ConceptThe concept of the nursery came from researchers from the National Institute of Oceanography in Israel who participated in a cooperative research project with the PMBC and researchers from 4 other countries, UK, Italy, Singapore and Philippines, under the programme “Developing ubiquitous practices for restoration of Indo-Pacific reefs”, REEFRES, supported by European Commission. The nursery method is a way of cultivating coral fragments using traditional forestation techniques. By removing limited amounts of coral fragments this reduces the impact to the donor colonies and aids reproduction of new coral colonies. The nursery is suspended above the substrate which allows the fragments to grow with reduced threats from corallivoes, such as parrotfish, crown of thorns and drupella.
Method.The main frame of the nursery is made from forklift truck pallets. They are bolted together and suspended off the substrate by inflated inner tubes which are fixed on the underside. The whole nursery is tethered in place by ropes attached to screws that are fixed into the substrate. Coral fragments are carefully removed from the donor colonies. Fragments range from 2 cm to 5 cm in length. Care must be taken not to handle the fragments too much and to cause unnecessary damage to the donors. Each donor colony is tagged with cable ties and then monitored to see what is the effect of removing the branches. The fragments are then inserted into plastic tubes. In some cases we need to add a small drop of superglue to fix the fragment to the tube. Care is taken not to effect other parts of the fragment with the superglue. The next step is to place the fragments into a sheet of meshing which will support the fragment for the next 6 months. The trays are then fixed onto the floating pallets.
CleaningEach month algae and molluscs grow onto the pallets and racks. The algae is a greater problem since it can suffocate the fragments as is shown in the left hand photo below. This photo shows algae growth that nearly covered the fragments when left uncleaned for nearly 2 months.
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MonitoringThe most time-consuming part of the project is the monitoring. Each month a team of local volunteer divers helps to clean the barnacles and algae growing on the frame work. Each tray also has 10 control fragments which we photograph and measure for comparison (280 control fragments). Lastly all the fragments are counted and examined for health to establish the survival/mortality rates. At initial stages, measuring growth rates is quite easy since the fragment generally grows noticeably in one direction, (discounting the encrusting around the support tube). However as the months pass by it is increasingly difficult to get accurate measurements, as the fragments starts to grow other branches. Furthermore, coral fragments that have already been transplanted to permanent sites are monitored to check the survival/mortality/growths statistics... |
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In January 2008 we shall be setting up a new batch of fragments in the coral nursery. Volunteers interested in assisting us please email us. |
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Please email us if you have any other questions regarding data or methods about the coral nursery |
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Friday 21st of November 2008 GMT+6 |