认知，同时可辅助设计与评估环境管理措施，以及判定物种的定殖情况。