Bird tlocks are one of the best signs of the presence of 

 tuna schools (fig. 17). Presumably these birds are competing 

 with the big fish for the little fish near the surface. On 

 Project Porpoise cruises the Smithsonian Institution would 

 observe and collect the sea birds. By July 1967, the Institu- 

 tion will have already banded about 1.5 million birds on 

 islands in the trade wind zone. It hopes now to study their 

 distribution away from the breeding islands. It will study 

 the development, composition, and behavior of bird flocks 

 in relation to tuna schools, information that would be of 

 immense value to the fishermen. One project calls for a 

 comparison of stomach contents of birds and of tunas feeding 

 in the same area. 



Field work is now scheduled to begin in the fall of 1968. 

 The next several months will be devoted to more detailed 

 planning and to an effort to broaden the list of participants 

 so that the venture can give the great scientific return. 



Wakes in Lee of Islands 



Another study in oceanography at the Laboratory in 

 Honolulu has defined an area in the central Pacific where 

 semipermanent features in the oceanic circulation may pro- 

 vide conditions conducive to the aggregation of fishes. 

 including tunas. 



The island of Hawaii, a volcanic mass whose 4,021 square 

 miles make it about the size of the State of Connecticut, 

 stands in the path of the westward-moving currents of the 

 central Pacific Ocean like a stone in a sluggish stream. 

 Bathed during most of the year by the highly saline waters 

 of the north central Pacific, the island in summer frequently 

 lies within the less saline waters of the California Current 

 Extension. When these waters reach as far north as the 

 island of Oahu. the State's skipjack tuna catch (a full third 

 of which is taken no more than 20 miles off Oahu) is usually 

 good. 



As these currents diverge around the volcanic mass of 

 Hawaii, says oceanographer Richard A. Barkley, they estab- 



FIGURE 18 In the top drawing, all of the islonds of the Stole of 

 Hawoii hove been obliterated except the "big islond," Hawari itself 

 Extending westward from fHowoii is o theoreticol von Kormon woke, 

 generated by the flow of o generally west-moving current I not shown I 

 around the gigontic volconic obstruction of the island. In the bottom 

 drawing, the remaining islonds of the State hove been restored to 

 their normal position and an actual current pattern, observed in 

 March 1953, drawn in. As in the theory, clockwise and counter- 

 clockwise eddies appeor downstream from the islands. Such eddies 

 moy profoundly influence fish distribution. 



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