in this figure is a summarization of past data, with absolutely no account taken of secisons, there 

 is naturally a need for correction based on a consideration of the data by seasons. Such a 

 correction would probably change to some extent the magnitude and positions of the peaks on the 

 curve amd the differences in their slopes, but it Ccin hairdly be thought that it would give rise to 

 conspicuous changes in the generad. trend of the curves. Therefore, this figure can probably be 

 regarded as showing in general outline the distributional pattern of the yellowfin tuna in the 

 northwestern Pacific Ocean aM it relates to latitude. Because of the lack of fish measurements 

 and other data, it is impossible to come to any decision at present concerning the relationships 

 between the schools which make up the peak of the catch rate, that is of the density of distribution 

 in the area centered around 20 N. latitude and the schools which make up the peak in the low 

 latitude area centered around the Equator. Thus we cannot in the absence of further study come 

 to any conclusions concerning such important questions as whether or not these schools belong to 

 different stocks, whether they belong to the same stock but represent different age compositions, 

 or whether fish of exactly the same stock have, because of oceanographic conditions or their 

 relationships with other aquatic life, formed two centers of distribution where the density of 

 occurrence is high in comparison with the surrounding waters. However, the phenomena of a 

 generally improving catch rate throughout the area south of 25 N. in May and a sinnilar sinnulta- 

 neous rise in the catch rates in the area west of 140 E. longitude in October are considered to be 

 data which tend to deny the validity of the idea that there are a large number of stocks in the 

 western Pacific region. 



E. Spearfishes 



Chart V shows the distribution of spearfish catch rates throughout the year, 

 chart all of the spearfishes are lumped together. 



In the 



If we look at the areas on the chart where the catch rates jire over 1.0, we see that 

 they include almost all of the Celebes Sea, the coastal waters on the east side of the Philippine 



jmd the waters 



o o 



Islands, Formosa and Okinawa, the vicinity of 7 to 10 N 



140° to 150° E. 



around the Izu, Ogasawara, and Mariana islands. Catch rates are also over 1.0 in the areas 



centered around 35 to 40 N. , 150 to 160 E. Other sea areas where the catch rates are high 



o o o 



are in the Kinan sea area and in the vicinity of 29 to 39 N, at 100 E. Other fishing grounds 



with comparatively high catch rates can be recognized south of 10 N. in the vicinity of 155 to 



160 E. There are almost no data worth considering from the operations of research vessels, 



but judging by the reports of commercial vessels the Marshall Islands region also appears to be 



a superior fishing ground for spearfishes. From the foregoing it is seen that, with the exception 



of the broadbill swordfish, the good fishing grounds for other spearfish species are in waters 



comparatively close to islands or the continental shelf. 



As for the catch by species, there are many cjises in which it is impossible to tell 

 because of deficiencies in the data, but in general it may be said that the waters adjacent to 

 Fornnosa have an abundance of white marlin that is unparalleled elsewhere. Sailfish are adso 

 extremely abundant. The proportions of spearfish species in the catch are shown in the following 

 table. 



Table 114. --Catch by species in Formosa (Takao and 

 Suo fish markets, 1943) 



155 



