nSHERY BULLETIN: VOL. 79, NO. 1 



clearly downward. In the Texas area, 1975 and 

 1976 were years when CPUE was unusually high, 

 but in 1977 and 1978 CPUE dropped back to levels 

 more consistent with earlier years. 



DATA ANALYSIS— ALL AREAS 



Only tournament data are available from the 

 recreational fishery in areas other than the Gulf of 

 Mexico, hence a fishing power analysis similar to 

 the one conducted for the gulf is not presented. It 

 is informative, nevertheless, to examine CPUE 

 data from all sources throughout the western At- 

 lantic and Gulf of Mexico in view of the results of 

 the analysis presented for the gulf. 



Blue Marlin 



■OSn 



.04- 



w 



a. .03- 



.02- 



ATLANTIC AND 

 CARIBBEAN 



GULF OF MEXICO 



— I . 1 ,1 I I 1 I — 



1971 72 73 '74 '75 '76 '77 



YEAR 



'78 



FIGURE 10.— CPUE, in number offish hooked per hour of fishing, 

 from the recreational fishery for blue marlin in the two major 

 fishing areas, 1971-78. 



Data on blue marlin were divided into two areas: 

 the Gulf of Mexico and the Atlantic and Caribbean 

 (Figure 10). Both tournament and dock sampling 

 were combined for the gulf. This division does not 

 necessarily mean we support a separate stock 

 theory for these areas, but merely that the geo- 

 graphical separation of fishing effort indicates 

 that this is a logical division for comparative pur- 

 poses. If, however, trends in CPUE from the two 

 areas are similar, one might conclude that there is 

 at least prima facie evidence of a single stock. 

 Figure 10 shows that trends between the two areas 

 are similar only from 1973 to 1976, which is obvi- 

 ously inconclusive. It should also be noted that 

 there is little fluctuation in CPUE over the time 

 series presented, particularly when compared 

 with white marlin (Figure 11) and sailfish (dis- 

 cussed below). Normally one would expect CPUE 

 for a long-lived species with numerous age groups 

 contributing to the fishery to fluctuate much less 

 than that for a species with a relatively short life 

 span where the impact of a large or small incoming 

 year class would be much greater on the fishery. 

 Although no reliable age and growi;h data are 

 available on blue and white marlins, the Atlantic 

 blue marlin grows to a much larger size than 

 either the white marlin or the sailfish, occasion- 

 ally reaching weights of over 580 kg (Interna- 

 tional Game Fish Association 1979) and would 

 therefore appear to be the longest lived of the three 

 species. The trends in CPUE for the three species 

 appear to conform to the general pattern one 

 might expect based on their presumed relative life 

 span and the length of time they would be expected 

 to contribute to the recreational fishery. 



.14' 



O. 



u 



0.8' 



< 

 UJ 

 K 0.6- 



U 



bJ 



ae 



0.4- 



0.2^ 



• .208 



• ■217 



NORTH CAROLINA* 

 TO 

 NEW JERSEY 



GULF OF 

 MEXICO 



BAHAMAS 



— I — 

 1971 



— T— 

 V2 



— I— 

 '72 



1 



'74 



YEAR 



— I— 



'75 



— I — 

 '76 



— f— 

 '77 



— 1 — 

 '78 



Figure U. — CPUE, in number offish hooked per hour of fishing, 

 from the recreational fishery for white marlin in three major 

 fishing areas, 1971-78. 



White Marlin 



Data on catch and effort for white marlin were 

 divided into three areas (Figure 11). Mather et al. 

 (1972) hypothesized that the gulf and Atlantic 

 stocks of white marlin were separate based on tag 

 return data and the distribution of CPUE in the 

 Japanese longline fishery. More recent tag return 

 data, however, indicate that there may be consid- 

 erable mixing of white marlin between the Gulf of 

 Mexico and the Atlantic Ocean. "• There is rather 



■■Che-ster C. Buchanan, U.S. Fish and Wildlife Service, An- 

 chorage, AK 99503, pers. commun. June 1977. 



64 



