Department of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL, United States of America.
Department of Biology, University of West Florida, Pensacola, FL, United States of America.
PLoS One. 2019 Nov 13;14(11):e0222830. doi: 10.1371/journal.pone.0222830. eCollection 2019.
As the use of environmental-DNA (eDNA) expands as a method to detect the presence and quantity of aquatic taxa, factors potentially impacting the efficacy of this technique must be investigated. Many studies have examined the effects of abiotic parameters on the degradation of environmental-DNA (e.g. UV radiation, pH, temperature, etc.), however, few have focused on biotic effectors. Through high-filtering rates coupled with dense colonization, Asian clams (Corbicula fluminea) are able to drastically alter the quantity of particulate matter through translocation into the sediment, potentially including sources of eDNA in lotic and lentic systems. Using a longitudinal, laboratory experiment, we tested the effect of varying densities of Asian clams on the translocation rate of common goldfish (Carassius auratus) DNA. Target DNA in testing tanks was quantified through quantitative PCR (qPCR) at regular intervals and compared. Tanks housing the highest density of Asian clams produced significantly lower DNA concentrations over time compared to tanks of lower densities. These results show, for the first time, a density-dependent reduction of local eDNA sources by bivalve filtration that may lead to the obstructed detection of target species through the sampling of eDNA. Based on these findings, we recommend highly concentrated bivalve populations be taken into consideration when choosing the time and locality of eDNA sampling efforts.
随着环境 DNA（eDNA）作为一种检测水生分类群存在和数量的方法的广泛应用，必须研究可能影响该技术效果的因素。许多研究已经检验了非生物参数对环境 DNA 降解的影响（例如，紫外线辐射、pH 值、温度等），然而，很少有研究关注生物效应物。亚洲淡水贝类（Corbicula fluminea）通过高过滤率和密集的定殖，能够通过转移到沉积物中，极大地改变颗粒物的数量，这可能包括溪流和池塘系统中的 eDNA 来源。通过纵向实验室实验，我们测试了亚洲淡水贝类不同密度对常见金鱼（Carassius auratus）DNA 易位率的影响。通过定期定量 PCR（qPCR）定量检测试验罐中的目标 DNA，并进行比较。与低密度罐相比，高密度亚洲淡水贝类的罐中随着时间的推移产生的 DNA 浓度显著降低。这些结果首次表明，双壳类过滤的密度依赖性减少了本地 eDNA 来源，这可能导致通过采样 eDNA 来阻碍目标物种的检测。基于这些发现，我们建议在选择 eDNA 采样时间和地点时，应考虑高浓度的双壳类种群。
