A Manhattan-sized floating mass of pumice bits in the Pacific that erupted from an underground volcano could turn out to be a lifesaver for Australia’s Great Barrier Reef, scientists say.

The “pumice raft” was spotted by the NASA Earth Observatory after a suspected volcanic eruption near Tonga, according to officials.

The mass — headed to Australia — consists of various-sized pieces of the porous rock that are ideal for tiny sea creatures to make their homes. The pumice will be carrying a bounty of new life forms once it reaches the Great Barrier Reef early next year, scientists said.

An Australian couple sailing a catamaran to Fiji encountered the unusual phenomenon earlier this month and posted photos, observations — and a warning to other craft — on Facebook. The pumice, which they described as a “rubble slick,” can scratch boats and jam engines and rudders.

“Catamaran ROAM sailing to Fiji encountered volcanic rock (pumice) completely covering the ocean surface,” the post noted. “Rubble slick made up of rocks from marble to basketball size such that water was not visible.”

Marine life, including barnacles, corals, crabs, snails and worms, are “hitching a ride” on the mass as it moves through the Coral Sea, geologist Scott Bryan of the Queensland University of Technology told the Australian Broadcast Corp. That’s good news for the Great Barrier Reef, which has been devastated by coral bleaching due to climate change and toxins.

“Based on past pumice raft events we have studied over the last 20 years, it’s going to bring new healthy corals and other reef dwellers” to the reef as it begins to close in on Australia in about seven months, Bryan told The Guardian.

“Each piece of pumice is a rafting vehicle. It’s a home and a vehicle for marine organisms to attach and hitch a ride across the deep ocean to get to Australia,” he added.