Coral nurseries and artificial reefs are a form of active restoration aimed at increasing coral health, diversity, or abundance. Corals themselves are colonial organisms which reproduce primarily asexually to grow larger or repair damaged areas. Because of this feature, we are able to grow new coral colonies from smaller or broken pieces of coral, called fragments. Coral may naturally become broken due to many different threats such as large storms and waves, boat anchors, fishing nets, or irresponsible diving and snorkeling practices. These broken corals, when rolling around the sand, have almost no chance of survival, and usually die. But, by securing these fragments in good growing conditions they can be rehabilitated, nursed back to being a mature colony, and then transplanted back out onto the reef or onto artificial reef structures.
In fact, it was Charles Darwin who first realized this about corals. He noticed that corals rolling around under the boat quickly turned white and died, but by securing the loose coral to a piece of bamboo pounded in the sand they would survive. For this he is credited with being the first coral restorationist. This is the basis of our coral nursery program initiated in 2007, with our first site placed in Ao Leuk Bay. Our materials and methods have changed considerably since the time of Charles Darwin, but the ultimate goal is the same, secure dying corals before its too late.
We have constructed many nurseries and explored a wide variety of techniques over the last 8 years, and have learned what works well for our area, and through which methods we can receive the maximum level of benefits with the lowest amount of material or labor costs.
Then, in 2010, Thailand and the rest of the South China Sea experienced one of the worst coral bleaching events in the last decade. After this event, the Thai Government, along with local Universities met to discuss ways in which we could alleviate damages and protect our reefs in subsequent events. Representatives from New Heaven RCP attended several conferences and meetings in Bangkok, and pushed forward a plan to make local stakeholders more responsible for taking a proactive approach to reducing threats to reef health. Coral nurseries were identified at that meeting as one of the most accessible and efficient means of increasing reef resilience and helping corals rebound from bleaching.
Next, we worked with the Save Koh Tao Group, the Thai Department of Marine and Coastal Resources, and the Prince of Songkla University to start and Adopt-A-Reef Program here on here island. Other than New Heaven, 5 dive schools signed up to the program, and we worked together to increase the size and scope of coral nurseries around the island. In fact, the DMCR and PSU donated 48 coral nursery tables for our island dive schools to use and look after. Currently we look after the tables in Chalok Ban Kao and Ao Leuk, which is also where we have our own coral nurseries.
In other areas, such as the Tanote Bay reef balls site, artificial reefs have been established between the DMCR and the local community, and so it is our job to maintain them. Every week we spend at least one or two days working on coral nurseries and artificial reefs around the island. It is important that they are maintained regularly, and there is always work to do there. In order to get more people involved, including the local community, we have also done projects aimed specifically at using coral nurseries to teach people about the threats to reefs and what can be done. For example, we did a 1 month science fair project with the local school kids to assess what types of materials and methods work the best. We also have completed projects together with the DMCR specifically aimed to get non-divers involved (see the article from January 2013 here).
Students in our program receive training on the theory and science of coral restoration and the uses of coral nurseries. They practice their skills regularly diving and maintaining our nursery and artificial reef sites. Students also receive training in designing, constructing, and deploying artificial reefs to add or replace structure for corals to grow on. Some of our interns have also done projects or written papers about the artificial reefs we manage. Topics have included comparing growth rates on the Hin Fai Biorock to other sites or looking into the effectiveness of artificial reefs around the island,
Most of our day-to-day artificial reef and coral nursery work goes on in Ao Leuk and Chalok, which are both very interesting sites that we have been restoring for about 4-5 years now. In Chalok we have the problem of repeated anchor dropping, so we construct structures to fill add substrate where the reef has been reduced to rubble (read more about the Chalok site here). In Ao Leuk we are trying to create a new reef, as an alternative dive site to reduce diving pressure on the natural reefs (find out more about the Ao Leuk Coral Nursery and artificial reef site here)