SEACHANGE is a synergetic alliance bought together to unlock the richness of oceanic history. Funded by European Research Council (ERC) Synergy Grant, this 6-year project will combine interdisciplinary research approaches to quantify the impact of major cultural transitions on marine ecosystem functioning and biodiversity, setting new baselines for understanding ocean environmental change. By understanding how the seas of today are different from the past, we will be able to better manage them for the future