[ad_1]
Left: The Reef Design Lab's newest modular artificial reef structure in the Maldives is 8.2 feet tall and has a footprint of 13 square feet. Right: 3D printing reefs allow researchers to experiment with restoration methods, such as how coral fragments are attached to reefs (here, using zipped links).
(Photos: Alex Goad)
Local fishermen were skeptical. On the deck of a small motorboat, scuba divers grabbed strange ceramic pieces – which one could describe as rocky brains stuck on stubby stilts – and dipped in aquamarine waters . The diving team has collected the pieces in a few circles of ballistae to investigate the agitation. After only two air tanks (about an hour each), they had locked all the elements in the final product: an artificial coral reef.
The three-dimensional printed reef, installed at the Summer Island Maldives complex last month, is the first of its kind on any of the 1,200 Maldives islands. Each ceramic component of the artificial reef was printed in 3D with a custom design and then fitted with coral fragments that developers hope to see grow throughout the structure.
3D printers have become faster, cheaper and more accurate over the last decade, allowing enthusiasts to develop neat trinkets such as toothpaste presses and custom pasta machines. Australian entrepreneur Alex Goad had a more ambitious application: coral reefs with 3D printing. He formed the nonprofit Reef Design Labs will apply the flexibility of 3D printing to coral restoration research.
"I created Reef Design Labs to support marine research, which is our main business," says Goad. "I was interested in ceramics and how it could be used as the ideal material for coral nurseries, so we looked at it."
A customizable approach to reef restoration
RDL calls its patented technique for 3D modular coral formation, modular artificial reef structure, or MARS. Instead of using steel or concrete, popular substrates for artificial reefs, the RDL prints hollow ceramic blocks that can be molded into complex shapes and fill them with concrete for added stability. Divers bring these blocks under water and assemble them as Legos to form a coherent and resistant structure.
The 3D printing of artificial reef structures may seem like something to attract attention, but Goad suggests several benefits of a custom reef mold. Coral begins its life cycle as drifting larvae looking for an unexposed place protected from predators and water currents. 3D printing can replicate the complex structure of existing reefs needed to promote the growth of new corals. Within minutes, the small alcoves and overhangs of the Maldivian MARS also began to attract curious fish; It could someday harbor crustaceans, sponges and anemones to form a marine community.
A previous installation of MARS, a few months after its deployment, has become home to various marine species. Although 3D printing will not solve the global threats facing the reefs, it can support targeted small-scale restoration efforts.
(Photo: Alex Goad)
"[Reef Design Labs] Aminath Shauna, originally from the Maldives and spokesman for Summer Island Maldives, actually designed the structure from the corals that grow the most in the Maldives.[The 3-D-printed reefs] have all these outlines and shapes that mimic the natural reefs, so that the corals can easily settle … what we can not do just by building regular concrete structures. "
Goad was not the first to build 3D printed reefs; another Australian, James Gardiner, associated with Sustainable Oceans International to sink sandstone blocks among the sections of a damaged reef system in the Persian Gulf in 2012. The benefit provided by MARS is a convenient installation. Rather than using barges to transport sturdy concrete pieces to the sea, divers can hand-assemble a customizable set of MARS pieces to form a sturdy skeleton with shapes inspired by the native coral community.
A Tasmanian blennie takes refuge in one of the 3-D printed homespaces of Reef Design Labs.
(Photo: Alex Goad)
Reef Design Labs has also applied its technology to other forms of marine life. In June 2017, RDL participated in the largest shellfish restoration in Australia, dropping more than 18,740 tonnes of limestone near the Yorke Peninsula, then releasing tiny oyster larvae to settle on the new structures. In April 2016, the lab teamed up with Riot Games to design marine sculptures, including a popular online video game character, as attractive hangouts for fish communities. The lab is currently working with Volvo to build a massive dike to protect the Sydney Harbor from erosion.
The design and implementation of each project solicits the contribution of marine biologists, who monitor structures to evaluate the methods that produce the most permanent habitats for corals and other reef organisms.
Reef Design Labs is partnering with Riot Games to cast several structures serving as fish dens in Moreton Bay, Australia. This is one of the sculptures, the day of installation and 15 months later.
