No. 5i.— 1900.] 



PEARL FISHERIES. 



187 



The question of discovering means of successfully securing 

 pearl oysters against their enemies is a most difficult one to 

 solve. Currents are uncontrollable, and as regards living 

 and unknown enemies, success against their predations 

 appears to me to be very doubtful. Yet in these wonderful 

 progressive times there is no knowing what the employment 

 of scientific skill to deal with these questions might be able 

 to accomplish. 



Artificial Cultivation of Pearl Oysters. 



I have tried a small experiment in cultivating pearl oysters 

 by depositing a quantity of young oysters in an excavation 

 which I had made for them in the Sillavaturai coral reef, 

 three miles from the shore ; but it was not successful. 



In March, 1885, I had 12,000 oysters eighteen months old 

 lifted from the Cheval Paar and placed in the tank on the reef 

 three hours after they were lifted, having been kept in the 

 meantime in a boat half filled with sea water ; but when I 

 returned to Sillavaturai the following year they had disap- 

 peared. I then constructed a new tank on a more sheltered 

 part of the reef, 12 feet square and 4 feet deep at low water. 

 Much mud was found between the branches of the coral, but 

 it was all well cleared out, and a quantity of coral stone was 

 placed in the bottom of the tank and around the side on 

 the top of the reef, to protect the tank from the wash of 

 the sea at high water. 



When this new tank was completed it seemed an ideal 

 place for such an experiment, — beautiful clear water in it and 

 not a sign of mud. 5,000 oysters two and a half years old taken 

 from the Cheval Paar were placed in it ; and 1,000 in a large 

 wooden cage, made for the purpose, which was weighted with 

 stone and sunk in 9 feet of water, half a mile from the beach. 



I left Sillavaturai on that occasion in hope of my experi- 

 ment being successful ; but alas ! on my return a year 

 afterwards I found the oysters in the beautiful tank on the 

 reef all dead — having been smothered in 18 inches of mud 

 at the bottom of it, which had been washed into it from 



F 106-01 



