c/EPA
United States
Environmental Protection
Agency
Environmental Research
Laboratory
Corvallis OR 9^330
EPA-600 3-80-040
March 1980
Research and Development
The Fate and
Effects of Crude Oil
Spilled on Subarctic
Permafrost Terrain in
Interior Alaska
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special'1 Reports
9. Miscellaneous Reports
This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal spe-
cies, and materials. Problems are assessed for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine the fate of pollutants and their effects. This work provides the technical basis
for setting standards to minimize undesirable changes in living organisms in the
aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
EPA-600/3-80-040
March 19,80
THE FATE AND EFFECT OF CRUDE OIL
SPILLED ON SUBARCTIC PERMAFROST TERRAIN
IN INTERIOR ALASKA
by
L. A. Johnson, E. B. Sparrow, T. F. Jenkins, C. M. Collins
C. V. Davenport and T. T. McFadden
Alaskan Projects Office
U.S. Army Cold Regions and Engineering Laboratory
Fairbanks, Alaska 99703
Grant Number EPA-IAF-D7-0794
Project Officer
Ronald Gordon
Corvallis Environmental Research Laboratory
Con/all is, Oregon 97330
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CORVALLIS, OREGON 97330
-------
DISCLAIMER
This report has been reviewed by Corvallis Environmental Research
Laboratory, U. S. Environmental Protection Agency, and approved for
publication. Approval does not signify that the contents necessarily
reflect the views- and policies of the U. S. Environmental Protection
Agency, nor does mention of trade names or commercial products constitute
endorsement or recommendation for use.
ii
-------
FOREWORD
Effective regulatory and enforcement actions by the Environmental
Protection Agency would be virtually impossible without sound scientific data on
pollutants and their impact on environmental stability and human health.
Responsibility for building this data base has been assigned to EPA's Office of
Research and Development and its 15 major field installations, one of which is
the Corvallis Environmental Research Laboratory.
The primary mission of the Corvallis Laboratory is research on the effects
of environmental pollutants on terrestrial, freshwater and marine ecosystems;
the behavior, effects and control of pollutants in lakes and streams; and the
development of predictive models on the movement of pollutants in the biosphere.
This publication reports results of a study to determine the effects of
crude oil spills on permafrost terrain in subarctic interior Alaska.
Thomas A. Murphy, Director
Con/all is Environmental Research Laboratory
iii
-------
Abstract
This study was conducted to determine both the short and long-term
effects of spills of hot Prudhoe Bay crude oil on permafrost terrain in
subarctic interior Alaska. Two experimental oil spills of 7570 liters
(2000 gallons) each on 500 m2 test plots were made at a forest site under-
lain by permafrost near Fairbanks, Alaska. The oil spills, one in
winter and one in summer, were conducted to evaluate their effect during
these two seasonal extremes. Oil movement, thermal regime, botanical
effects, microbiological responses, permafrost impact, and composition
of the oil in the soil were monitored for two years.
The results indicate that oil movement during the winter spill
occurred within the surface moss layer beneath the snow. In the summer
spill, movement of the oil was primarily below the moss in the organic
soil. The oil movement in the summer spill was more rapid, moving 30 m
downslope in the first 24 hours and 41 m total through the summer. The
oil in the winter spill moved only 18 m downslope in the first day and
stopped. Remobilization occurred in the spring allowing the oil in the
winter spill to move an additional 17 m. The total area affected by the
summer spill was nearly one and one-half times as large as the winter
spill (303 m2 vs 188 m2 or 40 m2/m3 of oil vs 24 m2/nPof oil).
The heat of the initial spilled oil had little measureable effect
on the underlying frozen soil at the time of the winter spill or on the
depth of thaw in the summer spill. However, significant changes in
depth of thaw occurred following two full thaw seasons. The greatest
increases in thaw depths occurred in areas where the surface was black-
ened by oil.
Chemical studies have shown that evaporation of volatile components
is the most significant natural weathering process in the first two
years. C^ and C-2 components were lost from surface oil in the first 24
hours with only small concentrations of components smaller than Cg
present after five months. There was somewhat slower evaporation of
volatiles from oil carried deeper in the soil profile. Changes in
composition usually attributable to microbial degradation have not been
observed.
The indigenous soil microbial populations responded differently to
winter and summer oil applications. The responses ranged from inhibition
to stimulation, with stimulation of growth and activity appearing to
predominate.
Vegetation showed both immediate and long term damage effects from
the oil. Damage was greatest near the top of the slope and in surface oil
blackened areas. Deciduous species showed damage more rapidly than
evergreen species. Additional black spruce died up to two years after
the spills.
This report was submitted in fulfillment of grant number EPA-IAF-D7-
0794 under the sponsorship of the U.S. Environmental Protection Agency.
This report covers a period from 1975 to 1978 and work was completed as of
October 1979.
iv
-------
TABLE OF CONTENTS
Page
Abstract iv
List of Tables vi
List of Figures viii
Summary xl
Introduction 1
Methods
Site Description 2
Oil Application 4
Physical Characterization 5
Thermal Characterization 7
Oil and Oily Soil Characterization 7
Soil Microbiological Methodology 9
Vegetation 12
Results and Discussion
Oil Movement 13
Effects on Permafrost 19
Compositional Changes 22
Microbiological Responses 36
Oil Effects on Vegetation 63
Conclusions 74
Recommendations 76
Literature Cited 78
Appendices 85
-------
LIST OF TABLES
Page
1. AVERAGE THAW DEPTH (CM) 21
2. INITIAL CHARACTERISTICS OF PRUDHOE BAY CRUDE OIL USED IN
STUDY 23
3. LOSS OF VOLATILES FROM SPILL PLOTS 25
4. ALKANE/AROMATIC AND PRISTANE/n-C17 RATIOS FOR TOPPED SOIL
EXTRACTS (CARIBOU-POKER CREEK AREA SPILLS) 31
5. ALKANE/AROMATIC AND PRISTANE/n-C.., RATIOS FOR SAMPLES FROM
OTHER ALASKAN SPILLS 33
6. ANALYSES OF SAMPLES COLLECTED IN JULY 1978 35
7. 1976 HETEROTROPHIC BACTERIAL COUNTS (X 106/g SOIL) IN
OILED AND UNOILED (CONTROL) PLOTS 37
8. 1977 HETEROTROPHIC BACTERIAL COUNTS (X 106/g SOIL) IN
OILED AND UNOILED (CONTROL) PLOTS 37
9. 1978 HETEROTROPHIC BACTERIAL COUNTS (X 106/g SOIL) IN
OILED AND UNOILED (CONTROL PLOTS) 38
0. 1976 FILAMENTOUS FUNGAL PROPAGULE COUNTS (X 10 /g SOIL)
IN OILED AND UNOILED (CONTROL) PLOTS 39
1. 1977 FILAMENTOUS FUNGAL PROPAGULE COUNTS (X 104/g SOIL)
IN OILED AND UNOILED (CONTROL) PLOTS 39
2. 1978 FILAMENTOUS FUNGAL PROPAGULE COUNTS (X 104/g SOIL)
IN OILED AND UNOILED (CONTROL) PLOTS 40
3. 1976 YEAST COUNTS (X 105/g SOIL) IN OILED AND UNOILED
(CONTROL) PLOTS 40
4. 1977 YEAST COUNTS (X 105/g SOIL) IN OILED AND UNOILED
(CONTROL) PLOTS 41
5. 1978 YEAST COUNTS (X 105/g SOIL) IN OILED AND UNOILED
(CONTROL) PLOTS 41
6. 1976 COUNTS (X 105/g SOIL) OF PROTEOLYTIC BACTERIA IN
OILED AND UNOILED (CONTROL) PLOTS 42
VI
-------
Page
17. 1976 COUNTS (X 105/g SOIL) OF ANAEROBIC BACTERIA IN OILED
AND UNOILED (CONTROL) PLOTS 43
18. 1976 IN VITRO SOIL RESPIRATION RATES (mg CO /24 HR/100 g
SOIL) IN OILED AND UNOILED (CONTROL) PLOTS 57
19. 1977 AND 1978 IN VITRO SOIL RESPIRATION RATES (mg C02/24
HR/100 g SOIL) IN OILED AND UNOILED (CONTROL) PLOTS. ... 57
20. 1976 IN SITU SOIL RESPIRATION (g CO /24 HR/m2) IN OILED
AND UNOILED (CONTROL) PLOTS 58
21. 1976 SOIL WATER CONTENT (%) IN OIL AND UNOILED (CONTROL)
PLOTS 58
22. 1977 AND 1978 SOIL WATER CONTENT (%) IN OILED AND UNOILED
(CONTROL) PLOTS 59
23. OIL CONTENT (%) IN SOIL 5 m DOWNSLOPE FROM POINT OF OIL
APPLICATION 60
24. NUTRIENT CONTENT OF BLACK SPRUCE FOLIAGE 67
25. MORTALITY OF BLACK SPRUCE 68
26. PRE-(1976 AND 1977) AND POST (1978) VEGETATION ANALYSTS
(AVE % CHANGE) 69
27. RESPIRATION OF ECTOTROPHIC MYCORRHIZAL FEEDER ROOTS. ... 73
vii
-------
List of Figures
Page
1. Location of oil spill site near Fairbanks, Alaska 3
2. View looking downslope prior to oil application on summer
spill plot 4
3. Typical profile of Saulich soil at Caribou-Poker Creek
spill sites 5
4. Oil being spilled along a 5 m length of perforated pipe
at winter spill plot 6
5. Following oil flow downslope on the summer plot by visually
inspecting wooden dowels 6
6. One meter square quadrat used for sampling vegetation. . . 12
7. Snow melting near the header during hot crude oil application
on the winter plot 13
8. Downslope movement of oil follow spillage 15
9. Surface and subsurface oiled areas 16
10. Vertical penetration of oil into soil profile 18
11. Cross section thaw depths in 1977 and 1978 at 3 meters
downslope of oil applications 20
12. Gas chromatogram of the crude oil used for the Caribou-Poker
spills obtained on a Dexsil Scot column 23
13. Headspace chromatograms of oil taken from the pool on the
winter spill plot 26
14. Headspace chromatogram of oily soil from the winter spill
plot, 17 months after spillage 27
15. Headspace chromatogram of oily soil from the summer plot,
12 months after spillage 28
16. Headspace chromatogram of oil soil from the Prudhoe Bay
spill site, 12 months after spillage 29
17. Chromatograms of oil extracted from soil taken from
several Alaskan oil spill sites 34
Vlll
-------
Page
18. 1976 MPN counts of denitrifying bacteria in oiled and
unoiled (control) plots 44
19. 1977 MPN counts of denitrifying bacteria in oiled and
unoiled (control) plots 45
20. 1978 MPN counts of denitrifying bacteria in oiled and
unoiled (control) plots 46
21. 1976 MPN counts of cellulose-utilizing bacteria in
oiled and unoiled (control) plots 47
22. 1976 MPN counts of cellulose-utilizing fungi in oiled
and unoiled (control) plots 48
23. 1976 MPN of oil-utilizing bacteria in oiled and unoiled
(control) plots 49
24. 1976 MPN counts of oil-utilizing yeasts in oiled and
unoiled (control) plots 50
25. 1977 and 1978 MPN counts of oil-utilizing bacteria in
oiled and unoiled (control) plots 51
26. 1977 and 1978 MPN counts of oil-utilizing yeasts in oiled
and unoiled (control) plots 52
27. 1976 MPN counts of oil-utilizing filamentous fungi in
oiled and unoiled (control) plots 54
28. 1977 and 1978 MPN counts of oil-utilizing filamentous
fungi in oiled and unoiled (control) plots 55
29. Respiration in situ in oiled and unoiled (control) plots
in 1977 56
30. Cottongrass tussocks growing despite being surrounded by
surface oil and dead moss and lichens 64
31. Soil pit for determining rooting habits and belowground
oil movement
32. Cottongrass (Eriophorum vaginatum) roots growing through
oil soaked soil 66
33. Steele Creek oil spill along the trans-Alaska Pipeline
system
34. Flowchart representing the observed effects of a massive
crude oil spill on a subarctic permafrost site 75
IX
-------
Acknowledgements:
The authors wish to acknowledge the assistance of the following
persons:
Dr. Fred Deneke, U.S. Forest Service, St. Paul Minnesota., for his
guidance and consultation in experimental design of vegetation studies;
Dr. Brent McCown, Institute for Environmental Studies, University
of Wisconsin, Madison, for his review and critique of vegetation studies
and his review of this report;
Dr. Charles Slaughter, Institute of Northern Forestry, Fairbanks,
Alaska, for his help in project initiation, planning and preliminary
site work;
Dr. Arthur Linkins, Department of Biology, Virginia Polytechnic
Institute, for his assistance in providing data on root respiration;
Mrs. Elinor Huke and members of the USACRREL drafting group, under
the supervision of Mr. Ed Perkins, for preparation of illustrations
used in this report;
Dr. Ronald Gordon, Arctic Environmental Research Station, for his
consultation on and critique of the microbiological studies and his
review of this report;
Mr. Paul Sellmann, USA CRREL, for his review of this report;
Mr. Daniel Leggett, USA CRREL, for his help in sampling the winter
spill and his review of this report;
Ms. Ellen Foley and Ms. Helen Hare, both of USA CRREL, for their
technical support in analytical chemical determinations;
Mrs. Ruth McFadden, Ms. Joan Forshaug and Mr. Robert Jackson, for-
merly of USEPA, for technical support of the microbiological studies.
x
-------
SUMMARY
In February and July, 1976, two experimental 757CH (2000 gal) oil
spills of hot Prudhoe Bay crude were conducted in subarctic interior
Alaska in the Caribou-Poker Creeks Research Watershed. The following
types of information were obtained during the subsequent three year
study:
1. The movement of the oil downslope with time
2. The movement and current presence of oil in the soil profile
3. The change in oil composition with time after spillage
4. The responses of various soil microbiological populations
5. The botanical effects of oil contamination
The following results and conclusions were obtained.
1) There are distinct differences in the effects of a winter oil spill
and a summer oil spill.
2) In both winter and summer spills, oil flowed downslope following
the microtopography of the site for distances of 35 and 41.5 m, respec-
tively. The total area impacted by the summer spill was nearly one and
one half times as large as the winter spill (303 m2 vs 188 m2). Down-
slope movement in the summer spill was primarily in the organic soil.
In the winter spill, initial movement occurred beneath the snow, over
and through the moss layer, resulting in a much larger area of surface
flow (76.3 m2), relative to the summer spill (30.3 m2), respectively.
Oil movement stopped after one day in the winter spill. The oil then
remained immobilized until snow melt when it moved further downslope,
this time generally in the organic soil.
3) The total area impacted by these spills was surprisingly small
primarily due to the ability of the thick moss layer and organic soil to
absorb large quantities of oil. In addition, evaporation of volatiles
reduced the volume and mobility of the oil. The average oil content in
the impacted areas for the winter and summer spills was 41 and 25 1/m2,
respectively (or 24 and 40 m^/m^ of oil).
4) The location of oil in the soil profile differed in the two spills.
In the upslope portion of the winter spill plot, the oil resides primarily
in the moss and organic soil. Further downslope, where movement occurred
after spring breakup, the oil resides primarily in the organic soil. In
the upslope portion of the summer spill, most of the oil is in the
organic soil, but oil has penetrated as deep as 8 cm into the mineral
soil. In areas further downslope in the summer spill, the oil is pres-
ent in a narrow band in the organic soil.
xi
-------
5) The initial heat input of the hot crude oil did not significantly
affect either the frozen soil surface in the winter spill or the depth
of thaw in the summer spill.
6) After two full thaw seasons, increased depths of thaw have been
observed in the oiled area, with the greatest thaw below visibly oiled
(blackened) surface areas. If this trend continues, thermokarsting and
reduction in slope stability could result.
7) Compositional change in the spilled crude oil during the first two
years is primarily a result of evaporation of volatiles. No observable
translocation of water soluble components was found below the area of
physical oil movement. The type of oil degradation usually attributed
to microbial activity was not observed in the first two years after
spillage.
8) The oil will probably remain largely intact for long periods in the
soil unless some measures are used to accelerate oil degradation.
9) During the first growing season after the winter spill, the fila-
mentous fungal population was inhibited whereas the heterotrophic
bacterial population was stimulated. After the summer spill, a brief
initial depression of both the filamentous fungal and bacterial popula-
tions occurred but was followed by a general enhancement. In both oil
spill plots, denitrifying, proteolytic, oil-utilizing and cellulose-
utilizing microorganisms (including yeasts) were favorably affected by the
oil spills.
10) During the second and third growing seasons following the oil
spills, the filamentous fungal populations were inhibited in both oiled
plots. Inhibition was greater in the winter than in the summer plot.
The heterotrophic bacteria and yeasts were stimulated in both oiled
plots, with greater stimulation in the summer plot. Numbers of denitri-
fying bacteria, oil-utilizing bacteria and oil-utilizing yeasts in the
oiled plots remained elevated.
11) After an initial decrease 24 hours after the oil spills, in vitro
soil respiration generally increased in both oiled plots relative to the
control for the duration of the study. Soil respiration in situ* in-
creased in the oiled plots only in areas where plants killed by the oil
were not removed. This indicates that the increased substrate from
dead plant material is at least partially responsible for the increased
soil respiration.
12) The effects of crude oil on indigenous soil microbial populations
and their activities appear to be both direct and indirect. The fila-
mentous fungal population may be inhibited by toxic crude oil components
and reduced aeration while other microbial populations and in vitro**
* In place, on site
** In the laboratory
xii
-------
soil respiration may be stimulated by the addition of carbon substrate
in the oil and in plants damaged or killed by the oil.
13) Vegetation mortality was highest within areas of surface flows in
the upslope portions of the plots. Damage to vegetation was delayed and
reduced in areas which were both further downslope and impacted by
subsurface flows.
14) In general, deciduous species showed the most rapid injury.
Evergreen species displayed more delayed symptoms. Injuries have con-
tinued to appear up to the present with additional mortality of black
spruce in the winter spill site through the third growing season.
15) Rooting characteristics, as well as above ground growth form, signi-
ficantly influence sensitivity to the oil. Cottongrass tussocks, with
their vertical rooting habit, appear to be the most oil resistant species
on this site.
16) There is no evidence of recovery by vegetation in areas of surface
flows in these spills. Other crude oil spills in Alaska have shown some
vegetative recovery within the same time frame, possibly because of
greater soil moisture.
17) Because of the complex interactions of the effects of crude oil
spills, a variety of scientific disciplines is necessary to assess
environmental impact.
xiii
-------
INTRODUCTION
During the last 15 years, oil exploration and development, spurred
on by increasing demand for oil and declining petroleum reserves in
temperate regions, has been increasing in the Arctic and Subarctic.
One large pipeline for transporting crude oil, the Trans-Alaskan Pipeline
System (TAPS), was completed in 1977 and other smaller ones have been
constructed in Canada and the Soviet Union. These projects have resulted
in spills of crude oil and the inevitability of more spills remains.
Regulatory agencies and scientists became interested in ascer-
taining the environmental effects of petroleum spills as soon as develop-
ment of petroleum reserves began in the northern regions. In the early
seventies a number of small scale studies were begun to document the
effects of spills, (Deneke e^ ^1., 1975; Hutchinson et al., 1974) while
other studies examined biological recovery after spills (Hunt, 1972;
Cook and Westlake, 1974; McGill, 1977). Other individuals recorded the
effects of refined petroleum spills along a military pipeline in Alaska
(Deneke jet a^. , 1975; Rickard and Deneke, 1972; Hunt et_ al_., 1973).