(Photo: Alex Goad)
The materials and methods of installation for an artificial reef should be chosen and carefully prepared, or the structure can do more harm than good for the marine environment. 3D printing also requires specialized equipment and expertise, and custom reef design can be expanded. Goad recognizes that there are limits to practice.
"People assume that 3D printing will be something magical that will save the coral reefs, of course not.This must be used for small coral nurseries," he says. "I was interested in how MARS could help this cause: a complex permanent structure and allowing other species of reefs. [besides corals] to have a house. "
MARS serves as a platform for targeted research on optimal methods of coral culture. Impressions can be adapted to specific experiments, for example by testing how different techniques for fixing coral fragments affect growth. This research could help scientists better understand and adapt to the threats to coral reefs.
Coral bleaching threatens reefs around the world
Corals face a number of global threats, such as White band disease, coral skeletons dissolving from ocean acidification and coral bleaching, the last of which particularly affected the Maldives. Warm ocean temperatures stress the corals and push them to eject the algae cells that live there, which they depend on to produce energy. Prolonged separation kills both corals and algae, leaving nothing but a white skeleton of bone.
"[T]The ecological impacts of bleaching are almost instantaneous and can be serious, "said Dr. Christopher Perry and Dr. Kyle Morgan, who the quantified coral loss in the Maldives in 2016. "Such events therefore also have the ability to cause very rapid and potentially severe declines (…) in terms of reef growth potential."
The Maldives are the largest atoll in the world, a geological formation composed of thousands of years of coral growth. The nation also has the seventh largest reef system in the world, but it is changing rapidly.
In 2016, a huge El Niño event, a change in the global wind, and naturally occurring rainfall patterns every two to seven years caused a dramatic warming of the waters of the Indian and Pacific Oceans. This heat shock, combined with the continued increase in global temperatures, disrupted one third of the Australian Great Barrier Reef coral cover and killed about 75% of the southern Maldivian coral cover.
Shauna recalls the summer of 2016 distinctly.
"There is a reef we would go snorkeling near Male [the Maldivian capital], she says. It is a beautiful reef, one of the healthiest reefs I've seen near the capital. And in a week, we saw it completely white. "
Corals benefit coastal communities in the Maldives and beyond because they attract fish (and tourists). they protect the coast from storms and erosion. The Maldives are particularly vulnerable to sea level rise: the highest peak in the country on Addu Atoll is eight feet above sea level. Shelves created by Coral growth acts as a wall that dampens the impact of waves, reducing constant flooding and beach erosion, of which there is very little left in the Maldives.
"I remember in 2016, when we were swimming, we felt like being in a bath," Shauna adds. "And it's not just 2016 … every year it's warmer, and with El Niño, corals do not have time to recover."
Optimism despite disastrous global conditions
Research and creative approaches to reef restoration are a glimmer of hope in the face of global threats that have already destroyed much of the world's coral ecosystems. Ecologists have identified corals that thrive in warm waters and others that are associated with unique algae to withstand high temperatures.
Goad maintains his optimism in the most difficult moments: "What really motivates me is the amount of research that is being done.There is work on understanding heat-tolerant corals and identifying the constitution. genetics on how to start coral farms en masse. "
The charisma and flexibility of 3D printing will do little to help the reefs if the ocean temperature continues to reach levels at which corals can not survive. However, technology such as RDLs can facilitate research to understand how we can adapt to climate change. Goad is experimenting with approaches to solving the problems facing coastal communities.
"We are starting to look at 3D modular design as a revolutionary technology [to prevent storm damage and flooding]. It's really interesting because it's really needed in a place like the Maldives. "
Mr. Goad said he hoped this work would engage researchers and local communities, demonstrating the ease of coral restoration and inspiring others to follow. "Installing the structures under water, it's very fun," he says. "Everyone just loved that."
And those skeptical fishermen from the Maldives who are watching the installation? "Now," says Goad, "they start their own coral nurseries."
This story originally published on the World Conservation Information Web site Mongabay.com. Get updates on their stories delivered in your inbox, or follow @Mongabay on Facebook, Instagram or Twitter.
Source link
