In 2014, Texas conservationists built a 54-acre underwater reef from artificial substrate; four years later oysters covered 70% of its surface

Half Moon Reef, a once-thriving oyster reef in Texas' Matagorda Bay, had been severely degraded after decades of overharvesting and environmental pressures. In late 2013, The Nature Conservancy and its partners began rebuilding the reef, placing about 100,000 tons of limestone across 54 acres of bay bottom to create hard surfaces where oysters could attach and grow.

Raccontata datimesofindia.indiatimes.com