KASAHARA: JAPANESE DISTANT-WATER FISHERIES 



7n 





<o 3 





2- 



Mothership trawl fishery 



Hokutensen 



/ Northern seas _: 

 ^ trawl fishery"*;- 



-I 1 1 1 1 " ■■I V" I 1 1 1 



60 62 64 66 68 



Year 



Figure 2. — Catches of pollack (Theragra chalco gramma) 

 by Japanese fisheries, 1959-69 (from Ministry of Agri- 

 culture and Forestry, 1971). 



(Figure 2). The number of vessels decreased 

 to 12 motherships with 173 catchers by 1969, 

 though with greater average tonnages of both 

 motherships and catchers. 



Trawl fishing in waters south of the Alaskan 

 Peninsula began in 1960 when some of the catch- 

 er boats of a fish meal factoryship did explora- 

 tory fishing with trawls, longlines, and bottom 

 gill nets. After 5 years of trial fishing, the gov- 

 ernment issued, in 1965, regular licenses for 

 fishing in the Gulf of Alaska west of long 135°W 

 under a different set of regulations. Explora- 

 tory fishing expanded into waters off British 

 Columbia and the State of Washington. In 1967, 

 the licensing of these vessels was combined with 

 that of independent trawlers, mostly large stern 

 trawlers, operating in the Bering Sea. 



Independent trawlers in the northern areas. — 

 Vessels in the category called "the Northern 

 Seas Trawl Fishery" are licensed separately 

 from vessels belonging to the mothership trawl 

 fishery, but many of them are large stern trawl- 

 ers sometimes accompanied by smaller trawlers 



(before 1967, some of these trawlers had been 

 licensed as motherships) . Emphasis is on ocean 

 perch in the Gulf of Alaska and the Aleutians 

 and on pollack in the Bering Sea. Distinction 

 between this fishery and the mothership fishery 

 is somewhat arbitrary, but it is reasonably cor- 

 rect to say that the former consists mainly of 

 large stern trawlers, while the latter include 

 motherships and factoryships accompanied by 

 smaller trawl vessels of different types. In the 

 Japanese regulatory system, the vessels of the 

 former category have been licensed, since 1967, 

 for fishing in both the Bering Sea and the Gulf 

 of Alaska, while those of the latter category have 

 been allowed to fish in the Bering Sea only. 



Thus, the northern trawl fisheries have under- 

 gone rapid changes in the past 15 years. The 

 exploitation of many of the important stocks has 

 reached or exceeded the level of maximum sus- 

 tainable yield, including yellowfin sole, halibut, 

 sablefish, ocean perch, and shrimp {Pandalus 

 borealis) in the Bering Sea; ocean perch in the 

 Gulf of Alaska; and perhaps some others, Sovi- 

 et fishing for flounders and ocean perch had ad- 

 ditional effects on these stocks. The Japanese 

 fisheries in Kamchatka and the Bering Sea are 

 now largely dependent on one species, pollack, 

 to be processed into fish meal and minced fish 

 meat (on motherships and factory trawlers, as 

 well as on land) . The total amount of pollack 

 taken in the Bering Sea and Kamchatka by the 

 Japanese and Soviet fisheries now probably ex- 

 ceeds 2.5 million metric tons. Fishing intensity 

 is still mounting, and effects of fishing are be- 

 coming apparent. The catch per unit of effort 

 in the southeastern part of the Bering Sea has 

 shown a decrease, and the average size and age 

 of fish also have decreased. Fishing grounds 

 have spread over the deeper portions of the cen- 

 tral Bering Sea shelf. Further improvements 

 in the method of catching pollack are under 

 study, for pollack occur not only near the bot- 

 tom of the shelf and upper slope but also in mid- 

 layers of deeper waters. The maximum level of 

 exploitation will be reached fairly soon if it has 

 not been already. There may be a further in- 

 crease in the Japanese share of ocean perch in 

 the Gulf of Alaska if Soviet efforts are drastically 

 reduced. Japan has not fished for hake to any 



235 



