is explained by the high population of this fish off the coast of Norway 

 and the use of purse seines, which accounted for 455,000 t. The Soviet 

 Union has greatly intensified its fishing for mackerel in recent years, 

 in the northwestern Pacific (to 80,000 t) and off West Africa (to 

 150,000 t) . Doubtless, mackerel fishing is quite promising. 



The catch of Carangidae had increased by a factor of 16 by 1970 in 

 comparison to the prewar level (1938), and there is every reason to 

 assume the possibility of further increases. Thus, off the coast of 

 Japan in some years the catch of this fish has even been artificially 

 held down. Large accumulations of mackerel have recently been found off 

 the Tasmanian coast. In the opinion of many scientists, it will be 

 possible to catch as many as 1 million tons of pelagic fish per year 

 near New Zealand, including many Carangidae. The greatest quantity of 

 Japanese mackerel are caught in the East China Sea and off the coast of 

 Japan (510-560«10-^ t), as well as in the Philippines (lOO'lO^ t) . Other 

 species of Carangidae are caught off the west coast of Africa, where 

 fishing is conducted primarily by ships of the USSR (ISO'lO-^ t) , Angola 

 (170 .10^ t) and Spain (70 -lO-^ t). 



A lesser role in the sea fish catch (up to 1.7'10" t) is played by 

 the tuna, although due to the high value of the meat of this fish, tuna 

 fishing is significantly more successful economically than fishing for 

 most other types of fish. Therefore, the tuna catch develops from year 

 to year, and at the present time is conducted in the open Pacific, 

 Atlantic and Indian Oceans. Tuna inhabit the great water areas of the 

 ocean, forming no dense accumulations, making it more difficult to catch 

 them. However, information on the results of tuna fishing indicates 

 that the trend is doubtless toward decreasing effectiveness (Table 

 12). For example, the catch of yellowfin and blue-finned tuna decreased 

 from 8 fish per 100 hooks on a longline in 1950 to 2 in 1965. The 

 reserves of large tuna are being caught with great intensity in almost 

 all regions of the ocean, and the only hope for any significant 

 development of tuna fishing lies in more intensive fishing of the 

 smaller and stripe-bellied tuna. 



The overwhelming majority of tuna (50-60%) is caught by Japan. 

 Significantly smaller quantities are caught by the fisherman of the USA, 

 France, Spain and Peru. The Soviet Union catches but a few thousands of 

 tons of the valuable fish. 



When tuna is fished using longlines, swordfish and sharks are 

 caught in large quantities. Sharks, rays and chimaera are also the 

 objects of a specialized fishing industry. The annual catch of sharks- 

 in recent years (1968-1975) has held steady at a level of about 400' 10"^ 

 t, of rays at 90-140 -lO-^ t. This is much less than their actual 

 reserves. The shark catch in the World Ocean could be at least doubled. 



In addition to the commercial fish mentioned above, the world catch 

 includes many representatives of various families of demersal fish, 

 caught during trawling and other types of bottom fishing: 

 Pleuronectidae (see Table 8), sea perch, Ammodytes, etc. (Table 13). 



374 