However, before 1975 only one study, in the Mackenzie Valley of Canada,
had attempted to experimentally determine the effects of larger petroleum
spills (MacKay et_ _aJL. , 1974; Hutchinson jet _ajl., 1974; Cook and Westlake,
1974). Recently a collection of articles summarizing past and ongoing
oil spill research in Alaska, including interim reports of the research
presented here, have been published (Arctic 31(3), 1978).
In 1975 the Alaskan Projects Office of the U. S. Army Cold Regions
Research and Engineering Laboratory (USACRREL) received funding from the
U. S. Environmental Protection Agency, Arctic Environmental Research
Station, to study the fate and effects of crude oil spilled on perma-
frost terrain. This study was specifically designed to simulate the
size and location of an actual crude oil spill from a functioning pipeline.
An open black spruce stand, representative of interior subarctic Alaska,
was selected in the Caribou-Poker Creeks Research Watershed. Two spill
plots were designated and 7570 £ (2000 gal) of hot (57°C) Prudhoe Bay
crude oil were applied to each. The spills, one in winter and one in
summer, were conducted in order to assess differences in behavior and
impact of the crude oil at the two temperature extremes of the subarctic
climate.
There were four overall objectives of the study:
1) to document the physical effects of crude oil spills on black
spruce forest, in the interior of Alaska, emphasizing the mode of trans-
port, area of impact with time, and effects on the underlying permafrost;
2) to determine the fate of petroleum, once spilled in subarctic
terrestrial environments;
-------
3) to evaluate the effect of crude oil spills on soil microbial popu-
lations and their activities;
4) to evaluate the effects of crude oil spills on vegetation.
In order to meet these multidisciplinary objectives the following
personnel were engaged on the project:
1. Geologist: to determine the physical extent of oil spread and
thermal effects on underlying permafrost (Charles Collins);
2. Engineer: to determine the factors influencing the thermal regime
of the soil and design of spill systems (Terry McFadden);
3. Chemist: to determine the changes in the chemical composition
of the petroleum over time and over the extent of the spill
(Thomas Jenkins);
4. Microbiologist: to determine the response of soil microbial
populations to winter and summer oil spills (Elena Sparrow and
Charlotte Davenport);
5. Botanist: to determine the effects of the crude oil upon the
existing vegetation species and the extent of their recovery
(Larry Johnson).
METHODS
Site Description
The study site lies in the lower reaches of the Caribou-Poker
Creeks Research Watershed, 48 km north-east of Fairbanks, Alaska (Fig.
1). The site is about 300 m above sea level and situated on a moderate
(7-8%) west-facing slope. Two study plots, each 10 m by 50 m with the
long axis downslope, were established for oil application. Control
areas were designated nearby. The closest stream is Poker Creek, 800 m
downslope of the site. An abandoned water diversion ditch lies between
the study site and Poker Creek, guarding against inadvertent oil con-
tamination.
The study site is an open black spruce (Picea mariana (Mill.)
Britt, Stearns & Pogg.) stand (Fig. 2) with a shrub understory of
Labrador tea (Ledum decumbens (Ait.) Hult.) and Ledum groenlandicum
((Oeder) Hult.), resin birch (Betula glandulosa Michx.), and blueberry
(Vaccinium uligonosum L.). A few scattered willows (Salix spp.) occur
in the area. Mosses and lichens cover 50% or more of the ground surface
and various herbs can be found. Cottongrass tussocks (Eriophorum
vaginatum L.) have scattered distribution but are of local importance
(Troth et al., 1975).
-------
65°I5'-
65°00'
Fairbonks \
ALASKA I
0 5 10 15
I 'i' 'i ' i1ii '
20km.
lOmi.
~ Caribou-Poker Cr.
Watershed-
OIL SPILL STUDY AREA
148
Fairbanks' 24km(l5mi)
I47»
Figure 1. Location of oil spill site near Fairbanks, Alaska.
Elevated crosswalks were installed at 5 m intervals across the
treatment plots to allow direct access to the entire surface of the
plots with minimum disturbance from surface trampling (Fig. 2) .
The soil on the site is typical of the Saulich series found in the
lower slopes of the watershed (Rieger et al. , 1972) . A typical profile
consists of 25 to 5 cm of moss (0,), 8 to 0 cm of reddish-brown peat
0 to 8 cm of brown mixed organic and silt loam (A}) and greyish
silt loam extending to permafrost (2) (Fig. 3). The soil, a histic
pergelic cryaquept, is poorly drained with an active layer depth of
15 cm to 50 cm depending on the thickness of the organic mat and proxi-
mity to shrubs and trees. The pH of both the organic and mineral soils
is acidic, generally about pH 4 (Troth et_ a^. , 1975; Rieger et al. ,
1972).
-------
Figure 2. View looking downslope prior to oil application on summer
spill plot (note elevated crosswalks installed for access
to plot).
Oil Application
The crude oil for the study was obtained from Prudhoe Bay and
hauled by truck in 55 gal drums to an area near the site. The oil was
transferred to a 2000 gal tank and transported to the spill site on a
large tracked vehicle. The oil was heated using heat tapes, to 57°C,
in a closed system to preserve the volatile components, and was spilled
through a 5 m length of perforated pipe (Fig. 4) at about 170 1/min over
a 45 minute period. The winter spill was conducted on 26 February 1976
at an ambient air temperature of about -5°C (23°F). The summer spill
-------
TV^-VV. '"T^v-. i >-'->' -V.-I "* Y -".^"'TV^S V-n "y i^**^**. I ^ . "TT^C ^S^-yy T^"-?^1 ^ I
pP^^M": : :^:(bi^^^^-^:^-^
0, Moss
Reddish-brown Peat
°2 Reddish-brown Peat ~i
A, - Brown Mixed Organic and Silt LoamJ0r9anic
C2 Grey Silt Loam
Figure 3. Typical profile of Saulich soil at Caribou-Poker Creek
spill sites.
was carried out on 14 July 1976 to approximately coincide with the peak
of the growing season and maximum yearly temperatures. The air tempera-
ture during the summer spill was 25°C (77°F). In each test 7570 £ (2000
gal) of oil were spilled.
Physical Characterization
The rate of oil flow downslope following the spill was determined
by probing with wooden dowels at predetermined locations on a grid with
one meter intervals (Fig. 5). The presence of the crude oil was readily
-------
Figure 4. Oil being spilled along a 5 m length of perforated pipe at
winter spill plot (note in the background the tank in which
the oil was heated prior to the spill).
Figure 5. Following oil flow downslope on the summer plot by visually
inspecting wooden dowels.
-------
discerned by sight and smell, and confirmed by UV-fluorescence (Deneke et
al., 1975) when questionable.
In July 1978, small pits were excavated at selected sites on the
two spill plots to determine the vertical distribution of the oil in the
soil profile. Penetration of the oil was determined visually.
Thermal Characterization
Vertical thermocouple arrays were installed with individual thermo-
couples at five levels (See Appendix, Figures Al and A2, Table Al).
To determine changes in the depth of thaw in the plots, probings
were conducted during the thaw periods. Six cross sections were laid
out at 1, 3, 6, 9, 14 and 20 m downslope from the spill point in each
plot and frequent probings were taken at one meter intervals each summer.
Oil and Oily Soil Characterization
Initial oil samples were obtained at the time of the spills, cooled
rapidly to preserve their integrity with respect to volatile components,
and characterized along with samples collected later by the following
techniques:
1) headspace analysis for volatiles by gas chromatography;
2) silica gel/alumina column chromatography to obtain major oil
components (alkanes, aromatics, asphaltenes, and NSO's);
3) characterization of the alkane fractions by capillary flame
ionization gas chromatography (Apiezon L and Dexsil SCOT
columns);
4) Characterization of all oil fractions by scanning infrared
spectroscopy.
Soil cores were collected initially, and then periodically over a
three-year period. Each sample was taken with a 5.7 cm diameter corer,
divided visually into overlying moss (0^, brown organic layer (02 and
A ) and greyish-brown silt loam (C2), and individually stored in pre-
washed glass canning jars. The samples were iced immediately and kept
frozen until analysis. Additional samples were collected in July, 1978
from small soil pits excavated at selected points in the contaminated
areas.
The soil samples were analyzed as follows. A subsample was taken,
placed in a scintillation vial, sealed with silicone rubber septum
material, and equilibrated at room temperature (approximately 22°C) for
24 hours. The headspace was sampled with a gas-tight syringe, and
analyzed by gas chromatography (McAuliffe, 1971). Gas chromatographic
analysis was conducted as follows:
-------
. analytical column - 5% Durapak, Carborax 400 on Porasil C
(9 ft x 1/8 in.)
oven temperature - programmed from -20°C to 150°C at 10°/min.
flow rate - 20 ml/min of helium carrier gas
detector - flame ionization
The remainder of the soil sample was manually extracted with
chloroform (Mallinckrodt, nanograde). For oily soils, extractions
were continued until the color of extract was visually similar to that
from a control soil (up to 15 individual extractions). The extracts
were combined and the chloroform removed by evaporation. The residue,
containing material C.,. and greater, was determined gravimetrically.
The dry weight of the soil was obtained by oven drying the extracted
soil at 105°C for at least 24 hrs. Percent oil was calculated by divid-
ing the chloroform extractable residue by the dry weight of soil.
The extracted oil was fractionated as follows. The asphaltene
material was removed by precipitation with pentane and determined
gravimetrically. The remainder of the material was fractionated by
silica gel-alumina column chromatography in a manner similar to that
described by Bailey et al., (1973). In our study, the column was
sequentially eluted with 100 ml of pentane, 150 ml of benzene, and 100 ml
of methanol (Mallinckrodt, nanograde) with the amount of material in
each fraction determined gravimetrically.
The alkane fraction was further characterized by gas chromato-
graphy. Several 50 ft x 0.02 in. SCOT columns were used including
Dexsil 300 GC and Apiezon L. Identification of individual peaks was
initially obtained by comparison to standard samples and confirmed later
by gas chromatography/mass spectroscopy (HP 5992). Ratios of pristane
(2, 6, 10, 14 tetramethylpentadecane) to n-C-7 (heptadecane) were obtained
by measuring the peak heights of these components in the Apiezon L
chromatograms. The peak heights (and thus their ratio) are not absolute
measurements and are dependent on the degree of separation achieved for
these two components. The higher numbers reported elsewhere for this
ratio (Jenkins et al., 1978) were obtained on a different analytical
column of the same variety.
Infrared spectra of all the fractions, obtained by silica gel-
alumina fractionation, were determined on a PE 167 scanning IR spectro-
photometer.
Inorganic analysis of soil was done on dried, sieved (2mm), mineral
(C2.) and organic (02, Aj) soils which had been treated with chloroform
to remove the oil. Soil pH was obtained with a digital pH meter (glass
electrode) on a 5:1, distilled water to dry soil, suspension according
-------
I I I I J_ I
to Jackson (1958). Exchangeable Ca , Mg , Na and K were obtained by
further extraction of a subsample of the dried soil with IN ammonium
acetate (Jackson, 1958) and determination by atomic absorption spectro-
metry (PE 303). Exchangeable ammonium was determined on a second soil
subsample by extraction with IN KC1 and determination by the automated
phenate method (Technicon Industrial Method #98-70W, 1973). Soil ni-
trate was determined in the KC1 extract by the automated cadmium reduc-
tion method (Technicon Industrial Method //271-73W, 1973). All values
for Ca++, Mg"*"1", Na+, K+, NH^ and NC>3 are reported on a dry weight soil
basis.
Soil water samples were collected in July, 1977. These samples
were obtained by digging small pits on each spill plot (and in a control
area), just beyond the farthest downslope point where visible oil was
detectable in the soil profile, and allowing water to collect in the
pits. Several of these water samples were analyzed for total organic
carbon by combustion infrared analysis using a Beckman 915 Total Organic
Carbon Analyzer. The dissolved volatile material (
-------
g/1) was used for counting heterotrophic and anaerobic bacteria.
Martin's medium (Martin, 1950) was used for enumerating filamentous
fungi and yeasts. A gelatin medium and the procedure described by
Rodina (1972) was use'd to count proteolytic bacteria. A nitrate medium
and a five-tube MPN procedure (Alexander, 1965) was employed to deter-
mine the abundance of denitrifying bacteria. Five replicate plates or
five tubes per dilution were used for microbial enumeration except for
the anaerobes which were done in triplicate. Incubation at 20°C for one
week and 4°C for two weeks was used for all groups except the denitri-
fiers which were incubated for one month at both temperatures. Anaero-
biosis for the determination of the abundance of anaerobic bacteria was
attained by evacuating Brewer jars, flushing with nitrogen gas contain-
ing 5% carbon dioxide, and using copper sulfate treated steel wool (Parker,
1955).
The enumeration of oil-utilizing microorganisms was a two-step
process using a five-plate MPN procedure. Initially, samples were
plated on a modified silica gel medium containing 1% Prudhoe Bay crude
oil. After one month incubation (at both 4°C and 20°C), these plates
were replicated onto plate count agar to estimate the bacterial popu-
lation and onto Martin's medium to estimate the fungal populations. The
replica plates were subsequently incubated, one week for the 20°C plates
and two weeks for the 4°C plates. The presence of one or more colonies
on the replica plate constituted a positive test.
Silica gel plates were prepared according to the procedure of Funk
and Krulwich (1964) with the mineral salts medium of Bushnell and Haas
(1941). Our modification was the addition of a sufficient quantity of
colloidal silica (Cab-0-Sil MS obtained from Cabot Corp., Boston, Mass.)
to the mineral medium to make a final concentration of 1% colloidal
silica in the gel plates. The colloidal silica was added to help main-
tain dispersion of oil in the gel plates. In making the silica gel
plates, the components were autoclaved separately and allowed to come to
room temperature before use. Sterilized oil (Robertson et al., 1973)
was added to the mineral-colloidal silica medium and the medium was
mechanically mixed to disperse the oil. Then the other components were
added, the mixture shaken, and the plates poured. Gelling occurred
within one minute, which was important in maintaining dispersion of the
oil in the plates.
The estimation of the numbers of cellulose-utilizing microorganisms
was also done on silica gel plates using the five plate MPN procedure.
The silica gel plates for this determination contained 1% cellulose
(Sigmacell-Type 20 ) as a sole carbon source and the colloidal silica
was not added.
c. Soil respiration measurements:
In vitro* respiration rates of soil samples were determined by
measuring carbon dioxide evolution rates in biometer flasks (Bellco
* In the laboratory
10
-------
Glass, Inc.) according to the procedure of Johnson and Curl (1972). Five
replicate determinations were done on samples from each soil horizon in
each test plot with incubation at 4°C and 20°C.
In situ* soil respiration was determined by measuring carbon
dioxide evolution rates in the field. Open-ended cylinders (7.5 cm
diameter) were sunk into the test plots. In the control plot, the live
moss plant layer was clipped before the ten cylinders were embedded, to
ensure that only litter, root, and soil respiration were being measured.
In the oiled plots, two sets of cylinders were embedded, one with the
killed moss layer removed (5 cylinders per plot) and one with the killed
moss layer intact (10 cylinders per plot). Carbon dioxide evolution
rates were determined according to Coleman (1973), with the exception
that the alkali jars were suspended (from the rubber stoppers used to
cap the cylinders) instead of being placed on the soil surface. Control
cylinders containing only jars of alkali were run simultaneously during
the 24 hour-period that respiration rates were being measured.
d. Soil water, pH, and oil determination in soil microbiological samples:
Water content of soil samples was determined using the gravimetric
method described by Gardner (1965). The pH of fresh soil samples was
measured using a glass electrode in a 1:1 soil-distilled water sus-
pension (Peech, 1965).
Oil content in soil samples was determined gravimetrically on
benzene extracts of soil. Three replicates of approximately 15 g of wet
soil from each soil sample were dried at 105°C for 24 - 48 hr. Each
replicate soil sample was then extracted 4 to 5 times with 50 ml por-
tions of benzene. The extracts were combined, evaporated to dryness in
a fume hood at room temperature, and the residue weighed. The percent
dry residue obtained from the unoiled soil was subtracted from the
percent dry residue from oiled soil to give corrected percent oil from
oiled plots. The weight of the oil contributing to the dry weight of
soil was taken into consideration in the calculation of the oven dry
weight of oiled soils.
e. Statistical analyses of microbiological data:
Counts of microorganisms and in vitro soil respiration rates are
expressed on the basis of oven dry weight of soil. Plate counts, soil
respiration rates, and water content (untransformed data) were statis-
tically analyzed using analysis of variance and Duncan's multiple range
test (Duncan, 1955). Confidence limits were calculated for the MPN
counts. For the comparison of two MPN estimates, non-overlap of the 95%
confidence limits was considered indicative of a significant difference
between the estimates (Cochran, 1950).
* In place, on site
11
-------
Vegetation
Prior to the spill, the vegetation was characterized using a
number of one meter square quadrats within both spill plots (Fig. 6).
All quadrats were sampled again in July 1978. Data were collected
according to methods of Ohmann and Ream (1971) as previously used in the
research watershed (Troth j^t al., 1975). Nomenclature follows Hulfen
(1968) for herbaceous species, Viereck and Little (1972) for shrub and
tree species, Crum et^ al_. (1973) for moss species, and Hale and Culberson
(1966) for lichen species.
Figure 6. One meter square quadrat used for sampling vegetation.
Pre- and post-spill measurements were made of percentage of cover
and frequency of occurrence of vegetation species. The number of stems
or individuals was also recorded for some shrub and herbaceous species.
The site was visited during the growing seasons, biweekly during
1976 and 1977 and monthly during 1978, in order to record the time and
extent of oil related injuries. Visual estimates of damage were made
and photographs were taken of affected quadrats.
Samples of the current year's spruce needles from trees within and
outside the winter and summer spill areas were taken in 1975 and 1976.
These were analyzed for total nitrogen, phosphorus, and potassium using
a Technicon Autoanalyzer to determine if the spills significantly affected
nutrient content.
12
-------
Dr. Arthur Linkins, Virginia Polytechnic Institute, took several
soil cores from both the winter and summer oil spill plots during the
1977 growing season. These were used to evaluate ectotrophic root
respiration for species including black spruce, blueberry, and Labrador
tea. Root respiration rates and respiratory quotients (ratio of carbon
dioxide released to oxygen absorbed) were determined in a Gilson differen-
tial respirometer using the direct KOH method.
Dead black spruce on the plots were marked in August, 1977. In
August, 1978 both plots were re-examined in order to determine if any
additional spruce had died. The number of dead spruce was recorded
through 1977 and for 1978.
Soil pits were dug within the plots during July 1978 to determine
vertical and horizontal root distribution. Root distribution was then
compared with oil distribution.
RESULTS AND DISCUSSION
Oil Movement
The winter spill was conducted on 26 February, 1976. The 57°C oil
was applied from a 5-m-wide "header with 6-mm holes spaced every 10 cm.
The oil was spilled on top of a snow pack which was approximately 45 cm
in depth. The hot oil rapidly melted holes in the snow, with the snow
melting and collapsing one to two meters downslope of the header (Fig. 7)
Figure 7. Snow melting near the header during hot crude oil applica-
tion on the winter plot.
-------
The oil then moved dowtislope under the snow without disturbing the snow
surface. Most of the movement occurred just above and within the moss
(QI) above the frozen organic (02, A^) and mineral (C^) horizons.
Although the oil was not visible from the surface, its presence beneath
the snow was obtained by probing and is plotted with respect to time in
Figure 8a.
