WATER ECOLOGY
Using driftwood to provide an optimal habitat for fish
Fish like to hide around logs that lie in rivers. A researcher has investigated how to provide them with an optimal habitat.
Revitalising the River Emme near Biberist using dead wood, shortly before it joins the River Aare. | Photo: IUB Engineering AG (L. Meier)
Branches and logs are not welcome guests in Swiss rivers – there is always a danger that they might cause flooding by getting wedged against bridges or stuck in weirs. But by interrupting the continuous flow of water, logs can actually provide valuable nooks and alcoves for young fish, for example. Isabella Schalko is an environmental engineer at the Massachusetts Institute of Technology. She has been using a glass-walled flow channel with a fixed bed to investigate where best to place logs in order to create the biggest possible zones with calm, nutrient-rich water. Logs placed at the channel’s sidewall or submerged in the centre provide the best results. Schalko believes that placing logs like this can help to revitalise our rivers.
