490 THE PEARL FISHERIES OF CEYLON. 



^ioiis o-iven in m}^ preliminary report (July, 1002) to the governor 

 of Ceylon ran as follows : 



1. The oysters we met with seemed, on the whole, to be very 

 healthy. 



2. There is no evidence of any epidemic or of mnch disease of any 

 kind. 



'^. A considerable number of parasites, both external and internal, 

 both Protozoan and Vei-mean, were met with, but that is not unusual 

 in mollusks, and we do not i-egard it as atiVcting- seriously the oyster 

 population. 



4. Many of the larger oysters were reproducing actively. 



5. AVe found large quantities of minute '' spat " in several places. 



6. We also found enormous qTiantities of young oysters a few 

 months old on many of the paars. On the Periya Paar the number 

 of these probably amounted to over 100,000 million. 



7. A very large number of these young oysters never arrive at 

 maturity. There are several causes for this. 



8. They have many natural enemies, some of which we have deter- 

 mined. 



9. Some are smothered in sand. 



10. Some grounds are nnich more suitable than others for feeding 

 the young oysters, and so conducive to life and growth. 



11. Prol)ably the majority are killed by overcrowding. 



12. They should therefore be thinned out and transplanted. 



13. This can be easily and s})eedily done, on a large scale, by 

 dredging from a steamer, at the ])roi)er time of year, when the young 

 oysters are at the best age for ti'ansi)lanting. 



14. Finally, there is no reason for any despondency in regard to 

 the future of the pearl oyster fisheries, if they are treated scientific- 

 ally. The adult oysters are ])lentiful on some of the paars and seem 

 for the inost ]>art healthy and vigorous, while young oysters in their 

 first year, and masses of minute spat just de})osited, are very abun- 

 dant in many places. 



To tiie biologist two dangers are, however, evident, and, paradox- 

 ical as it may seem, these aiv overcrowding and overfishing, liut the 

 superabundance and the risk of dei)leti()n are at the oj)])osite (MuIs o«^ 

 the life cycle, and therefore both are possible at once on the same 

 ground — and either is sufficient to cause locally and temj)orarily a 

 failure of the pearl oyster fishery. AVhat is rt'ijuired to ob\ iate these 

 two dangers ahead and insure more ccmstancy in the fisheries, is 

 careful sn2)ervision of the banks by some one who has had sufficient 

 biological training to understand tlic life ])i'()blems of the animal, 

 and who will therefoi'e know when to cai'i'v out simple measures of 

 farming, such as thinning and transplanting, and when to advise as 

 to the regulation of the fisheries. 



