Effects of nuisance submerged vegetation on the fauna in Norwegian rivers

Abstract The abundance of aquatic vegetation is increasing in rivers and lakes worldwide. aim this study was to find how the macrophyte Juncus bulbosus Linnaeus affects salmonids benthic macroinvertebrates Norwegian rivers. proliferation J. commenced after development hydropower 1960s 1970s. now considered a nuisance for humans many areas We found higher density juvenile fish density, weight species richness invertebrates with than gravel, suggesting that not limiting invertebrates. This may be because macrophytes increase surface area provide shelter, food variety ecological niches. Adult salmonid can negatively affected when their spawning grounds are covered by vegetation. However, overgrowth common take years since clear river bed during redd digging, indicating competition between riverbed habitat. Our results suggest one should assume outgrowths have negative impacts on ecosystem. It important map all distinguish from effects