How 17.5 Tons of Corals were saved, and 5000 New Coral Colonies were created in Antigua

Martin Dudley (a lifetime resident of Antigua pictured to the left) has followed the activities of the Reef Ball Foundation for several years and heard that the Reef Ball Foundation was on Antigua doing a coral propagation project for Maiden Island.  Having always been an advocate for Antigua's reef systems, he knew of places on the Island where man's activities where imperiling coral reefs.  So, Martin took it upon himself to call the Reef Ball Foundation to see if anything could be done to rescue the soon to be lost corals....most of which would be gone within days if action was not taken.

The Reef Ball Foundation asked Stanford Development Company, Ltd.  if the propagation project could be delayed so the Foundation's volunteers on Antigua could be re-assigned to a coral rescue effort.  Stanford immediately approved the changes and offered additional funding to bring in experts that could handle adult colonies of corals safely and for additional supplies needed to attach adult corals.

Martin called several of his diving friends for additional local help to remove the corals from impending danger.  The local volunteers and the Reef Ball Foundation's international volunteers rounded up every kiddy pool, cooler and bucket that could hold sea water to transport the corals. The team filled the boats to capacity, each boat could hold about 2000 pounds of live corals per trip.  Over five days, twenty one boatloads of corals were removed from danger and transported to Maiden Island.   The site where the corals were saved provided a rich abundance of corals and thankfully nearly all the corals were saved.  Later, as a special assignment, the rescue boats became 'scouting' boats.  The goal of  'scouting' boats was to find specific species of imperiled corals to strengthen the breeding depth of the newly built reef.  The scouting boats and found imperiled Staghorn, Elkhorn, Pillar, Sea Fan, Lettuce, and (Green) Finger corals and were able to save them and in the process get a better balance, genetically, on the new reef.

The common sea fan (Gorgonia ventalina) has not been present at Maiden Island since hurricane Luis because larger corals were no longer present to create the kind of wave surge sea fans need to survive.  As part of the reef design, an area was created called 'Y-Canyon' which was designed as a snorkeling swim through that would create the kind of surge needed for sea fans to live.  (See picture at the upper right: 'Y-Canyon' from the air).



Marsha Pardee a marine expert from the Turks and Caicos Islands shows the tools used to remove the corals from the area where dredge work would kill them.  





Hydrostatic Attachment of Corals (traditional restoration)

Marsha Pardee from the Turks and Caicos is adept at re-attaching adult coral colonies with hydrostatic cement (mixed with microsilica for pH control and strength).  She lead the team in the initial replanting of the largest colonies of corals which require the hydrostatic cement instead of the underwater epoxy putty which is used for smaller colonies.  

Movie showing how the Hydrostatic/Microsilica  attachment method works

Above: Rescued Brain corals waiting to be replanted by traditional hydrostatic cement techniques.


Reef Ball Foundation Coral Propagation with Attachment Adapter System.

The traditional method of coral restoration requires that adult coral colonies are rescued from impending death.  No new corals are added to the oceans and any loss from the rescue operations represent a direct loss of reef.  This is obviously not a way to restore ocean ecosystems which is the mission of the Reef Ball Foundation.  Therefore, the Foundation has developed a method of taking imperiled coral colonies and dividing them into many new colonies to create more coral colonies than originally present.  This method of asexual coral reproduction is called propagating or fragmenting corals.  Hobbyist in the aquarium industry have been doing this for years and even commercial aquaculturalists culture both hard and soft corals for the aquarium industry.  There is a small percentage of fragments that do not survive the propagation process, therefore, each coral colony is divided into plenty of fragments so that the in the end, there is always more healthy colonies than originally.  This process has been used successfully around the world.  The Reef Ball Foundation has propagated corals in American Samoa, Malaysia, Maldives Islands, Bahamas, Curacao, USA, Kuwait, Mystique, Dominica, and now Antigua.  In areas where tropical coral reefs exist, adding propagated corals to artificial reefs can speed development of a new reef by 10-20 years.  Because the genetics of propagated corals are known (a propagated coral is an exact genetic clone of the original colony), species can be planted to strengthen sexual spawning (for example, planting several different coral of the same species but different genetic makeup on the same Reef Ball) or species can be selected for specific traits (for example, corals that have survived disease outbreaks, bleaching events, sedimentation or pollution events).  Other goals can be obtained such as planting a Reef Ball with multiple plugs of the same genetics so when the adult corals grow to the size where they touch, they will fuse to form a single large colony.  The big advantage, however, of the attachment adapter system is volume.  Using traditional methods, a skilled diver may plant 10 corals in an hour.  Using the Reef Ball plug system a relatively unskilled diver can transplant 100 corals or more per hour.  This ten fold increase in efficiency and ability to use quickly trained volunteers instead of life long experts makes coral restoration practical on a large scale.

How the System Works

1. Imperiled corals are gathered and brought to the area of the 'coral prop table' which is placed in shallow water. As they arrive, they are cut into small fragments using special tools and methods.  Note: The 'coral prop table' was specially designed by the Reef Ball Foundation to allow corals to remain in healthy water at all times and to make the 'plugging' process fast and efficient.  In Antigua, teams of 6 could turn out over 1,000 coral plugs in a day.

