introduction to coral propagation



Recent abrupt changes in global weather patterns, climate change and human activity has devastated coral reefs around the world, reducing their area coverage by over a third in the past decade and threatening its very existence, along with the millions of species that rely on it for sustenance, humans included.

Corals are disappearing at an increasingly alarming rate for a variety of reasons, some global (such as global warming and heat waves), others more localized (such as destructive fishing techniques, environmentally unfriendly tourism and pollution).

While some of these issues need to be tackled at a global scale by governments and countries as a whole, others can be managed by local authorities and local businesses. 

By reducing the amount of local stress factors on an area we can limit and counter the effect of global threats such as heat induced bleaching.

Bleaching is by far the biggest threat to coral reefs worldwide. Raising average water temperatures and recurring heat waves are causing coral colonies to lose their symbiotic algae, causing starvation and death.

Some coral colonies are more resistant to bleaching than others. Some recover more quickly and others bleach at higher temperatures. It is still unclear what the specific genetic factors that control these resistances are, so until we fully understand the underlying mechanics of this phenomenon we need to find other ways to safeguard our corals.

The belief at the core of our coral propagation effort is that by replicating and multiplying the stress resistant corals in an area, we effectively increase the resilience of the reef as a whole.

The Ocean Quest Coral Propagation Course on which our program is based on is developed around 3 core concepts:


  • Anyone can propagate coral: The methodology is very simple to actuate and does not require any in-depth coral biology knowledge.
  • The materials used are cheap and easy to find: Ordinary tools are converted for use in coral propagation. If conducted in the laboratory, most of the tools used for coral fragging are borrowed from the medical industry. In the field, stronger and cheaper tools can be used.
  • The method used will cause no additional damage/stress: many other propagation methods acquire coral fragments by breaking pieces off healthy coral in order to multiply it. While this can be considered an adequate technique in certain areas, we believe it does not suit our purposes here. Coral reefs that are in dire need of propagation are usually already under a noticeable amount of stress, so we do not want to add any more. Our source of coral will be colonies that have already been broken either by natural or anthropic causes.


Nursery Sites & Structure

Since 2018 we have established 2 coral nurseries, both located on the island of Koh Yawasam,  off the coast of AoNang, Krabi. As we continue expanding our program, we expect to establish a number of new nurseries both on islands and on shore. 

While the original Ocean Quest method does not entail any artificial structure, it does require a certain setup to ensure the optimum functionality of the nursery as a whole.

Each nursery has a number of different areas which have different functions:


Source Areas: area of reef from which coral fragments and substrates are collected. Source areas should always be less than 5km away from the nursery area to maintain the species diversity of the corals we propagate as similar as the local reef al possible. 

Quarantine Areas: Temporary holding locations for newly propagated coral. The substrates on which coral fragments have been attached will be kept in this area and monitored for signs of infection, damage, or stress. Corals that are unhealthy will be removed to minimize the chance of disease spreading. By the end of the quarantine period the bonding agent will have dissolved,  and the coral  fragments should be attached to the substrate autonomously.

Nursery Area: Once the quarantine period is over, the substrates with the fragments will be moved to the actual nursery area, where they will be left to grow. The specific location of each nursery area is usually chosen to increase ecosystem connectivity and overall reef surface coverage. 

Cemetery Area: location where we take diseased coral to prevent further infection. This location is always a sandy area far away from any natural reef. 

Substrate & Fragment Gathering

Upon arrival to our destination, Coralyfe staff and SCUBA diving customers will set out to collect substrates and broken coral fragments to be propagated.

The substrate we search for is natural rock of approximately the same size as two hands. The rock can be be host to a variety of life forms, although we chose not to utilize rocks that are already hosting a coral colony of any kind. This is to allow naturally occurring corals to continue growing without the additional stress of being temporarily removed from the water, and to allow them have enough space to expand on their substrate without any added spatial competition.

The coral fragments we search for are, generally speaking, any coral that is found already broken, and otherwise of healthy appearance. We will not be using any bleached or unhealthy looking coral. We will also not harvest coral fragments by breaking them off healthy colonies.

Substrate and coral fragments will then be brought back to the boat, where they will be placed in holding tanks filled with seawater until ready to be worked with. 


Collected coral fragments will be further cut down to small pieces of about 3cm in length for branching type corals, or about 3cm*3cm in surface area for boulder/plate type. The reasons behind this small chosen size are primarily two: smaller coral fragments have been observed to grow faster, and small fragments offer little resistance to water movement, reducing the chance of the newly propagated fragment to be broken off its substrate by a wave or water current. 

Coral fragments will then be paced in many small different holding tanks based on their species and other factors, to reduce stress caused by other nearby corals. 


Coral fragments will then be selected to best match a certain substrate, based on their size and shape.

The ideal spot we look for is a crack or hole on the substrate inside which the fragment can fit firmly, even without the use of a bonding agent. Once the ideal location is found and the fragment is inserted, a few drops of superglue will be added to secure the fragment to the substrate and minimize the chance of it accidentally falling out due to water movement. A proprietary bonding catalyst will also be used to harden the glue rapidly, and to provide additional calcium, as well as having antibacterial properties. 

A detailed exemplification of each step of the process will be provided by Coralyfe staff upon arrival, as well as individual assistance throughout the day. 

In the majority of cases only a single coral fragment will be bonded to each substrate to provide enough space for each coral to develop into a colony without the added issue of spatial competition with other corals. 

Deposition and Quarantine

Once the coral fragments are bonded to their substrate they will passed on to a snorkeler, who will in turn deliver each substrate to a SCUBA diver positioned on the Nursery Area. The propagated corals will be placed on the nursery area and observed for the following 3-4 weeks for any sign of disease, bleaching, or breakage. 

Any unhealthy coral will be removed to increase the survival chance of the remaining ones. 

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