A Review of the Longline Fishery 

 for Billfishes in the Eastern Pacific Ocean 



JAMES JOSEPH, WITOLD L. KLAWE, and CRAIG J. ORANGE 1 



ABSTRACT 



Catch and effort statistics from the Japanese longline fishery are used to examine the quarterly 

 distribution of each of the sl\ species of billfishes taken in the eastern Pacific Ocean east of long. 130°W. 

 Striped marlin appear to be the most widely distributed hillfish in the eastern Pacific. Blue marlin are 

 confined more to the equatorial high seas regions than the other species. Sail fish are extremely abundant 

 within 600 miles of the shoreline along Mexico and Central America. Shortbill spearfish are relatively 

 sparsely distributed and less abundant in inshore waters than are sailfish. Black marlin are the least 

 widely distributed and least abundant of the billfishes in the eastern Pacific. Swordfish are abundant in 

 waters around Baja California, Mexico and near northern Peru and southern Ecuador. They are also 

 frequently encountered in or near the cool upwelled waters along the equator. 



Trends in abundance, as reflected by catch/1, 000 hooks and total catch, are discussed. On the 

 southern grounds of the striped marlin fishery, apparent abundance of this species has dropped to about a 

 third of its highest level, but fishing success has remained constant on the northern grounds. Catches of 

 striped marlin reached their peak in 1968 (337,000 fish); by 1970 the catch had dropped to 180,000 fish. 

 Apparent abundance and catches of blue marlin also decreased from levels in the early 1960's. In 1963, 

 75,000 blue marlin were taken but the catch decreased to about 22,000 fish by 1966 and has fluctuated 

 about that level since. Because so few black marlin are taken in the eastern Pacific, trends in the 

 abundance of this species are not discussed. The longline fishery for sailfish in the eastern Pacific began in 

 a substantial way in 1965 with a catch rate of about 80 fish/1,000 hooks on the major sailfish grounds but 

 by 1970 this had dropped to about 11 fish/1,000 hooks. Also catches on these grounds dropped from a 

 peak of about 370,000 fish in 1965 to about 210,000 fish in 1970. Catches of swordfish contined to increase 

 from the beginning of the fishery in the 1950's until 1969, the peak year, when about 112,000 fish were 

 landed. Catches decreased in 1970, although effort decreased also. The apparent abundance of swordfish 

 has shown no general decreasing trends. 



A general discussion of the needs of scientific research on billfishes is given in the final section of the 

 report. 



Billfishes are distributed throughout nearly all of 

 the temperate and tropical oceans of the world and 

 are caught by commercial and sport fishermen. Six 

 species of billfish occur in the Pacific Ocean. The 

 nomenclature of billfishes has been a controversial 

 subject for some time. For the purposes of this 

 paper we chose to utilize the scientific nomencla- 

 ture of Nakamura, Iwai, and Matsubara(1968). We 

 also show the common names in English, Spanish, 

 Japanese, Korean, and Chinese. 



'Inter-American Tropical Tuna Commission, c/o Scripps In- 

 stitution of Oceanography, La Jolla, California 92037. 



Xiphias gladius Linnaeus 



Chinese (People's Republic of China PRC): 

 chien-yii 



Chinese (Republic of China RC): chien-ch'i-yii 



English: Swordfish 



Japanese: mekajiki 



Korean: whang-sae-chi 



Spanish: pez espada 

 Tetrapturus angustirostris Tanaka 



Chinese (PRC): hsia-wen-ssu-chi'i-ch'i-yii 



Chinese (RC): 



English: Shortbill spearfish 



Japanese: furajkajiki 



Korean: 



309 



