Kawasaki, T. 1967. Ecology and dynamics of the skip- 

 jack population (11). Resources and fishing con- 

 ditions. Japan Fishery Resources Protection 

 Association. [Translated by U.S. Joint Publica- 

 tions Research Service (66 typed pages).] 



General history of Japanese, Hawaiian, and 

 United States fisheries; methods and catch 

 trends. Presented a population catch struc- 

 ture based on size-frequency modes, growth 

 differential, and behavior. Listed numerous 

 "groups" in various areas. Compared trends 

 among the areas over time. Presented a model 

 of the skipjack population in the central and 

 North Pacific; basically a migration of large 

 spawners into the central Pacific with young 

 fish moving to the peripheral regions to feed 

 and mature; these then — once they reach large 

 size--move offshore to the central area 

 again. Author gave little credence to 

 serological subgroups such as described by 

 Sprague. Discussed env i r onmenta 1/oceano- 

 graphic influences on fishing skipjack near 

 Japan which were strongly associated with 

 fronts and edges of water masses where two 

 masses meet; migratory skipjack fishing 

 grounds occurred mainly at current bound- 

 aries; skipjack grounds were formed in bound- 

 aries where warm waters thinly covered the 

 surface . 



KEY WORDS: tuna, skipjack, catch, popula- 

 tion, migration, currents, front, season, 

 spawning, stock. 



Kawasaki, T. , and Y. Aizawa. 1956. On the ecology of 

 the albacore in waters adjacent to the northeast 

 of Japan. [In Jpn . , Engl, summ.] Bull. Tohoku 

 Fish. Res. Lab. 6:81-92. 



Study of the migration of albacore by age- 

 and length-group and temperature. Migrations 

 were led by old fish during westward move- 

 ment; during eastward movement younger fish 

 took the lead. Considered relations between 

 age and season and sea surface temperatures. 



KEY WORDS: tuna, albacore, age, season, 

 temperature, habitat. 



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