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-Ramler.JPG/jcr:content/See%20eDNA%20(c)%20Ramler.JPG "The photo shows a large lake in Austria, surrounded by forested hills and small settlements; a tall mountain can be seen in the very background, in the center. Surveying the fish community of a large lake requires a significant amount of personnel and effort. eDNA methods may be used to supplement the traditional approach in the future.")
© BAW Research/Ramler zoom gallery -
-Rund.jpg/jcr:content/Vampir_sampler%20(c)%20Rund.jpg "Das Foto zeigt eine blau behandschuhte Hand, die eine akkubetriebene Pumpe über das klare Wasser eines Sees hält. Über einen Schlauch wird Seewasser durch eine Filterkartusche gepumpt, um darin enthaltene Umwelt-DNA (eDNA) zu sammeln. Im Hintergrund sind emerse Makrophyten, bewaldete Berge und ein blauer Himmel zu sehen. Das Sammeln von eDNA durch Filtration bildet den ersten Schritt des Arbeitsablaufs. Dabei werden ganze Zellen sowie an Partikel gebundene DNA aus dem Wasser herausgefiltert und auf dem Filter angereichert. Anschließend wird die zurückgehaltene DNA im Labor extrahiert, sequenziert und bioinformatisch verarbeitet.")
© BAW Research/Rund zoom gallery
The implementation of the European Water Framework Directive requires Austria to regularly assess the ecological status of its surface waters. The biological quality element “fish” is evaluated using the established assessment methods Austrian Lake Fish Index and Fish Index Austria. However, the conventional fishing surveys required for this purpose are very time-consuming, labor-intensive, and costly, meaning that complete assessment cycles for large lakes can take up to 15 years, and many assessments are now outdated. Furthermore, some of the methods used can be harmful to fish populations.
Against this backdrop, the analysis of environmental DNA (eDNA) is gaining increasing importance as a non-invasive and efficient alternative. By analyzing DNA traces in water samples, fish species can be reliably detected. The eDNA-Screen project investigates the extent to which eDNA can be used as a screening method for fish ecological monitoring.
The goal is to develop and validate a standardized sampling, analysis, and assessment protocol for lakes and rivers. Based on the fish species identified using eDNA, screening indices will be developed to detect changes in the fish community at an early stage. If the results of the preliminary screening show a significant difference from those of previous conventional sampling and calculations, targeted, standardized fishing surveys will still be necessary in the future for a more detailed assessment.
If, on the other hand, the eDNA prescreening confirms the data known to date, the previously established fish ecological assessment of the water body can be retained. In this way, a large number of water bodies can ultimately be screened cost-effectively or, if necessary, efficiently sampled using standardized methods.