Movement of oil continued at a gradually decreasing rate for 24
hours following the spill before it became immobilized over an area
extending 18 m downslope of the header. The oil remained stationary
throughout the remainder of the winter and did not remobilize until snow
melt in May, 1976. With the onset of warm weather, portions of the oil
gradually moved an additional 17 m downslope. The remobilized oil moved
beneath the moss layer and was visually undetectable at the surface, in
contrast to the initial winter oil movement which occurred over and
within the moss layer. The total area affected by the oil is about
188 m^ or about 24 m^/m^ of oil, with an average oil concentration in
the impacted area of 41 H/m?.
The summer spill was conducted on 14 July, 1976 in the same manner
as that in the winter spill. A similar spill rate of 170 1/min was used
and the oil temperature at the header was also 57°C. As the oil spilled
onto the surface, it rapidly penetrated to the peat (02) horizon and
moved downslope beneath the moss. Oil disappeared from view less than a
meter downslope from the spill point and was only visible downslope in
surface depressions where pools formed. Oil movement continued rapidly
for approximately 24 hours at which time it had moved 28 m downslope.
After 48 hours the oil had moved only an additional 6 meters. Oil
continued to move downslope until winter freeze up in October, 1976, at
which time it had moved another 7 meters. Oil movement plotted with
respect to time is shown in Figure 8b.
2 23
The total area affected by the summer spill was 303 m or 40 m /m
of oil, more than one and a half times the area affected by the winter
spill._ The average concentration of oil in the impacted area was about
25 £/m , considerably less than in the winter spill. The areas affected
by the oil in both cases compare favorably with the range of 20 to 100
m^/m of oil predicted by MacKay et^ ad., (1974). However the subsurface
flow found in the summer spill differs from that observed by MacKay
^t ail., (1974) where surface flow over water saturated moss occurred.
The differences observed are likely a result of a lower moisture content
in the moss and upper soil layers of the summer spill which allowed the
oil to quickly penetrate to the organic soil where downslope flow occurred.
If the moss layer had been very wet at the time of the summer spill, it
would probably have caused the oil to float on top of the moss and flow
downslope on the surface.
14
-------
Spill
Application
Spill
Application
149 Days
No Oil
172 Days
284 Days
140
10m
I Om
Figure 8a. Downslope movement of
oil following the winter spill.
Figure 8b. Downslope movement of
oil following the summer spill.
Figures 9a and 9b are plane views of the summer and winter spills
showing the total areas affected by oil and the areas where oil is visibly
present on the surface.
:
-------
0 2 4 6 8 10 12 14 m
I lil
Figure 9a. Summer spill showing sur-
face and subsurface oiled areas.
Figure 9b. Winter spill showing
surface and subsurface oiled areas.
16
-------
2
Only 10% of the total summer spill area of 303 m has oil visible
on the surface. On the other hand, 40% of the 188 m winter spill has
visible surface oil. The difference in visible oil on the surface
reflects the different modes of oil movement in the two spills.
In July 1978 the vertical penetration of oil into the soil profile
was determined at several points in the two spill plots. A diagram of
the location of oil in the soil profile at each site is shown in Figure 10.
Five locations were chosen and labeled with site coordinates across slope
and downslope (see Figures 9a and 9b for locations) as follows:
Summer 1-2*, 8-9** (Figure lOa)
A site with no visible oil on the surface, near the edge of
a visibly impacted oil area.
Summer 4-5, 8-9 (Figure lOb)
A location in the upper portion of the summer plot which had
80% of the surface visibly impacted by oil.
Summer 7, 34 (Figure lOc)
A location near the bottom of the oiled area which was
impacted by oil movement several days after the spill.
Winter 8-9, 11-12 (Figure lOd)
A site impacted from above at the time of the winter spill
which had a heavily oil impacted surface.
Winter 15, 34 (Figure lOe)
This location was affected by previously immobilized oil
which began moving through the organic layer following spring
break-up, several months after the spill.
The diagrams from locations downslope on the summer spill (Fig.
10 a-c) confirm that movement occurred predominantly in the organic
layer. Upslope, in the heavily oil impacted zone, oil flowed through
the overlying moss and penetrated the mineral soil to a depth as great
as 8 cm (Fig. lOb). Oil generally penetrated only 1 cm into the mineral
soil further downslope (Fig. lOc). Oil movement upwards from the
organic soil into the overlying moss was also reduced downslope to
approximately 1 cm.
* Across slope coordinate (Fig. 9a)
** Downslope coordinate (Fig. 9a)
17
-------
(a)
(b)
(c)
Summer 12,8-9
0, Moss
62'
C2 Mineral
Permafrost
Summer 4-5, 8-9
45>-
Permafrost
Oil~9cm thick
(e)
! Oil -10cm thick
Permafrost
Winter 15, 34
49:
! Oil 3-4cm thick
Permafrost
Figure 10a,b,c,d,e. Vertical penetration of oil into soil profile.
18
-------
Oil contamination in the first 18 cm of the winter plot occurred
from above as shown in Figure lOd. The major portion of the oil in this
section was found in the moss layer with significant amounts in the
upper part of the organic layer. Little oil was found in the mineral
soil in this region.
The distribution of oil in the lower portion of the winter plot was
quite different. This area was impacted by remobilized oil after break
up. Oil in this region was in a narrow band about 3 cm in thickness
within the organic layer (Fig. lOe). No oil was found in either the
moss or mineral soil in this section of the plot.
While the average concentrations of oil in the summer and winter
plots were 41 and 24 1/m it is clear that this oil was not uniformly
spread over the contaminated zone. Areas such as summer 4-5, 8-9 have
much higher amounts of oil while those such as winter 15, 34 have very
little.
It is useful to compare the physical behavior of these controlled
spills with two actual spills from the Trans Alaskan Pipeline System
(TAPS) at Valve 7 (19 July, 1977) and Steele Creek (15 February, 1978).
At Valve 7 more than 300,000 £ (80,000 gal) of crude oil were sprayed
under high pressure as far as 1200 m downwind, but the oil only saturated
the vegetation within an area 230 m from the valve (Walker et al.,
1978). In contrast, at Steele Creek more than 1,900,000 £ (500,000 gal)
of crude oil sprayed down into the gravel workpad. Although some minor
amounts sprayed into the air, most of the oil seems to have flowed on
or under the surface. While some oil flowed in the upper organic layers
of the soil underneath the snow (similar to the CRREL winter spill) large
amounts also flowed over the top of the snow surface. Evidently the
oil, which had reached a temperature of only 10°C(50°F) in the pipe,
cooled sufficiently before reaching the snow so that it could flow over
it. The behavior of these actual spills seems to combine aspects of
both the experimental spray spills conducted by Deneke et al. (1975) and
the experimental point spill studies reported here.
Effects on Permafrost
Very little modification to the underlying frozen ground occurred
during the actual spills. During the winter spill, most of the heat of
the oil was dissipated by the melting of snow. There may have been some
minor thawing of the permafrost table in the upper levels of the summer
spill plot at the time of the spill. However, the actual thermal mass
of oil, even at 50°C, was negligible compared to the thermal mass of the
underlying permafrost. In addition, the oil moved downslope so rapidly
that there was little concentration or pooling of oil which could supply
enough heat to thaw the permafrost table. Insulation, such as the soil
and peat layers above the permafrost, increases the time and the amount
of heat required to penetrate to the permafrost.
19
-------
Oil blackened surface areas have a lower albedo than non-affected
vegetation causing the surface to warm above that of non-affected areas,
This can result in long term increases in depth of thaw. Figure 11
presents the maximum thaw depths in 1977 and 1978 for cross sections
of the two spill plots and a control area at three meters downslope.
The greatest thaw depths in the winter and summer plot generally cor-
respond to the surface-oil impacted areas.
Winter
Oil-affected area
Surface oil area
(Ometers
Thaw 50-
Depth
100
3m.
9/20/77
Summer
0 2
100
Control
0 2
100
Figure 11. Cross section thaw depths in 1977 and 1978 at 3 meters
downslope of oil application.
Table 1 summarizes the average thaw depths of the six cross sections
in each of the three plots at 1, 3, 6, 9, 14, and 20 meters as well as
the percent change in thaw depths from 1976 to 1977 and from 1977 to
1978. The thaw depth profiles were obtained at thermally equivalent
times during each year at near maximum thaw depths. On 28 September
20
-------
TABLE 1 AVERAGE THAW DEPTH (CM)
WINTER
CROSS
SECTIONS
AVERAGE
THAW FOR
YEAR
SUMMER
CROSS
SECTION
AVERAGE
THAW FOR
YEAR
CONTROL
CROSS
SECTIONS
AVERAGE
THAW FOR
YEAR
1M
3
6
9
14
20
1M
3
6
9
14
20
1M
3
6
9
14
20
DEGREE DAYS
OF THAWING
1976
55.4
53.9
54.2
49.5
44.9
47.2
50.9
48.6
43.6
45.2
46.6
48.1
51.3
47.2
3575.
1977
73.3
67.4
67.4
56.1
53.4
52.6
61.7
58.0
57.6
52.4
54.9
54.4
55.4
55.5
62.3
61.6
52.0
52.0
54.6
55.6
57,1
3567.
1978
87.8
81.4
74.9
62.9
57.6
54.7
69.9
65.8
60.3
60.3
62.3
57.1
58.6
60.7
63.7
61.9
52.4
52.4
53.5
56.3
57.5
3576.
% Change
76-77
+32.3 %
+25.0 %
+24.4 %
+13.3 %
+18.9 %
+11.4 %
+19.3 %
+32.1 %
+15.9 %
+17.8 %
+13.1 %
+ 8.0 %
__
% Change
77-78
+19.8 %
+20.8 %
+11.1 %
+12.1 %
+ 7.9 %
+ 4.0 %
+13.4 %
+ 4.7 %
+15.1 %
+13.5 %
+ 5.0 %
+ 5.8 %
+ 2.2 %
+ 0.5 %
+ 1.6 %
+ 0.8 %
- 2.0 %
+ 1.3 %
Average Average
% Change % Change
76-77 77-78
21.2 % 13.2 %
17.5 % 9.4 %
+ 0.7 %
-------
1976 there had been a total of 3575 degree days of thawing. On 20
September 1977, there had been 3567 degree days of thawing. And on
26 September 1978 there had been 3576 degree days of thawing.
One full thaw season (1977) following the summer spill, significant
increases occurred in the average thaw depth in the winter and summer
spills as compared to 1976, 21.2% and 17.5% respectively. Data from the
control plot is unavailable for 1976. We assume there was little or no
change in depth of thaw from 1976 to 1977 in the control plot. This is
based on the lack of change from 1977 to 1978 and the equivalent degree
days of thawing for 1976, 1977 and 1978.
After the second full thaw season, additional smaller increases
in the thaw depths in the winter and summer plots occurred. Thaw depths
in the summer plot increased by 9.4% over the previous year and in the
winter plot, with its greater surface-oiled area, by 13.2%. Although
others have reported little increase in the active layer beneath crude
oil spills (Hutchinson and Freedman 1975; Freedman and Hutchinson
1976), measurements of the active layers in this study show an increasing
active layer several years after the initial spills.
Two full years of this data are insufficient to predict the long
term effects of the oil on permafrost. The thawing trend underway may
stabilize or even reverse itself, for example, if vegetation starts to
re-establish on the spill areas. Continuation of the present trend could
result in catastrophic thermokarsting. However, stabilization of thaw
seems most likely as long as the organic mat above the mineral soil is
not destroyed.
Compositional Changes
The Prudhoe Bay crude oil used in the study was characterized by a
number of chemical methods in order to assess changes due to natural
weathering on slope. These included fractionation with respect to major
classes of components by column chromatography and further characterization
of each fraction by gas chromatography and infrared spectroscopy. Some
of the pertinent data obtained are summarized in Table 2. A gas chroma-
togram of the original oil is shown in Figure 12.
The major processes thought to contribute to weathering of oil
after a terrestrial spill are evaporation of volatiles, solubility and
translocation of water-soluble components, and microbiological degra-
dation. Of these, the loss of volatiles was found to make the largest
initial impact. Photochemical degradation, many times the controlling
factor in degradation of oil in marine spills, is negligible in terres-
trial systems where the amount of oil exposed to sunlight is small.
22
-------
TABLE 2. INITIAL CHARACTERISTICS OF PRUDHOE BAY CRUDE
OIL USED IN STUDY
Specific Gravity
% Sulfur
% Volatiles (C^-Cg)
(c9-c15)
Major Components of Residue (C. ,--C/n)
Alkanes
Aromatics
Asphaltenes
Soluble NSO
Insoluble NSO
0.89
1.0%
8%
15%
33%
30%
22%
11%
4%
Pristane/n-C1 -. Ratio
PH
Alkane/Aromatic Ratio
0.65
7.2
1.12
30
Retention Time
40
(minutes)
Figure 12. Gas chromatogram of the original oil used for the Caribou-
Poker spills obtained on a Dexsil Scot column (50 ft x 0.02 in.,
temperature programmed from 75° to 350° at 4°C/min.).
23
-------
Samples of the original oil, oil from pools in the spill area, and
oily and control soil, were analyzed by head space gas chromatography to
characterize changes in the most volatile fraction (Cj through Cg).
Changes in the presence of these components in the equilibrium headspace
at a given temperature are a direct reflection of their change in con-
centration in the liquid (oil) phase. Results of these analyses are
shown in Figure 13 and Table 3. These chromatograms, obtained for
samples collected from a surface pool of oil on the winter spill site,
show a rapid loss of methane and ethane (Ci and C2> in the first few
hours. Components in the C-j-Cg range (propane-octanes) declined through
the first day with reduction by a factor of four in the first two
months. Only small amounts of these components (C3~Cg) were observable
in the five-month sample. The retention of these low molecular weight
volatile substances for some time after spillage undoubtedly maintained
greater fluidity in the oil resulting in substantial remobilization of
the oil downslope at spring breakup. This pool of oil on the winter
slope was sampled again and analyzed for volatiles 17 months after
spillage. No detectable components in the Cj - Cg range were found at
that time. Estimates of the percent of volatiles in the C^ - Cg range
lost with time, based on these chromatograms, are presented in Table 3.
Two months after spillage, over 10% of this volatile material was still
present in the oil located on the surface of the soil.
Analyses were also obtained for the oil in the soil profile from
the control and spill plots. No volatiles in the C. - CR range were ever
detected in any of the control soils. Results from the winter spill
soils indicate a slower loss of volatiles when compared with the surface
pool of oil. Results from this analysis for soils collected 17 months
after spillage are presented in Figure 14 and Table 3. Significant
amounts of volatiles, in the C,. - C_ range, were still present in the
mineral and organic soils at that time. No detectable volatiles were
present in the surface moss after 17 months however.
Analysis of volatiles in soil from the summer spill plot were also
obtained. Initially the volatiles were present in much higher concen-
tration than in the winter spill since fresh oil penetrated the soil at
the time of the summer spill. In contrast, oil in the winter spill re-
mained on the surface for several months until warmer temperatures
allowed it to penetrate into the organic and mineral soil. The loss
rate of volatiles in the summer spill soils, in general, was greater
than that found for the winter spill. Thus after 12 months exposure
in the summer spill, there were lower concentrations of volatiles (Fig.
15 and Table 3) than in the winter spill plot after 17 months (Fig. 14),
for both the organic and mineral soils.
These results, showing substantial retention of volatiles well
after the spill, conflict with those reported for arctic tundra soils at
Barrow, Alaska (Sexstone and Atlas, 1977). At Barrow complete loss of
24
-------
Table 3. LOSS OF VOLATILES* FROM SPILL PLOTS.
Time after
spillage
Percentage of volatiles* evaporated
Surface Oil Oil in Moss Oil in organic Oil in mineral
soil soil
Original Oil
1 Hour
1 Day
2 Months
5 Months
17 Months
Original Oil
1 Hour
2 Hour
3 Hour
4 Hour
22 Hour
2 Days
3 Days
2 Months
8-1/2 Months
12 Months
12-1/2 Months
0%
0.8%
34.6%
88.6%
99.3%
100%
0%
1.7%
17.6%
26.2%
17.2%
46.6%
64.6%
59.0%
Winter Spill Plot
98.2%
100%
Summer Spill Plot
89. 2%
99.9%
99.9%
71.3%
96.6%
89.8%
99.1%
99.0%
75.2%
94.9%
98.3%
99.9%
* Volatiles are considered the components in the Cj - Cg range and
account for about 8% of the oil by weights.
the volatile fraction (
-------
xBOO
a. Original
x800
c. I Day
x8OO
d. 2 Months
x80
e. 5 Months
x20
x200
f. 17 Months
Figure 13. Headspace chromatograms of oil taken from a pool on the
winter spill plot. (5% Durapak 400 on Porasil C, 9 ft x
1/8 in., temperature programmed from -20° to 150°C at
26
-------
x20
a. Surface Moss
x20
b. Organic Soil
x20
c. Mineral Soil
"Figure 14. Headspace chromatograms of oily soil from winter spill plot, 17 months after spillage
(GC conditions were identical to those given for Figure 13).
-------
x20
'8
to
00
a. Surface Moss
x20
b. Organic Soil
x20
c. Mineral Soil
Figure 15. Headspace chromatograms of oily soil from the summer spill plot, 12 months after
spillage. (GC conditions were identical to those given for Figure 13).
-------
C6
Figure 16. Headspace chromatogram of oily soil taken from the Prudhoe
Bay spill site, 12 months after spillage. (GC conditions
were identical to those given for Figure 13).
Thus it appears that volatiles are retained much longer in the soil
profile than originally believed. Some of these volatile substances,
particularly the lower molecular weight aromatics (i.e. benzene, toluene,
xylenes), are thought to be very toxic to plants and microorganisms.
Their continued presence well after the spill may be biologically signi-
ficant.
Runoff is undoubtedly responsible for some translocation of water-
soluble material out of the spill areas. Attempts at measuring the
amounts of materials removed by this mechanism were unsuccessful. Water
samples collected at locations just downslope of visible oil movement
were analyzed by a simplified stripping method developed by Leggett
(1979). No detectable quantities (>10 g/ml) of individual components
were found in any sample. An attempt at utilizing total organic carbon
analysis to look at the total dissolved material was also unsuccessful
due to large concentrations of organic carbon (>50 mg/X,) in the natural
soil solution of this region.
In general, the most water-soluble components of the oil are also
the most volatile. This was demonstrated in a study of the aqueous
solubility of Prudhoe Bay crude oil (MacKay and Shiu, 1976). A decrease
in solubility from over 29 mg/1 for fresh oil to less than 0.06 mg/1 for
oil in which the volatiles had been removed by evaporation was found.
The loss rate of equally volatile substances, which differ widely in
solubility, can be used to qualitatively assess the importance of this
mechanism relative to volatilization. Losses of two very soluble com-
ponents of the oil, benzene and toluene, were found to be similar to the
29
-------
losses of alkanes of equal volatility but much lower solubility. Thus,
at least for the lower molecular weight oil fraction, the contribution
of solubility to loss rate is less significant than volatilization.
Results obtained from silica gel-alumina chromatography (to be
presented later) indicate that compositional changes of relatively
water-soluble material versus highly insoluble material in the oil
extracted from soil samples are insignificant. These results are con-
sistent with information reported by Raymond j^t a^. (1976) in a study in
a more temperate climate where no loss of material was observed via
runoff or leaching in oiled field plots. They also agree with results
obtained for spills directly onto fresh water (Phillips and Groseva,
1977) and salt water (McAuliffe, 1977) where evaporation was shown to be
the predominant process for short-term changes in oil composition after
spills.
