MAJOR submarine pumice eruptions have occurred repeatedly during the past 25 years in the Tonga–Kermadec region1–3. Pumice from this area drifts through Fiji and New Caledonia, reaching Australia roughly one year after an eruption1,2. Coral larvae settle and grow on the floating pumice fragments (Fig. 1). The geographic pattern of abundance and size distribution of rafted corals found on drift pumice in relation to the pumice source area suggests massive transport of corals into the Great Barrier Reef from regions of lower diversity lying far to the east and southeast. Dispersal range is not limited by longevity of larvae and centres of diversity may be sites of species accumulation rather than sites of species origin.