Australia’s Great Barrier Reef (GBR), the world’s largest reef system, is a significant part of the marine ecosystem. According to the annual long-term monitoring report from the Australian Institute of Marine Science (AIMS), Australia’s northern and central Great Barrier Reef has experienced high levels of coral reef cover over the past 36 years. However, these gains could be quickly reversed due to rising global temperatures.
Key Highlights from the Monitoring Report
The AIMS report indicates that reef systems are resilient and capable of recovery after disturbances such as accumulated heat stress, cyclones, or predatory attacks. The hard coral cover in the northern part of the GBR reached 36%, while the cover in the central region reached 33%. However, coral cover levels showed a decline in the southern region, going from 38% in 2021 to 34% in 2022.
The report credits the high level of recovery to the increase in fast-growing Acropora corals, a dominant type in the Great Barrier Reef. These corals are also most susceptible to environmental pressures such as rising temperatures, cyclones, pollution, and attacks by crown-of-thorn starfish (COTs) that prey on hard corals.
The Threat of Climate Change to Coral Reefs
Despite many global initiatives, the health of the reef continues to be threatened by climate change-induced heat stress, resulting in coral bleaching. Sea temperatures are predicted to increase by 1.5°C to 2°C by the end of the century. The United Nations assessment in 2021 warns of increased bleaching as the world will reach a 1.5°C rise in temperature in the next decade.
The Significance of Coral Reefs
Corals are marine invertebrates that do not possess a spine. They are the largest living structures on the planet and form colonies by multiplying themselves. They support over 25% of marine biodiversity even though they occupy only 1% of the seafloor. The marine life supported by reefs contributes greatly to global fishing industries. Moreover, coral reef systems generate USD 2.7 trillion in annual economic value through goods and service trade and tourism.
About Australia’s Great Barrier Reef
The GBR stretches across 2,300 km and comprises nearly 3,000 individual reefs. It hosts 400 different types of coral and provides shelter to 1,500 species of fish and 4,000 types of mollusc. In pre-Covid-19 times, the Reef generated USD 4.6 billion annually through tourism and employed over 60,000 people, including divers and guides.
Crisis of Coral Reefs and the Way Forward
Coral reefs are among the most threatened ecosystems on Earth. To reduce human impact on coral reef ecosystems, societal-level changes are essential. The achievement of Sustainable Development Goals (SDG 14) by 2030 could provide significant improvement to ocean resources. Protecting top predators, identifying key herbivorous fish species for protection, halting destructive fishing, boating and diving, and managing the exploitation of reef fish are some of the necessary steps. However, more aggressive action and education from the top down to grassroots efforts are required to achieve a carbon-neutral planet and protect coral reefs.
Last Modified: February 18, 2024