Several types of microorganisms, including bacteria, actinomycetes,
yeasts, and fungi have been shown to be capable of degrading many of the
organic components of crude oils (Davis, 1967). The total amount of oil
present on the site at one time cannot be directly measured without
destroying the site. Hence, it is impossible to determine the change
due to microbial activity in the amount of oil present. Laboratory
studies, however, have shown preferential decomposition of certain
fractions of the oil. Bailey jit al. (1973) and Katov ejt al. (1971) have
shown that the alkane fraction (saturates) decompose more rapidly than
other components. Shorter chain n-alkanes (straight chains) were found
to decompose fastest of all. Isoprenoid alkanes (branched chained
species), such as pristane, have been shown to be more resistant to
microbiological degradation (Jobson et al., 1972).
Aromatic components tend to degrade at the next fastest rate to the
alkane fraction with degradation of asphaltene and NSO material being
very slow. An increase in asphaltene material as a by-product of decom-
position of more degradable material has even been reported (Bailey et
al., 1973). Assessment of the extent of microbial degradation is thus
possible, in principle, by analysis of oil compositional changes with
time.
The method chosen to investigate these changes was fractionation
using silica gel-alumina column chromatography. This procedure sub-
divides the residue obtained by chloroform extraction of the oily soils
into its major organic components: alkanes, aromatics, asphaltenes and
NSOs. The ratio of alkane to aromatic material was chosen as an indi-
cator of compositional change with time. These ratios obtained from oil
extracts from the soil from July, 1976 through June, 1978 are presented
in Table 4. The Prudhoe Bay oil used for the spill has an initial 1.12
alkane/aromatic ratio.
30
-------
TABLE 4. ALKANE/AROMATIC AND PRISTANE/n-C.., RATIOS*
FOR TOPPED** SOIL EXTRACTS (CARIBOU-POKER CREEK AREA SPILLS)
Sampling
Date
Winter Mineral Soil
(c2)
Winter Organic Soil
(0^)
Winter Moss
7/15/76
9/17/76
3/29/77
4/5/77
7/13/77
8/1/77 ***
1/5/78
6/27/78***
a
1.03
1.29
1.08
1.04
1.17
1.11
b
0.59
0.56
0.58
0.53
0.50
0.54
a
.10
.27
.05
.29
1.17
1.09
0.98
0.58
0.53
0.55
0.56
0.55
a
,22
.23
.25
.28
1.01
0.84
b
0.57
0.61
0.58
0.62
0.67
0.71
Summer Mineral Soil Summer Organic Soil
Summer Moss
7/15/76
9/17/76
3/29/77
4/5/77
7/13/77
8/1/77***
1/5/78
6/27/78***
(C
a
1.12
1.05
0.98
0.77
1.10
a Alkane/aromatic
b Pristane/n-C, 7
2>
b
0.61
0.56
0.54
0.68
0.71
ratio
ratio
(02A1)
a
1.12
1.05
1.36
1.00
1.04
1.14
0.87
0.96
(The measured
(The precision
b
0.59
0.64
0.56
0.55
0.51
0.60
0.60
0.58
precision of
a
1.03
1.12
0.99
1.02
0.94
"
this ratio
of this determination is
b
0.59
0.58
0.56
0.63
0.76
"
is +0.03).
estimated
to be +0.03)7
* Original topped Prudhoe Bay oil had ratios of 1.12 for alkane/aromatic and
0.65 for Pristane/n-C.. ?.
** Topped extracts are those in which the volatile fraction (^jr) ^as been
removed by evaporation.
*** These samples were collected as described in the soil microbiological
methodology. All others were collected as described in the oily soil
characterization section.
31
-------
A second method based upon gas chromatographic analysis of the
alkane fraction was developed to follow the ratio of pristane, an iso-
prenoid alkane, to n-C^j. Since these species have similar volatility
and very low solubility, a change in their ratio should be indicative of
microbiological degradation. The results of these analyses are also
presented in Table 4. Initially Prudhoe oil had a 0.65 pristane/n-C17
ratio.
The results from both of these determinations indicate very little
or no compositional change with time through the first two years with
respect to these parameters. The only possible exception could be the
oil in the summer mineral soil, where some increase in pristane/n-Cjy
ratio was observed in the 8/1/77 and 6/27/78 samples. Samples taken
July 1978 (to be discussed later, see Table 6) do not confirm this trend.
Oil in the moss may also show some small change. Additional sampling in
the next several years will be required to confirm that observable
compositional change due to microbial activity is occurring.
If these parameters are accepted as a measure of the effect of
microbial activity, little compositional change due to microbial activity
can be inferred thus far. If, however, microbial degradation is occur-
ring in a more non-specific fashion relative to the various oil compo-
nents, these parameters might not be useful to discriminate this type of
natural weathering. Some recent evidence does suggest that degradation
in field conditions can be less preferential (Raymond ^t a^., 1976;
Horowitz and Atlas, 1977) than has been observed in laboratory studies.
In order to assess if these parameters are useful in detecting
changes due to microbial activity, several other oil spill plots in
Alaska, some dating back to 1970, were sampled and analyzed in a manner
similar to the Caribou-Poker spills. Chromatograms for oil from some of
these spills, as well as from initial Prudhoe crude, are shown in Figure
17. The results of these analyses are shown in Table 5.
The results from the 1970 Barrow spills show considerable changes
in the pristane/n-C.7 ratios with the value for the plot 313 showing
nearly a tenfold increase to 5.1. The other Barrow spills are also
elevated above that found in the Caribou-Poker spills. The chromatograms
from which these values were obtained for Barrow plots 313 and 311 are
presented in Figure 17. The chromatograms for Barrow plot 313, in
particular, show a drastic change from original Prudhoe Crude Oil, with
the normal alkanes being much reduced relative to branched chain material.
The alkane/aromatic ratio shows much less change relative to the values
typically found in the Caribou-Poker spills. Barrow sample 313 did show
a decrease in alkane/aromatic ratio to about 0.84 from values generally
greater than 1.0 for the Caribou-Poker sites. These results indicate
that the pristane/n-Cjj ratio may be a useful tool to assess the effect
of microbial activity on the oil composition in the soil. The alkane/
aromatic ratio was found to be much less diagnostic.
32
-------
SAMPLE (Spill
Date)
TABLE 5. ALKANE/AROMATIC AND PRISTANE/n-C17
RATIOS FOR SAMPLES FROM OTHER ALASKAN SPILLS
Sample Date Alkane/Aromatic Pristane/n-Cj-
Ratio Ratio
Prudhoe Oil used
For Prudhoe
Spill (July
1976)
Prudhoe 2CR (1976)
Prudhoe SCR (1976)
Caribou-Poker
Winter Spill
(Feb. 1976)
Caribou-Poker
Summer Spill
(July 1976)
0.96
0.64
July 1977
July 1977
1976-1978
1976-1978
1.06 0.55
0.97 0.56
(see Table 4) (see Table 4)
(see Table 4) (see Table 3)
Oil in Soil
Barrow 313 (1970)
Barrow 311 (1970)
Barrow 152D(1971)
Fox (1971)
July 1977
July 1977
July 1977
July 1976
0.84
1.00
0.96
0.92
5.1
0.80
0.81
0.63
4.4%
-
13.3%
249%
7.7%
11.6%
Moss 137-267%
Organic 7.3-190%
Mineral 3.0-9.8%
Moss 69-207%
Organic 9-311%
Mineral 1.5-3.4%
Soil samples were also obtained from the Fox spill site. This site
is quite similar to the Caribou-Poker area, and is located on a subarctic
permafrost location. The amount of oil present in the soil at Fox is
very high relative to the Barrow site and again similar to the Caribou-
Poker area. A chromatogram of the alkane fraction of the oil from this
site is given in Figure 17. Even after five years, there appears to be
no evidence of significant microbial decay at this location (Table 5).
The oil extracted from soil at the Prudhoe Bay spills also shows
little compositional change relative to the original oil after one year
(Fig. 17 and Table 5). The percent oil in the soil at this site is
similar to the Barrow spill areas and much lower than found in Fox or
Caribou-Poker. This lower amount should make a small change in compo-
sition due to microbial activity much more observable in the future.
33
-------
Figure 17. Chromatograms of oil extracted from soil taken from several
Alaskan oil spill sites (Apiezon L SCOT column, 50 ft x 0.02 in.,
temperature programmed from 175° to 250° at 4°/min.).
The analyses reported thus far for the Caribou-Poker spills were
taken in the upper, heavily impacted areas of both plots. Additional
samples were collected in July 1978 to determine the vertical distribu-
tion of oil at various downslope locations in both plots (Fig. lOa-f)
and to assess if different amounts of weathering were occurring at
other locations.
The amount of oil in the various soil horizons of the winter and
summer spill plots was found to vary drastically from location to loca-
tion (Table 6). In general, the moss and upper organic soil has the
greatest amount of oil in the upslope portion of the winter spill plot
with amounts in the moss varying from 137% to 267% of the dry weight of
the soil. Amounts of oil in the organic and mineral soil of the winter
plot vary from 7.3% to 190% and 3.0% to 9.8%, respectively.
34
-------
TABLE 6. ANALYSES OF SAMPLES COLLECTED IN JULY 1978
SAMPLES
S 4-5, 8-9
S 1-2, 8-9
S 7, 34
S 4-5, 8-9
S 7, 34
S 1-2, 8-9
S 1-2, 8-9
S 8-9, 8-9
W 8-9, 11-12
W 8-9, 11-12
W 7, 34
W 8-9, 11-12
S ORGANIC
S MINERAL
W ORGANIC
W MINERAL
(MOSS)
(MOSS)
(MOSS)
(ORGANIC)
(ORGANIC)
(ORGANIC)
(MIN)
(MIN)
(MOSS)
(ORGANIC)
(ORGANIC)
(MIN)
June 1978
11 ii
ii ii
ii M
% Oil Pris/n-C17
183.0 0.71
43.1 0.54
135.0 0.67
311.0 0.56
131.0 0.54
57.9
2.4
22.0
246.0 0.61
91.3 0.54
30.8
21.1 0.58
1.76 0.71
16.8 0.55
3.89 0.54
% Alkanes
31.8
-
31.9
36.8
32.0
32.9
22.1
30.0
32.4
33.0
30.6
33.5
30.9
26.6
33.0
31.0
Alk/Arom
0.77
-
0.94
1.05
0.81
0.97
0.89
0.96
0.93
0.94
1.01
0.98
0.96
1.1
0.98
1.06
35
-------
In the upper portion of the summer spill area, the largest amount
of oil is in the organic soil and lower moss. Amounts of oil in the
moss vary from 69% to 207% and in the organic layer vary from 9% to 311%
The mineral soil, on the other hand, contained much less oil varying
from 1.5% to 3.4%.
In the lower sections of both spill plots, the location of oil in
the profile is considerably different. In the winter plot, the oil
resided in a narrow band within the organic soil with an oil content in
this region of about 30% (Fig. 12). In the lower portion of the summer
plot, the oil was present throughout the organic layer with small amounts
present in the lower moss and upper mineral layers as well. The moss
and organic soil contained in excess of 100% of oil in this region.
Analysis of the residual oil extracted from soil samples collected
in July 1978 at various locations in the two spill plots showed little
difference in composition (Table 5). Thus there does not seem to be a
drastic difference in the amount of microbial or other types of natural
weathering in various areas within the plots.
Microbiological Responses
A preliminary examination of the data suggests that the microbial
populations and their activities showed similar response trends at
both incubation temperatures of 4°C and 20°C (20°C incubation results are
presented in appendix C). Also, respiratory activity and some microbial
populations were stimulated to a greater extent at 4°C than at 20° C.
Thus only the 4°C data is presented here since 4°C more closely approxi-
mates the soil temperature in the research watershed areas where our
test plots are located (Appendix Table A-l). The dilution plate count
method and MPN enumeration procedures were used in this study. Despite
their limitations these methods are sensitive to differences in microbial
counts among the test plots or within a plot over a period of time.
Relative changes in numbers of microorganisms are more important than
absolute numbers.
The effect of oil application on heterotrophic bacterial counts is
shown in Tables 7, 8 and 9. In 1976, beginning immediately after the
spill in the winter plot, the numbers of heterotrophic bacteria were
increased relative to the control plot, and the increased counts per-
sisted into September. In the summer plot, after an initial depression
of the heterotrophic bacterial counts, there was a continual increase in
numbers with the highest counts occurring in September. These increased
bacterial counts in the oiled plots persisted through 1977 (Table 8)
and 1978 (Table 9). The increases in bacterial numbers in both oiled
plots were significant relative to the control plot indicating a stimu-
latory effect of the spill on the heterotrophic bacterial population, the
extent of stimulation being greater in the summer. Our findings on the
response of heterotrophic bacterial populations to oil agree with those
of Sexstone and Atlas (1977) and Loynachan (1978).
36
-------
TABLE 7. 1976 HETEROTROPHIC BACTERIAL COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
Control
plot
Winter
plot
Summer
plot
AI Horizon
February
June
Julyb
August
September
o
February
June
Julyb
August
September
2.8
6.8
3.9
2.4
0.7
1.2
2.2
0.9
1.4
0.3
5.4**
120**
430**
170**
210**
C« Horizon
1.8*
2.1
41**
14**
12**
-
-
2.8*cc
340**cc
640**cc
-
-
0.6**cc
25**cc
210**cc
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
* Significantly different from the control at 5% level.
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
TABLE 8. 1977 HETEROTROPHIC BACTERIAL COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS.
Sampling
time
June
July
Aueus t
Control
plot
7.7
1.9
1.0
Winter
plot
A, Horizon
540**
240**
99**
Summer
plot
1400**cc
900**cc
460**cc
June
July
August
C9 Horizon
1.1 36**
0.3 63**
0.4 40**
210**cc
110**cc
77**cc
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
37
-------
TABLE 9. 1978 HETEROTROPHIC BACTERIAL COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS.
Sampling Control Winter Summer
time plot plot plot
A. Horizon
June 2.9 220** 480**cc
July 1.6 190** 150**c
June
July
0.8
0.4
C~ Horizon
58**
42**
43**cc
21**cc
** Significantly different from the control at 1% level.
c Significantly different from the winter at 5% level.
cc Significantly different from the winter at 1% level.
Numbers of filamentous fungal propagules (Table 10) were reduced in
both soil horizons immediately following the winter spill and remained
so throughout the growing season. The immediate impact of the summer
spill was to reduce fungal counts in the A^ horizon, but by September,
fungal counts were five times higher than in the control. In the C^
horizon there was an overall increase in counts with an apparent re-
duction occurring in August. However, in 1977 (Table 11) and 1978
(Table 12), fungal propagules were significantly reduced in both soil
horizons of the oiled plots. The extent of oil inhibition on the
filamentous fungal population was greater in the winter plot than in the
summer plot. The inhibitory effect of oil spills on fungal populations
(investigated by the dilution plate method) were similarly observed by
other workers (Miller et al., 1978; Antibus and Linkins, 1978), who used
direct counting techniques to estimate the fungal populations. Warcup
(1967) suggested that the dilution plate method may not necessarily
correlate with fungal biomass or activity. However, according to
Griffiths and Siddiqi (1961) and Montegut (1960), the dilution plate
counts can be used as an indication of the fungal populations and their
activities.
In 1976, yeast counts in both oiled plots were significantly in-
creased above their initial levels and relative to those in the control
plot (Table 13). These increases in counts relative to the control
persisted in 1977 (Table 14) and 1978 (Table 15). Numbers in the summer
plot were consistently higher than those in the winter plot during the
three consecutive growing seasons after the oil spills. The significant
increases suggest an enhancement of the yeast population resulting from
the oil applications. A similar response was noted by Scarborough and
Flanagan (1973) and Campbell et al (1973).
38
-------
TABLE 10. 1976 FILAMENTOUS FUNGAL PROPAGULE COUNTS (x 104/g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
f\
February
June
Julyb
Augus t
September
Control
plot
130
120
120
34
24
Winter
plot
A, Horizon
92*
14**
18**
23**
10**
Summer
plot
-
-
49**c
31*
100**cc
February
June
Julyb
August
September
19
24
13
14
5
C« Horizon
4**
0.7**
8**
4**
2**
-
-
17**cc
5**
7*cc
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
* Significantly different from the control at 5% level.
** Significantly different from the control at 1% level.
c Significantly different from the winter at 5% level.
cc Significantly different from the winter at 1% level.
TABLE 11. 1977 FILAMENTOUS FUNGAL PROPAGULE COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
June
July
Augus t
June
July
Augus t
Control
plot
110
64
60
30
4.8
11
Winter
plot
A Horizon
27**
13**
1.4**
C7 Horizon
2.1**
1.3**
0.6**
Summer
plot
43**
34**cc
18**cc
15**cc
5. Ice
5.4**cc
* Significantly different from the control at 5% level.
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
39
-------
TABLE 12. 1978 FILAMENTOUS FUNGAL PROPAGULE COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
June
July
June
July
Control
plot
78
62
12
19
Winter
plot
A. Horizon
19**
18**
C_ Horizon
5.6**
6.7**
Summer
plot
56**cc
43**cc
7.4**cc
12 **cc
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
TABLE 13. 1976 YEAST COUNTS* (x 10 /g soil) IN OILED AND
UNOILED (CONTROL) PLOTS
Sampling
time
a
February
June,
Jul?
August
September
^ , a
February
June,
July*
August
September
Control
plot
1.9
3.4
1.3
0.9
1.1
0.9
0.8
0.5
0.4
0.2
Winter
plot
A. Horizon
4.7**
320 **
31 **
44 **
12 **
C_ Horizon
1.0
2.9**
5.0**
7.4**
3.3**
Summer
plot
-
-
3.1**cc
640 **cc
650 **cc
-
-
0.7cc
64 **cc
290 **cc
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
40
-------
TABLE 14. 1977 YEAST COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
June
July
August
June
July
August
Control
plot
2.0
3.2
3.2
.19
.16
.20
Winter
plot
A. Horizon
32 **
14 **
6.3**
C.., Horizon
1.3**
2.7**
1.3**
Summer
plot
140
64
54
23
3.
3.
**cc
**cc
** cc
**cc
6**cc
6**cc
** Significantly different from the control at 1% level.
cc significantly different from the winter at 1% level.
TABLE 15. 1978 YEAST COUNTS (x 10 /g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
Control
plot
Winter
plot
Summer
plot
June
July
June
July
2.4
3.3
0.8
0.6
A. Horizon
38**
23**
Horizon
10**
11**
300**cc
95**cc
18**cc
24**cc
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
The response of proteolytic bacteria was monitored only during
1976. In both oiled plots, there were significant increases in counts
above their initial levels and relative to the control (Table 16). This
indicates a general stimulation of the proteolytic bacterial population
due to the oil applications, with the extent of stimulation being signifi-
cantly greater in the summer plot compared to the winter plot.
41
-------
TABLE 16. 1976 COUNTS (x 105/g soil) OF PROTEOLYTIC BACTERIA
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
o
February
June
Julyb
August
September
Q
February
June
Julyb
August
September
Control
plot
1.9
1.7
1.0
0.9
1.0
0.6
0.4
0.7
0.2
0.2
Winter
plot
AI Horizon
2.6
3.1**
100 **
57 **
95 **
C_ Horizon
0.6
6.3
23 **
5.1**
5.3**
Summer
plot
-
-
1.1 cc
1000 **cc
1100
-
-
0.2**cc
110 **cc
370 **cc
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
The effect of the oil spills on anaerobic bacterial counts were
followed only in the months of July and September in 1976. In the
winter plot, significant increases in counts relative to the control
plot occurred during both months; in the summer plot, significant
increases occurred in September (Table 17). These results indicate an
enhancement of anaerobic bacterial growth during the first growing
season after the spills. Loynachan (1978) reported similar findings on
the effect of oil on anaerobic bacteria.
