Hin Fai: Reflections on 5 years at the Biorock

Corals growing on the Hin Fai Biorock Site. 2014

Corals growing on the Hin Fai Biorock Site. 2014

Biorocks™, or mineral accretion devices, are artificial reefs that use low-voltage electricity to actually change the conditions in which corals are growing. Most coral reef restoration techniques focus on only the structure of the reef or transplanting corals, or a combination of the two. Mineral accretion devices have the added benefit of increasing coral growth rates, and allowing corals to survive and grow even when conditions are poor. Click here to find out more about our use of this technology.


In 2008, 17 local dive centers and the local community joined together to raise 1 million baht and construct Thailand’s largest Biorock structure, the Hin Fai Site. The site provides new areas for the growth of corals, fish, and related reef organisms, as well as providing an alternative dive site to reduce pressures on the natural reefs. Since its deployment, the NHRCP has been making nearly weekly trips out to Hin Fai to maintain the site, transplant corals, take data, and just enjoy the great marine life there.


By 2014, the site is teaming with life. Coral diversity on the domes is some of the highest we can find in the area, with almost every local genera represented. Many of the corals are still relatively small, but are growing and encrusting along the biorock structures in incredible ways. Watching the leading edge of the corals as they grow, it is interesting to observe the competition between species as space becomes more limited. In many of the faster growing Acroporas (branching and bushy corals), there are whole schools of juvenile butterfly and damsel fishes bouncing in and out to escape the predatory jacks and groupers that are always close by.


2 years of growth for one of the many large Acropora table corals on the Hin Fai Biorock

2 years of growth for one of the many large Acropora table corals on the Hin Fai Biorock

Years ago, we would spend much of our time at the site cleaning, brushing, and scraping off algae or other unwanted organisms. Today, feeding along the domes are schools of Parrot fish and Java Rabbit fish, removing algae and preventing the growth of tunicates or encrusting sponges so that the hard corals can flourish. Under the domes we can often find the resident moray eel, scorpion fishes, or sometimes a reef octopus.


After 5 years, the Hin Fai site has become a personal favorite for our conservation team. Not only is it a great place to do conservation work, but it is a great place to fun dive. We have had several students do project involving the site, including a detailed study of growth rates by Gerianne Terlouw. Over the next year we hope to start analyzing the data we have been collecting over the last 5 years, and get a more objective and scientific analyses of how the site has progressed, and how the reef health there has compared with other areas around the island during the same time.


Working with the mineral accretion technology at HinFai over the last 5 years, and the Taa Chaa site the 3 years before that, we can clearly see the benefits of such technology. Corals, giant clams, and other reef organisms have grown much faster, and healthier, on the structures than in the surrounding areas. During the bleaching event of 2010, corals on the Hin Fai site experienced less bleaching, less mortality, and less subsequent death due to disease or predation. Truly we would like to use this technology in every degraded or threatened reef around the island.



There are however a few downsides to using the technology over other artificial reefs types, but in our experience they would be issues of cost and maintenance. As a patented technology, reef managers and communities around the world are not able to readily learn about or utilize it. Expensive licensing fees, consulting fees, equipment purchases through the company, and other fees make initial costs of the technology restrictive to most reef managers. Patenting has also greatly hindered the progress of scientific experimentation and debate on the technology, which could have lead to greater efficiencies and cheaper costs. Although maintenance of the devices is higher than a conventional artificial reefs, maintenance is not necessarily restrictive to its use by local managers with limited resources.  What does impede users is that as a proprietary technology, users are not able to maintain or repair the devices on their own when they break (which all inevitably will).

Maintaining the Biorock

As with many new technologies, it takes time to fully understand the best way to use it, and to bring down costs so that it is democratically available. Although we feel this process in the case of Biorock has been largely stalled over the last fifteen years, we look forward to a future where the technology will become more widespread, and local reef managers will be able to test and share their experiences more easily. Mineral accretion devices are a necessary and effective tool on the belt of any reef manager, and we look forward to a day when there will be used at such. In the meantime, we are continuing to enjoy our days at Hin Fai, always looking forward to seeing how our corals are growing, and what new and unique marine animals await us during our visit. . .


Hin Fai 2


Have you used Biorocks? If so, what was your experience? Please help us to share and spread accurate information about mineral accretion technologies by adding your comments below.