FISHERY BULLETIN: VOL. 73, NO. 2 



Brachidontti recurvus 

 Macoma balthica 

 Macomc mitchtlli 



Figure 15.-Setting patterns of other 

 bivalves at stations A, B, and D from 

 September 1970 to January 1972. Data 

 combined at deep and shallow sta- 

 tions. 



fall of 1970 was very low, with about 28.32 mVs 

 (1,000 cfs) input in September and October. This 

 low input allowed measurable-salinity water to 

 extend as far upstream as mile 45. Input was high 

 and variable during the winter and early spring of 

 1971. The peak for the 2-yr period of 2,747 mVs 

 (97,000 cfs) was recorded on 1 June 1971. The 

 summer input was fairly low but quite variable 

 and river flow during September and October was 

 considerably higher than the previous fall. The 

 salinity was rarely measurable at station B 



100,000 T 



-^ 10,000 - 



o 



3 



1000- 



throughout the fall and winter months of 1971. 



The annual temperature pattern for station B 

 (Figure 17) is representative of the study area. 

 Within relatively narrow limits, all deep stations 

 exhibited similar temperature profiles. Lowest 

 temperatures were measured during late January 

 and early February, followed by a relatively 

 smooth increase to a maximum of 29°C during 

 early August. A period of stable high tempera- 

 tures was recorded from June through September. 



Dissolved oxygen concentrations in this region 



1970 



Figure 16.— Freshwater input into the James River at 4-day intervals. The data include input from the Appomattox and 



Chickahominy Rivers. 



424 



