Active acoustics, making a sound and listening for the echo using an echosounder, is a very powerful tool in fisheries ecology. Ship-based hydroacoustic surveys are routinely used to evaluate the biomass and spatial distributions of fish and zooplankton, but stationary transducers monitoring passing animals are also increasingly used by researchers. Our approach is to use these two technologies to answer key questions on fish population dynamics around Greenland. The research projects focus on species that are either directly exploited or are a major food source for traditionally and commercially harvested fish, birds and marine mammals. Our overarching goal is to better predict the response of Greenlandic fish populations to climate change, which will help us in designing sustainability and adaptation strategies, such as modifying fisheries when resource availability changes.