Assessing environmental quality in a historically polluted fjord, a comparison of benthic meiofaunal eDNA and morphospecies approaches

This study is the first assessment of foraminifera (meiofauna) diversity using sedimentary eDNA from one of the most polluted fjords in Scandinavia, comparing the assemblage response reported by morphology-based and molecular ecosystem assessment techniques.Although genetic data processing decisions influence the EcoQS assessment category determined by each technique, both datasets report congruous responses in the benthic foraminiferal assemblages to pollution and environmental stress factors. Genetic methods tend to overestimate EcoQS at highly anoxic sites probably due to a presence of dormant propagules or extraorganismal DNA, suggesting that morphological methods would still be necessary for EcoQS assessment in such conditions.

本研究首次利用斯堪的纳维亚半岛污染最严重的峡湾之一的沉积物环境DNA（eDNA）评估有孔虫（小型底栖生物，meiofauna）的多样性，并对比了基于形态学与分子生物学的生态系统评估技术所揭示的群落响应。尽管遗传数据处理流程会影响各技术所判定的生态质量状态（EcoQS）评估等级，但两类数据集均显示底栖有孔虫群落对污染与环境胁迫因子的响应趋势一致。遗传分析方法往往会在严重缺氧位点高估生态质量状态，这大概率源于休眠繁殖体或胞外DNA的存在，这表明在这类环境条件下开展生态质量状态评估时，形态学方法仍不可或缺。