Data from: Quantifying relative fish abundance with eDNA: a promising tool for fisheries management

Assessment and monitoring of exploited fish populations are challenged by costs, logistics and negative impacts on target populations. These factors therefore limit large-scale effective management strategies. Evidence is growing that the quantity of eDNA may be related to not only species presence/absence, but also to species abundance. In this study, the concentrations of environmental DNA (eDNA) from a highly prized sport fish species, Lake Trout Salvelinus namaycush (Walbaum 1792), was estimated in water samples from 12 natural lakes and compared to abundance and biomass data obtained from standardized gillnet catches as performed routinely for fisheries management purposes. To reduce environmental variability among lakes, all lakes were sampled in spring, between ice melt and water stratification. The eDNA concentration did not vary significantly with water temperature, dissolved oxygen, pH and turbidity, but was significantly positively correlated with relative fish abundance estimated as catch per unit effort (CPUE), whereas the relationship with biomass per unit effort (BPUE) was less pronounced. The value of eDNA to inform about local aquatic species distribution was further supported by the similarity between the spatial heterogeneity of eDNA distribution and spatial variation in CPUE measured by the gillnet method. Synthesis and applications. Large-scale empirical evidence of the relationship between the eDNA concentration and species abundance allows for the assessment of the potential to integrate eDNA within fisheries management plans. As such, the eDNA quantitative method represents a promising population abundance assessment tool that could significantly reduce the costs associated with sampling and increase the power of detection, the spatial coverage and the frequency of sampling, without any negative impacts on fish populations.捕捞鱼类种群的评估与监测工作面临着成本高昂、后勤保障困难以及对目标种群产生负面影响等多重挑战，上述因素也因此制约了大规模高效渔业管理策略的推行。越来越多的研究证据表明，环境DNA（environmental DNA, eDNA）的含量不仅可反映物种的存在与否，还与物种的种群丰度存在关联。本研究以极具垂钓价值的游钓鱼种湖红点鲑（*Salvelinus namaycush* (Walbaum, 1792)）为研究对象，对12个天然湖泊的水样中的eDNA浓度进行了定量检测，并将检测结果与渔业管理常规开展的标准化刺网捕捞所获取的种群丰度与生物量数据进行了对比分析。为降低不同湖泊间的环境异质性，所有采样工作均于春季融冰后至水体热分层前开展。研究结果显示，eDNA浓度与水温、溶解氧、pH值及浊度均无显著相关性，但与以单位捕捞努力量渔获量（catch per unit effort, CPUE）估算的相对种群丰度呈显著正相关；而其与单位捕捞努力量生物量（biomass per unit effort, BPUE）的关联则相对较弱。eDNA可用于反映本地水生物种分布情况的价值，进一步通过eDNA分布的空间异质性与刺网法测得的CPUE空间变异间的相似性得到了验证。综合与应用：本研究获得的eDNA浓度与物种丰度间关联的大规模实证证据，为评估将eDNA技术纳入渔业管理方案的可行性提供了重要支撑。据此，eDNA定量分析法有望成为极具应用前景的种群丰度评估工具，其可显著降低采样相关成本，提升检测效能、空间覆盖范围与采样频率，且不会对鱼类种群造成任何负面影响。