At Station 59A (about 7 miles from Station ?7.0 on August 9, there 

 was only 0.78 part per million of oxygen at the bottom, representing 

 8.6 per cent of saturation. Thi-s is the only instance of almost complete 

 exhaustion of oxygen which was found in three seasons of investigation 

 in the Island Section. Judging by the temperature data of Station 59A, 

 the layer of water low in oxygen did not exceed 3 meters in depth. 

 Accompanying the oxygen depletion, there was an excess of 7.3 parts per 

 million of free carbon dioxide. This pH was 7.3. Since there was a 

 marked temperature gradient at Station 37A on August 9, it is reasonable 

 to suppose that the partial depletion of oxygen noted on Aut;ust 5 had 

 become more pronounced by August 9, perhaps as much so as at Station 59A 

 on the same date. It is probable that the v/ater was mixed completely 

 on August 10 and 11 because the winds were rather brisk on those two 

 dates . 



Free carbon dioxide at the surface of Station 37A ranged from 

 +3.0 to -2.2 parts per million. In the period April-July there was an 

 excess of the gas on six of the eight dates. In August and September 

 the samples showed a deficiency of carbon dioxide. Judging by the pH 

 on October 2, there vras a deficiency on that date also. At the bottom 

 there was an excess on all dates until August 23; on that date and 

 thereafter there was a deficiency. On September 6 and 19, the deficit 

 at the bottom v.'as greater than at the surface. The largest amount of 

 free carbon dioxide at the bottom was +5.7 parts per million, on 

 June 20. A possible relationship with the phytoplankton is seen in the 

 rather large excess of the gas at the surface on July 2, following the 

 decline of plankton. Also the greatest deficie.icy of the gas was observed 

 on September 19, when plankton was abundant. 



Dissolved oxygen in the surface vjater ranged from 8.1 to 12.6 parts 

 per million, and the water was never less than 89 per cent saturated. In 

 one case it was supersaturated. There is little or no evidence of a re- 

 lationship between the amount of oxygen and the abundance of phytoplankton. 

 On May 7, before the plankton has increased greatly, (Fig. lij) the surface water was 



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