For the past 2 months I have been living on Koh Chang, one of Thailand’s largest islands. Near Koh Chang there are many coral reefs, and there are local initiatives to tackle the issue of coral bleaching, and dying coral reefs. Not only on Koh Chang, but all over the world people are responding to this same problem by creating new artificial reefs for coral to colonize, using different approaches. The idea of creating an artificial reef has been gaining momentum for the last 15 years. So why are people trying to create artificial coral reefs? The answer is that coral reefs contain a large percentage of the oceans biodiversity and ability to sequester carbon from the atmosphere. So why is this happening? It is a combination of over fishing, global warming (which has many sources), and increased coral reef tourism. Here, I simply want to present all of what I have found concerning coral reef restoration, and different approaches for creating an artificial reef.
At this point, I’m sure many people have heard of Jason Decaires Taylor’s under water sculptures in Cancun, Mexico. He has been receiving the most attention in the last few years, so I won’t go into too much detail about his work. What Taylor has done is a combination of two things. On the technical side, he has adapted the approach of an organization called Reef Balls. On the artistic side, he has almost completely adopted the process artist Antony Gormley used while making Domain Field, a project he did in 2003 at the Baltic Center for Contemporary Art in Gateshead, England. During the creation of Domain Field, Gormley made plaster life casts of 250 people from the town of Gateshead and Newcastle, and used those plaster molds as templates for constructing steel sculptures that loosely delineate the shape of each person. Gormley has also had molds of himself made to make iron casts that are installed facing the sea in Another Place, in Wattenmeer Cuxhaven, Germany. Where Gormley creates softly formed iron casts of his own body, and abstracted forms of the community members of Gateshead, Taylor creates detailed cement casts of people from the communities close to where his sculptures are installed that are softened by the coral over time. Where Gormley has a vast and diverse body of artistic work, Taylor does not.
At the same time, Taylor has had remarkable success with growing coral, the true aim of his sculpture. I find this the most impressive thing about his work, especially in comparison with the other methods of artificial reef creation I have come across.
Reef Balls, the name of an NGO that could only be American, also creates underwater structures using pH neutral cement, which is what Taylor uses in creating his cement life casts. PH neutral cement being the key phrase, here. According to Reef Ball research, normal cement has a pH of 13, and alkaline levels are too high for coral to colonize when the structures are initially installed, therefore more aggressive life forms, such as barnacles and algae get there first and inhibit coral growth. The pH in the cement is neutralized through mixing additives, such as micro silica, and curing of the cement for at least 30 days. Here is a photo some finished Reef Balls before and after installation:
Ideally, aided by transplanting coral from existing reefs, it takes only a couple of years for coral to grow over the entire structure.
Though the above photo is the ideal result, I have seen many photos of Reef Balls that look unsuccessful as well. Reef Balls are installed all over the world, and I’m sure it must be hard to guarantee success for every installation. They mention on the website that they have a patent to ensure quality, but I would guess they play a role in project management as well. So if the project does not use official Reef Balls, than most likely the cement isn’t being mixed properly and the site location isn’t carefully thought out either.
All in all, Reef Balls are an impressive organization who have found diverse applications for their design. There are also a few related companies, one of which is called Eternal Reefs, who specialize in creating artificial reefs, or ‘memorial reefs’, which are mixed with the ashes of loved ones, complete with an engraved memorial plaque on the side. Fun!
More practical applications of the Reef Ball design are taken on by another offshoot of Reef Balls called Reef Beach, where Reef Balls are used to prevent beach erosion and act as a ‘submerged breakwaters’, surrounding long stretches of shoreline. In some cases, the Reef Balls are simultaneously used to grow oysters. Reef Beach is also undertaking Mangrove restoration using the Reef Balls.
The Reef Ball Foundation is not alone in their quest for reef restoration and coral cultivation. I came across another, more science fiction approach called Biorock, which makes similar claims to successful coral growth. Biorock has an interesting history. Originally thought of to be used in conjunction with ocean thermal energy conservation, Biorock uses the process of electrolysis to create calcium carbonate, the same substance that coral produces naturally. A steel frame is constructed and hooked up to an electric current, and over time the steel is encased in calcium carbonate produced by electrolysis. The calcium carbonate coating will then naturally attract coral, and provide an appropriate substrate where coral can be transplanted. Biorock claims to provide a substrate that makes the coral more hardy, and able to survive coral bleaching where natural coral cannot.
Here is a great informative/promotional video from one of the founders of Biorock, Thomas Goreau Ph.D:
The founders of Biorock are a well decorated team in terms of education and work experience and the videos out there for Biorock are pretty convincing. Here is a video of a Biorock reef filmed after 2 years of growth in North Sulawesi, Indonesia:
Each method boasts positive results, but as it is noted on the Reef Ball website, no project can be successful without sufficient scientific data to back it up. The water must first be tested, and the site must be thoroughly analyzed to assess whether or not it will be a good location for coral. For example, I doubt that building a Biorock structure in already polluted water will have good results.
That being said, both approaches leave something to be desired aesthetically. There must be a good team of biologists behind Jason Decaires Taylor work.
In addition to intentionally created artificial reefs, I also came across an unexpected and unintentional source of artificial coral reefs — the offshore oil industry. I had never thought of it before, but oil rigs also act as artificial reefs. Though I’m sure the health of marine life around active rigs is up to debate, this video shows oil rigs teeming with life:
The unintentional results of an ultimately environmentally damaging industry, are amazing. Yet decommissioned oil reefs are taken apart or even blown up, destroying the newly created reefs along with them, adding insult to injury, but there is hope. Here is a link to the Rigs-to-reefs program taken on by the U.S. Department of Interior in Texas.
My favorite method that I have found was good ol’ fashioned gardening. There is no electricity, sparing use of concrete, and a wonderful educational element behind what biologists in Fiji and the Florida keys are doing. Here are two videos about coral proliferation, or ‘coral gardening’.
To create new coral reefs, there must be a combination of good science, simple gardening (coral proliferation), and good site location with a suitable substrate. That is a lot to ask, but it is frustrating to see other examples of projects that are driven by people with no patience or true appreciation for science. Like these concrete cube frames thrown into the ocean by the Thai government, or Osbourne reef attempt off the coast of Florida.
Just because sea-wrecked ships look cool, and eventually grow coral, doesn’t mean throwing trash in the water will ‘help the fish’ and give them a place to live.