Since 2019, disease is known to have affected corals and turtles within the Region. The incidence of disease is expected to increase with warming temperatures and consequences could be significant. There are concerns that the Region could be affected by new outbreaks of disease occurring overseas (for example, stony coral tissue loss disease), but these diseases have not yet been observed in the Region.

Crown-of-thorns starfish outbreaks continue to affect reefs across the Region. However, in the past 5 years, increased crown-of-thorn starfish control efforts have reduced the impact of outbreaks on coral reefs, at both local and regional scales.

Since 2019, new introductions have occurred in both marine and island areas within the Region, while effective eradication programs have occurred on some islands. Biosecurity strategies and management measures are being implemented to help mitigate the risk, although some potential pathways for introduction of non-native species remain.

A long-term increase in Trichodesmium abundance has continued at the Yongala National Reference Station. High numbers of Drupella snails have been recorded at some reefs, but no outbreaks have been reported.