Evanthia Mantzouki, James Campbell, Emiel van Loon, Petra Visser, Iosif Konstantinou, Maria Antoniou, Gregory Giuliani, Danielle Machado-Vieira, Alinne Gurjao de Oliveira, Dubravka Spoljaric Maronic, Filip Stevic, Tanja Zuna Pfeiffer, Itana Bokan Vucelic, Petar Zutinic, Marija Gligora Udovic, Andelka Plenkovic-Moraj, Nikoletta Tsiarta, Ludek Blaha, Rodan Geris, Marketa Frankova, Kirsten Seestern Christoffersen, Trine Perlt Warming, Tonu Feldmann, Alo Laas, Kristel Panksep, Lea Tuvikene, Kersti Kangro, Kerstin Haggqvist, Pauliina Salmi, Lauri Arvola, Jutta Fastner, Dietmar Straile, Karl-Otto Rothhaupt, Jeremy Andre Fonvielle, Hans-Peter Grossart, Christos Avagianos, Triantafyllos Kaloudis, Theodoros Triantis, Sevasti-Kiriaki Zervou, Anastasia Hiskia, Spyros Gkelis, Manthos Panou, Valerie McCarthy, Victor C. Perello, Ulrike Obertegger, Adriano Boscaini, Giovanna Flaim, Nico Salmaso, Leonardo Cerasino, Judita Koreiviene, Jurate Karosiene, Jurate Kasperoviciene, Ksenija Savadova, Irma Vitonyte, Sigrid Haande, Birger Skjelbred, Magdalena Grabowska, Maciej Karpowicz, Damian Chmura, Lidia Nawrocka, Justyna Kobos, Hanna Mazur-Marzec, Pablo Alcaraz-Parraga, Elzbieta Wilk-Wozniak, Wojciech Krzton, Edward Walusiak, Ilona Gagala, Joana Mankiewicz-Boczek, Magdalena Toporowska, Barbara Pawlik-Skowronska, Michal Niedzwiecki, Wojciech Peczula, Agnieszka Napiorkowska-Krzebietke, Julita Dunalska, Justyna Sienska, Daniel Szymanski, Marek Kruk, Agnieszka Budzynska, Ryszard Goldyn, Anna Kozak, Joanna Rosinska, Elzbieta Szelag-Wasielewska, Piotr Domek, Natalia Jakubowska-Krepska, Kinga Kwasizur, Beata Messyasz, Aleksandra Pelechata, Mariusz Pelechaty, Mikolaj Kokocinski, Beata Madrecka, Iwona Kostrzewska-Szlakowska, Magdalena Frak, Agnieszka Bankowska-Sobczak, Michal Wasilewicz, Agnieszka Ochocka, Agnieszka Pasztaleniec, Iwona Jasser, Ana M. Antao-Geraldes, Manel Leira, Armand Hernandez, Vitor Vasconcelos, Joao Morais, Micaela Vale, Pedro M. Raposeiro, Vitor Goncalves, Boris Aleksovski, Svetislav Krstic, Hana Nemova, Iveta Drastichova, Lucia Chomova, Spela Remec-Rekar, Tina Elersek, Jordi Delgado-Martin, David Garcia, Jose Luis Cereijo, Joan Goma, Mari Carmen Trapote, Teresa Vegas-Vilarrubia, Biel Obrador, Ana Garcia-Murcia, Monserrat Real, Elvira Romans, Jordi Noguero-Ribes, David Parreno Duque, Elisabeth Fernandez-Moran, Barbara Ubeda, Jose Angel Galvez, Rafael Marce, Nuria Catalan, Carmen Perez-Martinez, Eloisa Ramos-Rodriguez, Carmen Cillero-Castro, Enrique Moreno-Ostos, Jose Maria Blanco, Valeriano Rodriguez, Jorge Juan Montes-Perez, Roberto L. Palomino, Estela Rodriguez-Perez, Rafael Carballeira, Antonio Camacho, Antonio Picazo, Carlos Rochera, Anna C. Santamans, Carmen Ferriol, Susana Romo, Juan Miguel Soria, Lars-Anders Hansson, Pablo Urrutia-Cordero, Arda Ozen, Andrea G. Bravo, Moritz Buck, William Colom-Montero, Kristiina Mustonen, Don Pierson, Yang Yang, Jolanda M. H. Verspagen, Lisette N. de Senerpont Domis, Laura Seelen, Sven Teurlincx, Yvon Verstijnen, Miquel Lurling, Valentini Maliaka, Elisabeth J. Faassen, Delphine Latour, Cayelan C. Carey, Hans W. Paerl, Andrea Torokne, Tunay Karan, Nilsun Demir, Meryem Beklioglu, Nur Filiz, Eti E. Levi, Ugur Iskin, Gizem Bezirci, Ulku Nihan Tavsanoglu, Kemal Celik, Koray Ozhan, Nusret Karakaya, Mehmet Ali Turan Kocer, Mete Yilmaz, Faruk Maraslioglu, Ozden Fakioglu, Elif Neyran Soylu, Meral Apaydin Yagci, Sakir Cinar, Kadir Capkin, Abdulkadir Yagci, Mehmet Cesur, Fuat Bilgin, Cafer Bulut, Rahmi Uysal, Latife Koker, Reyhan Akcaalan, Meric Albay, Mehmet Tahir Alp, Korhan Ozkan, Tugba Ongun Sevindik, Hatice Tunca, Burcin Onem, Jessica Richardson, Christine Edwards, Victoria Bergkemper, Eilish Beirne, Hannah Cromie, Bastiaan W. Ibelings

• Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed inUnder ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.…