The denitrifying bacterial population consistently showed signifi-
cant increases in both winter and summer plots relative to the control
plot (Figs. 18, 19 and 20). The significant increases in the denitrifying
bacterial numbers in the oiled plots suggest an increase in denitrifica-
tion potential and indicate a stimulatory effect of oil. This is in
agreement with findings of Lindholm and Norrell (1973). However, the
stimulatory effect of oil on the denitrifying bacterial population
seems to diminish with time. A decrease in population levels in both
oiled plots is apparent in 1978 relative to 1977 or 1976 levels, with
1977 counts being lower than 1976 counts.
42
-------
TABLE 17. 1976 COUNTS (x 105/g soil) OF ANAEROBIC BACTERIA
IN OILED AND UNOILED (CONTROL) PLOTS.
Sampling
time
Julya
September
Julya
September
Control
plot
5.1
3.0
2.0
2.0
Winter
plot
A. Horizon
54 *
36 **
C Horizon
7.7 **
4.5 **
Summer
plot
3.6cc
42 **
1.6cc
10 **cc
a Within 24 hours after summer oil spill.
* Significantly different from the control at the 5% level.
** Significantly different from the control at the 1% level.
cc Significantly different from the winter at the 1% level.
Microbial populations capable of utilizing cellulose as a sole
carbon source were monitored only in 1976. Cellulose-utilizing bacte-
rial numbers (Figure 21) increased in the winter plot relative to the
control. In the summer plot, this population was initially unaffected,
but by September significant increases in counts over the control occurred,
On the other hand, numbers of cellulose-utilizing fungi (Figure 22) re-
mained comparable to the control in both oiled plots. The significant
increase in cellulose-utilizing bacteria suggests stimulatory effects of
oil on this population.
In 1976 oil-utilizing yeasts and bacteria (Figures 23 and 24
respectively) in the winter plot were significantly increased relative
to the control. In the summer plot, counts of these oil-utilizing
populations were initially comparable to the control but by September
increases had occurred. The significant increases in the oil-utilizing
bacterial population in both oiled plots continued through 1978 (Figure
25). However for the oil-utilizing yeasts, significant increases rela-
tive to the control persisted through 1978 only in the AL horizon of
the summer plot (Figure 26). In the C horizon of both oiled plots,
counts of this yeast population were significantly higher than the con-
trol only in 1978.
43
-------
IO7
IO6
CO
o»
i io5
0>
O
u.
0>
| IO4
3
Z
IO3
4r)
m*m^^m
^*
^»
»
__
M
»
^M»
f^m^^m^
(»
MIM»
M^
M^i^
IM^
^^^^^
IM
!
»
^^
r
^~
- o
- o
V
«
t
A, Horizon
*
P
«
>
»
r
«
^
»
C
0
o
V
2 Horizon
m
M
O
? r
i
j
»
Mi
L»
2
z
=
^
cws cws cws cws
Jul Sep Jul Sep
Figure 18.
1976
MPN counts of denitrifying bacteria in oiled and
unoiled
(control) plots. C = Control Plot; W = Winter Plot; S =
Summer Plot; Brackets represent 95% confidence intervals.
44
-------
Horizon
!06r-
io5
(0
"QJ
O
Q)
A
E
3
IO4
IO3
o
o
IO2
r
o
o
Horizon
o
o
o
o
C WS
Jun
CWS
Jui
CWS
Aug
CWS
Jun
CWS
Jul
CW S
Aug
Figure 19. 1977 MPN counts of denitrifying bacteria in oiled and unoiled
(control) plots. C = Control Plot; W = Winter Plot; S =
Summer Plot; Brackets represent 95% confidence intervals.
45
-------
I06
I05
I04
o
T5
_o
E
D
I03
I02
10'
AI Horizon
Horizon
C w S
Jun
C W S
Jul
C W S
Jun
C W S
Jul
Figure 20. 1978 MPN counts of denitrifying bacteria in oiled and unoiled
(control) plots. C = Control Plot; W = Winter Plot; S =
Summer Plot; Brackets represent 95% confidence intervals.
46
-------
IU
I08
"5
(fl
(0
"5
o
«*-
o
W. 1 /~\ O
-------
I07
:= 10
O
O
Q.
O
- 10'
0)
10
10
A, Horizon
C2Horizon
C WS
Jul
Figure 22.
C W S
Sep
C WS
Jul
C W S
Sep
1976 MPN counts of cellulose-utilizing filamentous fungi in
oiled and unoiled (control) plots. C = Control Plot; W =
Winter Plot; S = Summer Plot; Brackets represent 95% con-
fidence intervals.
48
-------
o
0)
0)
o
0)
E
io8
I07
IO6
10 5
IO4
in3
MMM^
M
B
MM*
M»
m^B
^^^M
^Ml
»
>
MM»
»
IM^M
^^^B
^^M
^
i
A
»
i
^^
*
Horizon
M
»
«
«
^
1
mm^
C2Hor
^
r
»
^
^
MB
*M1
1
«
M
N
I
ft
*1
zon .
i
mm
^
«1
»
=
^
C WS
Jut
C
Sep
Jul
Sep
Figure 23. 1976 MPN counts of oil-utilizing bacteria in oiled and unoiled
(control) plots. C = Control Plot; W = Winter Plot; S =
Summer Plot; Brackets represent 95% confidence intervals.
49
-------
8
I07
o
CO
O
O
I0
E
13
I0
A| Horizon -r
C2 Horizon
r"
C W S
Jul
C W S
Sep
C W S
Jul
c ws
Sep
Figure 24. 1976 MPN counts of oil-utilizing yeasts in oiled and unoiled
(control) plots. C = Control Plot; W = Winter Plot; S =
Summer Plot; Brackets represent 95% confidence intervals.
50
-------
I08
107
I06
O
«4-
o
o> I05
.Q
E
3
I04
I03
A,
El Horizon
Horizon
cws
1977
CWS
1978
CWS
1977
CWS
1978
Figure 25.
1977 and 1978 MPN counts of oil-utilizing bacteria in oiled
and unoiled (control) plots. C = Control Plot; W = Winter
Plot; S = Summer Plot; Brackets represent 95% confidence
intervals.
51
-------
10'
I07
I06
o
**-
o
o> I05
.a
e
r Ai Horizon
!04
10
Horizon -i
C WS
1977
C WS
1978
C WS
1977
CWS
1978
Figure 26. 1977 and 1978 MPN counts of oil-utilizing yeasts in oiled
and unoiled (control) plots; C = Control Plot; W = Winter
Plot; S = Summer Plot; Brackets represent 95% confidence
intervals.
52
-------
In 1976, counts of the oil-utilizing fungal populations in both
oiled plots showed no significant change relative to the control (Fig-
ure 27). This trend continued through 1977 (Figure 28). In 1978 in-
creases relative to the control plot occurred in both horizons in the
summer plot and in the C2 horizon of the winter plot. However, the
increases may not be significant because of the unexplained decrease
in control plot (Dunts in 1978 relative to the preceeding years.
The effect of oil on in vitro soil respiration rate during 1976 is
shown in Table 18. An immediate depression of soil respiration rates
was apparent one day after the spill in both horizons of the winter plot
and in the C- horizon of the summer plot. However, by the end of the
growing season, the overall effect of oil on soil respiration rates was
one of enhancement. The higher respiration rate in the A. horizon of
the control plot in February relative to the other months is not too
surprising in view of the evidence presented by Greenwood (1968) that
freezing and thawing of soil results in increased organic matter decom-
position.
The enhancing effect of oil on soil respiration observed in 1976
continued into 1977 (Table 19) . This effect is greater in the A-^
horizon of the summer plot than in the winter plot, paralleling the
enhancing effect on microbial populations.
The effect of oil spills on soil respiration in situ is shown in
Table 19 and Figure 29. In 1976 and 1977, soil respiration rates were
not significantly affected by the addition of oil in cylinders with the
killed moss layer removed. However, in cylinders with the killed moss
layer intact, respiration rates were significantly increased. These
results suggest that the enhancing effect of oil on soil respiration
in situ may be due to an increase in available substrate from plants
killed as a result of the oil spill. It is interesting to note that the
in situ respiration rates were higher in the summer plot relative to the
winter plot in 1976 while the reverse was true in 1977. In 1976 (Table
20), respiration rates within a set of cylinders in the test plots had
standard errors ranging from 0.31 to 1.81. This high variation may be
due to a methodology artifact or more likely due to the heterogeneity of
the soil within each plot. Because of the suspected heterogeneity in
the test plots, 1977 in situ respiration measurements were pooled (Figure
29).
The soil pH of the site is generally 4.8 to 5.6. The addition of
oil did not appear to cause a significant change in soil pH (Appendix,
Table C-7. The soil water content in control plot and in both spill
plots 5 m downslope from the point of oil application in 1976 through
1978 is presented in Tables 21 and 22. These measurements show distinct
differences in water content among the three test plots. During 1977
and 1978 water content in both spill plots was less than the control
except for one sample date. Furthermore, the water content in the winter
plot was consistently lower relative to both the control and the summer
plots.
53
-------
107F
i: A, Horizon
10
o
/>
o»
§J05
o
ex
o
-------
I07
I06
o
(f)
o>
I05
Q)
O
a
o
CL |04
a>
X)
E
10
I02
r AI Horizon
Horizon -i
C ws
1977
cws
1978
CWS CWS
1977 1978
Figure 28.
1977 and 1978 MPN counts of oil-utilizing filamentous fungi
in oiled and unoiled (control) plots. C = Control Plot;
W = Winter Plot; S = Summer Plot; Brackets represent 95%
confidence intervals.
55
-------
8
CVJ
CM
E 4
CM
o
o
0
Without Dead
Moss Layer
With Dead
Moss Layer
Control Winter Summer
Figure 29. Respiration in situ in oiled and unoiled (control) plots in
1977. Histograms with dissimilar letters are significantly
different at 1% level. (Respiration rates are means of
three consecutive weekly determinations within each set of
cylinders.)
56
-------
TABLE 18. 1976 IN VITRO SOIL RESPIRATION RATES (mg C02/24 hr/100 g soil)
IN OILED AND UNOILED (CONTROL) PLOTS.
Sampling
time
«a
February
Julyb
Augus t
September
Control
plot
27.2
8.0
8.6
3.8
Winter
plot
A1 Horizon
11.2**
16.6**
15.6**
15.6**
Summer
plot
20.2**
30.6**cc
37.8**cc
Horizon
0
February
Julyb
Augus t
September
2.6
3.6
3.8
2.4
n. d.
6.0**
7.8**
5.6**
-
1.2**cc
6.2**
13.6**cc
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
n.d.Not detectable by method used.
* Significantly different from the control at the 5% level.
** Significantly different from the control at the 1% level.
c Significantly different" from the winter at the 5% level.
cc Significantly different from the winter at the 1% level.
TABLE 19.
1977 and 1978 IN VITRO SOIL RESPIRATION RATES (mg C02/24 hr/100 g
soil) IN OILED AND UNOILED (CONTROL) PLOTS.
Sampling
time
1977
June
July
August
June
July
August
1978
July
July
Control
plot
21.5
14.4
14.6
5.7
4.7
4.6
19.7
6.6
Winter
plot
A, Horizon
32.3**
17.1*
16.7
C~ Horizon
12.2**
9.5**
7.6**
A, Horizon
24.1*
10.3*
Summer
plot
79.9**cc
35.1**cc
41.5**cc
25.6**cc
8.5**
6.6*
31.4**cc
11.4**
* Significantly different from
** Significantly different from
cc Significantly different from
the control at 5% level.
the control at 1% level.
the winter at 1% level.
57
-------
TABLE 20. 1976 IN SITU SOIL RESPIRATION (g CO /24 hr/m ) IN
OILED AND UNOILED (CONTROL) PLOTS.
Date
Control plot
Winter Plot
Summer plot
June 10
July 16
August 3
August 12
September 1
a
4.7
3.7
4.8
2.2
2.9
b
_
-
4.6
3.3
1.6
c
7.0
5.1
5.8
4.8*
4.0
b
_
-
5.7
2.7
4.5
c
_
5.7
8.6*
5.7**
6.4
a Respiration cylinders embedded after removal of live moss layer.
b Respiration cylinders embedded after removal of dead moss layer.
c Respiration cylinders embedded without removal of dead moss layer.
* Significantly different from control at 5% level.
** Significantly different from control at 1% level.
TABLE 21. 1976 SOIL WATER CONTENT (%) IN OILED AND
UNOILED (CONTROL) PLOTS.
Sampling
time
o
February
June,
Jill?
August
September
Control
plot
295
214
155
113
95
Winter
plot
AI Horizon
154*
119*
122**
96
81**
Summer
plot
-
171* cc
162**cc
153**cc
a
February
June
Julyb
August
September
56
114
71
62
55
C9 Horizon
70
56**
71
63
50
_
99**cc
53**cc
83**cc
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
* Significantly different from control at 5% level.
** Significantly different from control at 1% level.
cc Significantly different from winter at 1% level.
58
-------
TABLE 22. 1977 and 1978 SOIL WATER CONTENT (%)
IN OILED AND UNOILED (CONTROL) PLOTS.
Sampling
time
1977
June
July
Augus t
Control plot
243
168
194
Winter plot
AI Horizon
102 **
77 **
74 **
C« Horizon
Summer plot
177
137
137
** cc
* cc
** cc
June
July
August
1978
June
July
June
July
92
62
60
159
146
64
58
62 **
48 **
46 **
AI Horizon
97 **
86 **
C? Horizon
59 **
55
105 ** cc
58 * cc
55 ** cc
190 ** cc
113 ** cc
70 ** cc
51 **
* Significantly different from the control at 5% level.
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
The concentrations of benzene-extractable oil in the oiled soil
samples are presented in Table 23. It is apparent that the oil con-
centrations in the AI horizon were higher than those in the C2. The
vertical migration of oil through the soil horizon with time is evident,
the distribution of oil in the soil layers of the winter plot being
different from the summer.
Although the concentration of oil was greater in the Aj_ layer, the
impact of oil was not limited to this horizon. Both AI and C2 layers
showed significant increases in microbial populations and respiratory
activity, and in the case of the filamentous fungal population, signifi-
cant reductions immediately following and up to the third growing
59
-------
TABLE 23. OIL CONTENT (%) IN SOIL 5 M DOWNSLOPE FROM
POINT OF OIL APPLICATION
Sampling
time
Winter plot
Summer plot
1976
Horizon
February
June,
July15
August
September
8.0
17.9
8.8
4.3
5.1
12.2
6.3
6.5
Horizon
February
June.
Jul?
August
September
0.2
0.1
1.5
1.0
1.4
1.3
0.2
0.9
1977
A.. Horizon
June
July
August
12.5
4.7
4.5
25.0
9.2
6.8
C_ Horizon
June
July
August
2.2
2.9
1.6
3.3
0.8
0.8
1978
June
July
9.3
9.0
A. Horizon
10.7
8.0
Horizon
June
July
2.1
1.4
0.9
0.3
a Within 24 hours after winter oil spill.
b Within 24 hours after summer oil spill.
60
-------
season after the oil spills. However, the response in the C^ layer was
sometimes slower to appear. In comparing the enhancing effect of oil in
the two horizons, its extent was generally greater in the A. than in the
C2 layer.
The relationship of respiration rates to microbial counts and the
relationship of oil concentrations to microbial counts and respiration
rates were also examined. Significant linear correlations were found
between in vitro soil respiration rates and numbers of heterotrophic
bacteria or filamentous fungi (Appendix, Tables C-8, C-9, C-10, and
C-ll). Similarly, in the oiled plots, significant linear correlations
were found between concentrations of oil and in vitro soil respiration
rates or microbial numbers (Appendix, Tables C-14 to C-21).
The data indicate that the soil microbial populations showed a
rapid and differing response during the first year after the oil spills.
Immediately after the summer spill the initial depression in numbers of
heterotrophic bacteria and filamentous fungal propagules, and in res-
piratory activity appear to be due to toxicity of volatiles present in
the crude oil. At the time of the spill in July, concentrations of
volatiles in the summer plot exceeded those in the winter plot. How-
ever, loss of volatiles in the spilled oil was faster in the summer plot
than in the winter plot. By the second growing season, greater con-
centrations of volatiles are present in the soil in the winter than in
the summer plot.
At the end of the first growing season in the summer plot, counts
of filamentous fungi and heterotrophic bacteria, and soil respiratory
activity significantly exceeded initial summer and control levels. In
the winter plot, numbers of filamentous fungal propagules were reduced
immediately after the spill and remained depressed throughout the
initial plant growing season, although bacterial counts and soil respira-
tion rates were significantly higher than in the control by the end of
the first season. During the second and third growing seasons, signifi-
cant reductions in filamentous fungal propagules were evident not only
in the winter plot but also in the summer plot while significant in-
creases in counts of heterotrophic bacteria and yeasts occurred.
It is apparent that filamentous fungi are more sensitive to the
presence of oil and in fact were adversely affected by the oil spills.
The extent of inhibition by the oil was greater in the winter plot than
in the summer plot. The effect of oil on this microbial population could
be due to direct toxicity of the oil components or may be related to the
aeration status in the oiled plots. Significant amounts of volatiles,
particularly the C5-Cs fractions, were found up to the second growing
season in the organic and mineral soil layers of both oiled plots. Con-
centrations were higher in the winter plot. Other workers (Teh and Lee,
1973, 1974) have shown that mycelial growth and spore germination of some
61
-------
fungi are inhibited by n-hexane, n-heptane and n-octane which are compo-
nents of the volatile fraction of oil. Also, filamentous fungi as a
group are strict aerobes (with a few exceptions). When oxygen diffusion
becomes inadequate to meet the microbial demand for aerobic metabolism, the
fungi are first to suffer (Alexander, 1977). The significant increases
in numbers of anaerobic and denitrifying bacteria in the oiled plots
suggest the possibility of decreased oxygen availability in the oiled
plots. The differences in the mode of flow, concentration, and physical
properties of the spilled oil in the winter and summer plots may ac-
count for differences in aeration status.
Because of oil damage on higher and lower plants shown by other
studies (Hunt ^t al., 1973; McCown et al^., 1973; Miller et^ al. , 1978;
Antibus and Linkins, 1978), the input of plant residues into the soil
system in oil perturbed areas may be considerable. In this study,
during the first year of the spills, damage to vegetation was similarly
observed, the damage being more rapid and extensive in the summer plot
(in the heavily oil impacted areas). This coincides with our finding of
greater increases in microbial populations and soil respiration rates
in the summer plot compared to the winter plot. This suggests that the
increase in levels of soil microbial populations and activity may be
due not only to the presence of petroleum substrate but also to the
presence of substrates released from dying or dead plants. It can be
postulated that readily available carbon substrates are released rapidly
by the solvent action of oil on plant cell membranes. The burst of
microbial growth and respiratory activity observed shortly after the oil
spills may have been triggered by the sudden release of readily utiliz-
able carbon substrates from plants in addition to those present in the oil.
A lag time may occur before oil is utilized because of the time needed for
development of microbial populations capable of degrading oil and because
of the adaptive nature of hydrocarbon enzymes (Zobell, 1950; Van der
Linden and Thijsse, 1965). However we did not determine this in our study.
We did observe significant increases in oil-utilizing bacteria and yeasts
two months after the summer spill and five months after the winter spill.
Increases in these populations may have occurred sooner but earlier enu-
merations were only done 24 hours after the summer spill.
