Monitoring fish populations, migration and water quality through environmental DNA

This spring research gets underway into an innovative manner, through ‘fish DNA’ in the water, of monitoring the numbers and species of fish present in rivers and streams. At various test sites within the areas of the Roer and Overmaas, Aa and Maas, and Brabantse Delta waterboards, water samples will be taken from which environmental DNA (eDNA) will be isolated and identified. The sources of this eDNA include fish slime and faeces.

The goal of the research is to develop a rapid, qualitative and quantitative method of measuring the distribution and migration of fish populations, which would for instance allow waterboards to monitor and assess the effectiveness of fish passages. Monitoring fish populations by means of fishing is often a rather time-consuming and costly activity. Using the information that the eDNA water samples can provide, researchers want to set up a reliable and cost-effective method of determining the distribution of fish populations in a fluvial basin. A method which would moreover be fish-friendlier: catching and releasing the fish would no longer be necessary. The monitoring of fish populations and fish migration is essential as a means of determining the quality of surface water.

Reliable, cost-effective and fish-friendly

The research is partly financed by TKI Water Technology and builds upon previous TKI projects, such as Ecological Monitoring and Environmental DNA. Besides KWR and the three above-mentioned waterboards, engineering consultancy Witteveen+Bos, environmental consultancy ATKB and Baseclear are also partners in the project. As project leader, KWR bears principal responsibility. The partners will jointly develop and optimise sampling and eDNA determination, and compare the information from the eDNA with that obtained about fish populations through the traditional ‘catch, weigh, count and release’ method. The results of this research programme, which runs until 2018, will contribute to a reliable, cost-effective and fish-friendly monitoring of fish populations, fish migration and water quality.