REVIEW PAPERS 



A Review Of The World Commercial Fisheries 



For Billfishes 



SHOJI UEYANAGI 



ABSTRACT 



This report gives a general "overview" of the commercial fisheries for billfishes. The present world 

 production of billfishes is approximately 100,000 tons per year, of which more than 909c is taken by the tuna 

 longline fishery. Japan alone produces about 70°c of the world's catch of billfishes and is the principal 

 consumer nation of these fish. 



Although billfishes account for only about 18% of the longline catches, they are presently of consider- 

 able importance, especially among the fishery products utilized in Japan. This report discusses the value 

 and utilization of billfishes in Japan, and describes how billfishes have gained status as a quality fish, 

 commanding prices comparable to the tunas. In addition, the expansion of the longline fishery is described, 

 showing that by 1965 the fishery had covered the entire distributional range of the billfishes. Catch and 

 effort data for billfishes indicate that 1 ) swordfish is the only species which has shown an increase in landings 

 in recent years, 2) blue marlin landings have decreased in recent years in the South Pacific. Atlantic, and to 

 a slightly lesser degree, also in the Indian Ocean, and 3) the catch of the striped marlin has fluctuated 

 greatly from year to year. 



Billfishes 2 have been known to man since ancient 

 times. Bones of billfishes — fragments of vertebrae 

 and spears of sailfish, striped marlin, and 

 swordfish — have been found among relics discov- 

 ered in a shoreside cave at the tip of the peninsula 

 bordering Tokyo Bay (Kaneko et al., 1958). These 

 remains date back to the Jomon Era, some 3,000 to 

 4,000 years ago. 



Since such ancient times billfishes have been 

 taken in Japanese coastal waters, albeit in small 

 numbers, by harpoon fishing. It was with the de- 

 velopment of the tuna longline fishery that these fish 

 have emerged as an important world resource of 

 today's magnitude. 



The present world production of billfishes, ac- 

 cording to FAO statistics (FAO, 1971), is approxi- 

 mately 100,000 metric tons per year, of which more 

 than 90% is taken by the tuna longline fishery. Japan 

 produces about 70% of the world's catch of billfishes 

 and is the principal consumer nation for these fish. 



'Far Seas Fisheries Research Laboratory, Shimizu, Japan, 

 ^o distinction is made in this report between the different 

 species which may exist in the various oceans, as for example 

 between the Atlantic blue marlin and the Indo-Pacific blue marlin. 

 Only the generally applied common names are used throughout 

 this report. 



Japan's average annual total catch of billfishes 

 during 1968-70 amounted to 69,000 tons (Ministry of 

 Agriculture and Forestry, Japan, 1972). Combining 

 the longline catches of tunas and billfishes. the bill- 

 fish catch comprised 18% of the total landings (Fig- 

 ure 1). The proportion contributed by billfishes is 

 about the same as that of the albacore (Thunnus 

 alalunga) and both fall below the catches of yellow- 

 fin tunafT. albacares) and bigeye tuna(7\ obesus). 

 These statistics suggest that billfishes are only an 

 incidental by-product of the longline fishery, and to a 

 certain extent, this is true. Nevertheless, billfishes 

 are presently of considerable importance among the 

 fishery products utilized in Japan. 



Among the billfishes, the striped marlin and 

 swordfish predominate, each accounting for approx- 

 imately 30% of the total catch (Figure 2). Blue marlin 

 and black marlin together make up 25% of the land- 

 ings, and the sailfish, 14%. 



VALUE AND UTILIZATION 

 OF BILLFISHES IN JAPAN 



Figure 3 shows the average annual prices for bill- 

 fishes for the 10-year period from 1961 to 1970. 



