Research from IFB presented at the Ecological Society of Japan conference

The Ecological Society of Japan held its annual conference online from the 17th to the 21st March 2023. This year Leanne Faulks, from the Institute of Freshwater Biology, Nagano University, presented a poster titled “How important are anthropogenic waterways for freshwater biodiversity”. The poster presented preliminary results from a local-scale survey that IFB researchers are conducting in waterways around Ueda. Natural waterways are increasingly disturbed due to dams, weirs, and habitat degradation, meaning that anthropogenic waterways such as irrigation and urban channels may become important supplementary habitats for freshwater biodiversity. IFB researchers aimed to assess freshwater biodiversity in natural tributaries like Uranogawa and Yodagawa compared to anthropogenic waterways like Hirusawa and Yadesawa. IFB researchers collected water samples for the analysis of eDNA and pesticide concentrations and also sampled fish and aquatic insects using traditional methods like electrofishing and netting. The results showed that many freshwater fish utilize anthropogenic waterways but also that anthropogenic waterways may be more disturbed by pesticides, may not be suitable for fish fry/larvae, have a lower diversity of fish species, have a lower level of genetic diversity, and may be more favorable for introduced species. This local-scale survey will be conducted again this spring/early summer and further analysis of the environmental conditions and connectivity of waterways in the Ueda area will be investigated. This research is part of the IFB’s river project that aims to assess the effect of fragmentation and disturbance on freshwater fish populations in Chikuma River by utilizing a combination of techniques such as electrofishing monitoring of invasive species movement, eDNA, and fish passage monitoring using video footage. The project is supported by the Ministry of Land, Infrastructure, Transport, and Tourism and includes collaborators from Shinshu University and the Nagano prefectural fisheries agency.