Hawaii is making moves to help protect the future of its coral reefs. Gov. David Ige is expected to sign a bill that passed last week that would ban the sale of certain sunscreens that may damage coral.

And in Australia, the government is pledging nearly $380 million to help save the Great Barrier Reef, which has been badly damaged by warming waters.

Some scientists say it might be too late to save the reef. Others say there's still hope.

C. Mark Eakin (@MarkEakin), coordinator of the National Oceanic and Atmospheric Administration's Coral Reef Watch program, is among those in the latter group.

"This bleaching event has been devastating, and people who have been working on reefs around the world have just been heartbroken by what's occurred," he tells Here & Now's Jeremy Hobson. "But I haven't given up on coral reefs yet."

Interview Highlights

On how the Great Barrier Reef is doing at this moment

"It's had a couple of bad years. We had huge marine heat waves that hit in 2016 and 2017. In 2016, the Great Barrier Reef lost about 29 percent of its corals, and in 2017, another 22 percent. All of this was a part of a global bleaching event that lasted for three years from, 2014 to 2017, and, as I say, reached all around the world. Climate change has increased water temperatures, and you add to that climate events like El Niños and La Niñas, and the high temperatures are causing the corals to bleach and die."

On bleaching

"Bleaching actually is when the corals eject the microscopic algae that live inside their tissues. Corals are animals, vegetables and minerals, and these algae that live inside their tissues give them most of their food. And when high temperature stresses them, they object the algae into the water column. It leaves them injured, starving and clear-looking. And so you're actually seeing right through the tissue into the skeletons — that's bleaching. If it lasts long enough, if it's severe enough, the corals will die."

This image shows the same reef in American Samoa before, during and after a coral bleaching event. (The Ocean Agency/XL Catlin Seaview Survey/Richard Vevers)

On bringing coral back

"It's not so much how do you bring them back, it's how do they bring themselves back. If it's a mild event, short-lived, the corals will actually — they have some algae still in their tissues and those algae will be able to reproduce and repopulate and you get the color back. Unfortunately, the coral is still injured, it's weaker and it's more susceptible to disease, as well. So sometimes they recover, and then they die. And, of course, the question is how do they come back after they die. Well, they're dead. It's just a matter of having the reef come back, and that takes at least 10 to 15 years for even the fast-growing corals to come back."