Australia's Great Barrier Reef has just recorded its largest annual decline in coral cover since observation began nearly 40 years ago, according to the Australian Institute of Marine Science (AIMS). Both northern and southern parts of the reef faced overwhelming coral bleaching, exacerbated by tropical cyclones and the invasive crown-of-thorns starfish, which devour coral. However, AIMS emphasizes that climate change-induced heat stress is the main culprit behind this decline.
Their latest survey, which monitored 124 reefs from August 2024 to May 2025, highlighted that the reef, spanning 2,300 km, is facing a tipping point where recovery might be impossible post-catastrophic events. Coral bleaching, often referred to as “underwater bushfires,” occurs when corals become stressed and lose their vibrant colors, posing a risk to around 25% of marine species that rely on coral for survival.
If coral experiences temperatures over its thermal limit for extended periods, the chances of recovery diminish significantly. Unusually high tropical waters have resulted in coral bleaching at alarming rates, and 2024 marked the sixth significant event since 2016.
To mitigate further damage, recovery is crucial and depends on both coral reproduction and reduced environmental disruption. Among the most affected species is the Acropora, known for its rapid growth yet high vulnerability to heat stress and predation by crown-of-thorns starfish. Conservation efforts, including successful government programs against these starfish, have been initiated but continue to face challenges.
Experts, such as Richard Leck from WWF, warn that without urgent climate action, the Great Barrier Reef might meet a fate similar to some coral reefs globally that are beyond the point of recovery. UNESCO has also indicated that this environmental wonder, heritage-listed for over four decades, is "in danger" due to rising ocean temperatures and pollution. The fight for the reef's survival remains imperative as its health reflects broader environmental concerns.
