III. Determination of Surface-drift over the Banks. 



An accurate knowledge of the movement of the surface-water over the pearl 

 banks is a matter of the utmost importance in their management. Without this 

 knowledge we cannot form even an approximately accurate idea of the source whence 

 comes the spat that from time to time replenishes one or other of our banks. So 

 long as we are in the dark upon this subject, we cannot define in what location a 

 reserve of oysters should be to produce the most useful results. There are banks so 

 situated as to be normally of no breeding value, of no importance in replenishing 

 the banks which are our reliance ; conversely certain banks must be of supreme 

 importance in the conservation of our beds, and it is obvious that information on these 

 points is of vital importance in the farming of the banks. It should be ascertained 

 whether any proportion of the spat that settles, say on the Toiayiram Par, originated 

 from the oyster beds on the Ceylon side of the Gulf of Mannaar, whether the converse 

 be the case, or again whether there be mutual interchange of spat. 



The plan offering the greatest advantages is to obtain the co-operation of the 

 Ceylon Government in order to secure both uniformity of method and mutual assist- 

 ance in carrying on this investigation. I recommend that batches of small sealed 

 bottles, each containing a post card inscribed in English and Tamil, be thrown into 

 the sea, at intervals and places yet to be determined, on both the Indian and the 

 Ceylon side of the Gulf of Mannar, and that small rewards be given to those finders 

 who place the cards in the hands of the nearest revenue officer or native headman, 

 who would despatch them to the authority appointed, with particulars of the date and 

 place of recovery. 



After investigation on these lines has been carried out systematically for two or 

 three years, it will become possible to determine the place of origin of much of the 

 oyster spat, and we shall be enabled to trace the course of its wanderings while in the 

 larval swimming condition, and in consequence know where to conserve breeding 

 reserves of oysters for the further replenishmeat of the banks. 



IV. Culture of the Banks. 

 (a) and (b). Transplantation and Cultching. — The principal means whereby the 

 banks can be permanently improved and the quantity of fishable oysters increased 

 lies in the adoption of the correlated operations of cultching and transplantation of 

 young oysters. The latter is admittedly the most important cultural means at our 

 disposal for increasing the harvest of the pearl banks and I am of opinion that it 

 might be adopted with very favourable financial results on certain of the Tutieorin 

 banks, notably upon the Toiayiram Par, provided there be proper organization of the 

 direr labour-force, so that when the oysters become of fishable age we may be assured 

 that the means will be adequate to bring the greater part of them ashore during the 

 limited available season of favourable weather. 



If this long-standing labour difficulty be removed I advise the fitting up of the 

 inspection steamer as an oyster dredger in order that, when young oysters are found 

 in profusion upon unsuitable ground, a substantial proportion may be transferred to a 

 bank where the conditions are favourable to the maturing of oysters. My experience 

 with the Ceylon dredging steamer " Violet" shows that from 500,000 to 700,000 

 oysters of the size attained in six months, may be transplanted during each day's 

 employment, equivalent to a transplantation of from 15,000,000 to 20,000,000 per 

 month — extremely satisfactory figures. 



The Toiayiram Par is a suitable bank and there I should advise the laying of 

 any oysters lifted from other localities, as it is in many ways the best for this purpose. 

 It has, however, the great defect of possessing an insufficient quantity of loose 

 stony fragments spread over the major part of the surface. To fit it to receive and 

 protect the oysters transplanted there to and to give satisfactory fishery results, I 

 recommend whenever transplantation is in operation that several hundred tons of 

 broken coral obtainable from the reefs fringing the coast in many places, be spread 

 over the bottom where the transplanted young oysters are laid. The cost would be 

 comparatively small, as coral collection is a local industry at Tutieorin and as the 

 laden ballams and dhoneys would proceed direct from the Hare Island reef to the 

 bank, where their cargoes would be scattered over culture areas marked out by meana 

 of flag- bearing buoys. 