Soil respiration rates measured in the test plots give an index of
organic matter decomposition under field conditions. The data on in
situ respiration showed an enhancement of soil respiratory activity
in the presence of oil and plants killed by the oil but no effect on
respiration when killed plant material was removed. This suggests that
the enhancing effect of oil on 1976 and 1977 soil respiration in situ
is indirect, that increased respiration may be due to increased decompo-
sition of carbon substrate released when vegetation was damaged by the
oil spills.
62
-------
This study has shown that growth of some microbial populations has
not been adversly affected. For the most part, growth has been increased
by the oil applications. This suggests that nutrient transformations
carried out by these populations may be stimulated. However, the actual
activity of these functional groups is determined by a balance of the
physiological requirements of the microorganisms and the existing
environmental conditions. It is interesting to note that in soil samples
collected from the treatment plots, microbial counts correlated signifi-
cantly with metabolic activity, i.e. soil respiratory activity.
Future studies are required to determine the effects of spilled oil
on different microbial processes in the carbon and nitrogen cycles, such
as nitrogen-fixation, denitrification, nitrification and ammonification,
and cellulose degradation.
The soil microbial populations showed a differential response
through the third growing season after the hot oil spills. Although the
effects ranged from inhibition to stimulation, stimulation of growth of
the indigenous soil microorganisms and their activities seems to pre-
dominate. Effects of oil appear to be both direct and indirect but
mechanisms involved need further study. Additional information is
necessary to determine whether microbial populations continue to sustain
their levels as oil damaged plant substrates are depleted, and whether
they may then utilize oil as the main substrate. With the vast amount
of carbon present in crude oil, it is inevitable that nutrient limita-
tions will occur. Consideration must be given to type and timing of
nutrient additions and to other means of enhancing natural recovery
processes such as improving aeration.
Oil Effects on Vegetation
Following application of the oil, vegetation damage was assessed
visually via changes in leaf color and leaf fall. There were three main
time frames for injuries: 1) immediate; 2) occurring during the initial
growing season; and 3) cumulative, occurring after the initial growing
season. Toxicity probably caused immediate injuries while delayed
injuries may either be due to indirect (physical) effects or to a combi-
nation of toxic and indirect effects.
Virtually all above ground foliage that came into contact with the
oil was quickly killed. Turbidity was immediately reduced and foliage
appeared dead within several days. In the winter spill the foliage was
dead when it was first observed in mid-May after snowmelt. Evergreens
such as cranberry retained the damaged foliage longer than deciduous
species such as birch. The zone of contact was generally limited to the
immediate areas below the 5-m wide oil feeder and to areas of low relief
in the path of aboveground flowing oil (Figure 9b). Lichens and mosses,
which tend to be concentrated in low areas and have a low-growth form,
63
-------
suffered particularly heavy mortality. In contrast, cottongrass tussocks
with a raised, upright growth form and species growing on areas of
higher relief kept most of their aboveground biomass above the oil.
These species continued to grow and flower, at least initially, despite
their being surrounded by oil (Figure 30).
Figure 30.
Cottongrass tussocks growing despite being surrounded by
surface oil and dead moss and lichens.
Since oil flowed into depressions and low areas, aboveground vege-
tation on higher relief was not in physical contact with the oil.
Belowground contact was difficult to accurately ascertain since the
nature of the study would not permit large-scale destructive sampling of
roots and soil.
However, the soil pits dug in August, 1978 provided some evidence
of species differences in rooting habits and the extent of belowground
oil contact (Figure 31). Very few (less than 10%) roots extended into
the mineral soil (C_) and these were all observed to be less than 1 mm
in diameter. Some species (Vaccinium uligonosum, Rubus chamaemorus,
Picea mariana) had roots which were concentrated in the Oj and upper 02
soil horizon but extended into both the Aj and C2 horizons. Since the
oil in most cases flowed within the 02 horizon it contacted roots of
most species to at least some extent.
In contrast to the other species observed on the site, cottongrass
tussock roots have primarily a vertical orientation instead of the more
commonly observed horizontal growth. Eriophorum vaginatum produces new
-------
Figure 31. Soil pit for determining rooting habits and belowground oil
movement. (Note dark band of oil just above light colored
mineral soil.)
roots annually which grow down following the receding frozen soil layers
as the growing season progresses (Chapin et al., 1979). In a soil pit
34 m downslope on the summer spill plot, cottongrass roots that appeared
vigorous and white had grown into the G£ horizon after penetrating 9 cm
of oil soaked soil, mainly within the 0_ horizon (Figure 32). Thus
cottongrass, by both its aboveground tussock growth form and its below
ground vertical rooting strategy minimizes the amount of biomass which
is in contact with oil. This undoubtedly helps to account for the low
mortality of cottongrass in the contaminated areas.
Damage during the first growing season varied with such factors as
species, position on slope, growth form, and season of spill. In gen-
eral, delayed injuries first appeared on foliage that was above the path
'
-------
Figure 32. Cottongrass (Eriophorum vaginaturn) roots growing through
oil soaked soil.
of the oil and near the top of the plot. Injuries subsequently appeared
farther downslope and in areas of subsurface flow immediately adjacent
to surface oil. Deciduous leaves turned brown and abscised prior to
evergreen leaves. For example, in the summer spill, resin birch foliage
turned brown 5 m downslope two weeks after the spill, but did not turn
brown at 10 m until four weeks after the spill. In contrast, Labrador
tea and cranberry leaves had only turned partially brown 10 m downslope
at the end of the growing season (six weeks). Black spruce had some of
the most delayed damage of any species. Although spruce in the upper
2 m of the winter spill began dropping needles by mid-June, the needles
had not entirely dropped until September. On the summer spill the
needles turned brown on several spruce and many had chlorotic foliage by
September. Most needles remained on the trees at that time.
66
-------
The nutrient analysis of black spruce foliage indicated a signi-
ficant decrease from 1975 to 1976 in the total nitrogen content of the
new foliage of trees exposed to oil (Table 24). Total phosphorus and
total potassium did not show consistent changes. Although there was
significant year-to-year variability in total nitrogen, the magnitude of
the nitrogen decrease on the oiled plots was great enough to be statis-
tically significant at the 5% level when compared with either the con-
trol plot during the same year or with the same plot from the previous
year when it was unoiled. The decrease in nitrogen content may be due
to: 1) disruption of the metabolism of root nutrient uptake; 2) coating
of the roots by a hydrophobic layer of oil which physically interferred
with nitrogen uptake; 3) immobilization of nitrogen by increased micro-
bial growth, in response to addition of readily utilizable carbon sub-
strates, or 4) some combination of these effects.
TABLE 24. NUTRIENT CONTENT OF BLACK SPRUCE FOLIAGE.
Avg/Std.Error Avg/Std.Error Avg/Std.Error
Year Treatment %N* %P* *£
1975 Control 0.91 (.03) a 0.07 (.01) a 0.56 (.04) a
(unoiled) Summer 0.90 (.02) a 0.08 (.01) a 0.54 (.01) a
winter 0.94 (.03) a 0.09 (.00) a 0.57 (.01) a
1976 Control 1-05 (.04) a 0.11 (.00) a 0.35 (.00) a
(oiled) Summer 0.75 (.06) b 0.10 (.01) a 0.32 (.01) b
Winter 0.86 (.02) b 0.10 (.00) a 0.37 (.00) a
* Figures with a common letter are not significantly different at the 5%
level using the t-test. Comparisons are made within years and within
columns.
Cumulative injuries were largely limited to evergreen species.
During the second growing season increasing amounts of black spruce
foliage became chlorotic, turned brown, and abscised. Similarly, foil
age of cranberry and Labrador tea continued to turn red and then brown
throughout the second growing season so that some injuries were apparent
as far downslope as 25 m on the winter spill and 35 m on the summer
spill. Cumulative injuries could be due to a combination of direct oil-
caused stress and problems of overwintering. This mechanism has also
been suggested by other studies (McCown et al., 1973; Linkins and Anti-
bus, 1978).
67
-------
The number and distribution of the killed black spruce trees and
saplings due to the oil is shown in Table 25. The total number of black
spruce trees killed over three growing seasons is similar on both spills,
but mortality was more delayed on the winter spill.
TABLE 25. MORTALITY OF BLACK SPRUCE
Thru 1977 1978
Max. Total Max. Total 3 Year
Distance Trees Distance Trees Total
Downslope (m) Killed Downslope Killed Mortality
Summer 10 26 10 2 28
Spill
Winter 9 ?0 20 10 30
Spill
The roots of the black spruce are concentrated in the Oj and 02
horizons and extend further away from the stem than do the roots of most
smaller species. Therefore the black spruce are not as likely as other
species to have their entire root systems surrounded by oil but are
more likely to have some roots in contact with the oil. The very slow
mortality of the black spruce may be due in part to chronic toxicity or
physical stresses on a portion of the root systems that continues to
increase for three or more years (Freedman and Hutchinson, 1976; Hutchinson
and Freedman, 1978).
Table 26 presents a comparison of vegetation data from the perma-
nent quadrats before and after the winter and summer spills. Quadrats
were grouped into 3 categories: 1) areas impacted by surface flows of
oil, 2) areas impacted by subsurface oil flows, and 3) controls - un-
disturbed areas. Surface flow areas showed the most severe effects in
both spill plots. Live ground cover was most reduced on the upper 5 m
of the winter spill but was also reduced on most of the surface oiled
summer spill.
It is difficult to accurately compare the summer and winter spill
quadrats because the oil flowed off to the side of the winter plot.
Only three permanant quadrats on the winter spill were impacted in
comparison to twelve on the summer spill. However, damage was more
severe in both spill plots on areas of surface flow where the oil could
contact both above and belowground plant parts. There were 76.3 m^ of
surface flow on the winter spill in comparison to 30.3 m^ on the summer
spill. This would imply that the real extent of severe vegetation
injury (as defined by a decrease in total live ground cover) was greater
on the winter spill. Stem counts of shrub species readily indicated
68
-------
TABLE 26. PRE (1975 & 1976) AND POST-SPILL (1978)
VEGETATION ANALYSIS (AVE. CHANGE)
Control
Winter Spill
Summer Spill
VO
Species or Category
Oiled ground-cover*
Frequency of occurrence
Trees
Picea mariana (trees) -cover
number of individuals
occurrence
(saplings) cover
number of individual
occurrence
Medium and low shrubs
Betula glandulosa-cover
number of stems
occurrence
Ledum groenlandicum-cover
number of stems
occurrence
Ledum decumb ens- cover
number of stems
occurrence
Vaccinium uligonosum-cover
number of stems
occurrence
Vaccinium vitis-idaea
L.- cover
occurrence
Dwarf shrubs and herbs
Rubus chamaemorus L. -cover
number of leaves
occurrence
Equisetum sylvaticum
L.- cover
occurrence
£3
Surface flow Subsurface flow Surface flow Subsurface flow
0
0,0
0
0
43,43
-33
0
43,43
0
-.6
100, 100
-4
-24
71, 71
0
-14
86, 86
-2.9
-5.3
100, 100
-43
100, 100
0
+ .25
57, 57
-10
71, 57
+80
0,100
-50
-2
100,0
-40
-4
100,0
-20
-4
50, 0
-25
-82
100,0
-
-
0,0
-30
-35.5
100, 0
-25
100, 50
-10
-3.5
100, 50
-10
100, 0
0
0,0
-10
-
0,0
-
-
0,0
0
0
100, 100
+10
-5
100, 100
-10
-4
100, 0
-20
-105
100, 100
0
100, 100
0
-5
100, 100
-10
100, 0
+43
0,100
-10
-15
33, 17
-15
-1
33, 17
-15
-7.5
100, 67
-5.6
-25.7
100, 83
-4
-17.6
83, 67
-5.6
-39.3
100, 83
-10
100, 100
-8.3
-15.8
100, 33
-10
50, 0
0
0,0
-5
-1
33, 17
0
-.5
33, 33
+23
-3.7
100, 200
+2
-6.4
83, 83
+1.7
-17.2
100, 100
0
-13.7
100, 100
+3.3
100, 100
+5
-6.2
100, 83
-10
33, 0
-------
TABLE 26. (Cont'd)
Control
Winter Spill
Summer Spill
Species or Category
Petasites hyperboreus
Rydb. -cover
number of leaves
occurrence
Eriophorum vagina turn
-cover
occurrence
Graminae: cover
occurrence
Mosses
Total: cover
occurrence
Pleurozium schreberi
(Brid) Matt-cover
occurrence
Polytrichum spp-cover
occurrence
Dicranum spp-cover
occurrence
Sphagnum spp-cover
occurrence
Lichen
Total: Cover
occurrence
Cladonia spp-cover
occurrence
Cetraria spp-cover
occurrence
Pel tig era spp-cover
occurrence
Total live ground cover
+3.3
+ .67
14, 28
-5.7
100, 100
+14
0, 14
-1.7
100, 100
-8.6
100, 100
-1.4
100, 71
-4.3
86.71
+5
57, 57
-12.9
100,
-8.7
100,
+ 1.4
100,
-10
100,
0
Surface flow
-10
-.15
100, 0
-15
100, 50
-
0,0
-60
100, 50
-35
100, 50
-20
100, 0
-20
100, 0
-
0,0
-35,
100, 50
-30
100, 50
-20
100, 50
-20
100, 0
-60
Subsurface flow
-20
-3
100, 0
0
100, 100
-
0,0
+10
100, 100
+10
100, 100
-10
100, 0
+10
100, 100
-
0,0
0
100, 100
0
100, 100
+10
100, 100
-10
100, 0
0
Surface flow Subsurface flow
_
0,0
0
100, 83
+1.4
0, 14
-8.3
100, 100
-10
100, 100
-4
83, 60
-5
67, 50
-6.7
100, 100
+ 1.7
100, 100
+ 1.7
100, 100
-5
100, 67
+6
50, 100
-16.7
0,0
0
100, 100
-
0,0
+10
100, 100
+5
100, 100
-3.3
50, 100
+1.7
100, 100
+10
83, 83
+6.7
100, 100
+5
100, 100
-4
83, 50
-2
83, 83
-3.3
* Ave. change in % vegetation cover
Pre-spill followed by post-spill frequency
a:l quadrat only
-------
injury within surface flows. Blueberry was especially susceptible
(Table 26). This could be explained by its very shallow rooting habit.
Resin birch and both species of Labrador tea were also readily injured.
Mosses and lichens were completely killed in quadrats with 80% of oiled
ground cover, but were only reduced in areas of less extensive surface
flow. Damage was most severe in the upper 10 m of the spills. Within
this area surface flows generally covered a greater percentage of the
ground and the penetration of the oil into the soil was greater (Figures
10 a-e).
Areas of subsurface flow had much less damage. Live ground cover
was not reduced. Mosses and lichens appeared healthy but shrubs and
black spruce were sometimes affected. Blueberry and cloudberry were
reduced in number of live stems while some black spruce trees and shrubs
were killed.
In summary, damage appeared more rapidly on the summer spill. This
could have been due to the more rapid flow downslope or the oil remain-
ing hotter for a longer period. Both of these factors could increase the
rate of uptake of toxic components by plant roots. In addition, actively
growing vegetation was subjected to greater contact with volatiles on the
summer spill since the vegetation was dormant at the time of the winter
spill. Many of the volatile components were lost prior to the start of
the first growing season following the spill on the winter plot (Figure
13 and Table 3). On both plots deciduous species showed a more rapid
browning of foliage, with resin birch being the most susceptible.
Blueberry and cloudberry were more delayed. Evergreen species continued
to exhibit new injury symptoms throughout the second growing season.
Foliage of Labrador tea and cranberry was still alive in the second
season in areas where all deciduous foliage was dead. Primarily during
the second growing season, some foliage of species outside the areas of
surface flows turned brown and abscised.
An important characteristic of both spills is that no regrowth has
been seen on any species which lost its foliage as a result of oil
damage. This result is in direct contrast to other reported studies
(Hutchinson and Freedman, 1975 and 1978; Wein and Bliss, 1973) and
probably is the result of root damage as pointed out by McCown et al.
(1973).
No regrowth or invasion by new individuals has occurred within
areas of surface flow. Observations of an earlier (1971) CRUEL crude
oil spill at Fox, Alaska, showed a similar situation except that feather
mosses had begun to encroach upon part of the surface flow area after
six growing seasons. However, the Fox site was considerably wetter
than the Poker Creek site.
71
-------
The two large actual spills along TAPS did show more regrowth. The
valve 7 spill, which was primarily a spray spill, showed extensive
recovery of both sedge and shrub species one year after the original
spill. The subarctic Steele Creek spill site was bladed by a bulldozer,
while the ground was frozen, and was subsequently burned twice, in May
and June, 1978. Portions of the spill were later tilled and/or fertilized
but were not seeded. By September, 1978 sedges and bluejoint reedgrass
(Calamagrostis canadensis) were regrowing in some areas of the spill (Figure
33). At both of these sites soil moisture was much higher than in the
CKREL spill site. Therefore, the oil would not have penetrated so
deeply into the soil so that regrowth could occur from belowground
vegetative parts.
Figure 33. Steele Creek oil spill along the trans-Alaska Pipeline
System. (Note regrowth of bluejoint reedgrass in the
foreground.)
Others have reported that intensive point spills are less damaging
than dispersed spray spills (Hutchinson and Freedman, 1978). However,
the valve 7 spray spill showed good recovery probably because of low
concentrations of oil per unit area.
72
-------
Root respiration was reduced at all oiled sites, with the summer
spill showing the greatest decrease (65%; Table 27). Studies on respir-
ation quotients (RQ), although limited, suggest that these RQ values
were raised by exposure to the crude oil in this study in contrast to
arctic studies which showed decreased RQ's (Linkins and Antibus, 1978).
TABLE 27. RESPIRATION OF ECTOTROPHIC MYCORRHIZAL FEEDER ROOTS.
DATA FOR 02 AND C02 GIVEN AS THE MEAN OF THREE EX-
PERIMENTS IN y GAS/HR G DRY WT RQ = RESPIRATORY QUO-
TIENT (FROM A.E. LINKINS, VPI)
Control
02 219
C02 155
RQ 0.71
Summer (6 m downslope)
0 77 (65% decrease)
C02 63
RQ 0.81
Summer '(21 m downslope)
0 163 (26% decrease)
co2 in
RQ 0.68
Winter (6 m downslope)
0 152 (31% decrease)
C02 154
RQ 1.02
The results of the vegetation study are consistent with the physical
and chemical changes of the oil as well as the microbial responses. The
two mechanisms hypothesized for oil induced vegetation damage are direct
toxicity and indirect physical disruption of plant functions by the oil.
Distance downslope reduces both toxicity, since the most toxic compo-
nents are volatiles which are rapidly lost, as well as physical dis-
ruption, since oil concentrations are reduced. Surface flows increase
both toxic and physical effects since they lead to contact of oil of
both above and below ground plant parts. However the relative impor-
tance of these two factors is not known.
73
-------
Subsurface flows will make contact with roots of different species
to varying extents because of differences in rooting habits. In addi-
tion, species may vary in their tolerances to contact with crude oil.
There may be critical levels of oil concentrations below which plant
species are undamaged. Both species' rooting habits and tolerances can
influence differential susceptibility to accidental spills.
The more rapid vegetation damage on the summer spill may be due in
part to a high initial concentration of volatiles. However the winter
spill had higher levels of toxic components during the second and third
growing seasons. Viscous, tarry oil on surface oiled areas of the
winter spill reduced infiltration and may have decreased soil moisture.
These factors may be responsible for the delayed mortality of the black
spruce on the winter spill. By the end of the third growing season, the
winter spill with its 250% greater area of surface flow may have more
total vegetation damage than the summer spill because of these differences.
