CEYLON PEARL BANKS. 205 



A REVIEW OF THE SCIENTIFIC WORK ON THE 

 CEYLON PEARL BANKS FROM 1902 TO 1912. 



By Joseph Pearson, 



Government Marine Biologist. 



Currents . . . . 214 

 Drift-bottle Experiments 21(> 

 Bearing of the Drift- 

 bottle Experiments . . 217 

 Summary of the Position 219 



Introduction. 



^T^HE intermittent nature of the pearl fisheries in the Gulf of 

 -*- Mannar is well known. Cycles of barren j^ears occur irregu- 

 larly, but none the less consistently. This lack of continuity is 

 unfortunate, and at the same time remarkable — unfortunate, in that 

 the value of the pearl banks as an important source of revenue to the 

 Colony is somewhat discounted ; and remarkable, since it presents 

 to the economic scientist points of supreme interest. Although the 

 spasmodic nature of the pearl fisheries must have caused serious 

 misgivings in the past, no organized attempt appears to have been 

 made to discover a cause and a remedj^ until the year 1902. With 

 the advent of Professor Herdman, who brought to the problem an 

 unrivalled experience of marine biological science, the fortunes of 

 the jjearl banks may be said to have entered upon a new phase, and 

 one has no hesitation in affirming that the last decade has proved 

 the most eventful in the history of the Ceylon pearl fisheries. In 

 addition to the fact that the methods of biological science were 

 introduced into the enterprise for the first time* the period in question 

 was rendered noteworthy by the formation of a Syndicate in 1906 

 to take over from Government the control of the pearl banks for 

 a term of twenty years. The Ceylon Company of Pearl Fishers 

 commenced its career under the most happy auspices, and as the 

 result of two successful fisheries in the first 3'ears placed itself in an 

 extremely sound condition. After the fishery of 1907, however, the 

 yield of pearl oysters failed, and since that date the banks have been 

 in a condition of absolute barrenness. The result was that after an 



* It must not be forgotten, however, that scientific operations ^vere con. 

 ducted on a small scale by Dr. Kelaart in the fifties and by Mr. Houldsworth 

 in the sixties. 



