Monitoring the near-extinct European weather loach in Denmark based on environmental DNA from water samples. (March 2015)

• Record Type: Journal Article
• Authors: Sigsgaard, Eva Egelyng; Carl, Henrik; Møller, Peter Rask; Thomsen, Philip Francis
• Is Part Of: Biological conservation. Volume 183(2015)
• Page Start: 46
• Page End: 52
• Publication Date: 2015-03
• Subjects: eDNA -- Fish -- Freshwater -- Cryptic species -- Misgurnus fossilis -- Monitoring effort; Conservation of natural resources -- Periodicals; Nature conservation -- Periodicals; Ecology -- Periodicals; Environment -- Periodicals; Environmental Pollution -- Periodicals; Electronic journals; 333.9516
• DOI: 10.1016/j.biocon.2014.11.023
• Languages: English
• ISSNs: 0006-3207

Abstract

Highlights: eDNA and fishing tools were used to monitor the weather loach in Denmark. Two localities were positive for loach eDNA, and eight were negative. Results of eDNA were supported by fishing surveys. Monitoring effort and costs were lower with the eDNA method. eDNA provides a reliable, cost-efficient method for monitoring rare fishes. Abstract: The European weather loach ( Misgurnus fossilis ) represents one of many European freshwater fishes in decline. Efficient monitoring is essential if conservation efforts are to be successful, but due to the species' cryptic biology, traditional monitoring methods currently in use are inefficient, time consuming and likely prone to non-detection error. Here, we investigate the usefulness of environmental DNA (eDNA) monitoring as an alternative or supplementary method for surveying the Danish weather loach population, which is presumed to consist primarily of a single group of no more than 50 individuals. In 2008, the majority of historical Danish localities were surveyed, using traditional fishing techniques. We then applied eDNA methods to a number of these, as well as other potential localities. We successfully detected the weather loach at multiple sites in the single known remaining locality; a result that was later confirmed when local managers caught eight live specimens. Furthermore, the eDNA method indicated presence of the weather loach in another historical locality, where the species has not been observed since 1995. At the remaining localities, weather loach eDNA was not detected, providing further evidence for its absence. Importantly, the eDNA survey required less effort in person-hours and lower costs than the traditional fishing survey. This study confirms that eDNA monitoring is a valid supplement to traditional monitoring methods currently applied to monitor rare freshwater fishes. We propose that by providing reliable distribution data at lower cost and limited effort, the eDNA method can allow for increased management efficiency of endangered freshwater species such as the European weather loach.