Years of collaborative work of scientists from MARS project published in Nature Ecology & Evolution in June 2020 (open access pdf link: Birk et al. 2020). From METU Limnology Laboratory Team, Meryem Beklioğlu, Tuba Bucak, Uğur Işkın and Erik Jeppesen were within 67 authors of this paper focusing on the Impacts of multiple stressors on freshwater biota across spatial scales and ecosystems. Study combines data across scales from 33 mesocosm experiments with those from 14 river basins and 22 cross-basin studies in Europe, producing 174 combinations of paired-stressor effects on a biological response variable. Paper suggests there are multiple stressors and nutrient pollution is the key stressor in European freshwaters. Moreover, in about a third of cases such multiple stressors interactions in European rivers and lakes yield ‘ecological surprises’.