bait is carried tha- amount of ice which can be carried for preservini_, the 

 catch is diminished. 



c. Fishing grounds and seasons 



The best fishinj grounds are probably those "/here the surface tempera- 

 ture is 17° and the temperature at 50 meters is about 11°, but the ron^c- 

 of migration is limited to small scattered areas and the schools are 

 small. It is thou.jht. that at tim.es the schools congregate densely near 

 the surface and at times they come to the surface in pursuit of squid 

 and small fish. The schools s?7im at rather hi^h speeds and it is believed 

 that it would be most efxeccive to chum them in to the boat and fish them 

 with poles, ho:uevor, since the range of occurrence of tbe schools is 

 small some difficulty is found in soarohing for them. As for the fishing 

 season, it is thought that the designated operating period is adequate. 



(a) Summary 



(A) General Aspect of the Distribution of '^.tcr Temperatures and Specific 

 Gravities (see Charts of Monthly Isotherms and Isctones) from the First Ten 

 Days of May On 



Operations were begun May 18 and during the month of May the operat- 

 ing vessels covered the v/hole area, rdth 5 vessels between 32° and 37°N. 

 This was about A° of latitude farther north than the operating areaof the 

 previous year. The surface water tem.peraturv-:s ranged from about 17° in 

 the north to about 20° in the southern part of the area, or a slope of 

 about 3° in 6° of latitude. This was about twice as gentle a slope as was 

 seen in the previous year. Just as in the previous year, the tomnerature 

 profiles in the eastern and western parts of the area were roughly parallel. 

 The zones of 17° - 19° water appeared to follow roughly the line of 35°N. 

 As for the vertical distributi'^n, the temperatures at 50 meters were 2^ 

 lower than those at the surface, those at 100 meters wore 1° lower than 

 those at 50 meters, and those at 200 meters were 1° lov/er than those at 

 the 100-meter level, /t each level the north-south and east-west pro- • 

 files had roughly the same slope as the surface temper-" turcs. The dis- 

 tribution of specific gravities in the surface v/atcrs was lower in the north 

 with a figure of 2600 in the southern part cf the area. At the 50-metcr, 

 lOO-metcr, and 200-meter levels the lowest values were in the cast, ^vith 

 25A0 to 2530. In the southern part west of a'iout 170°^ values of 2620 

 were obtained and differences v/ere seen between the surface waters and 

 those below the 50-moter level, 



June 



Eight vessels were in operation durin(_; this month and they covered 

 roughly the area between 32° and 38°N, Surface temperatures in these 

 waters ranged from about 17° in the north to 19° - 20° in the south, 

 showing a slope of about 3° in 6° of latitude, u'hen compared with the 

 water temperatures at the same latitudes in the last 10 days nf the pre- 

 vious month, they showed a rise of about l'^, and the zone of 17° - 19° 

 water had moved northward about 2° of latitude from its position of the 



152 



