29/05/06The Phuket Marine Biology Centre (PMBC) has set up a floating coral nursery on the island of Phi Phi Ley, which will serve as the temporary home to 1100 coral fragments for the next 6 months. The PPDC was asked to provide assistance and local marine knowledge to ensure the success of the project. (Photos) The concept of the nursery came from researchers from National Institute of Oceanography in Israel who participated in a cooperative research project with 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. |
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Assembling The Nursery
12 volunteers from Koh Phi Phi dive centres accompanied the PPDC and marine biologist Nalinee Thongtham (PMBC) aboard the PMBC research vessel which was used as a workstation for the two day operation.
Volunteers were split into three teams and aided the 20 PMBC staff in all aspects of the operation.
The first issue was to choose an appropriate location for the floating nursery that would be affected the least by monsoon weather and excessive boat traffic. At the same time site selection was based upon ample natural light, level of sedimentation, currents and the ability for corals to settle naturally in the area.
Members of the PMBC constructed a floating frame made from ¾” pvc piping and assembled it to form sixteen 1 meter sq panels. The frame was suspended 5 meters from the surface a 5 meters from the bottom by 30 marker buoys and secured to multiple moorings that were screwed into the substrate beneath the floating frame (photos).
Nalinee and a separate team selected colonies of acropora corals that would be the donors for the nursery. Using wire cutters the team selected the specific branches of acropora sp. and carefully snipped off fragments much like one would prune a bush. The fragments were carefully separated according to colony and placed into baskets. Separation of colonies was made so as to observe whether different colonies may grow at different rates although they are the same species. The fragments were then moved to the boat.
The colonies were submerged in a seawater bath during the transfer period. Each fragment measured between 2” and 3” and was inserted into a pre-cut 8mm plastic tube. Superglue was used at the very base of the fragment to secure the fragment to the tube. Care was taken not to contaminate other parts of the coral fragment with the glue. Gloves were worn and minimal handling of each individual fragment was recommended. The seawater in the resting tanks was regularly changed.
One in seven fragments was labeled for tracking.
The corals and tubes where then inserted into a rigid plastic mesh that was to a 1 meter sq frame made from the same pvc piping as the frame. Each frame contained the fragments from the same colony. In total sixteen frames were made containing 1120 coral fragments.
The frames were then inserted onto the floating nursery. A systematic method of photographing the corals was made, which will be used to create a month by month comparative journal to show the growth and survival rates.
Summary
The idea of the floating nursery was suggested by the PMBC as a means to improve survival chances of acropora coral fragments separated from their main colonies for the purpose of transplanting them into areas to increase coral growth and other coral settlement. The objective is to see whether suspending the fragments in mid water, reduces the threat from coral grazing animals and sedimentation, and allows the fragments to increase their size and strength prior to transplanting them into their permanent site.
Areas selected for transplanting will be chosen based on the conditions in the target area. Areas that show little natural coral growth or lack of hard rock or dead coral substrate are not regarded suitable.
In October 2006, 300 scuba divers are expected to attend a large coral ‘planting’ dive trip, to assist in the relocation of the coral fragments.
Throughout the next 6 months the PPDC will monitor the corals and nursery to collect data regarding the health, growth and survival rate of the fragments. The nursery will be cleaned regularly to reduce the growth of filamentous algae and molluscs.
Observations of the donor colonies will also be made to record the effects of pruning.
(Photos)
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PMBC full report (English) (Thai)
Wednesday 07th of January 2009 GMT+6 |