The number of new corals in the Great Barrier Reef of Australia has been reduced by 89% since the whitening events unprecedented in 2016 and 2017, according to scientists.
The events, which damaged two-thirds of the world's largest reef system, are now blamed for triggering a collapse in coral reef growth last year.
"Dead corals do not produce babies," said lead author Professor Terry Hughes of James Cook University in Queensland.
Scientists blame the problem with the increase in sea temperature.
The research, published in the journal Nature on Thursday, was conducted by a group of scientists last year.
He measured how many adult corals along the reef had survived after the mbadive whitening events and the number of new corals that had been produced.
"Along the Great Barrier Reef, there was an average decrease of 90% compared to the historic [1990s] recruitment levels, "co-author Professor Andrew Baird told the BBC.
& # 39; There is nothing left to replenish the reef & # 39;
Professor Baird said that the "quite extraordinary" descent was unexpected. It was probably the first reef regrowth problem on a mbadive scale, he added.
"Babies can travel long distances, and if a reef is removed, there are usually many adults on another reef to provide juveniles," said Professor Baird.
However, the bleaching in 2016 and 2017 affected a section of 1,500 km (900 miles) of the reef.
"Now, the scale of mortality is such that there is nothing left to replenish the reef," said Professor Baird.
The study also found that the mix of baby coral species had changed. He found a 93% drop in Acropora, a species that normally dominates a healthy reef and provides habitats for thousands of other species.
The researchers said that coral replacement could recover in the next five to 10 years if there were no future discoloration events.
However, given the current estimates, this probability was "almost inconceivable," said Professor Baird.
"We have reached the point where local solutions for the reef are almost useless, the only thing that matters is action on climate change," said Professor Baird.
The reef, a vast collection of thousands of smaller coral reefs that extend from the northern tip of Queensland to the city of Bundaberg in the southern state, received World Heritage status in 1981.
The UN says it is the "most biodiverse" of all World Heritage sites, and of "enormous scientific and intrinsic importance".