{"title":"Macroinvertebrate response to run‐of‐river hydropower tailrace inflow: Spatial assessment of community and traits","authors":"Janine T. Mihara, J. Negishi, Junyi Wu","doi":"10.1002/rra.4350","DOIUrl":null,"url":null,"abstract":"Run‐of‐river (R‐O‐R) hydropower dams introduce two discontinuities in the river: the dam and the tailrace. Discontinuities can lead to changes in the water quality that may affect the survival of aquatic macroinvertebrates, depending on their traits. We investigated the invertebrate assemblage and community‐level traits in an urban river influenced by a small hydropower tailrace in Hokkaido, Japan. As a result of the tailrace inflow to the main channel, the bypassed reach was warmer, and the areas below the confluence were colder. Temperature was a consistent factor affecting the distribution of indicator taxa and of the five major taxa that contributed the most to dissimilarity, but other environmental factors also showed significant effects. At the community level, the weighted mean of taxa with warm preference showed a significant positive relationship with temperature, but taxa with cold preference did not appear to be filtered by the cold water delivered by the tailrace. However, sensitive taxa such as Ephemerella have already started showing negative responses to temperature. The observed distribution of cold‐preferring scrapers could negatively affect the energy transfer from primary producers to higher consumers in the bypassed reach. Appropriate mitigation of climate change effects in hydropower systems can be achieved by increasing the flow in the bypassed reach, especially during the summer months, to maintain a temperature regime that is adequate for the survival of macroinvertebrate populations and maintenance of ecosystem functions.","PeriodicalId":21513,"journal":{"name":"River Research and Applications","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"River Research and Applications","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1002/rra.4350","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Run‐of‐river (R‐O‐R) hydropower dams introduce two discontinuities in the river: the dam and the tailrace. Discontinuities can lead to changes in the water quality that may affect the survival of aquatic macroinvertebrates, depending on their traits. We investigated the invertebrate assemblage and community‐level traits in an urban river influenced by a small hydropower tailrace in Hokkaido, Japan. As a result of the tailrace inflow to the main channel, the bypassed reach was warmer, and the areas below the confluence were colder. Temperature was a consistent factor affecting the distribution of indicator taxa and of the five major taxa that contributed the most to dissimilarity, but other environmental factors also showed significant effects. At the community level, the weighted mean of taxa with warm preference showed a significant positive relationship with temperature, but taxa with cold preference did not appear to be filtered by the cold water delivered by the tailrace. However, sensitive taxa such as Ephemerella have already started showing negative responses to temperature. The observed distribution of cold‐preferring scrapers could negatively affect the energy transfer from primary producers to higher consumers in the bypassed reach. Appropriate mitigation of climate change effects in hydropower systems can be achieved by increasing the flow in the bypassed reach, especially during the summer months, to maintain a temperature regime that is adequate for the survival of macroinvertebrate populations and maintenance of ecosystem functions.
期刊介绍:
River Research and Applications , previously published as Regulated Rivers: Research and Management (1987-2001), is an international journal dedicated to the promotion of basic and applied scientific research on rivers. The journal publishes original scientific and technical papers on biological, ecological, geomorphological, hydrological, engineering and geographical aspects related to rivers in both the developed and developing world. Papers showing how basic studies and new science can be of use in applied problems associated with river management, regulation and restoration are encouraged as is interdisciplinary research concerned directly or indirectly with river management problems.