The cruise data are presented according to 

 the method suggested by Montgomery (1954). 

 Three diagrams are used for each cruise 

 (figs. 2-13). The diagrams illustrate the fields 

 of temperature, dissolved oxygen and total 

 phosphorus superimposed upon salinity. Salin- 

 ity was chosen as the base field because of its 

 relative stability, in comparison with other 

 variables, in tidal estuaries. Each diagram 

 contains three longitudinal sections along the 

 axes of the major passage systems. These 

 are Mt. Hope Bay and the Sakonnet River, the 

 Providence River and East Passage, and 

 Greenwich Bay and West Passage. The vertical 

 arrows show the interconnections between 

 passages. They point in the direction of the 

 net nontidal drift. 



The field of salinity was drawn first for 

 each cruise. The fields of temperature, dis- 

 solved oxygen, and total phosphorus were then 

 drawn upon the salinity field. All observed 

 value points were included in the construction 

 of the contours. The contours however were 

 drawn to conform, whenever possible, to the 

 pattern of the underlying salinity distribution. 



Summarizing generalizations of each vari- 

 able are presented in tables 1-4. 



Stations were also made at the end of the 

 Narragansett Marine Laboratory pier during 

 the period, February 1957-February 1958. 

 Temperature measurements (using a reversing 

 thermometer and frame) and water samples 

 were obtained from the surface and bottom 

 at weekly intervals. The water samples were 

 collected with a Kemmerer bottle and analyzed 

 for their dissolved oxygen, chlorinity, and 

 total phosphorus contents as described above. 

 The results of this series are graphed in 

 figure 14. 



Study was financially supported by the U.S. 

 Fish and Wildlife Service and the U.S. Army 

 Corps of Engineers. Oscar W. Moreau of the 

 Branch of River Basin Studies, Fish and 

 Wildlife Service prepared the finished sec- 

 tional diagrams. I wish to express my ap- 

 preciation to Russell T. Norris and the 

 members of the Fishery Advisory Committee 

 (Narragansett Bay Hurricane Barrier Re- 

 search Program) for their encouragement and 

 advice. 



Table 1. --Seasonal salinity trends and ranges 



General surface tend- Winter Spring Summer Autumn 



ency from heads to 

 entrances Increase Increase Increase Increase 



General surface 

 range (°/oo) 



General bottom tend- 

 ency from heads 

 to entrances 



24.5-32.0 20.5-31.5 29.5-32.5 29.0-32.5 



Increase 



Increase Increase Increase 



General bottom, 

 range (°/oo) 



Uniform horizontal 

 gradient 



General tendency 

 from surface 

 to bottom 



29.0-32.5 27.0-32.0 31.0-32.0 30.5-32.5 



No 



Increase 



Yes 



Yes 



Increase Increase 



Yes 



Increase 



Vertical 



stratification Moderate 



Station no. 11 (77 ft. ) 2.2 °/oo 



Intense Light 



6.3°/oo 1.0°/oo 



Light 

 to none 

 0.1 °/oo 



