Simple art inspires a range of tools to maximize coral restoration

An environmentally friendly and cost-effective coral restoration toolkit can accelerate the restoration of degraded coral reefs along the coast of Saudi Arabia and beyond.

Coral reefs support about 30% of marine wildlife and provide invaluable ecosystem services, such as fishing, tourism and coastal protection. But these vital habitats are rapidly disappearing.

Despite international climate agreements to limit carbon emissions and curb global warming, scientists fear that coral reefs have passed a tipping point and will continue to decline even under the most optimistic of climate scenarios. “We have lost nearly a third of global coral cover in the past 50 years, and we urgently need effective measures to mitigate further decline,” says marine scientist Sebastian Schmidt-Roach.

Coral restoration can now be the best line of defense, but progress has been limited by the cost and labor intensity of working in marine environments. Current restoration projects and coral gardening, or “reefs,” tend to be small, covering only 500 square meters on average. “We need to target areas of thousands of square kilometres,” says evolutionary biologist Manuel Aranda. “One way to do this is through selective breeding of more resilient corals so that we don’t have to restore each reef ourselves, but rather leave some resilient colonies to do the job for us.”

To help achieve coral restoration on an industrial scale, the Coral Hub team, including Carlos Duarte and Charlotte Hauser, created MaritechtureTM – a suite of tools to selectively transfer cultured corals from lab to reef. The innovation has been published in the journal Frontiers in Marine Sciences.

The patented system includes tiles that act as a substrate for the growth of the corals: stackable boxes to which the tiles can be attached, and MaritechtureTM Reef screws that will not allow for quick attachment of the tiles to natural reef substrates. For reef surfaces where nails won’t work, they created MaritechtureTM Coral Pods – free-standing limestone structures consisting of two interconnected slabs to create a four-legged “pod” with plenty of surface area for attaching tiles or coral fragments.

The researchers estimated that a team of six divers could deploy 90 capsules, creating up to 250 square meters of coral reef in half a day. Coral tiles are manufactured with a microchip so researchers can see what works and where doesn’t. “It’s interesting that our structures have already attracted a lot of natural coral settlements,” adds Schmidt-Roach, a promising sign that these artificial corals can colonize themselves.

Created in collaboration with artist Julien Charriere, these pieces are inspired by the 20th century German Bauhaus style of simple, practical shapes and rational materials. “Its simple design allows for flexibility and low-cost, easy application across different habitats, including in developing nations,” says Schmidt-Roach.

“We’ve tried to reduce the use of plastic and metal. Limestone is a natural, reef-like material with much lower carbon emissions than traditional steel- or cement-based solutions,” explains Schmidt-Roach. Where necessary, the team uses acrylonitrile butadiene styrene, a non-toxic, recyclable plastic that does not degrade in water.