Report: Great Barrier Reef may not survive
CANBERRA: The Great Barrier Reef has survived five climaterelated ‘‘death events’’ over the past 30,000 years, but may not be resilient enough to bounce back from the current decline, a scientific report says.
The reef is the world’s largest coral system and one of most biodiverse ecosystems on the planet, but has suffered recently from an onslaught from a crownofthorns starfish epidemic, sedimentation, degradation of water quality, ocean acidification and massive backtoback bleaching events in 201617.
The 10yearlong multinational study, published in Nature Geoscience journal yesterday, is the first of its kind to reconstruct the evolution of the reef over the past 30 millennia in response to major and abrupt environmental changes.
The reef is more resilient to major environmental changes such as sealevel rise and seatemperature change than previously thought, the study found, but it remains an open question whether its resilience will be enough for it to survive the current decline.
The study used data from fossil reef cores at 16 sites and covers from the period before the ‘‘last glacial maximum’’ 20,000 years ago, when sea levels were 118m below current levels, to the emergence of the modern reef some 9000 years ago.
The reef suffered five widespread death events but was able to reestablish itself over time due to the continuity of reef habitats with corals and corallinealgae and its ability to migrate laterally at between 0.2m and 1.5m a year.
But the reef is unlikely to survive current rates of seasurface temperature rises, declines in coral coverage, coral bleaching, decreases in water quality and increased sediment flux since European settlement, the scientists say.
Previous studies have established a past seasurface temperature rise of a couple of degrees in 10,000 years, but the current forecast rise is about 0.7 degC in a century. — DPA