tie ear tags used in the PARR program produced a 

 much higher return rate (0.7%) than the dart tags 

 used in the WHOI program (0.1%). 



The results with the various types of dart tags 

 used in the WHOI program (Fig. 1) have not been 

 completely analyzed. Experience has shown, how- 

 ever, that the dart tags with plastic heads (types D 

 and E) are not as practical for tagging under the 

 conditions of this program. The applicators are 

 mounted on the end of a pole 1.0-1.5 m long, and the 

 fish are tagged without removing them from the 

 water, and preferably without handling them 

 (Mather, 1963). Under these circumstances, the 

 plastic heads of the type D and E darts are fre- 

 quently broken. The broken tags often jam in the 

 tubular applicators which are used for these tags, 

 and the applicators themselves are easily damaged 

 and difficult to repair or replace. The tags with 

 stainless steel darts (types A, B. C, H, M, N and 

 WH), which are used with slotted, solid stainless 

 steel applicators, are much more rugged and trouble 

 free, and do not jam in the applicators. The ap- 

 plicators themselves are also more rugged than the 

 tubular ones, and are much more easily repaired or 

 replaced when damaged. There has been no evi- 

 dence that the stainless steel dart is more injurious 

 to the fish than the plastic one, as was feared. 



There was some evidence that the streamers 

 sometimes separated from both types of darts, be- 

 cause of glue failure, defective assembly, or insuffi- 

 cient basic mechanical strength. The WH tag, with 

 the serial number on the dart as well as the 

 streamer, was developed with financial assistance 

 from P.A.B. Widener in hopes that valid returns 

 could be obtained even if the streamer had been 

 lost. Perhaps due to insufficient publicity, or 

 perhaps because this separation did not occur as 

 often as was supposed, these tags have not pro- 

 duced any significant increase in return rates. Re- 

 cent improvements in the construction of type H, 

 N, and WH tags, however, have so increased their 

 uniformity and mechanical strength that we do not 

 believe that tag separation will be a significant fac- 

 tor. 



SUMMARY 



1. The data suggest seasonal migrations between 

 summering areas in temperate waters (Gulf of Mex- 

 ico. U.S. coast from northern Florida to North 

 Carolina) and wintering areas in tropical waters 

 (Straits of Florida, West Indies, north coast of 



South America). These migrations may be related 

 to the location of the 25°C isotherm. 



2. The extremely localized nature of the intensive 

 southeast Florida sport fishery makes the local 

 movements within that area difficult to interpret. 

 More tagging in other areas might produce more 

 significant results. 



3. There are some indications of separate stocks, 

 but, if they are indeed separate, many of them 

 probably mingle with others. 



4. No reliable growth data were obtained. The 

 results suggest, however, that the growth rate of 

 sailfish decreases rather rapidly with increasing size 

 of fish. 



5. Times at liberty for recaptured sailfish ranged 

 up to 5 yr. but 95% were less than 1 yr. These 

 results indicate that the life span of the species is 

 short. 



6. Over 80% of the returned tags were recaptured 

 by the sport fishery. This indicates that commercial 

 fishing pressure on the stocks under study is slight. 



7. Tag return rates of less than 1% do not suggest 

 a high survival rate for released sailfish. 



8. This low return rate may be caused by low 

 fishing mortality and the short life span of the 

 species. Direct studies of the survival of released 

 fish are required. 



9. The cattle ear tag and the dart tag proved to be 

 the most practical of the types which were used for 

 tagging sailfish. The former produced higher return 

 rates than the latter, but the dart tag equipment is 

 less costly and easier to use. The dart tags with 

 metal heads were generally more satisfactory than 

 the ones with plastic heads. 



ACKNOWLEDGMENTS 



The authors are most grateful to all the organiza- 

 tions and individuals who have assisted this re- 

 search. Funding for the RSMAS program was pro- 

 vided by the Florida State Board of Conservation. 

 The principal financial support of the WHOI 

 program since 1956 has been from the National 

 Science Foundation (Grants G-861, G-2102, 

 G-8339, G-6172, G-19601, GB-3464 and 

 GH-82). the Bureau of Commercial Fisheries 

 (now National Marine Fisheries Service) (Con- 

 tracts 14-17-0007-272, -547, -870. -975, and -1110). 

 and the Office of Sea Grant, National Oceanic and 

 Atmospheric Administration, U.S. Department of 

 Commerce (Grant GH-82). Important additional 

 support has been received from the Sport Fishing 



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