1920 Forcers J on Condition of Sea-zcater 379 



n difference of 0.21 pH and 0.15 cc. of oxygen per liter. The higher 

 temperature, pH, and oxygen content were from water which had just 

 bathed eel-grass near station A and Brown Island. The other current 

 had its source from the main channel north and east of Brown Island. The 

 two samples were taken not more than 10 meters apart. From these 

 observations and also those made at the surface at different regions of 

 the Sound (see table 1), it seems that the water passing into an embay- 

 ment of comparatively deep water reduces the pH but increases the oxygen 

 content of that of tlie open water wlien entering. The pH of the water 

 bathing the vegetation as well as the oxygen content is materially increased 

 during daylight (see table 6) ; but the rise in the pH is completely 

 counteracted, and the oxygen content largely so, by the water of the 

 embayment proper, possibly due to decay taking place at the botton. This 

 is true of water only of the deeper portions of the embayment. Water 

 '■hat has bathed the vegetation along the shallower portions may flow 

 ,)ut of the embayment without mixing with that of the deeper portion and 

 thus still retain its high pH and oxygen content, provided that it is day- 

 light. Evidence which will be given later will show that probably this 

 is not true of water bathing the vegetation during the night. The obser- 

 vations made at station Q as well as those at stations D, A, B, F and Y 

 p.oint to the probability that the water entering the Sound at high tide has 

 a higher pH and a lower oxygen content than when flowing out at low 

 tide. This point needs further investigation. Station Q was not located 

 in the center of the main channel as it was dangerous there at times in a 

 row boat. Tims the water at station Q might have been affected more by 

 tlie water of the embaymcnts than that in the main channel proper. The 

 pH and oxygen content of the ocean water in the vicinity of the Puget 

 Sound region is not known. 



6. HvnROGEX-ION CONrEXTRATIOX OF SEA-WATER OF A SMALL LAGOON 



The lagoon chosen for these observations is located in tlie embayment 

 (station D) near the Biological Station. The connnuiiication with the 

 open water was completely cut off at about half tide. The bottom was 

 niore or less completely covered with Chui. This Viva, however, was 

 often disturbed l)y seining for the \iviparous perch and otherwise, as it 

 was the chosen bathing resort for the children of the village of Friday 

 Harbor. This lagoon without exce])tion showed a high ])H and was 

 supersaturated with oxygen. One determination gave 10.70 ee. of oxygen 

 per liter. No determinations wei-e made during the early hours of the 

 morning, but it is presumed that the pH and oxygen content were mater- 

 ially reduced during the night [see determinations made (7/23), table 7|. 



