The Meyberg fish passage in practice Fish are often hindered by obstacles such as weirs on their way to spawning or hatching grounds. Such structures generally have a detrimental effect on fish populations. A solution to the problem seems to be the ingenious and cost-effective fish passage developed by Jansen Venneboer in partnership with consultancy and engineering firm Tauw. It is based on the successful concept of Wim de Wit, being placed directly on the weir, and not affecting its functioning. Made of synthetic material, the Meyberg fish passage is a combination of a hinge and a unique floating body. It is very compact, making it suitable for weirs with a lowdischarge and a maximum difference in water level of 0.6 metres. This fish passage was launched on the Dutch market in 2007, and subsequently tested at four locations in the spring of that year and of 2008. Monitoring with fyke nets showed that a Total of 2717 fish, varying in size from 2 to 78 centimetres and belonging to 21 species, successfully used the passage to pass the weir and swim further upstream.