No-take marine reserves benefit fishery target species throughout the world’s oceans, and in many regions they also improve habitat condition, biodiversity and ecosystem resilience. The Great Barrier Reef Marine Park (GBRMP) is a mosaic of interconnected habitats with an overlaid patchwork of management zones allowing varying levels of human activity. This includes a network of no-take (green) reserves that collectively cover 33% of the GBRMP. Here, most research on the effectiveness of these no-take zones has focused on coral reefs. The largest benefits have been detected for target species of the coral reef fishery (coral trout and red throat emperor), and secondary target species from several fish families. Mean coral trout abundance, length and biomass were 50 - 100% higher in no-take zones, with similar benefits recorded for Serranidae and Lethrinidae and secondary target species (mostly Lutjanidae and Labridae). Between coral reefs, no-take benefits have now also been measured in coastal nursery seascapes and deeper shoals and sponge gardens. We synthesise benefits of no-take zones in the GBRMP beyond target species, including the increase in recovery rates and reduced COTS outbreaks, showing increasing evidence that intact fish assemblages buffer marine ecosystems from damage and degradation.