V 



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t^-i 



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pto-i- 



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FIGURE 17. Birds compete with tunas for prey Fishing vessels mam- 

 toin lookouts for the wheeling, diving Hocks of seo birds. The 

 Smithsonian Institution, which hos a Pacific-wide study of morine 

 birds, will cooperate in Project Porpoise. 



evidence that such discontinuities can also be identified in 

 deeper waters. Even at several hundred feet beneath the 

 surface, there can be, as there are in the atmosphere and at 

 the sea surface, pronounced changes within a very few miles. 



This study of subsurface fronts may have many implica- 

 tions in the distribution of fishes. As yet, it has been 

 possible to test the biological yield of subsurface fronts on 

 only one fishing expedition. In April 1966, the Laboratory 

 in Honolulu enlisted the cooperation of three Honolulu-based 

 longline vessels, the Kaku, Pidpo, and Aukai, in a joint 

 venture. The commercial vessels were to fish in the open 

 seas about 350 miles from Honolulu. The Toicnsend Crom- 

 well sailed farther south until she located a subsurface front. 

 Her longlines, fishing at a depth of about 300 to 500 feet, 

 straddled the front. 



The TownsencI Cromirell catches were compared with 

 those of the commercial longliners. Catch rates of tunas did 

 not vary greatly. On the other hand, the Tou-naend Croni irell 

 in the frontal area took more sharks and more mahimahi 

 (dolphin fish). The results thus suggested that the frontal 

 area might be richer, in terms of total fish production, if not 

 in tunas alone, than the other area. 



From the beginning of the Trade Wind Zone Oceanography 

 Pilot Study, the participation of other research laboratories 

 whose programs could complement the oceanographic work 

 has been sought. At the time of writing, it appears that the 

 Meteorology Department of the University of Hawaii may 

 undertake the investigations of the meteorology of the zone, 

 and the Smithsonian Institution, which participated in the 

 pilot study and which has a Pacific-wide investigation of 

 sea birds, plans to join Project Porpoise. 



Relying not only upon shipboard observations, but on such 

 sources as data from satellites, the meteorologists would 

 seek new insights on tropical and winter storms, on the 

 transformations of air masses, and on the as yet little 

 understood meteorology of the equatorial region. 



28 



