THE PEARL FISHERY OF 1904. 9 



tlie major part of the Oheval, the north, north-east, mid-cast and part of the south- 

 east and south-west, with all the three central sections, consists of sandy hottom 

 inadequately supplied with material suitahle to serve as foothold to oysters. 



We now have sufficieni knowledge of our local conditions to see that trans- 

 plantation must go hand in hand with extensive cultching if we are to obtain a full 

 return for the labour and money expended on the former operation indeed we may 

 go further and say that the transplantation of young pearl oysters will be labour 

 wasted unless adequate cultching operations he carried out concurrently. Appreciation 

 of the vital importance of this fact caused me to apply for authority to obtain several 

 hundred tons of broken rubble for cultching purposes as soon as transplantation was 

 seen to be advisable last March. The proposal was at once sanctioned, and while 

 waiting to begin transplanting I arranged, by the kindness of the Public Works 

 Department, for the preparation of a trial shipment of 100 tons of broken calcareous 

 sandstone from Kalpitiya. The stone was to be roughly broken to the size of the 

 fist about Sh X 3^ X 2^ inches. The full quantity had been prepared when the 

 transplanting scheme was arrested and now lies ready for shipment whenever it be 

 next required. 



" It may be useful to add here that whenever good prices cannot be obtained for the 

 pearl oyster shells accumulated during a fishery, the best purpose they can be put to 

 is to relay them upon the depleted banks, where the ground is in need of cultch. 



; ' I calculate that at the very lowest estimate 1 ton of shells will furnish as much 

 cultch as 3 tons of Kalpitiya stone or rubble. As this quantity of the latter 

 costs Rs. 11.25 (three tons at Rs. 3.7ft per ton) I believe that it will be more 

 economical for Government to refuse to sell the shells at any less price than Rs. 10 

 per ton, and to use them as cultch unless this minimum price be obtained. 



"Clean Banks Essential to Successful Cultivation. In this, as in the matter of cultching, 

 we may with great advantage profit by the experience of European oyster culturists. 

 They find it necessary to check the growth of many other organisms upon the banks, 

 not only those that are active enemies of the oyster star-fishes, whelks and the like- 

 hut also such animals as curtail the area which oysters may occupy or which consume 

 food that would otherwise fall to the oyster. Seaweeds, too, are for the most part 

 weeded out. As a consequence much can be done in cleaning ' foul ' beds by means 

 of the dredge. If the beds are in preparation to receive spat, all harmful matter is 

 taken ashore both direct enemies, such as star-fish, whelks, mussels, and also the 

 various other animals that compete for food and so may be termed the indirect enemies 

 of the oyster. 



" Fortunately the Ceylon pearl banks are comparatively ' clean.' No fact struck 

 me so forcibly when first I began to make diving descents as the paucity of 

 injurious life on the better quality of the oyster-bearing paars. Wherever oysters 

 were found thriving, wherever they were seen in vigorous growth and perfect health, 

 the bank appeared to be comparatively free from deleterious matters. 



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