I developed an interest in the ecology of river birds, showing for the first time how this group was affected by acid rain. These major themes — multiple global-scale pressures on freshwater ecosystems, river invertebrates and birds in aquatic habitats — have continued to provide my major research models. From 1984, I led a post-doctoral group investigating the ecological effects of acidification in upland rivers using surveys, models and ecosystem-scale experiments at the Llyn Brianne Stream Observatory. These experiments have now run for almost 40 years, and my ecosystem-scale work has expanded to encompass global change effects on freshwaters ecosystems on three continents. Most recent work with a wide range of colleagues continues to expand our evidence about the sensitivity of running waters to climate change while also telling the remarkable story of how the recovery of British rivers from gross sanitary problems has been tempered by the growing challenge of diffuse pollution from urban and rural sources. So far, my career total of over 300 scientific publications have been cited almost 16,000 times at H > 65 (Google Scholar).