Kevin Beentjes receives PhD on monitoring biodiversity in freshwater

April 8th, 2021
Kevin Beentjes

Kevin Beentjes received his PhD on 8 April for his research on monitoring biodiversity in freshwater at Naturalis Biodiversity Center, where he has been working for ten years now. Nowadays he is also involved in the ARISE program, which is perfectly in line with his research.

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Kevin's dissertation entitled 'From molecules to monitoring: Integrating genetic tools into freshwater quality assessments' will be digitally available after the PhD defence via the Leiden Repository.


“I investigated whether you can use DNA to monitor biodiversity in freshwater in order to measure water quality. Many measurements of water quality are currently being done using traditional methods such as simply using a scoop net and looking at what insects are in the water. What we looked into, is how you can replace this by looking at the kind of DNA in the water (environmental DNA) and whether this method works better or not.

by DNA

If you look at the DNA in the environment, you come across the same number of species as when you examine it by the traditional method. However, lots of them are different species. For some species that are very similar, this method is very useful because you can distinguish them from each other by DNA. Unfortunately, at the same time, there are many species of which we do not yet have DNA reference material. Therefore, we cannot find out exactly what species they are. Therefore, this method does not always work. In order to map the correct water quality, it is best to look at both DNA and morphological characteristics.


We conducted a large part of our experiments in the Living Lab in Leiden. It was very interesting to see that the use of pesticides had an effect not only on the insects that lived in the water, but also on other levels of the ecosystem, such as phytoplankton. We did not really expect this at all. Another remarkable and unexpected result was that the DNA in the water can be very different in the same place, but at different times. This difference is even greater than when you measure the DNA present in the water at several places at the same time.

No two days
the same

The best thing about my research was that the work is so varied, no two days are the same. One day you are in the lab, the next day in the field and there are also days where you are analyzing data behind your computer. In general, I liked doing fieldwork the most, except on cold winter days when it was raining.

to do

After I get my PhD, I still have plenty to do. There is another dataset ready that I have not used due to time constraints. I will analyze this next. In addition, I do not think I will be doing much more research. I mainly want to focus on ARISE, where we can identify species based on DNA."