Penaeus setiferus 



FALL 



NSOI NS04 NS07 NSII SSOI SS04 SS07 SSI 



UJ " 



o 



z 



< cr 



LHHr - ^ ih y k 



r 



2.0 

 1.0- 



WINTER 





< 



NSOI NS04 



Urn 1_U 



NS07 NSII 

 (_ 1 



SSOI 



SS04 SS07 



SSII 



_ o 









"■ 





g 



m io- 



NSOI NS04 NS07 NSII SSOI SS04 SSOT SSII 



i^ * - 5 1 [f - 



D 1975 



■ 19^6 



~i i " i ' i i i i i i i i i PT i r 



10 30 50 70 90 110 130 150 



TOTAL LENGTH (mm) 



Figure 7.— Seasonal abundance and length-frequency distribution of Penaeus setiferus within the North and South Sanlee Rivers. Ratios over the bars indicate number of col- 

 lections where shrimp were captured to total number of collections at a station. 



Biomass Estimates 



The estimated biomass, expressed in kg/ha, for fishes from 

 the North and South Santee Rivers was lower than biomass 

 estimates reported for other estuarine systems along the Gulf 

 and east coasts of the United States (Table 5). Greatest biomass 

 was obtained for northern temperate estuaries such as Nar- 



ragansett Bay, R.I. (Oviatt and Nixon 1973), and Mystic River, 

 Mass. (Haedrich and Haedrich 1947), while the number of fish 

 per hectare was comparable between these northern estuaries 

 and those in South Carolina. The reliability of our biomass 

 estimates is confirmed by the identical value (3.8 kg/ha) obtain- 

 ed by Shealy et al. (1974) in other South Carolina estu- 

 aries. 



Table 5. — Estimates of density and number of individuals/hectare for fishes caught by trawls from estuaries along the Gulf 



and east coasts of the United Slates. 



Geographic area 



Biomass Density 

 (kg/ha) (no./ha) 



Gear 



Reference 



Mystic River, Mass. 



26.16 



Narragansett Bay. R.I. 



31.68 



North Santee River. S.C. 



3.9 



South Santee River, S.C. 



3.8 



Cooper River — Charleston 





Harbor and Edisto system, S.C. 



3.8 



Doboy Sound, Ga. 



10.7 



GaJveston Bay, Tex. 



16.57 



462 4.8 m semiballoon trawl 



290 9.2 m balloon trawl 



287 6 m semiballoon trawl 



303 6 m semiballoon trawl 



Haedrich and Haedrich (1974) 

 Oviatt and Nixon (1973) 

 present study 

 present study 



433 6 m semiballoon trawl Shealy et al. (1974) 



4,190 12.2 m balloon shrimp trawl Hoese (1973) 

 8,511 3 m otter trawl Bechtel and Copeland (1970) 



12 



