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Hong Kong’s First Coral Transplant Project


Hong Kong has a long coastline and as many as 84 species of hard corals; one tenth of the total number of reef-building corals in the world. Corals are known as the "tropical forests" of the ocean as they provide complex microhabitats for many marine species to shelter and breed, enriching the marine ecology.

However, corals are very vulnerable to adverse impacts and require high water quality. Slight changes in sea water temperature, salinity or clarity can lead to their bleaching or even their death. Observations made by our divers reveal that the number of hard corals and their related ecosystems have been decreasing in recent years. For example, at Double Island, Sai Kung, the coral population has declined by up to 80% in the last decade. There are various reasons for this reduction, including global warming, pollution, net fishing and leisure water sports, which all affect corals to different degrees.

As hard corals grow and recover rather slowly, they are hard rebuild from damage through natural regeneration alone. However, artificial transplants can accelerate their recovery. Places around the world such as Taiwan, Malaysia and Singapore have all succeeded in artificial transplantation. Now, Hong Kong is carrying out its first project.

The first step of artificial coral transplantation is to collect suitable corals from other areas. In order not to harm the original coral colonies, divers will only collect coral fragments that have fallen off due to a variety of reasons such as typhoon damage. Divers will check the health status and species of the coral fragments, and transplants can be conducted upon suitability being confirmed. As corals can reproduce asexually, when divers fix the coral fragments in suitable target growing locations, the fragments will grow slowly and achieve restoration eventually.

Green Power working with Eco-education & Resources Centre and a group of local divers, carried out its first artificial coral transplant in June 2014. The present stage is rather experimental, focusing near Double Island. 1,500 square metres of hard corals are expected to be restored in 3 to 5 years.

2018
  • Ongoing
2017
  • Data being processed
2016
  • Collected approximately 80 pieces of coral fragments in the year, and selected 27 specimens for transplantation.
  • 15 of the 40 specimens transplanted in 2015 are secured on coral reefs.
  • 12 of the 43 specimens transplanted in 2014 are secured on coral reefs, and one of which has grown coral polyp.
2015
  • Collected approximately 100 pieces of coral fragments in the year, and selected 40 specimens for transplantation.
  • Half of the 43 specimens transplanted in 2014 are secured on coral reefs, one of which has grown coral polyp.
2014
  • Commencement of Coral Transplant Project. Approximately 100 pieces of coral fragments were collected, and 43 specimens were selected for transplantation.
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© Ken Ching

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