Blackburn, M. 1962. Tuna ecology. In Blackburn and 

 associates, Tuna oceanography in the eastern 

 tropical Pacific. U.S. Fish. Wildl. Serv., Spec. 

 Sci. Rep. Fish. 400, p. 36-42. 



Review of the STOR program. An hypothesis is 

 presented that: "the countercur rent exer- 

 cises a moderating influence on anomalous 

 temperature regimes in general, both low and 

 high, in the region between 5° and 10°N, 

 where it approaches the coast." The summary 

 section considers several hypotheses and 

 relations between tunas and oceanography. 



KEY WORDS: tuna, skipjack, yellowfin, ocean- 

 ography, currents, temperature, depth. 



Blackburn, M. 1962. Distribution and abundance of 

 eastern tropical Pacific tunas in relation to 

 ocean properties and features. [Abstr.] In J.C. 

 Marr (editor). Pacific Tuna Biology Conference, 

 August 14-19, 1961, Honolulu, Hawaii. U.S. Fish. 

 Wildl. Serv., Spec. Sci. Rep. Fish. 415, p. 21-22. 



Abstract only. The distributions of yellow- 

 fin and skipjack tuna corresponded, at the 

 extremes of the eastern tropical Pacific 

 region, to the seasonal march of surface 

 isotherms, particularly the 21°C isotherm in 

 the north area. In the central region, the 

 surface temperature almost always exceeded 

 21 C. Yellowfin and skipjack occurred in 

 most areas at most seasons, and skipjack may 

 have been excluded at sea surface temper- 

 atures over 28 C. The author suggested an 

 association between the deep themocline, 

 biological productivity of surface waters, 

 and tuna. In offshore island areas tunas 

 were more abundant near islands than in the 

 adjacent waters. 



KEY WORDS: tuna, yellowfin, skipjack, tem- 

 perature, distribution, season, thermocline, 

 enrichment . 



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