HISTORY OF THE PRINCIPAL TEARL BANKS. 85 



CONCLUSIONS. 



Tin's examination of the records of the principal pearl hanks has served to 

 emphasise some of the conclusions that were put forward in Part 1. of this Report. 

 In tracing the history of the different heds of oysters, in considering how the paars 

 differ from one another and in trying to find the causes of such catastrophes as have 

 occurred, we are brought to see : 



(1.) That man can do comparatively little to mitigate the severity of such 

 influences as tell against the life and prosperity of the pearl oyster. He 

 may possibly, if it be thought wise, to some extent diminish the ravages of 

 certain carnivorous fishes, and he may by dredging the banks improve their 

 condition and remove competing organisms, and also thin out beds that 

 are overcrowded, but he is powerless against the invasion of microscopic 

 parasites and of sand over-washes caused by monsoons, storms and tidal 

 currents ; 



(2.) That much can be done, however, to preserve and make the best of what 

 oysters we have, by careful inspections, by judicious transplantations and by 

 speedy fisheries undertaken at the right moment. 



Inspections should be as accurate, as frequent and as extensive as possible. They 

 should extend beyond the conventional limits of the known paars and aim at 

 exploiting new areas. It must be remembered that the greater part of the shallow 

 shelf that forms the Ceylon side of the Gulf of Manaar out to the 10-fathom or 

 12-fathom line is potential " paar ground" and that new deposits of spat might be 

 found any day on almost any part of it. It is impossible, of course, to inspect the 

 whole area in detail every year, but it is important that lines of observations should 

 be run across at least the more likely parts, and that could readily be done by means 

 of a series of dredgings from a small steamer. The inspections should give early 

 intelligence as to (a) new deposits of young oysters which might possibly require to 

 be transplanted to safer ground, and (b) the necessity for a speedy fishery in order to 

 save some threatened bed of adult oysters from being totally lost. 



The necessity for transplantation has already been pointed out in Part I. It will 

 suffice now to state that transplanting is the only means by which (a) many beds of 

 young oysters can be saved from almost certain destruction, and (b) large areas of 

 suitable ground can be supplied with a sufficient oyster population. 



The relative efficiency of different methods of transplanting and also of speedy 

 fishing by means of dredges or trawls to be used in emergencies, when a bed of 

 oysters might be lost if left unfished are matters upon which Mr. Hoknell, as 

 Inspector of the Pearl Banks, is now experimenting, and it is hoped that in our 



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