Lights off, sound on: Leiden University opens artificial river to study fish migration
image: Christi Waanders
On 16 June, Leiden University opens the MIGRADROME: a unique, seven-metre-long artificial river. Researchers will use it to study how light and sound affect migratory fish. ‘We’re recreating a real river, but under fully controlled conditions.’
A seven-metre glass tunnel, filled with flowing water, equipped with speakers and cameras. At first glance, it looks like a high-tech aquarium. But this is the MIGRADROME – Leiden University’s latest research facility. It’s an artificial river where biologists explore the impact of light and noise pollution on fish that migrate.
Number of migratory fish are declining rapidly
‘Migratory fish are struggling,’ says professor of behavioural ecology Hans Slabbekoorn. ‘From eels to salmon – their numbers are declining rapidly. Physical barriers like dams and sluices are well known, but light and sound can also block their path. Now we can finally test how and when that happens.’
The MIGRADROME is one of a kind. Inside, there’s a second tank that can be tilted, allowing researchers to simulate different flow speeds, from upstream to downstream. What also sets it apart is that the team can precisely control both natural and artificial light and sound conditions.
‘We want to find out how willing fish are to migrate under certain circumstances,’ Slabbekoorn explains. ‘How strong is their drive to migrate when there’s light pollution? What happens when a boat passes by? These are the kinds of questions we can now answer properly.’
Setting up the facility wasn’t without its challenges – finding a suitable location and adapting it took longer than expected – but the result is impressive. The first tests, using sticklebacks, will begin later this month. Eventually, the researchers even hope to observe young sturgeon swimming through the tunnel.
‘If we understand what’s holding fish back, we can give better advice’
With the MIGRADROME, the team aims to contribute to the recovery of freshwater fauna (many of which also spend time at sea), one of the most threatened groups of animals worldwide. ‘If we understand what’s holding fish back, we can give better advice,’ Slabbekoorn says. ‘That’s what it’s all about in the end.’
Hoe is dit project tot stand gekomen?
The MIGRADROME was funded via the SATURN-project (SATURN: Solutions At Underwater Radiated Noise - MaREI) by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101006443.
The associated adjustments to the Sylvius building to accommodate the facility were funded by the IBL and the Leiden University Faculty of Science.
Additional support came from the BioCLOCK NWO-NWA project: Bioclock Project | The impact of light on our biological clock and AquaPLAN, a follow-up EU Horizon project.
The MIGRADROME was designed in collaboration with Fleuren & Nooijen B.V.