Drone Imagery Reveals Alarming Coral Mortality Rates at Lizard Island

Recent research conducted by a team of scientists from Griffith University and other institutions has unveiled staggering coral mortality rates of 92% following the 2024 global bleaching event at Lizard Island, part of Queensland's Great Barrier Reef. This event is recognized as one of the most severe coral mortality incidents ever documented globally, raising urgent concerns about the health of coral ecosystems under increasing climate stress.

The study, titled "Coral bleaching and mass mortality at Lizard Island revealed by drone imagery," was published in the journal Coral Reefs on July 4, 2025. It highlights the impact of the Fourth Global Coral Bleaching Event, which was officially declared by the National Oceanic and Atmospheric Administration (NOAA) in April 2024. This unprecedented event resulted in extensive coral bleaching and mortality across the reef system, affecting 96% of living corals in the surveyed areas (Raoult et al., 2025).

Lead author Dr. Vincent Raoult, from Griffith University's School of Environment, emphasized the extraordinary nature of these findings. "Despite lower heat stress levels at Lizard Island compared to other regions of the Great Barrier Reef, the mortality rate has reached unprecedented levels," Dr. Raoult stated. The research team employed high-resolution drone technology to map coral bleaching in March 2024 and conducted follow-up assessments in June to measure survival and mortality rates.

Professor Jane Williamson, a senior author on the study from Macquarie University's School of Natural Sciences, underscored the urgent need for climate action. "Using drone-derived imagery, we can analyze the effects of bleaching over larger areas with high precision," she explained. The drones used, including the DJI Mini 3 Pro and Autel Evo II, provided crucial data that revealed mortality rates exceeding 99% in certain locations. Notably, no significant differences in mortality rates were observed between the northern (North Point Reef) and southern (Palfrey Island Reef) sites of the island.

The implications of these findings are profound. Coral reefs are vital ecosystems that support a vast array of marine life and provide significant economic benefits through tourism and fishing. The alarming mortality rates documented at Lizard Island are indicative of the broader challenges faced by coral ecosystems globally, particularly in light of the increasing frequency and intensity of extreme heat events attributed to climate change.

The research team is conducting further surveys at Lizard Island to monitor potential recovery in coral populations through 2026, supported by an Australian Museum Lizard Island Critical Grant. The findings call attention to the fragility of coral ecosystems and the urgent need for comprehensive climate policies to mitigate further damage.

This study not only serves as a wake-up call for environmental stakeholders but also emphasizes the critical intersection of technology and ecological research. The use of drone technology in ecological assessments represents a significant advancement in our ability to monitor and understand the impacts of climate change on vulnerable ecosystems like coral reefs. As researchers continue to delve deeper into the ramifications of coral bleaching, the findings from Lizard Island could inform conservation strategies and policy decisions moving forward.