FISHERY BULLETIN: VOL. 81, NO. 4 



Table 6. — Monthly summary statistics (mean, standard deviation of mean, and skewness) of king mackerel length data used to 

 compare size composition among gear and results of chi-square comparisons among length frequency distributions. 



Table 7. — Annual summary statistics (mean, standard deviation of mean, and skewness) of king mackerel length data used to 

 compare size composition among gear and results of chi-square comparisons among length frequency distributions. 



SIZE COMPARISONS AMONG 

 YEARS AND AREAS 



The following categories were used to compare size 

 compositions between years: 1) Northwest Florida, 

 recreational hook and line: 1968, 1969, 1977, and 

 1978; 2) south Florida, commercial hook and line: 

 1968, 1969, 1977, and 1978; and3) Texas, Louisiana, 

 and North Carolina, recreational hook and line: 1977 

 and 1978. Monthly data were combined by summing 

 frequencies within length intervals and plotted to 

 yield figures of annual size composition for each 

 category (Figs. 4, 5). 



Size composition varied considerably in northwest 

 Florida between 1968 and 1978 (Fig. 4). Modal 

 lengths decreased from 749 mm in 1968 and 1969 to 

 649 mm in 1977 and 549 mm in 1978. The mean 

 length was over 115 mm, smaller in 1978 than during 

 any of the other three years. During 1978, few fish 

 >700 mm FL were caught, but a large percentage of 

 the fish during each of the other three years was 

 >700 mm FL. 



In south Florida, no large differences in size com- 

 position among years were apparent. Modal lengths 



in the commercial hook-and-line data remained con- 

 stant among years, while mean lengths ranged be- 

 tween 752 and 778 mm. Percents offish above 700 mm 

 FL were high and did not vary greatly among the four 

 years. Size composition could have varied con- 

 siderably in the population, however, and may not 

 have been reflected in the catches owing to gear 

 selectivity. 



In Texas, Louisiana, and North Carolina differences 

 in size composition between 1977 and 1978 were 

 opposite that observed in northwest Florida (Fig. 5). 

 From 1977 to 1978, modal and mean lengths 

 increased in Texas (749-849 and 785-872, respec- 

 tively), Louisiana (949-1,049 and 1,050 - 1,145), and 

 North Carolina (649-849 and 718-850). 



Recreational hook-and-line data from 1977 and 

 1978 were used to compare size composition be- 

 tween the following areas: Texas, Louisiana, northwest 

 Florida, and North Carolina (Fig. 5). South Florida 

 data were compared also but were collected in 

 January-March 1979. The comparisons produced 

 the following results: 1) Texas and North Carolina 

 size compositions were more similar than any other 

 areas; 2) Louisiana catches were composed of much 



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