Great Barrier Reef
Climate change remains the greatest threat to the Australian natural treasure, and things are not looking good.
The volcanic rock could transport Pacific sea organisms to restock the bleached reef off Australia.
The catastrophic die-off from recent ocean heat waves severely affected the reef's ability to produce new corals and bounce back.
While none will single-handedly save the world, extreme and sometimes controversial plans are gaining traction.
Last year's oceanic heat wave wasn't as destructive as one the year before, scientists said.
But advocates say it's too soon to write off the reef.
But environmentalists caution that it's not enough.
Rising temperatures in 2016 caused a catastrophic die-off of almost 30 percent of the iconic reef.
“The dire situation is here now," said the coordinator of NOAA’s Coral Reef Watch.
In the northern Great Barrier Reef, juvenile green sea turtles are 99 percent female.
"Before the 1980s, mass bleaching of corals was unheard of."
"Serious concern" about the threats facing the reef remain, though, according to the United Nations agency.
“You can’t be the world’s biggest coal exporter and at the same time be taking action on climate change."