Report visit at the south sea pearlfarm near Phuket, Thailand, September 2001
Fig.1: Hatchery
The South Sea Farm is owned by mr. Kriangsak Ung. When he started diving, at the age of 16 years, he became intersted in marine life and especialy in pearls. Later he started a pearlfarm near Phuket and he has aquired a lot of knowledge about pearl cultivation. Untill a few years ago akoya's and Pteria penguin were cultivated. But the bronze coloured Pteria pearls were at that time not in demand (a pity, as they are beautiful!), and even with the white half-pearls from this species the farm was not very profitable.
Now only white lipped Pinctada maxima are cultered.
Fig.2: Growing spat
At the farm 10 workers are employed. Most of the work is making all kind of preparations for the breeding and maturing of pinctada maxima white-lipped oysters. As is the problem with Naga Pearls (report 2), also here there is lack of funds. A new boat and a new equipment is needed. The main problem for the Thai pearlfarms is the supply of young oysters. Wild young oysters can hardly be found anymore in the Andaman Sea, so oysters have to be imported for a high price (US$ 2-3 a piece).
To solve this problem mr. Kriangsak has started his own hatchery. He buildt a few concrete basins with a water purification system, fig. 1.
The spat is growning on synthetic sheets with very fine netting in saewater free of bacteria, fig. 2, fig. 3. A few bacteria are neccesary for the cultures. The nourishment of the oyster consists of three types of plankton; sometimes other types are added for variety and to make the oysters stronger. The three types of plankton are also cultured, fig. 4. Mr. Kriangsak knows exectly which types he needs. To set up the cultures he first seperates them under a microscope in seawater. In plastic bags filled with seawater and with constant air supply the plankton multiplies, fig. 5.
Fig.3: Spat on sheets
Fig.4: Culturing plankton
Fig.5: Culturing plankton
Fig.6: Oysterrack at sea
After two months the oysters are 1,5 to 2 cm large, at this stage they start to grow very fast. In 5 to 6 months they are 6-7 cm when they are set out at sea on concrete slabs protected by fine netting against other animals.They are frequently checked by divers.
When they are two years old, the oysters are operated upon and 7-8 mm nucleus inserted. The operated oysters are put in racks and suspended in the sea at a depth of 2-3 meters, fig. 6. After another two years the pearls are harvested. The thickness of the nacre deposit is then over 2 mm. When the pearl is pulled out of the oyster the pearl is measured and a slightly larger nucleus is inserted.
The quality of the few pearls I saw at this farm was very good. There was also a faint yellow off-round pearl of 17,3 mm.
The nucleï mr. Kriangsak uses he produces himself from the shell of the maxima's, fig. 7. He had a sawing machine and a grinding machine for pre-forming constructed and bought a tumbler for polishing the nucleï, fig. 8, fig. 9.
Fig.7: Empty shells
Fig.8: Cut piece
of shell
Fig.9: Nucleï
from P. maxima
It was for me very nice to see a pearl farm with the complete cycle from spat to pearl, and I hope mr. Kriangsak will have a bigger succes in future with his business.