The Fish on the Ladder: Fishways Mediating Hydraulic Engineering and River Ecologies alongside German Watercourses, 1870 – 1930

• In Event: Envirotech Histories

Abstract

Fishways are highly specific technologies constructed by humans but used by salmon and trouts. They help fishes to conquest physical obstacles that block their migration to spawning grounds. However, fishways only serve their purpose if they imitate the natural habitats of local fish fauna. Since ecological and hydrological conditions differ from one river basin to another, fishways are rarely designed as one-size-fits-all. It has always posed a challenge for engineers to adapt this technology to site-specific environmental features.
Drawing on findings from different northern German waterscapes, this paper traces the development of fishways around 1900. Early “salmon ladders” entered hydraulic engineering in the last decades of the 19th century, when hydroelectric power plants emerged. In the early days of this technology, however, fishways were often “flawed” and “unsuccessful”, fishermen claimed. One major obstacle was a lack of knowledge by engineers about the habits and behaviors of local fish populations – a kind of knowledge that was far away from classical know how in hydro engineering. It took several decades until constructors adapted ecological expertise. They studied the migratory nature of most inland species and collaborated with fish biologists on modifications in fishway design. In this respect, fishes and hydraulic conditions themselves contributed to the technological transformation of fishway design.
To make these interrelations between humans, technologies, animals and the environment visible, this paper combines two analytical approaches: First, I rely on Sara Pritchard’s “envirotechnical analysis,” which highlights the historical co-construction of technology and the environment. Second, I extend her analytical tool with Dolly Joergensens` reflections on the place of animals in technological development. In doing so, the paper demonstrates how integrating these approaches into the history of fishways deepens the historical understanding of a technology that is widely neglected in historical research but highly discussed in present debates on water protection.

Author

• Christian Zumbraegel, Technical University Berlin