76 CEYLON PEARL OYSTER REPORT. 



Captain Donnan in his forty years' experience has only had one fishery on the 

 Periya Paar the only one to his knowledge (he told us) that had ever occurred. It 

 lias frequently, at an inspection, been found to have abundance of newly deposited 

 small oysters, while at the next inspection these oysters have gone and a fresh deposit 

 of younger ones may be in their place. Occasionally a few may have remained for 

 a second year, but they have always disappeared before becoming large enough to fish, 

 except in the one case of the fishery in 1879 and even that was of limited extent 

 and only involved a small part of the bank. 



The shallow-water plateau round the coast in the northern part of the Gulf of 

 Manaar, upon which the pearl-oyster paars are placed, can usually be distinguished 

 very clearly by the navigator on account of the difference in the tint of water. Even 

 20 miles from shore, in fine weather, the yellow sandy bottom shows up through the 

 clear water, and the slope is so steep that there is an abrupt change from the dark blue 

 of the deep ocean " out of soundings " to the lighter tint of the plateau. I am told that 

 captains who know the district, making for the Pamban Pass, know it is useless to take 

 soundings for the banks until the lighter coloured water is reached ; and the line of 

 junction is usually sharply marked. 



Now the Periya Paar is close to the edge of the plateau, about 18 miles from land 

 and at a depth of 8 to 10 fathoms (fig. 21). It runs for about 11 nautical miles north 

 and south, and varies from 1 to 2 miles in breadth, and this for a paar large extent of 

 ground has been called by the natives the " mother-paar " under the impression that 

 the young oysters, that come and go in fabulous numbers, arise there and migrate or 

 are carried inwards to supply the inshore paars with their populations. During a 

 careful investigation of the Periya Paar and its surroundings we satisfied ourselves 

 that there is no basis of fact for this belief, and it became clear to us that the 

 successive broods on the Periya Paar, amounting probably within the last quarter 

 century alone to many millions of millions of pearl oysters, which if they had been 

 saved would have constituted enormous fisheries, have all been overwhelmed by 

 natural causes, due mainly to the configuration of the ground and its exposure to the 

 south-west monsoon. 



The following table shows in brief the history of the Periya Paar for the last 

 twenty-four years : 



