128 MARINE PRODUCTS OF COMMERCE 



Singapore, but was later fished all over the world. Today the Red Sea fisheries 

 (Jibuti, Massawa) and those of Australia are of great importance. The Fiji 

 Islands, New Caledonia, and Australia are producing various qualities of Trochus 

 for industrial purposes. So far only small quantities have been brought to the 

 United States as they are difficult to handle and to process. For many years enor- 

 mous quantities of Trochus buttons have been imported into the United States 

 from France and Japan. 



Haliotis (Abalones). These shells exhibit a splendid range of colors and are con- 

 sequently used for inlaid work (opera-glass cases, etc.) and also for buttons. In 

 Japan they are known as "Awabi," or "ear shells," but constitute an unimportant 

 article of commerce. 



Green Ears— Red Ears— Blue Backs. These are not very important commercially. 

 They originate in California and the lower peninsula. The "red ears" are almost 

 worthless; the "blue backs" make a cheap button; and the "green ears" are 

 adapted for fancy work and inlays as the color is vivid. An inferior kind of 

 "green ear" comes from New Zealand. 



Mother-of-Pearl Fisheries 



Fishery Methods. The pearl, mother-of-pearl, and blister pearl fisheries are in 

 reality one fishery; for the shells of mollusks yielding pearls are nearly always 

 utilized for their mother-of-pearl. On the other hand in many fisheries, as in the 

 Australian, mother-of-pearl is the chief product and pearls a valuable by-product. 



The methods employed in taking pearl shells are, of course, the same as those 

 of the pearl fisheries (naked diving, scaphander diving, and dredging). Since 

 these have been described in the preceding chapter and in the chapter on Sponges 

 (page 747), and since it is obviously impracticable to discuss the details of these 

 methods as employed in the various shellfisheries, these points will not be con- 

 sidered in this section. 



Australian Fisheries. The Australian pearl fisheries are the most important in 

 the world for the production of mother-of-pearl. They have been in active opera- 

 tion since 1868, especially on the northwestern coast of Australia from Cape York 

 to the Northwest Cape, a distance of 2,000 miles. To these fisheries must be added 

 those of the Torres Straits and Queensland. The chief revenue is derived from 

 the pearl shells although a certain number of pearls found become the property 

 of the captain of the fishing craft. 



The pearl-shell grounds of Queensland, Australia extend northward from 

 Thursday Island almost to the shores of New Guinea, as well as westward from 

 Booby Island, eastward from Bramble Bay, and southward to Cooktown. For 

 many years the center of the fishery has been Thursday Island. The pearl shell 

 found there is the Margaritifera maxima Jameson. The less valuable smaller 

 variety, locally termed "black-lip," Margaritifera margaritifera, is taken principally 

 in relatively shallow water. 



According to the Australian Commonwealth Fisheries Office the average yearly 

 production in Australia for the period 1932 to 1941, inclusive, was 2159 tons of 

 pearl shell, with approximately 180 fully equipped boats operating. In the 1947 

 season 91 boats were used. Of these, 70 were the usual 52-foot ketch type; the 

 rest included a torpedo recovery craft, an M.F.V. type, and 8 regular size and 13 



