FISHERY BULLETIN: VOL. 74, NO. 1 



3% in 1970). No tags were recovered at the plant 

 in the eastern area whose vessels fished only in 

 that area. Fewest second year recoveries were at 

 plants in the eastern area (3% in 1969; 6% in 

 1970; 1% in 1971). Most second year recoveries 

 were at plants in the western area for fish tagged 

 in 1969 and in the central area for fish tagged in 

 1970 and 1971. 



AUTUMN RELEASES AND 

 RECOVERIES 



Fish were tagged in autumn (September) only 

 in 1969, when 900 were tagged in the western 

 area, 2,100 in the central area, and 5,103 in the 

 eastern area (Table 5). By the end of the fishing 

 season in October, 6% had been recaptured. In 

 the following year 33% were recovered. For all 

 years combined 42% were recovered. 



As with tags of fish released in spring, tags of 

 fish released in autumn were recovered mainly at 

 plants in the area of release in both the first 

 and second year Few fish tagged in the western 

 area were recovered in the eastern area and few 

 fish tagged in the eastern area were recovered 

 in the western area. No fish tagged in the west- 

 ern area were recaptured at the plant in the 

 eastern area whose vessels fished only in that 

 area. Approximately 90% of the tags of fish re- 

 leased in the eastern area and recovered in the 



Table 5. — Numbers of adult Gulf menhaden tagged in autumn 

 of 1969 and the estimated nxmibers recaptured in subsequent 

 fishing seasons, by area. 



central area were at plants whose vessels fished 

 up to 25% of the time in the eastern area. 



CONCLUSIONS 



The pattern of first year tag recoveries shows 

 clearly that adult Gulf menhaden make no exten- 

 sive east-west movement along the coast during 

 the fishing season from April to November. 

 Nearly all tags were recovered at plants located 

 in the same area in which the fish were tagged. 

 Some fish that were released in one area but 

 whose tags were recovered at a plant in another 

 probably were caught in the release area, since 

 vessels at most plants, though fishing mostly 

 within their own area, also were far-ranging. No 

 fish tagged in the eastern area were recovered at 

 plants in the western area; few fish tagged in the 

 western area were recovered at plants in the east- 

 ern area. At plants whose vessels fished exclu- 

 sively in either the eastern or western area, no 

 tags were recovered except those from fish re- 

 leased in the same or adjacent area. 



Second year recoveries also point to little or no 

 mixing of fish from different areas during the 

 winter. Gulf menhaden apparently move offshore 

 during autumn and return again in spring to the 

 same general area they previously occupied. 

 Since the boundary between the western and 

 central areas is arbitrary and since we do not 

 exactly know where fish were recovered, the 

 greater number of second year returns in the cen- 

 tral, rather than western area of fish tagged in 

 the western area for 1970 and 1971 does not 

 necessarily indicate any significant shift of fish 

 from the western to the central area. 



Because there were no estimates of tag losses 

 due to shedding or deaths caused by tagging, 

 and because the variability in recovery efficien- 

 cies was large and some tags tended to remain 

 in plants for long periods, calculation of fishing 

 and total mortality rates would be no more than a 

 mathematical exercise. We can estimate from the 

 data, however, whether fishing mortality and ex- 

 ploitation rates are high or low. 



Both fishing mortality and exploitation rates 

 appear to be high. First year recoveries of spring 

 releases ranged from 21 to 43% of the number of 

 fish tagged. The total number of tags recovered 

 ranged from 30 to 51% for spring releases and 

 was 42% for the autumn releases. High tagging 

 mortality may account for the relatively low re- 

 turns for the 1969 and 1971 spring releases (30% 



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