132 THE FISHING INDUSTRY 



realized when we remember that practically half of the 

 total catch of fish in the world is discarded by the 

 curers as waste. 



Fish Leather. The hides of such marine mammals 

 as the walrus and the seal have long formed the basis 

 of a regular tanning industry. 



Of recent years, however, particularly in America, 

 successful attempts have been made to tan the skins of 

 certain fish, notably the shark. The skins are treated 

 with alkali to remove fat and oil, the alkali is then 

 neutralized with acid, after which the skins are washed 

 and tanned. The leather is said to be soft and pliable, 

 and well adapted for many uses. 



Shark skins are also tanned hard, and used to print 

 a grain on imitation pigskin. 



Shark fishing was commenced off the American coast 

 in October, 1918. The fish are hunted from fast, power- 

 ful motor boats, with specially constructed nets. A small 

 shark 5 ft. long will yield a hide 10 sq. ft. in area. 



Shark skin is naturally very tough and durable, and 

 in its untanned condition is used by jewellers as a natural 

 emery paper for grinding and polishing metal surfaces. 

 It is also used as an abrasive in working hard woods and 

 ivory. 



A method has been devised by which a shark skin 

 can be split into three. The first split, after tanning, 

 is strong and thick, and suitable for high grade, heavy 

 shoes. The second furnishes leather suitable for 

 second grade foot wear, and the third resembles suede 

 and is used in making fancy articles. In addition to 

 the shark's skin, the fins, blood, teeth, flesh, and oil 

 of the fish are also utilized commercially and yield a 

 satisfactory profit. 



