relatively high values in Charlotte Harbor at other times (June and early 

 August 19U9 S for instance) were not accompanied by unusual values at Station 

 It in the ship channel. Only in late August 19u9 (September survey) is there 

 a clear case of high concentration in Charlotte Harbor affecting the phosphorus 

 concentration three miles offshore. 



The concentration of organic phosphorus usually exceeded the concentra- 

 tion of inorganic phosphorus except in the Peace River. In this body of 

 water the inorganic phosphorus usually exceeded the organic and represented 

 on the average 70 percent of the total (table 1) . No doubt this condition 

 was due to the release of phosphate from the deposits inland. Some time may 

 have to elapse before the plankton can incorporate this inorganic materia, 

 into the biomass. Perhaps the phosphorus requirements of the phytoplanktc >n are 

 more than fulfilled and some other element becomes the limiting factor for 

 growth* Such a condition might leave a large excess of inorganic phosphorus. 



At the Caloosahatchee River station the mean value for organic phos- 

 phorus exceeded that for inorganic phosphorus (table 1) but there were some 

 instances when the reverse condition obtained (table U) . The unusually high 

 values of total phosphorus occurring in July 19U9 and April 195>0 were due to 

 high values of inorganic phosphorus. 



In Charlotte Harbor the concentration of organic phosphorus usually 

 exceeded that of inorganic but there were several times when the values for 

 inorganic were greater, notably after the hurricane of August 19u9 when 

 large quantities of phosphate were brought down the Peace River. 



At the channel station in the Gulf, three miles offshore, Station k, 

 the concentration o f organic phosphorus exceeded that of inorganic at all 

 times except after the storms of August 19u9. From the latter part of 

 August until October inorganic phosphorus exceeded organic at this station, 

 which is further evidence that the high values were due to excessive amounts 

 of inorganic phosphorus carried down the Peace River. 



At Station 5, fourteen miles offshore, the effects of the outflow from 

 Charlotte Harbor after the 19^9 storms were not evident. At this station and 

 at all stations further from shore the organic phosphorus usually exceeded 

 the inorganic. 



Phosphorus in the Open Gulf 



Station data 



The data for individual stations are presented in table 5>. At Station 

 5>, fourteen miles offshore, the concentration of inorganic phosphorus was 

 always relatively low. The high values of total phosphorus observed at cer- 

 tain times were due to increased amounts of organic phosphorus. 



11 



