Temperatures of Coral Sea at Great Barrier Reef Highest in 400 Years

According to a study commissioned by the Great Barrier Reef Foundation, the GBR is worth A$56 billion in total economic value; and is responsible for 64,000 jobs. According to a study recently published in the journal Nature by professors from the University of Melbourne, the GBR is also in critical danger from oceans that are hotter than at any time in the last 400 years.

The GBR is one of the seven natural wonders of the world. It is 2,300 kilometers long, covers an area larger than New Zealand, and is visible from space. It is home to hundreds of thousands of marine and coral species. The Global Fund for Coral Reefs just approved $25 million in aid to support the health and restoration of coral reefs, with Peter Bryant, Builders Initiative’s Program Director for Oceans, and GFCR Executive Board Member saying:

“Without collective action at pace and scale, scientists estimate that 90% of remaining coral reefs may be lost by 2050, with dire consequences for the communities and economies they support.”

But though scientists and environmentalists hope that innovative solutions, such as growing coral that is resilient to heat and acidified ocean water, will mitigate the problem, the Melbourne study expressed concern about the ability of current coral systems–like the GBR, which has existed for hundreds of years—to survive.

 “Most rapid changes depend on a history of exposure to key genetic types and extremes,” the study said. “And there are limitations to genetic adaptation that prevent species-level adaptation to environments outside of their ecological and evolutionary history. Model projections also indicate that rates of coral adaptation are too slow to keep pace with global warming.”

The research, led Benjamin J. Henley, Lecturer, Sustainable Urban Water Management School of Agriculture, Food and Ecosystem Sciences, asserted that even if humanity manages to limit global warming to the Paris Agreement’s ambitious 1.5 °C level, we’re still facing the loss of 70–90% of corals that are on reefs today.

“The reconstruction shows that sea surface temperatures were relatively cool and stable for hundreds of years, and that recent January–March ocean surface heat in the Coral Sea is unprecedented in at least the past 400 years,” the study said. “The coral colonies and reefs that have lived through the past several centuries…are themselves under serious threat.”

More than a million visitors come to the GBR every year, fueling tourist business from scuba diving companies to hotels, restaurants, airlines. The reefs themselves provide habitat for species that feed the fishing industry and harbor materials used in pharmaceuticals and other industries. Medicines for cancer, Alzheimer’s, chronic pain and other conditions have come from coral reefs, or from the creatures that inhabit them.

Beyond the environmental loss, the economic loss would be significant.

“… In the absence of rapid, coordinated and ambitious global action to combat climate change,” the study said, “we will likely be witness to the demise of one of Earth’s great natural wonders.”