The Australian Institute of Marine Science (AIMS) released a new study that reports that the Great Barrier Reef has lost half of its coral cover in just the last 27 years. This is an astounding rate of loss. The findings were based on the most comprehensive reef monitoring program available. This program began broad surveillance of 100 of the reefs in 1985 and has performed detailed surveillance of 47 reefs since 1993.
The study reports that 48% of the loss was due to storm damage, 42% was due to crown of thorns starfish, and 10% was due to bleaching. “We can’t stop the storms but, perhaps we can stop the starfish. If we can, then the Reef will have more opportunity to adapt to the challenges of rising sea temperatures and ocean acidification”, says John Gunn, CEO of AIMS.
Bleaching occurs when temperatures in the oceans rise and the coral organisms cannot survive, leaving behind white skeletal structures. The crown of thorns starfish population has grown immensely, a problem because they feed on coral.
Climate change has a lot to due with this loss, causing increases in ocean temperatures, ocean acidification, as well as increase storm occurrences and intensities.
“We can’t stop the storms, and ocean warming (the primary cause of coral bleaching) is one of the critical impacts of the global climate change,” says AIMS CEO, John Gunn. “However, we can act to reduce the impact of crown of thorns,” he says. “The study shows that in the absence of crown of thorns, coral cover would increase at 0.89% per year, so even with losses due to cyclones and bleaching there should be slow recovery.”
CNN has reported that the rise in starfish population corresponds to a massive rise in plankton population. When the starfish are in the larval stage, they feed on plankton. Plankton populations increase when fertilizer runoff enters the ocean waters and causes a surge in nutrients. This is where the problem can be fixed with stricter regulations and monitoring.
The Great Barrier Reef is one of the world’s most spectacular natural occurrences. As climate change continues, we will surely see losses like this all over the world.