Both the nature of injury and the lack of vegetative recovery have
important implications for restoration following oil spills. The lack
of reinvasion by seedlings may be due to the hydrophobic surface of the
oil-soaked moss layer (Deneke ^t a.1. , 1975; McGill, 1977). However,
even if the hydrophobic surface were disrupted to allow for germination
as suggested by McGill (1977) the problem of toxic components of oil
within the soil might persist for a number of years. In addition,
restorative measures which disrupt the surface organic mat on a permafrost
site pose a threat to the thermal stability of the area.
Conclusions
The response of a subarctic permafrost community to a massive intro-
duction of crude oil is represented in Figure 34.
Crude petroleum spilled onto subarctic permafrost slopes penetrates
the moss layer. During periods of thaw the oil moves into and saturates
lower organic layers of the soil. The oil then spreads downslope and
largely follows drainage channels; this spread is concealed by the moss
cover. Thus the area actually contaminated is always larger (2.5 to
10 times) than the area where oil is readily visible on the surface.
Topography will have a significant effect upon the amount of land con-
taminated.
In winter, snow cover reduces the initial extent of areal spread,
but such cover also provides additional concealment as warm oil can
penetrate the snow and move along and into the underlying moss and organic
soil layers.
74
-------
Oil spilled on
subarctic perma-
frost slope
Albedo
changes
\
Saturation and'
S penetration of
urface moss layer
T
Volatilization
Increase in active
layer depth
Partial loss of
contaminant from
community
Foliar contact
Summer or
following snowmelt
Saturation of
specific soil
organic layers
\
Crude oil
degradation
Death of foliage
Movement
excess oil
downslope
Root contact/
stress, and death
Initial depression
of microorganism
activities
Plant damage
and death
*
Release of
substrates
Stimulation of
some groups of
microorganisms
Figure 34. Flowchart representing the observed effects of a massive
crude oil spill on a subarctic permafrost site. These
responses have been observed during the first three growing
seasons after the oil spill. Dashed lines indicate reac-
tions that have not been confirmed.
75
-------
Oil introduction into this ecosystem represents a strong perturba-
tion. Major changes in microorganism populations are evident. Foliage
immediately in contact with the contaminant is killed and slow death can
occur to plants that have roots exposed to the moving underground oil
mass. Some species appear resistant to the effects of crude oil in the
soil.
Crude oil contaminated areas in subarctic regions may not be stabil-
ized even several growing seasons after the spill. Death of plants,
microbial changes, oil compositional changes, and increases in the active
layer may continue for an undetermined time period.
Although volatiles in crude oil near the soil surface are lost
rapidly after a spill, in the lower soil horizons some of even the
most volatile components of the crude can remain for some time. No
evidence for the rapid biological degradation of the oil has been
obtained. In addition, no evidence of recovery by seedling establishment
on oil contaminated surfaces has been observed during the first three
growing seasons after the spill.
It appears that a. crude oil contaminanation will be damaging,
although not catastrophic to a subarctic community for many decades.
Recommendations
Based on the results obtained in this three year study, the fol-
lowing recommendations are made:
1) Consideration should be given to a "no clean-up strategy" for small
spills in subarctic permafrost areas (a few thousand gallons or less),
where no surface water course is involved and ready access is not avail-
able. Providing access to a site can be more destructive of sensitive
permafrost areas than the spilled oil. In any case, the size of the
spill should be considered since very large spills could have much greater
impact. Also the type of spill and product spilled will have varying
effects, however, these were not a consideration in this study.
2) Reaction to large summer oil spills needs to be rapid to minimize
the area impacted in the incident since the oil will continue to move
downslope for weeks following spillage. Reaction to winter spills can
be delayed since the oil will initially impact a much smaller area and
downslope flow will quickly stop as the oil cools. Clean-up operations
should be completed before snow melt when the oil may remobilize and
impact additional unaffected areas.
3) Research at the present site needs to be continued in order to
determine long-term changes. The uniqueness of the site in terms of
background information and size of the spills should be fully utilized
for future studies.
76
-------
4) Long term changes in chemical composition of the oil and the rate of
encroachment by native species of vegetation onto oil saturated areas
need to be determined.
5) The environmental factor(s) limiting oil degradation (e.g. tempera-
ture, moisture, nutrient availability, aeration, etc.) needs to be
documented in order to devise appropriate restorative measures and to
assess the importance of such environmental factors for natural recovery.
For example, soil moisture data in this study indicate reduced moisture
in heavily oil contaminated soil but aeration has not been measured.
77
-------
LITERATURE CITED
Alexander, M. 1965. Denitrifying bacteria. In: Black, C. A. (ed.).
Methods of soil Analysis. Part 2. Chemical and Microbiological
Properties. Wisconsin: American Society of Agronomy, pp. 1484-
1486.
Alexander, M. 1977. Introduction to soil microbiology. 2nd ed.
New York, John Wiley and Sons, Inc.
Antibus, R.K. and A.E. Linkins. 1978. Ectomycorrlizal fungi of Salix
rotundifolia Trantv. I. Impact of surface applied Prudhoe crude
oil on mycorrhizal structure and composition. Arctic, 31:366-386.
Arctic (1978) 31(3)
Atlas, R.M. 1977. Stimulated petroleum biodegradation. CRC Critical
Reviews in Microbiology. 6, (3): 371-386.
Bailey, N.J.L., A.M. Jobson and M.A. Rogers, 1973. Bacterial degradation
of crude oil: Comparison of field and experimental data. Chemical
Geology. 11:203-211.
Bushnell, L.D. and H.F. Haas. 1941. The utilization of certain hydro-
carbons by microorganisms. Journal of bacteriology. 41: 653-673.
Campbell, W.B., R.W. Harris and R.E. Benoit, 1973. Response of Alaskan
tundra microflora to crude oil spill. Proceedings, Symposium on
the Impact of Oil Resource Development on Northern Plant Communities.
Fairbanks, Alaska: University of Alaska Institute of Arctic Biology:
Occasional Publications on Northern Life No. 1). pp.53-61.
Chapin, F.S. Ill, K.VanCleve, and M.C. Chapin, 1979, Enhanced soil temper-
ature and nutrie t cycling in the tussock growth form Eriophorum
vaginaturn, J. Ecol. 67: 169-189, 1979.
Cochran, W.G. 1950. Estimates of bacterial densities by means of the
"most probable number". Biometrics 6: 105-116.
Coleman, D.C. 1973. Soil carbon balance in a successional grassland.
Oikos 24: 195-199.
Cook, F.D. and W.S. Westlake. 1974. Microbiological degradation of
northern crude oils. Environmental-Social Committee. Northern
Pipelines. Task Force on Northern Oil Development. Report No. 74-
1. Information Canada, Cat. No. R72-12774. Vancouver, B.C.,
Canada.
Crum, H.A., W.C. Steere and L.E. Anderson. 1973. A new list of mosses of
North America north of Mexico. Bryologist. 76:85-130.
78
-------
Davis, J.B. 1967. Petroleum Microbiology. Elsevier Publishing Company,
Amsterdam.
Deneke, F.J., B.H. McCown, P.I. Coyne, W. Rickard and J. Brown. 1975.
Biological aspects of terrestrial oil spills - USACRREL oil
research in Alaska 1970-1974. Hanover, New Hampshire: U.S. Army
Cold Regions Research and Engineering Laboratory. Research Report
346.
Duncan, D.G. 1955. Multiple range and multiple F tests. Biometrics. 11: 1-42.
Freedman, W. and T.C. Hutchinson. 1976. Physical and biological effects
of experimental crude oil spills on low arctic tundra in the vicinity
of Tuktoyaktuk, NWT, Canada. Canadian Journal of Botany. 54:2219-2230.
Funk, H.B. and T.A. Krulwich, 1964. Preparation of clear silica gels
that can be streaked. Journal of Bacteriology. 88: 1200-1201.
Gardner, W.H. 1965. Water content. In: Black, C.A. (ed.). Methods
of Soil Analysis. Part 1. Physical and mineralogical properties
including statistics of measurement and sampling. Wisconsin: American
Society of Agronomy, pp.82-125.
Greenwood, D.J. 1968. Measurement of microbial metabolism in soil. In:
Gray, T.R.G., and Parkinson, D. (eds.). The Ecology of Soil Bacteria.
Liverpool: University Press, pp.138-157.
Griffiths, E. and M.A. Siddiqi. 1961. Some factors affecting occurrence
of Fusarium culmorum in soil. Transactions of the British Mycological
Society. 44(33);343-353.
Hale, M.E., Jr. and W.L. Culberson. 1966. A third checklist of the lichens
of the continental United States and Canada. Bryologist. 69;141-182.
Horowitz, A. and R.M. Atlas, 1977. Continuous open flow-through system
as a model for oil degradation in the Arctic Ocean. Applied and
Environmental Microbiology. 33: 647-653.
Hulten, E. 1968. Flora of Alaska and neighbouring territories. Stanford,
California; Stanford University Press, 1008p.
Hunt, P.G. 1972. The microbiology of terrestrial crude oil degradation.
Hanover, New Hampshire: U.S. Army Cold Regions Research and Engineering
Laboratory, Special Report 168.
Hunt, P.G., W.E. Rickard, F.J. Deneke, F.R. Koetz and R.P. Murrmann,
1973. Biological effects Terrestrial oil spills in Alaska:
Environmental effects and recovery. Reprint from "Proceedings of
Joint Conference on Prevention and Control of Oil Spills, March
13-15, 1973. Washington, D.C." (available) Hanover, New Hampshire:
U.S. Army Cold Regions Research and Engineering Laboratory.
79
-------
Hutchinson, T.C. and W. Freedman: 1975. The impact of crude oil spills
on arctic and subarctic vegetation. In: Proceedings of the Circum-
polar Conference on Northern Ecology, September 15-18. Ottawa.
1:175-182.
Hutchinson, T.C. and W. Freedman, 1978. Effects of experimental crude
oil spills on subarctic boreal forest vegetation near Norman Wells,
N.W.T., Canada. Canadian Journal of Botany 56:2424-2433.
Hutchinson, T.C., J. Hellebust and M. Telford. 1974. Oil spill effects
on vegetation and soil microfauna at Norman Wells and Tuktoyaktuk,
N.W.T. Environmental-Social Committee, Northern Pipelines, Task
Force on Northern Oil Development. Report no. 74-14. Information
Canada, cat. No. R57-10/1974, Vancouver, B.C., Canada.
Jenkins, T.F., L.A. Johnson, C.M. Collins, and T.T. McFadden. 1978.
The physical chemical and biological effects of crude oil spills
on Black spruce forest, Interior Alaska. Arctic 31: 305-323.
Jobson, A., F.D. Cook and D.w.S. Westlake. 1972. Microbial utilization
of crude oil. Applied Microbiology, 23:1082-1089.
Johnson, L.F. and E.A. Curl., 1972. Method for research on the ecology
of soil-borne plant pathogens. Minnesota: Burgess Publishing
Company, pp.106-107.
Kator, H., C.H. Oppenheimer and R.J. Miget. 1971. Microbial degradation
of a Louisiana crude oil in closed flasks and under simulated field
conditions, proceedings of the Joint Conference on Prevention and
Control of Oil Spills, American Petroleum Institute. Washington,
D.C., p.287-296.
Leggett, B.C. 1979. Determination of dissolved nitrogen and oxygen in
water by headspace gas chromatography. CRREL Special Report 79-24.
Lehtomaki, M. and S. Niemela. 1975. Improving microbial degradation of
oil in soil. AMBIO. 4 (3):126-130.
Lindholm, G.P. and S.A. Norrell, 1973. Effects of perturbation nutrient
addition and oil spillage on soil nitrogen cycling at the College
hot pipe test site. Proceedings, Symposium on the Impact of Oil
Resource Development on Northern Plant Communities. Fairbanks,
Alaska: University of Alaska (Institute of Arctic Biology,
Occasional Publications on Northern Life No. 1). pp.72-79.
Linkins, A.E. and R.K. Antibus. 1978. Ectomycorrhizal fungi of Salex
rotundifolia Trautu II. Impact of surface applied Prudhoe Bay
Crude oil on mycorrhizal root respiration and cold acclimation.
Arctic 31(3):381-393.
80
-------
Loynachan, T.E. 1978. Low-temperature mineralization of crude oil in
soil. Journal of Environmental Quality 7(4): 494-500.
MacKay, D. and W.Y. Shiu. 1976. Aqueous Solubility of Weathered
Northern Crude Oils. Bulletin of Environmental Contamination
and Toxicology. 15(1):101-109.
MacKay, D. , M.E. Charles, C.R. Phillips, 1974. Physical aspects of
crude oil spills on northern terrain (second report). Environmental-
Social Committee, Northern Pipelines, Task Force on Northern Oil
Development. Report No. 74-25. Information Canada. Cat. No.
R-57-34/1974.
Martin, J.P. 1950. Use of acid, rose bengal and streptomycin in the
plate method for estimating soil fungi. Soil Science. 69:215-232.
McAuliffe, C.D. 1971. GC determination of solutes by multiple phase
equilibrium. Chemical Technology. 1:46-51.
McAuliffe, C.D. 1977. Evaporation and solution of C2 to C Q hydrocarbons
from crude oils on the sea surface. In: Wolfe, D.A. ted.), "Fate
and Effects of Petroleum Hydrocarbons in Marine Organisms and
Ecosystems." Elmsford, New York: Pergamon Press, p.363-371.
McCown, B.H., F.J. Deneke, W.E. Rickard, L.L. Tieszen. 1973. The
response of Alaskan terrestrial plant communities to the presence of
petroleum. In: Proceedings, Symposium on the Impact of Oil Resource
Development on Northern Plant Communities. Occasional Publication
on Northern Life No. 1., Univ. of Alaska, p.44-51.
McGill, W.B. 1975. A preliminary model of oil decomposition in soils.
In: Proceedings of the Conference on the Environmental Effects of Oil
and Salt Water Spills on Land, 6-7 November 1975. Banff, Alberta,
Canada, University of Calgary and Alberta Environment, University
of Calgary, Alberta.
McGill, W.B. 1977. Soil restoration following oil spills-a review.
Journal of Canadian Petroleum Technology. April-June 1977, p.60-67.
Miller, O.K., Linkins, A.E. and Chemielewski, M.A. 1978. Fungal biomass
responses in oil perturbated tundra at Barrow. Arctic 31:381-391.
Montegut, J. 1960. Value of the dilution method. In: Parkinson, D. ,
and Waid, J.S. (eds.). The Ecology of Soil Fungi: An International
Symposium. Liverpool: Liverpool University Press, pp.43-52.
Ohmann, L.F. and R.R. Ream. 1971. Wilderness ecology: A method of
sampling and summarizing data for plant community classification.
U.S. Forest Service Research Paper NC-49. 14p.
81
-------
Parker, C.A. 1955. Anaerobiosis with iron wool. Australian Journal of
Experimental Biology. 33:33-37.
Peech, M. 1965. Hydrogen-ion activity. In: Black, C.A. (ed.). Methods
of Soil Analysis. Part 2. Chemical and Microbiological Properties.
Wisconsin: American Society of Agronomy, pp.914-926.
Raymond, R.L., J.O. Hudson and V.M. Jamison. 1976. Oil degradation in
soil. Applied and Environmental Microbiology. 31:522-535.
Rickard, W.E. and F. Deneke, 1972. Preliminary investigations of petro-
leum spillage, Haines-Fairbanks military pipeline, Alaska, Hanover,
New Hampshire: U.S. Army Cold Regions Research and Engineering
Laboratory, Special Report 170.
Rieger, S., C.E. Furbush, D.B. Schoephorster, H. Summerfield, Jr. and
L.C. Geiger. 1972. Soils of the Caribou-Poker Creeks Research
Watershed, interior Alaska. Hanover, New Hampshire: U.S. Army
Cold Regions Research and Engineering Laboratory. Technical
Report 236.
Robertson, B., S. Arhelger, P.J. Kinney and D.K. Button. 1973. Hydro-
carbon biodegradation in Alaskan waters. In: Ahearn, D.G. and Meyers,
S.P., (eds.). The microbial degradation of oil pollutants.
Baton Rouge, Louisiana: Louisiana State University (Center for
Wetland Resources. LSU-S-73-01). pp. 171-184.
Rodina, A.G. 1972. Methods in Aquatic Microbiology. (Translated,
edited and revised by Colwell, R.R. and Zambruski, M.S.).
Baltimore: University Park Press, pp. 255-257.
Scarborough, A.M. and P.W. Flanagan. 1973. Observations on the effects
of mechanical disturbances and oil on soil microbial populations.
Proceedings, Symposium on the Impact of Oil Resource Development
on Northern Plant Communities. Fairbanks, Alaska: University of
Alaska (-Insitute of Arctic Biology, Occasional Publications on Northern
Life No. 1). pp. 63-71.
Sexstone, A.J. and R.M. Atlas. 1977. Response of microbial populations
in Arctic tundra soils to crude oil. Canadian Journal of Micro-
biology. 23: 1327-1333.
Teh, J.S. and K.H. Lee. 1973. Utilization of n-alkanes by Cladosporium
resinae. Applied Microbiology. 25:454-457.
Teh, J.S. and K.H. Lee. 1974. Effects of n-Alkanes on Cladosporium
resinae. Canadian Journal of Microbiology, 20: 971-976.
82
-------
Troth, J.L., F.J. Deneke and L.M. Brown. 1975. Subarctic plant communities
and associated litter and soil profiles in the Caribou Creek
Research Watershed, interior Alaska. Hanover, New Hampshire:
U.S. Army Cold Regions Research and Engineering Laboratory.
Research report 330.
Van der Linden, A.C. and G.J.E. Thijsse. 1965. The mechanisms of microbial
oxidations of petroleum hydrocarbons. In Nord, F.F. (e.d.). Advances
in Enzymology and Related Subjects of Biochemistry. Volume 27.
New York. Interscience Publishers, pp. 470-546.
Viereck, L.A. and Little, E.L., Jr. 1972. Alaska trees and shrubs.
U.S. Department of Agriculture, Forest Service, Agriculture Handbook
No. 410, 165 p.
Walker, D.A., P.J. Webber, K.R. Everett, and J. Brown, 1978. Effects of
crude and diesel oil spills on plant communities at Prudhoe Bay,
Alaska and the derivation of oil spill sensitivity maps. Arctic 31(3):
242-259,
Warcup, J.H. 1967. Fungi in soil. In: Surges, A and RAW, F. (eds.).
Soil Biology. New York: Academic Press, pp.51-110.
Wein, R.W. and Bliss, L.C. 1973. Experimental crude oil spills on
arctic plant communities. J. Appl. Ecol., 10:671-682.
Zobell, C.E. 1950. Assimilation of hydrocarbons by micro-organisms. In
Nord, F.F. (e.d.). Advances in Enzymology and Related Subjects of
Biochemistry. Volume 10. New York. Interscience Publishers, pp.
444-486.
83
-------
APPENDIX
l.25in.
(31.75mm)
Permofrost
Thermocouple.
Wooden Dowel
Moss
Peat
Organic Soil
Interface
Mineral Soil
V
Figure A-l. Vertical Thermocouple Assembly
85
-------
« Oil Flow Probe
D Thermocouple
Assembly
5 '
ICM
15-
20-1 o D a*
25-
35-
45-
50m-
10m
a* «a>
a* *r>
a a t>
i . . .
a a a
30-, .a a t>
ana
40 i »D D O*
D a a
Figure A-2. Spill Sites.
86
-------
TABLE A-l. AVERAGE SOIL TEMPERATURES
(for first 10 meters dcwnslope)
DATE
Thermocouple
LEVEL *
SPILL
SUMMER
SPILL
CONTROL
6/22/76
7/20/76
8/12/76
9/28/76
6/2/77
8A6/77
7/12/78
5.
