Smithsonian Magazine reports:

Climate change, water pollution and fishing practices have been decimating coral reefs for decades, threatening the ecosystem that’s home to 25 percent of all marine species. Within the next 15 years, nearly three quarters of all reefs will likely be damaged or destroyed.

Scientists have long been searching for ways to help repair these delicate living structures. They’ve replanted reefs, using both natural and artificial materials. They’ve tried replacing reefs’ algae with stronger varieties. They’ve even used electric current to help stimulate coral growth. Lately, they’ve been working with one of the technology community’s current darlings, 3D printing. Printed reefs can closely mimic natural ones, providing a home for baby coral to take root and grow. The process is still in its infancy—in 2012, the first 3D printed reefs were sunk in the Persian Gulf off the coast of Bahrain, where the existing reefs had been badly damaged. Similar projects are in the works around the world.