Williams, F. 1972. Consideration of three proposed 

 models of the migration of young skipjack tuna 

 ( Ka tsuwonus pelami s ) into the eastern Pacific 

 Ocean. Fish. Bull., U.S. 70:741-762. 



Three models proposed are: 1) active migra- 

 tion, 2) passive migration, and 3) gyral 

 migration. Mechanisms and timing in all 

 three models are dependent on oceanographic 



conditions and events in the central-east 

 Pacific, which thus have a controlling effect 

 on migration success. 



Williams, K.F. 1977. Sea surface temperature maps to 

 assist tuna fisheries off New South Wales, Austra- 

 lia. lT\ G.H. Tomczak (editor). Environmental 

 analysis in marine fisheries research--Fisher ies 

 Environmental Services, p. 38-55. FAO Fish. Tech. 

 Paper 70. 



Described an operational sea surface tempera- 

 ture mapping-advisory service to tuna fisher- 

 man and aerial spotters. Southern bluefin 

 apparently were regulated in their distribu- 

 tion by sea surface temperature and thermal 

 fronts along the southeast Australian coast. 



KEY WORDS: tuna, southern bluefin, oceanog- 

 raphy, temperature, fronts, season, migra- 

 tion, catch. 



Wyrtki , H. 1964. The thermal structure of the eastern 

 Pacific Ocean. ErgSnz. Reihe A{8 ), 6 Deut . 

 Hydrogr. Zeit. 



An analysis of the thermal structure and its 

 seasonal variation in the eastern tropical 

 Pacific Ocean. 



KEY WORDS: oceanography, temperature, depth, 

 season, thermocline, gradient. 



Wyrtki, K. 1965. The thermal structure of the eastern 

 Pacific Ocean. Deut. Hydrogr. Z. ErgSnzungsh . , 84 

 p. 



Analysis of thermal structure and seasonal 

 variations in the eastern Pacific using BT 

 data. Features and variability of thermal 

 structure made evident by the charted data 

 were discussed. 



KEY WORDS: currents, temperature, depth, 

 season . 



90 



