FISHERY BULLETIN: VOL. 70, NO. 2 



fisheries, and 75 converted to transport boats. 

 But as of 1969, there still existed about 29,000 

 vessels, indicating that the reduction plan was 

 not very successful. The fishery, however, is of 

 relatively minor importance in the Japanese in- 

 dustry, its total production in 1969 being only 

 262,000 metric tons, roughly half of which con- 

 sisted of shellfishes. 



Mothership trmvl fisheries in the Bering Sea 

 and adjacent areas. — In the Japanese regulatory 

 system, a mothership means a vessel with pro- 

 cessing facilities aboard which is accompanied 

 by one or more fishing vessels. Most of the 

 motherships do not fish themselves, but large 

 fishing vessels, such as factory stern trawlers, 

 or large tuna longliners, are also defined as moth- 

 erships if they are used for processing catches 

 delivered by smaller fishing vessels. The trawl 

 fisheries in the Bering Sea, Kamchatka, the Aleu- 

 tians, and the Gulf of Alaska consist of three 

 licensing categories: "the Northern Seas Moth- 

 ership Trawl Fishery"; "the Northern Seas 

 Trawl Fishery" conducted by independent trawl- 

 ers; and "Hokutensen," mentioned above. 

 Catches by these three categories in 1969 were 

 862,000 metric tons, 373,000 tons, and 768,000 

 tons respectively, the combined total being 2,0 

 million metric tons. 



Trawl fishing in the Bering Sea was carried 

 out even before and during World War II. As 

 early as 1933, two fish meal factoryships with 

 catchers were sent to Bristol Bay, The oper- 

 ation stopped after 1937 due largely to unprof- 

 itable fish meal trade. A freezer mothership 

 operated in the Bering Sea in 1940 and 1941; 

 a mothership operation for frozen and salted fish 

 was conducted in waters off west Kamchatka 

 during the war. The postwar mothership trawl 

 fishery began in 1954 with two freezer mother- 

 ships, accompanied by catcher boats, mostly otter 

 trawlers, to produce frozen flounders, particu- 

 larly yellowfin sole (Limanda aspera) in the 

 Bristol Bay area. The number of freezer moth- 

 erships increased to four in 1956, and a fish meal 

 factoryship entered the fishery in 1958, as well 

 as a mothership bottom-longline fleet. By 1961, 

 the fishery expanded to include five fish meal 

 factoryships (including one for processing 



Atheresthes for oil and meal) with 138 catchers, 

 and 18 freezer motherships with 154 catchers. 

 Three of the 18 motherships were specialized for 

 shrimp fishing in an area near the Pribilof 

 Islands, and eight (some of them were rather 

 small) combined trawling, longlining (for hal- 

 ibut and sablefish), and gillnetting (for her- 

 ring). The trawl catchers were from those li- 

 censed for fishing in the China Sea and coastal 

 areas and included all three types: otter trawl- 

 ers, Danish seiners, and pair trawlers. The Ber- 

 ing Sea trawl fisheries started as summer oper- 

 ations, but the season has since been extended, 

 and some ships have been seen in the Bering Sea 

 throughout the winter in the most recent years. 

 For regulatory purposes, the Bering Sea was 

 divided into several areas to allocate fishing 

 grounds among different fleets taking into ac- 

 count their historical interests. 



The next few years witnessed marked changes 

 in the Bering Sea mothership trawl fishery. The 

 yellowfin sole stock went down very quickly, as 

 might have been expected for a hitherto unex- 

 ploited flounder stock being subject to extremely 

 intensive fishing, and also from past experience 

 in waters along the Soviet coast (Kasahara, 

 1961) . Thus, the operation of fish meal factory- 

 ships became unprofitable; this coincided with 

 a slump in fish meal markets, both international 

 and domestic. The number of factoryships man- 

 ufacturing fish meal decreased from five (in- 

 cluding one producing fish meal from Atheres- 

 thes) in 1961-62 to only two in 1963 (including 

 one making a substantial amount of fish meal 

 from Atheresthes), with the catch of flounders 

 decreasing from 467,000 metric tons to less than 

 100,000 tons, A sharp decrease in the halibut 

 catch, combined with a decline in the sablefish 

 catch, made longlining less profitable. A sud- 

 den increase in herring production resulted in a 

 market crisis. The shrimp fishery near the 

 Pribilof Islands reached its peak in 1963 and 

 declined rapidly thereafter. Meanwhile, empha- 

 sis has shifted from yellowfin sole to pollack, 

 which is perhaps the most abundant species of 

 commercial fish in the region. The introduction 

 of a mechanized process to make minced pollack 

 meat further boosted fishing for this species, 

 and the catch has shown a phenomenal increase 



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