Inorganic phosphate was lowest In Section II and highest In Section V. 

 Total phosphate was highest in Section II and lowest in Section I. Chloro- 

 phyll A was lowest in Section I, slightly higher in Section II, and there- 

 after increasing, with the highest values observed in Section V. The data 

 on photosynthetic rate indicates the lowest levels to occur in Section II 

 and the highest in Section V. Water turbidity was greatest in Section II 

 and lowest in Section V. 



DISCUSSION 



General 



A major objective was to determine the contribution of oxygen from 

 phytoplankton photdsynthesls to the water of Grays Harbor. The data 

 indicate lowest oxygen values and lowest photosynthetic rates both occur 

 in Section II. Therefore the data were closely examined to determine the 

 reason for the lack of photosynthesis in this area. The chlorophyll data 

 shows that some plankton is present in Section II but the low photosynthetic 

 rate and the low assimilation numbers indicate that the phytoplankton 

 present, if alive, are not photosyntheslzing. The data also demonstrate 

 that water turbidity is quite high in Section II, inorganic phosphate is 

 quite low, and organic phosphorus is high. The highest photosynthetic rate 

 occurred when the Secchl disc values (light penetration) were greatest 

 (Trip 8) and lowest photosynthetic rate occurred when Secchi disc values 

 were lowest (the higher the value the clearer the water) . The magnitude of 

 the differences in the Secchi disc observations, however, is not great. Of 

 the above, information relative to phosphate and water turbidity seem par- 

 ticularly important. 



Inorganic phosphate is needed for primary productivity, and, in general, 

 particulate organic phosphorus is not immediately available for primary 

 productivity. Turbidity of the water decreases light penetration and causes 

 a corresponding decrease in the photosynthetic rate. 



To evaluate the findings in Grays Harbor from a different point of view, 

 comparisons were made with similar data from Wlllapa Bay. Wlllapa Bay is 

 similar to Grays Harbor in many respects. It is located on the coast of 

 Washington immediately south of Grays Harbor. Surface area is about 100 miles 

 and the bay is generally shallow with a majority of the bottom exposed at 

 low tide. The Department of Fisheries has been carrying on a major hydro- 



