In October of 2010, the Department of Marine and Coastal Resources deployed one of the largest and most ambitious artificial reef projects to date for Koh Tao. But then in 2015 they brought enough artificial reef cubes to make the 2013 project look tiny, with over 2,000 cubes being deployed around the island. Surely this is one of the biggest artificial reef projects in the Gulf of Thailand, and together with all of the other projects we have done over the last 9 years, must make Koh Tao the island with the most artificial reefs in all of Thailand, possibly even SE Asia.
The blocks are constructed from concrete, and are hollow in the center. Each one weighs about 1.2 tons, and is about 150 cm on each side. Traditionally they have been used as fish nurseries in order to increase fisheries yields around the country, but on Koh Tao they are being used to extend coral reef areas, restore areas where structure has been lost, and create alternative dive sites for the booming dive industry on the island. By increasing the available surface for coral recruitment and growth, it is hoped that the total amount of reef resources and services on Koh Tao can be maintained in the face of increased development and climate change. By removing divers from natural areas it is hoped that the dive industry on Koh Tao will have less of a negative effect on the natural reefs, and be able to perfect their buoyancy and self-awareness skills in areas they cannot damage.
When the blocks were put down in Ao Leuk, Hin Ngam, and Twins in 2013, our team spent the next three months doing most of the assembly work, and have subsequently spent over 50 dives and lots of our own money fixing corals onto the structures to attract fish life and jump start the restoration process. It has been great fun, and we really enjoyed all of the assembly work – moving 1.2 ton blocks of concrete underwater to build interesting structures. But as each step in the process is completed, it leaves us satisfied with the work we have done, but wanting more.
For the 2015 project, the 2,000+ blocks have been deployed in 4 locations; Hin Ngam, Tanote Bay, Ao Mao, and Mango Bay. The team deploying the blocks is much better than last time, and rather than pitching them off the front of the barge, they have been carefully arranging large sets of 4-16 blocks. But there is still plenty of work for us to do, after deployment we estimate that there is another 200-250 blocks that will need to be moved and assembled into the final place before restoration work can proceed.
Our team will begin in Ao Mao, where the blocks have been dropped in large groups, 2-3 levels high. Some of the blocks will be moved to create a perimeter to the pyramid like design, which is just 1 level high. This will increase the footprint of the site, and allow water to flow better over and around the area. The work is a bit deeper than the last set of blocks, at 18 meters, but unlike last time the blocks only need to be moved a few meters rather than over 100 meters.
Next, we will move to Tanote Bay, where the blocks have been laid in a single level, and move some to create second levels on some of the areas, which will increase the diversity of the new site. These blocks have been placed in an area that used to be coral reef, but was inundated by 1.5-2 meters of silt and sand in 2006-2007 after the construction of a large reservoir in the watershed above the bay. Together with the reef balls deployed in 2010 by the DMCR, it is hoped that this area can be brought back to what it once was.
The largest site from this installation is at Hin Ngam, with over 600 blocks deployed around the area. Many of the blocks have been placed adjacent to the existing coral reef, where there is a great supply of coral recruits, but very little except unsecured rubble for them to settle on. Like Tanote Bay, the blocks have been placed down in sets of 4, one level high. Although they are already full of fish, they are a bit monotonous for visiting divers, and so will be assembled into more interesting and diverse structures for the island’s divers to better enjoy.
The New Heaven Reef Conservation Team has been tasked with most of the assembly, restoration, and monitoring of all the DMCR blocks projects around Koh Tao. With a long history of working with artificial reefs and coral nurseries on our own and with the DMCR, they are happy to leave the rest of this project in our capable hands. Our expectation is to have most of the assembly done by September of 2015, when the restoration work can begin in earnest, but already we have begun that process.
When the blocks were put down, some corals were broken or damaged by the anchors used to secure the barge, or by the blocks themselves. The team doing the work did a great job ensuring not many corals were damaged, but when you use a 100 meter long ship to put down over 2,000 blocks near the coral reef something is bound to get broken. So, the week after deployment in March of 2015, our team has been working hard to get any dislodged coral or broken fragments secured onto the blocks, or on new coral nurseries. With quick action, none of these injured coral colonies should die, and now the blocks have some corals on them to get things started.
Our next phase of the project will be to establish large coral nurseries near each of the sites, using unsecured coral recruits or naturally produced coral fragments from a wide range of genera and collected over a wide geographic area. The corals on these nurseries will be allowed 6-8 months to grow, before being transplanted onto the blocks themselves. In the meantime, we expect to finish all of the arranging, and get the blocks in their final position. The actual restoration work on the blocks should take about 4 years, over which time we will also be doing regular monitoring and reporting back to the DMCR about the progress at each site. We have allocated 5 years total for the arranging, transplantation/maintenance, and monitoring of the project, which we feel is the minimum time needed for any large artificial reef project to ensure success.
We are excited to have been placed in charge of this project, and based on previous experience know that we can handle this role. Our team of dedicated and trained conservationists not only do a great job with this type of work, but also really enjoy doing it. If you are interested to get involved in this project you can email us directly and inquire about availabilities on our marine conservation training programs or our internship programs. Not only will you get to be involved in this great project and get experience in some amazing underwater coral restoration work, but the course fees paid is what funds most of our work and materials. If you support this project and want to help, but can’t make it to Koh Tao yourself, then we also accept donations to help us pay for SCUBA Tanks, coral nursery materials, and underwater epoxy.
Thank you for your support. And a big thank you to Khun Pitoon of the Department of Marine and Coastal Resources for bringing this mega-project to the island of Koh Tao, and entrusting its care and development to the NHRCP. Stay tuned over the next few months on our webpage and our facebook page for more updates and pictures of the sites and the work being done above and under the sea to make Koh Tao an even more amazing place than it already is.