FISHERY BULLETIN: VOL. 73, NO. 1 



SEPTEMBER SUMMARY 

 HOT SEASON 



SAN CARLOS CREEK 



SEPTEMBER SUMMARY 



MOT SEASON 



NICHOLS CREEK. 



JULY SEPTEMBER SUMMARY 



HOT SEASON 



BROWNS CREEK 



Figure 5. — Biomass per 100 m^ of fishes in the three creeks as estimated from seine collections. Presentation as in Figure 3. 



Figure 5 illustrates the biomass distributions 

 that were computed from the weights of fishes 

 obtained in the samples. The figure shows that the 

 differences in overall standing crops (grams per 

 100 m^) between the creeks conform quite closely 

 to the differences in density described earlier. In 

 June and July the estimated standing crop of total 



fishes in Browns Creek was approximately 2 to 3 

 times greater than that in San Carlos Creek and 

 2.5 times greater than that in Nichols Creek. In 

 September, following the aforementioned emigra- 

 tion of juveniles of many transient species, the 

 estimated standing crop in San Carlos Creek was 

 1.5 times greater than that in Browns Creek. 

 However, even in September, Browns Creek con- 

 tinued to support a standing crop approximately 

 2.5 times greater than that in Nichols Creek. 



Of greater significance than the overall differ- 

 ences in biomass described above, are the marked 

 differences in utilizable species that existed be- 



tween creeks. Throughout the entire collecting 

 period, the biomass of utilizable species (grams 

 per 100 m^) was from four to seven times greater in 

 Browns Creek than in San Carlos Creek and from 

 three to six times greater in Browns Creek than in 

 Nichols Creek. Whereas in Browns Creek the bulk 

 of the biomass was distributed among utilizable 

 species, in San Carlos Creek the bulk of the 

 biomass was distributed among species not 

 utilized by man. In San Carlos Creek, three 

 species of nonutilized fishes (F. grandis, F. 

 heteroclitus , and E. argenteus) accounted collec- 

 tively for 45 to 85% (average 62%) of the total 

 biomass. In Browns Creek these same species ac- 

 counted for only 8 to 16% (average 11.9%) of the 

 total biomass. 



Figure 6 illustrates the biomass distributions 

 among the various utilizable species. In San Car- 

 los Creek, the two species of mullet alone ac- 

 counted for 73 to 97% (average 86.7%) of the 



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