Laurs, R.M., and R.J. Lynn. 1975. The association of 

 ocean boundary features and albacore tuna in the 

 northeast Pacific. In Proceedings: Third S/T/D 

 Conference and WorksHo^p, February 12-14, 1975, p. 

 23-30. Plessey Environmental Systems, San Diego, 

 Calif. 



Migration of albacore into the U.S. fishery 

 and distribution were related to oceanograph- 

 ic conditions of the Transition Zone and 

 associated frontal structure. Albacore were 

 more available within the Transition Zone 

 than outside of it. Interannual variations 

 in the ocean structure were reflected in 

 albacore distributions. 



KEY WORDS: tuna, albacore, sea surface tem- 

 perature, discontinuity, distribution, migra- 

 tion, fronts. 



La 



urs, R.M., and R.J. Lynn. 1977. Seasonal migration 

 of North Pacific albacore, Thunnus alalunga , into 

 North American coastal waters: Di st r i but ion , 

 relative abundance, and association with Transi- 

 tion Zone waters. Fish. Bull., U.S. 75:795-822. 



Concluded that the shoreward migration of 

 albacore is linked to the Transition Zone 

 (T.Z.) and that variations in the pattern of 

 migration occurred in response to variations 

 in the character and development of the T.Z. 

 and its frontal structure. When the T.Z. was 

 narrow and the fronts well developed, the 

 migration was narrow and well defined; when 

 broad, the migration was broad and less well 

 defined. Gave speeds of albacore migration 

 as 48 k per day for 78-80 cm size fish. 

 Forage availability was likely an important 

 factor influencing the route of the migra- 

 tion. The albacore migratory route during 

 spring was thought to be determined by ocean 

 temperatures, and the limiting temperatures 

 were found near the northern boundary of the 

 T.Z. While temperature may play a role in 

 determining the southern limit of the alba- 

 core distribution and migratory route, the 

 major factor is the abundance and availabil- 

 ity of forage organisms which drop off sharp- 

 ly near the southern boundary of the T.Z. 

 Evidence was given for two groups taking 

 separate routes into the American Pacific 

 fishery. 



KEY WORDS: tuna, albacore, migration, stock, 

 distribution, food, season, temperature, 

 fronts, oceanography. 



48 



