David Hoole (Edited By) Professor Dave Hoole, is Professor Emeritus in Fish Diseases at Keele University, UK. He has since the early 1980s undertaken extensive scientific research in carp disease and immunology. He has published widely within the scientific literature and books, and given numerous presentations to scientific and non-scientific audiences. He has also served as a director of a fish health service, which scrutinises fish health prior to consent being given for movement of fish under UK legislative requirements. He also acts as a consultant to various UK Fish Health Accreditation bodies.Dieter Steinhagen (Edited By) Professor Dieter Steinhagen is Professor Emeritus at the Fish Disease Research Unit at the University of Veterinary Medicine Hannover, Germany. Since the early 1980s, he worked scientifically a various aspects of pathology and immunology of pathogen-related diseases in carp, on parasites as indicators of anthropogenic stress in ecosystems and on aspects of animal welfare in fish. This work has been funded by national and international organisation and the results have been published in articles and numerous presentations to scientific and non-scientific audiences.Verena Jung-Schroers (Edited By) PD Dr. Verena Jung-Schroers is working at the Fish Disease Research Unit of the University of Veterinary Medicine Hannover, Germany, since 2005 and is heading the institute since 2021. She is a specialised fish veterinarian and diplomate of the European Colleges of Aquatic Animal Health and is responsible for the further training of veterinarians in the field of fish diseases. In research projects she works on bacterial infections in fish and other aquatic animals, on the importance of the microbiome in aquaculture systems and on animal welfare. She has published the results of these and other studies in numerous articles and presentations.Mikolaj Adamek (Edited By) Dr Mikolaj Adamek is a Research Associate and Principal Investigator at the Fish Disease Research Unit of the University of Veterinary Medicine Hannover, Germany. Since the mid-2000s he has been working on various aspects of immunology, pathophysiology and diagnostics of pathogen-related diseases in carps, salmonids and tilapia. He works mainly with viral pathogens, looking for prevention and treatment measures that could lead to a reduction in the impact of the disease on fish welfare. His research is funded by national and international sources. The results have been reported in numerous scientific and non-scientific articles and presentations.