BEARDSLEY and CONSER: AN ANALYSIS OF CATCH AND EFFORT DATA 



clear evidence (Mather et al. 1972) that the group 

 of white marlin available to the recreational 

 fishery in the Florida Straits and Bahamas in late 

 winter and early spring (labeled Bahamas in Fig- 

 ure 11) is the same group that concentrates off the 

 northeastern coast of the United States in late 

 summer and early fall (labeled North Carolina to 

 New Jersey in Figure 11). If CPUE from the recre- 

 ational fishery is adequately measuring the rela- 

 tive abundance of white marlin stocks, one would 

 expect a high degree of correlation between CPUE 

 from a single stock from three widely separated 

 areas assuming a constant percentage of the total 

 stock was available in each area, each year. By 

 inspection, it is clear that for the time series avail- 



170n 



160- 



U 



^ 150- 



»- 

 O 



z 



bi 



-I 



ae 

 e 

 o 

 lb 

 I 



< 180-1 



O 170- 



160- 



GULF OF,'-' 

 MEXICO 



BAHAMAS • 



-•-^^_-. 



NORTH CAROLINA 



TO 



NEW JERSEY 



. --• 



2 FISH 



BAHAMAS I——- •-„,___^ 



GULF 0F» • *~"'^V.|i^ 



"*^'"*=° NORTH CAROLINA* 



TO 

 NEW JERSEY 



—I 



1971 



— I— 

 '72 



— I— 

 '73 



1 I 



'74 '75 



YEAR 



— r- 



'76 



77 



FIGURE 12.- 



-Length frequencies of white marUn from three 

 major fishing areas, 1971-77. 



able a close relationship appears to exist between 

 CPUE from the three areas sampled. It is also 

 interesting to note that 1975 was a good year in all 

 three areas. Although availability obviously plays 

 an important role in affecting CPUE, it seems 

 unlikely that it is the dominant factor in this case 

 since the three fishing areas are widely separated 

 geographically, and conditions affecting availabil- 

 ity would not likely be optimal in all three areas in 

 the same year Correlation coefficients were calcu- 

 lated for all three areas (5 yr) and for the Gulf of 

 Mexico and the Bahamas (7 yr). The multiple cor- 

 relation coefficient for all three areas was signifi- 

 cant at the 95% level {R = 0.925) and the simple 

 correlation coefficient for the Bahamas and the 

 Gulf of Mexico was significant at the 99% level ( r = 

 0.865). If we are indeed measuring relative abun- 

 dance, then the similarities in all three sets of data 

 support the hypothesis that the three general fish- 

 ing areas harbor a single stock of white marlin. 



Size data from 1971 through 1977 separated by 

 sex do not reveal any substantial differences 

 among fish in the three areas (Figure 12). Average 

 size has remained fairly stable over the period 

 with females averaging larger than males for all 

 areas. Earlier size data from the recreational 

 fishery, not differentiated by sex, and with the 

 Atlantic and gulf areas combined, suggest that a 

 moderate reduction in average size has occurred 

 since the late 1950's and early 1960's (Figure 13), 

 but that size may have stabilized since 1970. 



Sailfish 



CPUE data for sailfish were separated into 

 three areas (Figure 14). These are the major fish- 



190' 



a 180- 



z 

 w 



5 170- 



o 



I 



ui 



o 



160- 



150- 



• BOTH SEXES COMBINED \ ,.„., . 



07) \ '^°*-H74) 



, (464) y' *^*' 



(438) ^.^ 

 (542) 



FEMALE - ' 



(210) 

 J271>^* 



(128) 



(3,,_(.00)_,84)_(122)„3„ ,,34)^. 

 Air ^» • 



MALE 



— I r 



1955 



— I r 



1960 



1965 

 YEAR 



1970 



1975 



1977 



Figure 13. — Length frequencies of white marlin from the recreational fishery in the western North 

 Atlantic and Gulf of Mexico. The number of specimens measured is shown in parentheses. 



65 



