O 



cr 

 o 



o 



UJ 



> 

 -J 

 o 



C/> 

 C/> 



2 



o 



20 - 



10 - 



30 - 



20 - 



10 - 



MID NARRAGANSETT BAY 

 BLACKST0NE 



RIVER (xlO)* /\ 



A 



A* 





\ "\s> 



•g' VXHARLESTOWN^p 



°J& ND 



°£ 



i — i — \ — i — i — i 



OFF 



SUSQUEHANNA / 

 RIVER MOUTH , 



UPPER 



CHESAPEAKE / 

 BAY / 



/ A 



/.a 



T-7-1 — 1 — 1 



/ \ PAMLICO "RIVERS" / \ 



/ \ ' ^ 



Figure 1. Dissolved inorganic nitrogen concentrations over an annual 

 cycle in the fresh, estuarine, and inshore marine waters of three estua- 

 rine systems on the Atlantic coast of the United States. Data from Nixon 

 (unpublished) and Nixon and Lee (in press)for Narragansett Bay; from Whaley 

 et al. (1966) for Chesapeake Bay; and from Harrison and Hobbie (1974) and 

 Thayer (1974) for the Pamlico River and Sound. 



34 



