130 



MARINE PRODUCTS OF COMMERCE 



be refitted each season. The low price of pearl shell tends to retard extensive 

 exploitation. 



Philippine Pearl Shell Fisheries. While exact data regarding the output of the 

 Philippine pearl shell banks are not available, it has been estimated that the 

 annual vield of "gold-lip" pearl shells is probably between 300 and 400 tons, 



Fig. 8-2. Diver about to descend at 

 Thursday Island. Thursday Island divers use 

 lielmet and corselet only instead of full div- 

 ing equipment. 



(Courtesy Commomvcalth Fisheries Office) 



valued at from $175,000 to $200,000. A certain number of these shells are 

 exported unprocessed and the remainder made into buttons and other objects. 

 The value of the annual pearl yield is placed as high as $500,000, the proportion 

 of pearls being larger than those of the Australian or Celebes fisheries. 



Trochus Shell Fisheries. New Caledonia and the neighboring New Hebrides 

 supply France with considerable quantities of Trochus shells. The Macassar 

 fisheries, comprising the whole of the Dutch East Indian possessions, are a source 

 of supply for France and Japan. 



A considerable quantity now comes from Australia, most of it being taken 

 from the Torres Straits and the Barrier Reef. In 1947 the approximate total in 

 tons was 499, Thursday Island yielding 392, Cairns 92, and Derby 15. Approxi- 

 mately the same amount was taken from 1932 to 1941. These shells are about 3 to 

 4 inches high and almost smooth. Beneath the outer surface, which is frequently 



