Coral reefs are under increasing anthropogenic stress globally, resulting in the increased occurrence and intensity of mass bleaching events. With subsequent flow-on effects on fishes that utilize reef habitats, understanding how organisms respond to ecological disturbance contributes crucial information to understudied ecosystems. Corallivorous fishes that depend directly on live corals for nutrition are those most likely to be adversely affected by declines in coral health. Previous studies in other reefs have identified linear relationships between abundance of obligate corallivores and coral health metrics. Norfolk Island in the subtropical south pacific has experienced recent occurrences of bleaching events and coral mortality at its’ lagoonal coral reef. However, the responses of hermatypic corals have been atypical to those observed in tropical reefs. As such, the response of coral dependent fish taxa are likely unique to this system.
The present research used 15 min roving diver surveys across four sampling events (December 2023, March 2024, May 2024, December 2024, April 2025 n = 10 surveys per sampling event) in Kingston Lagoon at Norfolk Island to quantify the diversity and abundance of Chaetodon spp., aiming to identify potential shifts in such metrics before, during, and after a historical bleaching event. It was found that neither facultative nor obligate corallivores experienced significant declines between time points, nor were there significant shifts in Chaetodon species assemblages nor diversity indices. This research presents novel insight into the response of corallivores to coral bleaching at a high latitude/subtropical reef and indicates some resilience of these specialized animals to climate change induced disturbances.