An undated handout photo received from the ARC Centre of Excellence Coral Reef Studies on October 14, 2020 shows a damaged part of the Great Barrier Reef - the vast World Heritage-listed reef off Australia's northeastern coast [File: Andreas Dietzel/ARC Centre of Excellence for Coral Reef Studies via AFP] The reef is at risk of losing its coveted World Heritage Status because of ocean warming, fuelled by climate change, which is damaging its health.
You can check out LADbible's campaign aimed at gaining The Great Barrier Reef, the world's largest living organism, Australian citizenship here. The destruction was particularly pronounced after the mass coral bleaching events that occurred between 2016 and 2017.
Dr Dietzel says a major implication of coral size is its effect on survival and breeding. The reef suffered its most extensive bleaching event in March, the third one in five years.
The researchers assessed coral communities and their colony sizes along the 2300km length of the reef from 1995 to 2017.
While coral reefs cover only 0.2 percent of the oceans, they are home to 30 percent of marine biodiversity.
The reduction happened in both deeper and shallow water and across all species.
The research, published in Proceedings of the Royal Society, looked at coral communities and the size of the colony between 1995 and 2017 and found that almost all of the coral populations suffered depletions of various amounts.
It has more than 411 species of hard corals documented, as well as 1,500 species of fish and other animals. Bleaching does not kill corals right away, but if temperatures remain high, the corals will eventually die, destroying the natural habitat of many species of marine life.
"There are millions of small, baby corals in a vibrant coral population, and there are many bigger ones - big uncles who produce most larvae", said Andy Dietzal, a doctoral student at the ARC Center of Excellence for Coral Studies.
"We thought the Great Barrier Reef was being protected by its enormous size", Hughes said, but our results show that even the largest and relatively well-protected reef systems in the world are increasingly undermined and declining.
Authors of the study, published Wednesday in the journal Proceedings of the Royal Society B, warn "there is no time to lose" in ensuring carbon emissions are rapidly reduced.
"These were the worst affected by record-breaking temperatures that triggered mass bleaching in 2016 and 2017".
"We found the number of small, medium and large corals on the Great Barrier Reef has declined by more than 50 per cent since the 1990s", added co-author Professor Terry Hughes, also from CoralCoE.