In this episode (which is recorded in English) we will learn about how genes can change due to changes in the environment over time, and how we can use that information to produce salmon in a better and healthier way in the future. Ross Fisher Cairnduff is a Ph.D student at the University of Bergen, and will try to help us understand this complicated theme. His group are looking at changes in the gene expression in salmon that grow in the normal way, that is in the sea, and salmon that are landlocked, meaning they live their whole life in freshwater. Understanding the systems at play within the fish can help us improve how we manage these fish and therefore reduce welfare concerns.