Book excerpt: Tremendous advances in oceanographic observing and modeling systems over the last decade have led to unprecedented developments in the nature of information available to marine science. While improvements in observational technologies and networks have garnered much attention, remarkable developments in forecasting the ocean have received much less focus. Exploiting this new predictive skill to improve scientific understanding, generate advice and aid in the management of marine resources, is emerging as one of the new challenges of marine science. Translating predictions of the physical environment into biological outcomes, however, is not straightforward. Fisheries scientists, for example, have been trying to understand the links between physics and biology, and generate predictions of variables such as recruitment, for close to a century, with limited success. Nevertheless, spatial distributions and the timing of key events, which have received less focus, are often tightly linked to the physical environment and may have management-relevant applications. The first-such forecasts based on this skill are now starting to emerge. This Frontiers in Marine Science Research Topic provides a snapshot of the state-of-the-art in Marine Ecological Prediction. It covers the opportunities for developing such forecasts, technical approaches that could be employed, and examples where the technology is already being applied. This body of work therefore marks an important milestone on the route to developing this new and exciting field of marine science.