Bleaching hits the Great Barrier Reef... a year after it last struck

THE Great Barrier Reef has been hit by mass ‘bleaching’ for a second year in a row.

Conservationists fear such an extreme change could put the ecosystem – which stretches for 1,400 miles off the coast of Australia – at severe risk of dying if conditions do not change.

Bleaching occurs when algae in the coral are expelled due to stress caused by sustained changes in temperatures, turning the coral white.

The first aerial survey of 2017 has found severe bleaching in the central part of the reef, just a year after extreme heat had the same effect.

The Great Barrier Reef is the world’s largest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 mollusc species.

It is the habitat of wildlife such as the sea cow and the large green turtle.

Conditions on the reef are part of a global coral bleaching event over the past two years, as a result of unusually warm ocean temperatures.

Scientists argue this is as a result of climate change and a strong El Nino weather phenomenon that pushes temperatures up further.

Dr Neal Cantin, of the Australian Institute of Marine Science, said: ‘We are seeing a decrease in the stress tolerance of these corals. This is the first time the Great Barrier Reef has not had a few years between bleaching events to recover.’