Scientists have recently finished surveying portions of Australia’s Great Barrier Reef which recently experienced the largest recorded die-off of corals. In the northern sections of the Great Barrier Reef, there was an average mortality of 67% of all shallow-water corals over the past 9 months due to high temperature-induced bleaching. Where once lush and colorful expanses of corals and other reef-inhabiting creatures could be seen, now only large expanses of algal mats smother the substrate. However, further south, scientists were surprised to find that the death toll was much lower.
“Most of the losses in 2016 have occurred in the northern, most-pristine part of the Great Barrier Reef. This region escaped with minor damage in two earlier bleaching events in 1998 and 2002, but this time around it has been badly affected,” says Professor Terry Hughes, Director of the Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies based at James Cook University, who undertook extensive aerial surveys at the height of the bleaching.
While the northern regions suffered, only a 6% and 1% mortality of corals was observed in the central and southern regions, respectively.
Tourism along the Great Barrier Reef plays a major role in the culture and economy of Australia’s eastern coast. Over 70,000 people work in the tourism sector of the Great Barrier Reef and it generates upwards of $5 billion dollars each year. Given the patchy distribution of the worst damage along the reef, tourism can still thrive in the areas that weren’t hit as hard.
Researchers now expect that the northern, most devastated region could take at least 10-15 years to regain lost corals, if yet another future bleaching event doesn’t end up slowing the recovery.