People have been paying thousands of dollars for the rarest of coral species, the Pacific white-spot coral, and now some of the more expensive species have been hit by a new threat.
The coral bleaching that has wiped out the largest number of white-spotted coral species on the planet has hit more than 40 species, including the rareest of all.
Researchers have estimated that about 2,000 white-starved coral species have died since last year, with most of them thought to be extinct.
Some of these species are in trouble.
One of the most endangered is the black-bellied white-tailed dolphin.
Its population has dropped by half over the last two decades and now only about 30 live in the wild.
They were thought to have disappeared about 25 years ago, but scientists have discovered evidence of genetic problems that means the species may be extinct, at least in the Pacific.
The only hope of saving the species is to help restore it.
Scientists have estimated the blackbellied coral species is extinct, and that there are fewer than 30 left in the world.
In the past 20 years, a whole new group of coral, the black and white-sided white-straw coral, has appeared, which are very similar to the blackspotted species.
But the white-striped ones have been in decline.
For the last couple of years, the bleaching has caused some of these coral species to die off, and some have found new homes.
But scientists are worried that the loss of the blackstriped white-strips could bring about the extinction of the remaining white-stars.
“It is an incredibly important species, but at the moment, there are only about 300 white-straights left in all of the world,” said Richard Brown, a marine biologist at the University of Sydney, Australia.
“It would be a catastrophic loss for this species, which is the most abundant in the oceans, and it is critically endangered.”
Brown is not alone in his worries.
A recent study by scientists at the National Oceanic and Atmospheric Administration found that about 80% of white star-lined coral species could be wiped out by 2050.
White-stripe coral is a group of corals that are native to the Pacific Ocean and is the smallest group of species on Earth.
They have a flattened shape and a flat belly.