Throughout the years there have been a few mass bleaching events that have affected the Great Barrier Reef. In particular, the years of 2016 and 2017, saw the reef sustain two years of back to back bleaching periods. This long period accounted for an estimated loss of half of the coral life in the Great Barrier Reef. The parts of the reef that did survive were damaged, leading to an overall period of low coral reproduction. This was later followed by another bleaching event in 2020, making it the third bleaching event in five years. Studies found however that the results of the 2020 bleaching were not too severe, as it only affected a minimal amount of reefs, with most being in the lower to moderate levels of bleaching.
In early 2022 a study showed, 91% of coral in the Great Barrier Reef, have experienced some degree of coral bleaching. The reefs that had higher levels of bleaching, often were accompanied by higher overall air temperature. These temperature levels lasted all through the summer season in Australia, attributing to prolonged coral bleaching periods. Prolonged periods raise concern, as corals would not be able to reproduce and die out, leading to more loss of the reefs. However, recent reports from June 2022, have stated that the Great Barrier Reef, is currently recovering. Reefs affected by bleaching have lowered to 16% along different areas of the Australian Coast. As ocean temperatures continue to drop, we can expect bleaching levels to go down, and coral levels to increase. Though coral bleaching has gone down, predators of the coral reef, Crown-of-thorns starfish, are still impacting coral growth and development.