Water-quality and ecosystem impacts of recreation in streams: Monitoring and management

•Instream activities disturbed sediments, increasing contaminant concentrations.•Suspended solids, total N and phosphate increased with bather numbers.•High faecal coliform concentrations were mostly due to high background levels.•Bathers altered downstream algal but not invertebrate assemblages.•Cost-effective monitoring and management require site-based cause-effect models.