1920 Powers; on Condition of Sea-water SIS 



apparent exception to this relation in the first determination made at 

 station L. This determination was made not more than 300 meters 

 from the shore, in reality, in the embayment, when the tide was still going 

 out (see map). The second sample of sea-water was taken 600 meters 

 out and the third 1200 meters out. The condition of the water at the first 

 point was affected perhaps more by the condition of the water of the 

 embayment than that in the open. The water in the embayment close to 

 shore [compare with table 7 determinations for (7/23) made before 

 6:45 A. M.] had a lower oxygen content, which was perhaps due to the 

 time of day and the cloudy weather with rain the night before. Also the 

 drainage from the village of Olga emptied into this embayment, -which 

 would act as a contaminating factor. The high oxygen content of the 

 Sea-water in this portion of the Sound without an accompanying high PH 

 as compared with others is not understood. It might be explained by the 

 fact that the tide was going out to a very low tide, — 1.0 ft., and the 

 surface water was composed, at least partly, of the water that had been 

 bathing the vegetation along the margin of the shore of the embayment 

 which extends back cutting the island almost in two. (See map, page 372.) 

 This can be seen better by referring to a map of the Puget Sound region*. 

 This explanation is in keeping with observations made at the same time in 

 the eel-grass (Zostera marina) in the small embayment near station L. 

 At 10:35 A. M. the water bathing the eel-grass had a pH of 8.35 and an 

 oxygen content of 5.16 cc. per liter. This had a higher pH by 0.05 and a 

 lower oxygen content by 1.48 cc. per liter than open water near by at the 

 same time. At 1 :45 P. M. water bathing the same eel-grass had a pH of 8.4 

 and an oxygen content of 8.72 cc. per liter which was 0.53 pH and 1.39 

 cc. of oxygen per liter higher than water at station L proper. The water 

 bathing the eel-grass showed an increase of 0.05 pH and 3.56 cc. of 

 oxygen per liter in three hours and ten minutes despite the cloudy weather 

 and a light rain. The low pH of the water at station L as compared with 

 the oxygen content might be explained by the presence of accumulated by- 

 products of decaying substances due to the incomplete circulation of the 

 water of the embayment, a condition that is suggested by its physiography. 

 This would also favor the accumulation of oxygen, provided that the 

 excess oxygen produced by the photosynthetic action of the plants would 

 not all be used up by the metabolism of the animal and plant organisms 

 and the decaying organic matter of the embayment. This lower pH could 

 not have been due to the presence of hydrogen sulphide as was found by 

 Palitzsch (1911, 1911a, 1912) to be the case in the deeper water of the 

 Black vSea. The presence of hj'drogen sulphide in the sea-water is an 

 indication of a deficiency of oxygen (McClendon 1917). Palitzsch found 



* See Coast and Geodetic Survey map, Washington Sound. 



