miles per day; tip of Baja California to % the dis- 

 tance to the Hawaiian Islands, 11.7 nautical miles 

 per day; tip of Baja California to near Clipperton 

 Island, 16.3 nautical miles per day. 



For all striped marlin recoveries having accurate 

 records, the average days out is 89; the average 

 migration 281 nautical miles, and average distance 

 per day out, 3.16 nautical miles. 



For the limited number of sailfish recaptured the 

 average number of days out was 1 13, the migration 

 rate was 0.4 nautical miles per day. The longest 

 distance recorded for any sailfish was 250 nautical 

 miles in 457 days out. This was the longest release- 

 recapture time of any billfish tagged in the Pacific. 



Two black marlin were recovered, one near the 

 point of tagging in the Coral Sea 364 days after tag- 

 ging, the other 180 days after tagging, 1,440 nautical 

 miles northeast of Queensland, Australia. This bill- 

 fish averaged 8 nautical miles per day. 



The greatest migration rate in nautical miles per 

 day for any billfish was a short-term recovery of a 

 striped marlin tagged off the tip of Baja California 

 which averaged 31.6 nautical miles per day. 



DISCUSSION AND SUMMARY 



The concept of utilizing cooperating marine game 

 fish anglers to tag and release billfishes has proven 

 to be a practical approach to the study of billfish 

 migration patterns. 



Experience indicates that accurate estimates of 

 weights and lengths of tagged fish cannot be ex- 

 pected. 



After tagging, the angler is requested to return 

 the tag card. In 1968 a comparison was made of the 

 number of tags returned with a matching tag card on 

 file, with those that did not have a tag card. This 

 indicated that about 17% of the tag cards were not 

 being returned. As a result, an active campaign to 

 have the angler return the cards was begun. 



The number of billfishes tagged annually in the 

 Pacific has steadily increased since 1954, reaching a 

 total of 2,118 in 1971. The annual rate of billfish 

 recoveries rose to above the 0.90% level from 1966 

 through 1968, dropped to 0.40% in 1969, increased 

 to a peak of 1.16% in 1970, and dropped to a very 

 low 0.13% in 1971. The reason for the sharp decline 

 in recoveries in 1971 cannot be explained. The only 

 change in operation ot the National Marine 

 Fisheries Service program was the introduction of 

 the "H" type tag. During the latter half of 1971, 317 

 "H" tags were used, which equalled only 14.7% of 



the total tags used by the National Marine Fisheries 

 Service program during 1971. 



The recovery rate from FM-67 and FT-1 tags 

 used by the National Marine Fisheries Service and 

 California Department of Fish and Game in the 

 Pacific for striped marlin were comparable. The 

 California Department of Fish and Game program 

 obtained a 0.80% recovery rate using the FT-1 and 

 the National Marine Fisheries Service program ob- 

 tained a 0.42% recovery rate using the same tag, 

 giving an overall average of 0.66%. The California 

 Department of Fish and Game program restricted 

 its tag distribution to a limited number of experi- 

 enced anglers fishing from private boats. On an av- 

 erage these anglers were more experienced in tag- 

 ging billfish than most of the anglers participating in 

 the National Marine Fisheries Service program. 

 The FM-67 tag used for striped marlin shows a 

 greater recovery rate (1.06%) than any of the 

 four types of tags used. The recovery rate of 

 the California Department of Fish and Game FT-1 

 tag (0.80%) was near that of the FM-67. 



The National Marine Fisheries Service program 

 changed to the metal-plastic "H" type tag in 

 mid-1971 because of the recovery record (recovery 

 percent and time out) for white marlin (Tetrapturus 



albidus) and sailfish in the Atlantic Ocean experi- 

 enced by the Woods Hole Oceanographic Institu- 

 tion program. 



Although many factors such as seasons and areas 

 of fishing and economic value of billfishes influence 

 catch rates in the Atlantic and eastern Pacific, a 

 gross comparison of catch rates between the two 

 oceans can be made. Catch and effort data given by 

 the Japanese for Japanese longline operations in the 

 Atlantic and eastern Pacific Oceans and plotted by 

 Gottschalk (1972), show that the total effort in 

 hooks fished was only slightly greater in the Atlan- 

 tic than in the eastern Pacific for the period 1962 

 through 1970 (478 x 10 6 for the Atlantic and 442 x 

 10 6 for the eastern Pacific). Charts outlining longlin- 

 ing areas for striped marlin and sailfish in the east- 

 ern Pacific by Joseph et al (1973) and for sailfish and 

 white marlin in the Atlantic by Wise and Davis 4 

 show that these areas are near equal in geographical 

 extent. However, the catch-per-unit-effort 

 (catch/hook) for striped marlin in the eastern Pacific 

 has remained about three times greater over the 

 years than the catch-per-unit-effort for white marlin 



''Wise, John P. and Charles W. Davis. 1971 . Seasonal distribu- 

 tion of billfish in the Atlantic. Prepared for 22nd Tuna Confer- 

 ence, NMFS, Miami. Fla., 28 p. (mimeo.). 



235 



