168 



STATION 31 



d 60000-' RIVER DISCHARGE 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



STATION 32 



40,000- 

 20,000- 



cn 



UJ 



I 10. OH 

 o 



? 



30,0- 

 " 20.0 H 



20.00 



o 



J? 10.00- 

 



.....ll.llll 



PRECIPITATION 

  .■■.lllllll 





50.0 

 40 0- 

 30 

 20.0 



60.0 

 40.0- 

 20 0- 

 0- 

 12.0- 

 8.0- 

 4.0-1 

 



WATER TEMPERATURE 



SALINITY 



INORGANIC PO4 P 

 E € E E L J 



TOTAL PO4 P 



NO3 NOg N 



^ M 



LlI. 



0.30-| COPPER 



020- S 



0.10- _ _ B 



0-' 



I I I I I I I I I I I I I I I 

 ONDJFMAMJJASOND 

 1958 1959 



ll.llll 



i.llllll.^ 



feE^igEhlllllll 



I I I I I I I I I I I I I I I 



OND JFMAMJJASOND 

 1958 1959 



SURFACE — I 

 BOTTOM — I 



Figure 4. — River discharge, preeipitatton, and hydrological properties of Alalia River, Florida, October 1958-December 



1959. 



Concentrations of total phosphorus in the Little 

 Manatee River were in turn higher than in the 

 Manatee River, which shoM'ed higher concentra- 

 tions downstream, with little difference between 

 surface and bottom values (fig. 5) . 



The lowest concentrations of total phosphorus 

 were obsei-ved in the Hillsboi'ough River. In this 

 river the vertical distribution of total phosphorus 

 for the entire period showed liigher values near 

 the bottom whenever bottom salinity values were 

 above normal (table 1). In March an increase in 

 surface concentrations of total phosphorus and 

 vertical homogeneity was evident. The surface 

 and bottom total phosphorus concentrations re- 



mained variably high until the reappearance of 

 stratified conditions in November. The distribu- 

 tion of total phosphorus at upstream station 30 

 was somewhat similar to that of station 29, but 

 with greater vertical homogeneity (fig. 3). 



The spatial and temporal distribution pattern 

 of inorganic phosphate-phosphorus in the rivers 

 was essentially the same as that of total phosphate- 

 phosphorus (figs. 3, 4, 5, and 6). The mean in- 

 organic phosphate values for the individual rivers 

 represented 77 to 95 percent of the total. Organic 

 phosphorus exceeded inorganic on only one oc- 

 casion, at station 29 during September at the 

 period of maximum discharges. Unusually high 



