Reef Design Lab has designed Mars II.

Coral reefs are threatened globally by destructive practices like dynamite fishing, bottom trawling and increasingly powerful storms.

Mars II was designed to recreate complex, three-dimensional habitat underwater, improving biodiversity outcomes with a modular system.

The lightweight units are cast from moulds with marine-grade concrete. Designed to be diver-deployable, the units are bolted together underwater by hand.

Overhangs, cavities and caves create habitat for fish and other marine life, while their channelled texture offers stable surfaces where coral can be planted or colonise naturally.

"As corals and algae engulf the modules, the artificial structure establishes a living reef," said Reef Design Lab.