120 CEYLON PEARL OYSTER REPORT. 



close to the deep water are evidently unreliable, and yet may be made use of in 

 cultivation, and have probably in the past, on occasions, borne a crop of mature 

 oysters. 



The history of the Pearl Fisheries in the past, especially during the nineteenth 

 century, has shown that : 



(1.) Some of these paars, such as Jagerboom, Kallatidal, Aripu, Anaivelundan, 

 and others, are practically worthless from an economic point of view. 



(2.) Some, such as the Periya Paar, might be used as most valuable sources of 

 supply of young brood oysters for transplantation ; but cannot be relied upon 

 to produce an adult stock suitable for fishing. 



(3.) Some, such as the great Cheval Paar, with its various sub-divisions, and the 

 North and South Modragams, the Periya Paar Kerrai, and the Muttuvaratu 

 Paar, are very valuable and reliable grounds upon which most of the 

 successful fisheries of the past century have taken place. Others, such as 

 those off Chilaw and Karativo, are less reliable, but may be valuable on 

 occasions. 



It became clear to us during our work on the " Lady Havelock," when we began to 

 understand why it is that the Periya Paar is unreliable and the Cheval so much more 

 satisfactory, that the main hope of introducing constancy of result and a regular 

 succession of fisheries must rest upon a system of transplanting young strikes or 

 broods of oysters when they make their appearance upon useless or unreliable paars, to 

 wherever there is room for them at the time upon ground where we know they will 

 have a better chance of living and growing to maturity. 



This raises the whole question of the causes of death of the Pearl Oyster, the 

 reasons of the intermittence in the history of the fisheries, and the conditions which 

 render some paars more reliable than others. As we propose to have a section later 

 on dealing with our observations and experiments on the Pearl Oyster and ending 

 with our Recommendations, into which these matters will naturally fall, it will be 

 sufficient here to give the following summary of our results : 



(1.) The most important agent in causing wide-spread death of Pearl Oysters, both 

 young and old, in the Gulf of Manaar, is the shifting of sand due to the strong 

 currents, to the south-west monsoon, and no doubt occasionally to exceptional storms. 

 We obtained a good deal of evidence as to the manner in which the sand is carried 

 about and piled up by the currents, and is churned up in places by the heavy seas at 

 the time of the south-west monsoon, and we made observations as to the effect of 

 burying oysters of different sizes in various amounts of sand. The successive broods 

 which have appeared and as regularly disappeared upon the Periya Paar during the 

 last quarter-century have, there can be no doubt, been overwhelmed by the bottom 

 currents caused by the monsoon upon the bank which faces the deep water of the 

 Indian Ocean. 



