The Great Barrier Reef is still recovering from what was considered to be the worst coral bleaching event in recorded history. However, warmer ocean temperatures this year could cause another mass bleaching event.

A mass coral bleaching event this 2017 will make it the second year in a row. This is the first time that two mass coral bleaching events occurred so close together, highlighting the need for immediate actions.

"What's happening with global warming is that these events are becoming the new normal," Terry Hughes, from James Cook University's Centre of Excellence for Coral Reef Studies, told BuzzFeed News. "The gap between them is becoming shorter and shorter. This is the first time we've had back-to-back bleaching. It's a real wake up call."

Evidence of another mass bleaching event was apparent in the images released by Greenpeace. These images were backed up by a survey conducted by the Great Barrier Reef Marine Park Authority (GBRMPA). The survey was conducted over the area between Cairns and Townsville in northern Queensland.

The GBRMPA survey revealed that about two-thirds of coral coverage in a 700-kilometer stretch of reef north of Port Douglas in far north Queensland has died due to warmer ocean temperatures. Scientists note that it's too soon to access the damage done of this year's mass coral bleaching event compared to last year's.

"To some extent it's not as important whether this event is not quite as bad or worse than last year's," said David Wachenfeld, a researchers at GBRMPA, in a report from ABC News. "I think what's important is that the climate is changing and that is bringing a much greater frequency of extreme weather events to the Great Barrier Reef."

Experts warn that as bleaching events occur in close succession, affected corals will have a hard time coping up and repairing themselves. When the corals never fully recover from past bleaching events, it could put the whole reef system in danger.