Several observations on the effects of adding oil to soil samples within the respirometer 

 flasks were made. ; An equilibrium respiration rate was established followed by addition of oil. 

 Control samples showed no significant change in oxygen consumption while respiration in oil- 

 treated soils was stimulated by oil. The proposed explanation for differences in behavior between 

 control and oil-treated areas is that the latter had developed a relatively high microbial population 

 which could decompose oil. 



Preliminary evidence from site 1 suggested that the quantity and quality of microbial biomass 

 was affected by oil treatment. A two- to three-fold increase in bacteria numbers was indicated. 

 On the other hand, organisms such as fungi and algae appeared to be inhibited by oil. 



Aquatic. Study Pond E occupies the eastern half of a subrectangular depressed- center poly- 

 gon about 45 m square. In mid-July the pond was 36 m long (north-south) and 19 m wide (east- 

 west), with a maximum depth of 0.3 m and a mean depth of 0.2 m. The pond's western boundary, 

 which lies at the center of the polygon, is poorly defined and grades through the emergent vegeta- 

 tion into wet tundra meadow. The dominant emergent and surrounding terrestrial vegetation is 

 Carex aquatilis. 



On 16 July 1970, 200 gallons (760 liters) of Prudhoe Bay crude was applied to this small 

 tundra pond at a density of 1.3 liters/m^ or a thickness of 1.3 mm. Several hours after application, 

 the oil was distributed uniformly across the pond. By the following day, driven by the wind, it 

 had accumulated in a 3- to 5-m-wide band against the emergent vegetation on the west margin of 

 the pond. Figure 28 illustrates the accumulation of oil on the margins of the emergent vegetation. 

 A portion of the oil remained in the emergent vegetation on the west side of the pond, but approxi- 

 mately half the oil continued to migrate in response to changes in wind direction through August 

 and early September. The viscosity of the oil increased with time, and it began to adhere to the 

 stems of emergent vegetation in mid-August. Oil penetration into the organic sediments and wet 



finite? >■' 





•^»-r-;-r' 



v"\ -*». .^. ^' --.^ taV .■^^BI^^^• ^- 



Figure 28. Oil treated pond showing accumulation of oil amongst emergent 

 vegetation as a result ot wind action. 



78 