4.
3.
2.
1.
5.
4.
3.
2.
1.
5.
4.
3.
2.
1.
5.
4.
3.
2.
1.
5.
4.
3.
2.
1.
5.
4.
3.
2.
1.
5.
4.
3.
2.
1.
12.7°C
3.6
0.5
- 0.1
- 0.5
22.5
6.6
2.2
1.3
0.4
13.2
6.3
2.4
1.85
0.7
6.05
2.5
0.95
0.5
0.45
17.4
6.2
- 0.3
- 0.4
- 0.55
17.25
7.0
3.3
2.4
1.1
23.4
10.15
5.0
3.5
1.6
8.8
3.45
0.1
-0.35
-0.6
14.3
6.3
2.2
0.7
0.35
12.1
6.5
2.8
it.2
0.3
5.9
2.25
0.7
0.4
-0.1
14.4
4.7
0.5
0.15
-0.2
21.1
10.6
4.85
2.5
1.3
24.5
15.85
10.1
2.0
- 0.1
- 0.4
- 0.5
12.7
3.6
1.05
0.15
- 0.2
11.2
4.0
1.55
0.35
- 0.2
4.9
1.3
0.2
- 0.1
- 0.2
11.4
1.7
- 0.05
- 0.
- 0.
.2
.3
,15
,8
1.5
13.15
5.0
2.0
0.7
- 0.4
13.6
5.7
2.15
0.3
0.0
*See Figure Al,
87
-------
TABLE B-l. RESULTS FROM SILICA GEL/ALUMINA FRACTIONATION
OF OILY SOIL EXTRACTS FROM CARIBOU-POKER CREEKS
Major Oil components (%)
SAMPLE
Winter Min 7/15/76
Summer Min 7/15/76
Control Min 7/15/76
Winter Organic 7/15/76
Summer Organic 7/15/76
Control Organic 7/15/76
Winter Moss 7/15/76
Summer Moss 7/15/76
Control Moss 7/15/76
Winter Min 9/17/76
Summer Min 9/17/76
Control Min 9/17/76
Winter Organic 9/17/76
Summer Organic 9/17/76
Control Organic 9/17/76
Winter Moss 9/17/76
Summer Moss 9/17/76
Winter Organic 3/29/77
Summer Organic 3/29/77
Control Organic 3/29/77
Alkanes
30.4
22.9
0.9
32.9
33.0
0.7
42.1
37.6
1.1
41.1
27.6
0.5
42.1
33.8
0.2
40.0
40.4
36.6
48.9
0.1
Aromatics
29.4
20.4
1.3
30.0
29.5
2.4
34.4
36.6
0.7
31.8
26.4
1.0
33.1
32.3
0.7
32.4
36.0
34.9
35.9
0.8
Asphalfenes
16.4
34.8
92.8
11.7
13.9
88.5
8.4
7.4
87.0
10.6
18.8
98.0
8.0
14.8
87.8
11.6
8.4
10.7
8.8
93.0
sol.
8.9
13.6
7.2
8.7
8.1
12.0
9.5
12.8
17.9
8.8
10.4
11.3
8.7
8.8
12.3
9.5
8.8
9.5
8.2
6.5
insol.
14.8
8.3
0
16.7
15.4
0
5.6
5.6
0
7.8
16.6
0
8.1
10.4
0
6.4
6.4
8.2
0
0
88
-------
TABLE B-l (Cont'd)
SAMPLE
Winter Moss 3/29/77
Summer Moss 3/29/77
Winter Min 4/5/77
Summer Min 4/5/77
Winter Organic 4/5/77
Summer Organic 4/5/77
Winter Moss 4/5/77
Winter Min 7/13/77
Winter Organic 7/13/77
Summer Organic 7/13/77
Winter Moss 7/13/77
Summer Moss 7/13/77
Winter Min 8/1/77
Summer Min 8/1/77
Winter Organic 8/1/77
Summer Organic 8/1/77
Summer Organic 1/5/78
Winter Moss 1/5/78
Summer Moss 1/5/78
Control Moss 1/5/78
Winter Min 6/27/78
Summer Min 6/27/78
Winter Organic 6/27/78
Summer Organic 6/27/78
Alkanes
44.9
36.8
32.2
30.2
37.3
32.6
36.8
31.6
38.2
36.0
34.4
33.1
29.3
19.2
30.6
30.5
32.8
36.3
33.4
0
33.9
26.6
42.0
34.4
Major Oil components (%)
Aromatics Asphalfenes sol.
35.9
37.2
29.7
30.8
29.0
32.5
28.7
30.5
32.6
34.5
34.1
32.6
25.0
24.8
28.0
26.8
37.6
43.4
35.4
6.9
30.6
24.2
32.6
32.6
10.3
10.0
16.7
17.1
-
12.2
-
15.7
11.0
8.0
10.8
12.6
22.9
40.2
19.6
20.1
10.6
9.7
9.2
59.7
16.1
25.0
6.3
8.6
8.4
8.9
12.3
10.8
9.8
13.3
10.6
11.6
10.7
11.0
11.0
11.9
12.0
12.2
12.4
13.0
10.2
9.9
10.9
58.3
10.4
10.0
9.3
10.0
insol.
0.4
7.0
9.1
11.1
-
9.4
-
10.7
7.5
10.4
9.7
9.8
10.8
3.6
9.4
9.6
8.7
0.7
11.1
0
9.2
14.3
9.9
14.4
89
-------
TABLE B-2.
RESULTS FROM SILICA GEL/ALUMINA FRACTIONATION OF
SAMPLES FROM CARIBOU-POKER (7/27/78)
SAMPLE
Major Oil components (%)
Alkanes Aromatics Asphalfenes
NSO
sol. insol.
S 4-5, 8-9 Moss
S 1-2, 8-9 Moss
S 7, 34 Moss
S 4-5, 8-9 Organic
S 7, 34 Organic
S 1-2, 8-9 Organic
S 1-2, 8-9 Min
S 4-5, 8-9 Min
W 8-9, 11-12 Moss
W 8-9, 11-12 Organic
W 15, 34 Organic
W 8-9, 11, 12 Min
40.8
29.7
35.0
39.6
40.7
39.0
23.9
31.1
35.0
35.2
32.3
35.2
38.3
29.4
36.5
33.0
32.1
32.4
26.7
33.1
36.5
35.7
31.9
32.8
2.1
18.7
6.0
12.2
8.6
12.2
30.5
14.9
6.0
9.3
11.9
15.3
7.1
8.5
7.5
8.5
8.9
8.7
12.1
9.6
8.4
9.0
10.4
6.3
11.8
13.7
15.0
6.8
9.7
7.6
6.9
11.4
14.1
10.9
13.5
10.4
90
-------
TABLE B-3. RESULTS FROM FRACTIONATION OF SAMPLES FROM OTHER
ALASKAN SPILL AREAS
MAJOR OIL COMPONENTS (%)
LOCATION
Barrow 313
Barrow 311
Barrow 152 D
Fox
Prudhoe Oil
(orig. oil used
for spill)
Prudhoe 2CR
Prudhoe 5 CR
SPILL DATE
1970
1970
1971
1971
July 1976
1976
1976
SAMPLE DATE
July
July
July
July
-
July
July
1977
1977
1977
1976
1977
1977
Alkanes
22
34
31
32
35
37
36
.6
.4
.1
.4
.2
.5
.1
Aroma tics
26
34
32
35
36
35
37
.8
.3
.5
.1
.8
.5
.2
Asphaltenes
20
10
12
10
8
7
7
.6
.8
.1
.8
.4
.1
.7
NSO
Sol. Insol.
14.0
10.9
12.4
10.9
12.1
10.9
9.8
15.9
9.5
11.8
10.9
7.5
8.9
9.2
-------
TABLE B-4. OIL IN SOIL EXTRACTS (%)
SAMPLE DATE
7/15/76
9/17/76
3/29/77
4/5/77
7/13/77
8/1/77
1/5/78
6/27/78
Mineral
WIN. SUM.
9.81
6.52
-
4.03
4.70
3.6
-
3.89
1.65
3.85
-
3.38
3.00
1.5
-
1.76
Organic
CON. WIN. SUM.
0.73 89.0
0.45 33.5
24.1
0.10 115
0.10 190
0.2 7.3
-
16.8
57.6
7.09
181
26.9
283
12.4
50.1
31.1
CON.
1.35
2.03
2.29
0.76
0.70
0.6
-
-
Moss
WIN. SUM. CON.
266
249
255
137
234
-
183
-
207 2.49
211 0.91
147 2.12
0.82
194 1.90
-
69.3 -
-
92
-------
TABLE B-5. SOIL pH
Mineral Organic
SAMPLE DATE WIN. SUM. CON. WIN. SUM. CON.
7/15/76 - 3.4 3.5 3.5
9/17/76 3.6 3.5 3.6 3.3 3.5 3.2
3/29/77 - 3.5 3.4 3.5
4/5/77 3.9 4.0 3.9 3.9 3.8 3.8
7/13/77 - - - - - 3.7
93
-------
TABLE B-6. EXCHANGEABLE CATIONS IN SOIL SAMPLES (meq/100 g)
SAMPLE Na+ K+ Ca4"*" Mg"^ NH.+
Winter Mineral
Summer Mineral
Control Mineral
Winter Organic
Summer Organic
Control Organic
Winter Mineral
Summer Mineral
Control Mineral
Winter Organic
Summer Organic
Control Organic
Winter Organic
Summer Organic
Control Organic
7/15/76
7/15/76
7/15/76
7/15/76
7/15/76
7/15/76
9/17/76
9/17/76
9/17/76
9/17/76
9/17/76
9/17/76
3/29/77
3/29/77
3/29/77
0
0
0
0
0
0
0
0
0
0
0
0
.09
.10
.09
.26
.32
.19
.07
.07
.06
.10
.12
.19
-
-
0
0
0
1
1
1
0
0
0
0
0
0
.35
.37
.24
.38
.48
.20
.14
.15
.09
.33
.29
.60
-
-
-
12
15
18
24
89
43
4
6
3
8
13
16
.7
.1
.5
.0
.2
.6
.3
.5
.6
.4
.9
.4
-
-
-
2
3
3
4
13
7
0
1
1
2
3
4
.61
.25
.18
.48
.5
.74
.90
.91
.04
.86
.75
.78
-
-
-
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.035
.028
.044
.046
.051
.034
.065
.081
.064
.073
.077
.061
.082
.010
.060
94
-------
I08F
A| Horizon
10
o
(0
o>
o
JS 10
I
z
10
10
C2 Horizon
C W S
Jul
C W S
Sep
C W S
Jul
C W S
Sep
Figure C-l. 1976 MPN counts (20°C) of denitrifying bacteria in oiled and
unoiled (control plots. C = Control Plot; W = Winter Plot;
S = Summer Plot; Brackets represent 95% confidence interval.
95
-------
I08
I07
o
a, I06
O
0>
JD
E
D
I04
I03
Ai Horizon
Horizon
CWS CWS CWS
Jun Jul Aug
CWS
Jun
CWS
Jul
CWS
Aug
Figure C-2.
1977 MPN counts (20°C) of denitrifying bacteria in oiled and
unoiled (control) plots. C = Control Plot; W = Winter Plot;
S = Sxammer Plot; Brackets represent 95% confidence interval.
96
-------
IU
I07
'5
& I06
"5
o
«*-
o
v. I05
0)
.Q
E
D
z
I04
I03
^^
«»
HMI
BH^^V
~_
~
ll
»
A
M
i
Horizon
C W S
«
^
«
»
M
^
»
^v
m
Ca Horizon -:
r
«l
^
1
mm
«
m,
mm
mm
»
r
k
mm
c w s c w s c
Jun
Jul
Jun
mm
m
«
»
>
3
. I
^
m
.
^^
_
_
"
W S
Jul
Figure C-3. 1978 MPN counts (20°C) of denitrifying bacteria in oiled and
unoiled (control) plots. C = Control Plot; W = Winter Plot;
S = Summer Plot; Brackets represent 95% confidence interval.
97
-------
10
10
6
01 io7
CO
-------
8
10° E
r A. Horizon
- '°7
o
(0
X
(0
0)
3 I06
o»
o
a
o
u.
QL
° 10
E
z
10
10
C2 Horizon
C W S
Jul
C WS
Sep
C WS
Jul
C WS
Sep
Figure C-5. 1976 MPN counts (20°C) of cellulose-utilizing fungi in oiled and
unoiled (control) plots. C = Control Plot; W = Winter Plot;
S = Summer Plot; Brackets represent 95% confidence interval.
99
-------
I08
I07
o
0)
to
o>
u
*»-
o
i io5
JD
E
IO4
10 3
r A
-
«
«
i
m
-
«
Horizon
^
-i
»
i
^
1
»
*
mi
«
»
Ml
»
c
1
mm
«
2 Horizon i
«
m
MI
MI
M
M
Mi
»
i
H
v
1
Ml
»
Mi
Mi
W
m
mm
^
^
=
CWS CWS CWS CWS
Jul
Sep J
ul
Sep
Figure C-6. 1976 MPN counts (20°C) of oil utilizing-bacteria in oiled and
unoiled (control) plots. C = Control Plot; W = Winter Plot;
S = Summer Plot; Brackets represent 95% confidence interval.
100
-------
IU
I07
o
(0
S
o
I
D
z
I04
10 3
mm*
mmm
mm
mm
MHMMB
M»
^V
^>
»
»
^i*
^^^M
^^B
i*^»
>
^^
mm
m
A,
>
m
mm
^
Horizon
>
M
>
V
1
«
mt
m
m
v
MM
I
C2 Horizon
^
r
1
C WS C WS C W
Jul Sep Ju
«
»
>
S
^
Hi
HI
1
*
mm
M
r
*
cw s
Sep
Figure 07. 1976 MPN counts (20°C) of oil-utilizing-yeasts in oiled and
unoiled (control) plots. C = Control Plot; W = Winter Plot;
S = Summer Plot; Brackets represent 95% confidence interval.
101
-------
I08
I07
o
(O
I06
o
»*
O
i_
CD
-O
E
I05
I04
I03
r AI Horizon
C2 Horizon -f
CWS
1977
CWS
1978
CWS
1977
CWS
1978
Figure C-8. 1977 and 1978 MPN counts (20°C) of oil-utilizing-bacteria in
oiled and unoiled (control) plots. C = Control Plot; W =
Winter Plot; S = Summer Plot; Brackets represent 95% confidence
interval.
102
-------
I08
I07
I06
o
«4-
o
\_
-------
I08
o
en
en
- io6
o
Q.
O
-------
IU'
I06
"6
V)
o>
\
C/> |Q5
0)
of Propagul
o
*
V.
Q>
.a
E
D
z
I03
I02
mmmm*
E- A Horizon
mmmmm
mm
mmmm*
ffffffgfff.
mmt
mmmmm
mmt
IM^B
^»
i^^M
IB*
^^
^^»
^^M
mm
m^m
mm
I-
J-
^p
m
m
m
m
m
m
m
m
Cz Horizon -:
*
m
m
m
m
»
»
mm
L
M
m
"
mmmm
i
m
mmmmm
mmM
mmmm
mtm
mmmmmmmmm
mml
mm^*l
^mmmm
C WS C WS C WS C WS
1977 1978 1977 978
Figure C-ll. 1977 and 1978 MPN counts (20°C) of oil-utilizing fungi
in oiled and unoiled (control) plots. C = Control Plot;
W = Winter Plot; S = Summer Plot; Brackets represent 95%
confidence interval.
105
-------
TABLE C-l. 20°C HETEROTROPHIC BACTERIAL COUNTS ( x 106/ g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
1976
February3
June
Julyb
August
September
February a
June,
July5
August
September
1977
June
July
Augus t
June
July
August
1978
June
July
June
July
Control
plot
12
27
28
16
13
7
11
9
8
3
29
18
22
6
4
2
24
25
10
6
winter
plot
AI Horizon
11
300**
440**
280**
260**
&2 Horizon
5**
8
42**
24**
19*
AI Horizon
720**
330**
180**
C-2 Horizon
44**
94**
55*
AI Horizon
370**
380**
C2 Horizon
72**
56-«-'«
Summer
plot
18*cc
570**cc
1300**cc
7cc
28**
280**cc
1800**cc
1200**cc
880**cc
280**cc
170**cc
150**cc
700**cc
370**
71**
34** cc
a Within 24 hours after the winter oil spill.
b Within 24 hours after the summer oil spill.
* Significantly different from the control at 5% level.
** Significantly different from the control at 1Z level.
cc Significantly different from the winter at 1% level.
106
-------
TABLE C-2. 20°C FILAMENTOUS FUNGAL PROPAGULE COUNTS (x 104/g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
1976
February3
June
Julyb
August
September
February3
June
Julyb
August
September
1977
June
July
August
June
July
August
1978
June
July
June
July
Control
plot
100
230
160
110
62
25
33
13
20
7
270
170
150
35
10
22
170
160
25
26
Winter
plot
AI Horizon
160
15**
27**
80V
72
C-2 Horizon
8**
3**
n.d.
5**
3**
A]_ Horizon
47**
41**
21**
G£ Horizon
20**
8
A-j_ Horizon
420>*
500**
G£ Horizon
26
34**
Summer
plot
60** cc
75**
460**cc
35**
ll**c
91**cc
300cc
210*cc
180*cc
29**cc
20**cc
18** cc
470**
420**cc
n.ci.
37**
a Within 24 hours after the winter oil spill.
b Within 24 hours after the summer oil spill.
n.d. Not determined.
* Significantly different from the control at 5% level,
** Significantly different from the control at 1% level,
c Significantly different from the winter at 5% level.
cc Significantly different from the winter at 1% level.
107
-------
TABLE C-3. 20°C YEAST COUNTS (X 105/g soil) IN OILED AND
UNOILED (CONTROL) PLOTS
Sampling
time
1976
Februarya
June
Julyb
Augus t
September
February3
June
Julyb
August
September
1977
June
July
August
June
July
August
1978
June
July
June
July
Control
plot
5.4
8.1
2.7
7.0
11
1.2
1.0
0.6
1.4
1.1
3.1
5.1
4.0
0.7
0.2
1.2
14
12
1
2
Winter
plot
AI Horizon
7.2
790**
120**
340**
220**
C2 Horizon
1.2
8.6**
/ H** *^
25**
22**
AI Horizon
210**
330**
250**
C2 Horizon
53**
53**
48**
AI Horizon
3100**
3200**
C2 Horizon
410**
280**
Summer
plot
5cc
1500**cc
1800**cc
0.6cc
110**cc
590**cc
3100**cc
5200**cc
2900** cc
930**cc
400**cc
500**cc
3400**
2400**cc
390**
160**cc
a Within 24 hours after the winter oil spill.
b Within 24 hours after the summer oil spill.
** Significantly different from the control at 1% level,
cc Significantly different from the winter at 1% level.
108
-------
TABLE C-4. 20°C PROTEOLYTIC BACTERIAL COUNTS (x 105/g soil) IN
OILED AND UNOILED (CONTROL) PLOTS IN 1976
Sampling
time
February4
June
Julyb
August
September
February4
June
Julyb
August
September
Control
plot
67
200
68
34
24
16
25
17
8.1
8.2
Winter
plot
A-^ Horizon
60
1300**
800**
150**
630**
C2 Horizon
9.5
61
210**
n.d.
64**
Summer
plot
-
-
110**cc
3900**cc
4000** cc
-
-
40**cc
250**
1400**cc
a Within 24 hours after the winter oil spill.
b Within 24 hours after the summer oil spill.
** