Author(s): Seiya Aihara; Shinji Fukuda

Linked Author(s): Shinji Fukuda

Keywords: No Keywords

Abstract: Aquatic flora affects physical habitat conditions and thus need to be considered for fish habitat assessment. In this study, we conducted a series of ecohydraulic surveys in an irrigation channel network in Tokyo, Japan in order to investigate the effect of different ecological function of aquatic vegetation on fish habitats. Random forests was employed as a tool for habitat modelling based on physical habitat conditions and aquatic vegetation community. Variable importance and response curves were used for a deeper understanding of the complex interactions and relationships. As a result, almost half of the target fish species exhibited a species specific preference for vegetation assemblage, which implied the interdependencies between fish and vegetation assemblages. Furthermore, those fish species did not always distinguish native and non-native macrophytes for their habitats, which may partially suggest that non-native vegetation assemblage can substitute native vegetation as a fish habitat component. However non-native macrophytes should be carefully managed for its potential risks on native ecosystems. In conclusion, vegetation assemblage and its function were revealed important components for fish habitats, and thus both aquatic flora and instream flow conditions needs to be considered for conserving native aquatic ecosystems.

DOI:

Year: 2018