o o 



20 to 22 N. 



o o 



30 to 32 N. 



o o 



The low points on tlie curve appear at 1 to 1 2 N. , 



and 40 to 42 N. , being separated by about 10 of latitude just as were the peaks. Among these 

 various low points, it is doubtful whether the one at 10 to 12 N. is really as pronounced as it 

 appears on the figure because there are very few data for this area. It is also thought worthy 

 of note that the position of this low coincides perfectly with that on the yellowfin curve. 



The peak on this curve which appears at 4 to 6 N. is almost entirely composed of 

 black marlin, while that which appears at 14 to 16 N. is composed of black marlin and striped 

 marlin. The peak appearing at 24 to 28 N. is composed almost exclusively of striped marlin 

 while the peaks north of 30 N. are formed for the most part of broadbill swordfish. Conse- 

 quently, to state it very broadly, we can recognize a successive distribution from south to north 

 of black marlin, striped marlin, and broadbill swordfish. In the following figures the variations 

 in fishing conditions from month to month are shown for each sea area, just as was done in the 

 case of yellowfin and bigeye tuna. 



First of all, figure 32 shows the situation in the vicinity of the Equator from to 5 

 0° to 160° E. 



and from 150° to 160 E. 



N. 



I.O 



< 



0= 0.5 



X 



o 



o 



1 I I I \ I I I r 



• ■• TOTAL 



BLACK 

 SAILFISH 

 ■a STRIPED 



1 — r 



W^=xl 



J—i^-L 



^ 



I 2 3 4 5 6 7 8 9 10 II 12 

 MONTH 



Figure 32. --Spearfish fishing conditions by 

 months (0° to 5° N. , 150° to 

 160° E.) 



The increases Jind decrecises 

 in the catch rates are not very conspic- 

 uous, but in the catch rate for the spear- 

 fishes as a whole the peaks appear in 

 February, August, and November. The 

 catch is almost entirely made up of 

 black marlin, with sailfish next in 

 abundance and striped nnarlin extremely 

 scarce. There are no data for June, but 

 the sailfish appear to increase some- 

 what around August and September. 

 Striped marlin become somewhat more 

 numerous in January and October. 



Figure 33 shows the fishing 

 conditions in the waters around Palau. 



As the figure shows, the 

 peaks on the curve are in April, 

 October, and December- January. The 

 catch of each species is not known so 

 we cannot show what these peaks are 

 composed of, but from the form of the 

 curve, it is difficult to conclude that 

 they are all the same species. Com- 

 pared with the preceding figure, the 

 positions of the peaks and lows on the 

 curve are quite conspicuously different. 



o o 



Figure 34 gives the fishing conditions from 19 to 24 N. , 



140° to 155° E., 



i. e. , to 



the east of the area between the northern Marianas and the southern Volcajio Islands. 



For the total catch, the peaks on the curve appear in Jjinuary, March, May, and 

 August. They have been onnitted from the figure, but from December to February broadbill 

 swordfish increase somewhat in abundance. Striped marlin increase gradually from November 

 on and form a rather conspicuous peak in March. In April they decline quite rapidly, but increase 

 again sharply in May to attain their maxinnunn catch rates of the year. From June on they drop 

 off steeply and reach their low of the year in August. 



157 



