Table 2. — Summary by quarter of the year of the total numbers and numbers per 10 hours of scouting for bird flocks, total fish schools, 

 skipjack schools, and yellowfln schools in major sectors of the survey area 



RESULTS 



Results of these tabulations are shown in 

 charts 1-12, with a broad summary presented in 

 table 2. 



Three features of the distributions shown 

 in the charts are quite apparent: (1) high rates 

 of sighting were most prevalent in time-area 

 units containing island groups, (2) there were 

 distinct seasonal changes in rates of sighting, 

 and (3) the rate of sighting in the general Mar- 

 quesas area was much higher than for any other 

 area of similar size. 



Surface schools of fish and bird flocks were 

 almost completely absent between latitudes 25° 

 and 30° N. except near Midway Islands. To the 

 east of the Hawaiian Islands flocks and schools 

 were also scarce, and a definite band of low abun- 

 dance could be noted between the Hawaiian and 

 Line Islands in the vicinity of latitudes 10° N. - 

 15° N. 



A distinct seasonal trend can be seen in 

 the occurrence of flocks and schools near the 

 Hawaiian and Marquesan Islands (fig. 5). As 

 might be expected (Yamashita, 1958; Wilson and 

 Austin, 1959), the highest rates of sighting in the 

 Hawaiian area were in the June-August quarter, 

 while in the Marquesan area they were highest 

 in the December-February quarter. In the Line 



Islands area, just north of the Equator, seasonal 

 changes were less marked and somewhat irreg- 

 ular. Bird flocks were most abundant during 

 June-August (as in the Hawaiian Islands), total 

 fish schools were most numerous during Decem- 

 ber-February (as in the Marquesas Islands), and 

 a poorly defined ma.ximum for skipjack schools 

 occurred in September-November. 



Maximum rates of sighting per 10 hours of 

 scouting for any single 5°-quarterly unit in the 

 Marquesan area were 8.16 bird flocks (in June- 

 August), 3.00 skipjack schools (December-Feb- 

 ruary), and 6.86 total fish schools (December- 

 February). By contrast maximum rates for these 

 categories of sightings in the Hawaiian area were 

 6.17 bird flocks, 1.27 skipjack schools, and 5.42 

 total fish schools, all in the June-August quarter. 



Total scouting effort recorded from 1950 

 to 1961 was 35,116 hours, about 84 percent of 

 which was expended in the Northern and 16 per- 

 cent in the Southern Hemisphere. All but 13 

 hours In the Southern and 80 percent of the time 

 in the Northern Hemisphere, a total of 29,204 

 hours, were spent in the summary area shown in 

 charts 1-12. Total sightings, exclusive of aquatic 

 mammals and scattered birds, consisted of 7,439 

 blrdflocks and 4,506 fish schools. Of the latter, 

 1,531 were skipjack schools, 214 were yellowfln 



