Bioturbation of reef sediments aerates upper sediment layers and releases organic material to benthic communities. Despite being conspicuous bioturbators on coral reefs, the value of holothurians to reef ecosystems is relatively unknown. Here, we used remote sensing data from drone and satellite imagery to estimate the bioturbation rates of holothurians across the 19 km2 Heron Island Reef in Queensland, Australia. Ex situ bioturbation rates of the most abundant holothurian, Holothuria atra, were also assessed. Using density measurements of holothurians across reef flat zones in a 27,000 m2 map produced from drone imagery, we extrapolated bioturbation across the reef using satellite data. Individual H. atra were estimated to produce ~14 kg of bioturbated sediment per year. On a reef scale (excluding the reef lagoon) and accounting for varying densities of holothurians across different reef zones, total bioturbation from holothurians at Heron Reef was estimated at over 64,000 metric tonnes per year. These results highlight the scale of structural and biochemical impacts that holothurians have on reef flats and their importance to ecosystem functioning and services. Management of these animals is imperative as overharvesting may negatively impact sedimentary ecosystems and their biogeochemistry in corals reefs.