Measuring water life
Human activity, such as pollution, may disturb the balance of living water systems, which has consequences for biodiversity, but also for other functions such as water purification. Leiden University maps living water systems using the most advanced technologies.
In late 2016 a unique project was launched in Leiden. In the Bio Science Park, a bulldozer set the first steps towards a Living Lab, a system of 38 newly dug ditches. In this experimental location researchers investigate the effect of human activity on local biodiversity. ‘For the first time, we can look precisely at the interaction between all living organisms, their environment, and human activity,’ explains ecotoxicologist Martina Vijver. To date researchers were only able to study a few species and one stress factor at a time, and only in a lab environment. Vijver: ‘The Living Lab allows us for the first time to study the bigger picture, in a natural environment.’
One of the areas that Vijver investigates is the effect of toxic substances, such as pesticides and microplastics, but also nutrients, water balance and natural stress factors such as ‘eat or be eaten’. ‘It’s a complex puzzle,’ she says, ‘in which we also work on new analysis techniques and data processing methods.’ The ultimate goal is the sustainable management of natural water systems. ‘The Living Lab is a breeding ground for good ideas.’
Researcher Berry van der Hoorn from the Naturalis Biodiversity Center is one of the researchers working in the Living Lab. ‘We develop new methods for mapping biodiversity on the basis of DNA in water,’ he explains. Traditionally, this involved a strainer net and a microscope, but that is relatively expensive, time-consuming and error-prone: you always miss some species. In routine work, in particular, such as monitoring aquatic creatures as an indicator of water quality, this is a real challenge.
DNA research can change that. What if you could just press a button to analyse the DNA floating in a drop of water - and then be able to deduce water quality from the result? Van der Hoorn believes that such technology will become available in the near future. Naturalis is already working on creating such a ‘DNA Water Scan’. ‘But it does still require a lot of research,’ he says. ‘Chemical research: How does DNA behave in water? Biological research: Which species leave which DNA traces? And environmental biological research: How does human activity impact a species’ profile?’
DNA technology has really gained momentum in recent years. ‘This has been very fruitful, but the equipment is big and expensive, and only suitable for the lab,’ explains bioinformatician Christiaan Henkel. ‘What would really help us move forward is a device that you can easily carry with you and just stick in the water to produce instant measurements.’
This is no science fiction; in fact, this kind of technology is already available on the market. Henkel shows an example: the MinION - a device the size of a pencil case. ‘One day it will be an attachment on your mobile telephone,’ he predicts. ‘Not that I developed this myself. What we do is investigate how we can best use this technology.’
It can, for instance, be used for monitoring, as a ‘futuristic fishing net’, but also in more fundamental research on nature protection. For instance to investigate under what circumstances eels, a seriously threatened species, can be bred in captivity.