Mass bleaching event turns Australia's Great Barrier Reef white

The world's largest living structure, the Great Barrier Reef in Australia, is once again hit by a mass bleaching event as ocean temperature levels increased due to climate change, AFP reported.

The mass bleaching events have turned the once vibrant corals into a sickly shade of white. This is the seventh incident since 1998.

Australian Environment Minister Tanya Plibersek said in a statement, "We know the biggest threat to coral reefs worldwide is climate change. The Great Barrier Reef is no exception."

"We need to act on climate change. We need to protect our special places and the plants and animals that call them home," she added.

Coral bleaching occurs when underwater temperatures are more than 1 degree warmer than the long-term average.

As corals come under heat stress, they expel algae living within their tissues, draining them of their vibrant colours.

Ocean temperatures along the Great Barrier Reef have approached record levels in the past few weeks, according to official monitoring.

Some species of bleached coral have proven to be remarkably resilient and can recover if ocean temperatures cool.

But Professor Terry Hughes, one of Australia's foremost coral reef scientists, said bleaching events were now happening so frequently that reefs were struggling to recover.

The Great Barrier Reef is Australia’s most prized possession, attracting thousands of tourists every year. It is home to more than 1,500 different species of fish and 411 species of hard corals. It is the world's largest coral reef.