Monitoring the near-extinct European weather loach in Denmark based on environmental DNA from water samples

Abstract

a b s t r a c tThe 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.

Environmental DNA detects Critically Endangered largetooth sawfish in the wild

“…This is consistent with a rapidly growing body of research that is demonstrating the potential of eDNA as a survey technique for rare, threatened and invasive species in both freshwater (Jerde et al 2011, Sigsgaard et al 2015 and marine systems (Thomsen et al 2012). To date, eDNA research on elasmobranchs has been restricted to testing its ability to detect species in a large marine aquarium (Kelly et al 2014).…”

“…Jerde et al 2011, Janosik & Johnston 2015, Sigsgaard et al 2015. For rare species, detection rates using eDNA can be more effective and more efficient than documenting presence with traditional fish sampling techniques (Janosik & Johnston 2015, Sigsgaard et al 2015, although the approach should be viewed as complementing rather than replacing traditional surveys and monitoring methods (Thomsen & Willerslev 2015). This technique has not been tested under field conditions on elasmobranchs, but may be an approach that will help inform assessment and conservation efforts for threatened species, such as sawfishes.…”

The ecology of environmental DNA and implications for conservation genetics

“…In the UK, eDNA assays have been validated for detection of the threatened great crested newt Triturus cristatus (Rees et al 2014a). Sigsgaard et al (2015) reported that eDNA surveys for endangered fish in Denmark outperformed traditional methods. In the western USA, eDNA techniques have been optimized for detection of endangered Bull Trout Salvelinus confluentus (Wilcox et al 2013(Wilcox et al , 2014, and other efforts have targeted rare marine mammals in the Baltic Sea (Foote et al 2012).…”

Correction of Outliers in Temperature Time Series Based on Sliding Window Prediction in Meteorological Sensor Network

“…Meteorological observation data and meteorological information not only provide daily information for weather forecasts, but are also processed into important climate data for agriculture, forestry, industry, traffic, military, hydrology, health and environmental protection departments through long-term accumulation and statistics [1]. The meteorological disaster monitoring network using atmospheric remote sensing and high-speed communication transmission technology can directly issue a tornado, strong storm and typhoon weather warning in a timely way to the users [2]. The observation of air temperature is an especially important item in the ground meteorological observation.…”