A plant very prominent in the seep, but not encountered in the transects, was Eriophorum 

 scheuchzeri. This plant was found in patches completely surrounded by soil, tar, or asphalt, and 

 was Especially prominent where the seep tended to entrap water. Large bloom and seed heads 

 were plentiful and the plants were actively spreading by below surface shoots. 



Thaw depths measured on the three transects were greatest near the oil seep and changed 

 abruptly to shallow values between the second and third meters on aU transects. The deep thaw 

 values varied between 55 and more than 85 cm, whereas the shallow values were on the ader of 

 20-25 cm. The change in thaw was coincident with the change in vegetation types. 



Samples of Carex aquatilis from the edge of the seep were compared with plants from the un- 

 disturbed tundra in the vicinity. The plants from the seep were taller, had thicker stems, and were 

 mae advanced in flowering and fruiting. Whether this was just the effect of higher ground temp- 

 eratures around the seep or whether other factors were involved such as the availability of nutrients 

 or the presence of stimulatory chemicals remains to be determined. 



Comparison of soil and seep temperatures at the 10 cm depth revealed that the seeps are 

 warmer by some 3 to 5°C during the day and 1 to 2°C at night. 



The hydrocarbon content in the upper 8 cm of soil was generally insignificant (<0.5 mg oil/g 

 soil) except for one instance in transect 2 (25-40 mg/g). Even when considering the moisture 

 content of the soil and convertii^ the readings to a dry weight basis, the levels are probably too 

 low to cause an inhibition d growth. In fact, levels such as these have been shown to have a 

 stimulatory effect in temperate soils. At these low levels of hydrocarbon content, the presence 

 of oil in the soil probably did not act as an important factor in plant species distribution. 



The interrelationships between the vegetation, temperature effects, and the presence of the 

 various stages of oil seep development are obviously complex. It is probable that a succession 

 in plant type occurs on the seepage areas as the physical characteristics of the asphalt soil 

 change due to oxidation and breakdown of the oil. The stages of succession may progress from the 

 pioneer lichens and mosses to plants such as the Carex community and Eriophorum, and finally 

 to the Arctagrostis community when the soil becomes colder and the thaw shallower as a result 

 of plant cover and seepage inactivity. 



Comparison of water associated with the asphalt deposits at Cape Simpson with that from a 

 typical tundra pond showed some interesting differences in microorganism composition. The former 

 was approximately three orders of magnitude richer in bacteria, fungi, and algae. This would appear 

 to be good circumstantial evidence that microorganisms in situations like Cape Simpson for fairly 

 long periods of time are tolerant of oil and are capable of decomposing it. 



Twelve species of bacteria and yeast from Cape Simpson were cultured on a crude oil-mineral 

 salts medium. These organisms were capable of using hydrocarbons from crude oil as their sole 

 energy and carbon source. The exact components of crude oil used by the bacteria and yeast were 

 not determined. 



Aquatic. Four natural oil seeps in the Cape Simpson area were visited with site investigations 

 concentrating on small ponds associated with twoseeps (seeps B and D). Samples were taken fa 

 pH, alkalinity, and nutrient chemistry, and temperature and conductivity measurements were made. 

 The biological work consisted of "C primary productivity and plankton pigment determinations and 

 qualitative estimates of faunal abundance and diversity. In addition, preserved samples of plank- 

 tonic and benthic organisms were obtained. 



At seep B, three ponds were studied. Pond B-1 is a rather long pond extending along the 

 east margin of the major asphalt flow. Much of the water is in contact with unaltered fresh asphalt 

 a water-asphalt emulsions, and very little floating oil is present in this pond. Pond B-2 is located 

 about 100 m east of B-1 in an area free of any recent oil seeps, although old, completely revegetated 

 flows are adjacent. B-3 is a smaU pond on the west margin of the major asphalt flow, and there 

 is an active although small spill of fresh asphalt into this pond. 



84 