2. A special cement developed by the Reef Ball Foundation which is designed to set in less than 3 minutes and contains additives to adjust the pH and to stimulate 'basing' of corals is mixed with a Water/Adva Flow solution quickly.  (The mixing job is the one that requires the most training and usually a half hour of practice without live corals to perfect...too thin of a mixture and the plugs won't have the strength needed and hardening takes too long, too thick and the concrete goes of before there is time to add the corals.)

3. The concrete is poured into standard 'medicine' cups that have sand in the bottom to allow easy removal of the set plug from the cups.  

4. Wearing gloves which are sterilized between each new coral colony worked with, fragmented pieces of coral are inserted into the cement and after 2 minutes they are placed back in the water for full curing which takes 20 minutes before the plug is popped out of the cup.

4.a.) Some corals are placed in a temporary nursery to make sure the plugging process worked correctly before planting. 



5. Before planting, they are transferred to trays so the divers can take them to the Reef Balls.


6. Some species must be transported in the trays because they cannot touch each other (Staghorn on the left) whereas other corals can be carried to the reef in buckets or baskets because touch each other is not a problem (Pencil corals on the right).


7. The divers use a special underwater epoxy putty and fit the plugs in to special holes pre-built into the Reef Balls for this purpose.  Most corals are rescued, fragmented, plugged, and planted within a few hours.  This means they did not have to spend stressful time in an aquarium or other captive environment which is one of the reasons survival rates are so high.  

8. A baseline photograph with a reference frame is taken to document the corals progress.

9. After just 3 weeks, you can see the cut parts have overgrown with new coral tissue and buds and if you look closely you can see the coral is starting to grow out over the plug.  It will eventually grow out to the Reef Ball and be a permanent part of the reef.

10. After 2 years, these tiny plugs can become very large coral colonies.  The above Staghorn coral from the Curacao project is just 20 months old starting with a fragment of less than one inch.

Antigua Rescue Notes

Below: Rescued Staghorn corals waiting to be fragmented (propagated), plugged then replanted.

Some of the corals that were rescued had experienced quite a bit of sedimentation stress.  This requires special care.  For example, the team found only one family of Elkhorn coral (a family is defined as one or more colonies of the identical genetic origin) on the rescue site and it had already endured 11 days of being nearly covered by dredging silt.  Possibly, this coral had developed some resistance to sedimentation which meant it might be very special, genetically, even though the team thought that the chances of survival would be low.  Giving it their best effort and within minutes of rescue, the team scrubbed like surgeons and propagated the single piece of Elkhorn into 40 new corals.  Within an hour, they had planted them on Reef Balls.  Despite  this special care, only 4 of these fragments survived.  It was the first time the team experienced significant fragment loss.    Fortunately, this still yielded four new colonies from a single rescued coral and the genetics were preserved.  From a big picture perspective, only 200 of 5000 fragments were lost...almost all in the Staghorn/Elkhorn families.  All of the other species had survival rates that exceeded 95%.

The fastest growing hard corals, like the Elkhorn and Staghorn are the most difficult to work with without causing death to individual coral fragments.  Yet, they are the most rewarding species to propagate because they offer the fastest ability to recover an ailing reef structure.  The Reef Ball Foundation has developed methods to keep propagated fragment deaths to 10% or less (when working with healthy corals that are not previously stressed).  These fragment deaths are caused by Rapid Tissue Necrosis (RTN) which can be minimized with precautions such as glove changes between each family, use of antibiotic soaps, and keeping corals in high quality, stable water.  Because most  Acropora corals (Staghorn and Elkhorn) always exhibit some mortality as fragments, it is important that each coral family is propagated into enough pieces to insure survival of the family given the expected rate of propagate die off.  Gardeners use the same basic approach when cloning plants. Knowledge of all these special approaches to individual corals is key to maintaining high survival rates.  

Experts + Volunteers + Efficient Methods = Economically and Biologically Viable Restorations

The Reef Ball Foundation has learned that by teaming world experts with local volunteers, we can maintain professional reef restoration standards while still relying on volunteers.  The Reef Ball Foundation is fortunate to have experts who not only know about corals, but can teach others effortlessly.  John Walsh (Below left, placing coral plugs into the water), and Marjo van den Bulck (Below right, mixing hydrostatic cement with microsilica), were the two team leaders chosen for the Maiden Island coral team.  


The Reef Ball Foundation prefers to work with small volumes of imperiled corals and to propagate them to create totally new coral reefs which are an addition to natural reefs.   However, it is nice to know that when rescues are absolutely necessary or when coral reefs would be destroyed regardless of efforts to save them, that the technology exists to save the reefs.  It will take longer term scientific studies to know which yields more in the long run...a large number of small propagates planted or a smaller number of large adult coral colonies transplanted.  In the end, science will likely reveal that a combination of both methods, such as this project, may yield the best overall result.



All photos on this page are available in High Resolution Digital Format (4 mega-pixel resolution) and can be obtained by contacting  There are many other photos to choose from, by going to you can see more pictures from this project.  You may freely copy and use this press release as long as it remains unchanged.  If you wish to write your own version, we would be happy to set up interviews, provide digital photos or even arrange a site visit.  Use of photos requires acknowledgement that the source is


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