Active species reintroduction is an important conservation tool when aiming for the restoration of biological communities and ecosystems. The effective monitoring of reintroduction success is a crucial factor in this process. Here, we used a combination of environmental DNA (eDNA) techniques and species distribution models (SDMs) to evaluate the success of recent reintroductions of the freshwater fish Alburnoides bipunctatus in central Germany. We built SDMs without and with eDNA presence data to locate further suitable reintroduction sites and potentially overlooked populations of the species. We successfully detected eDNA of A. bipunctatus at all reintroduction sites, as well as several adjacent sites mostly in downstream direction, which supports the success of reintroduction efforts. eDNA-based species detection considerably improved SDMs for A. bipunctatus, which allowed to identify species presence in previously unknown localities. Our results confirm the usefulness of eDNA techniques as standard tool to monitor reintroduced fish populations. We propose that combining eDNA with SDMs is a highly effective approach for long-term monitoring of reintroduction success in aquatic species.

中文翻译：

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结合环境DNA和物种分布模型来评估淡水鱼的再引入成功。

在恢复生物群落和生态系统时，主动引入物种是一种重要的保护工具。重新导入成功的有效监控是此过程中的关键因素。在这里，我们结合使用了环境DNA（eDNA）技术和物种分布模型（SDM），以评估最近在德国中部重新引入淡水鱼Alburnoides bipunctatus的成功。我们在没有eDNA存在数据的情况下构建了SDM，以定位其他合适的再引入位点和可能被忽视的物种种群。我们成功地在所有重新引入位点以及几个相邻位点（主要在下游方向）成功检测到了双歧曲霉的eDNA，这支持了成功引入引入的努力。基于eDNA的物种检测大大改善了双歧曲霉的SDM，从而可以鉴定以前未知地区的物种。我们的结果证实了eDNA技术作为监测重新引入的鱼类种群的标准工具的有用性。我们建议将eDNA与SDM相结合是一种长期有效监测水生物种再引入成功的有效方法。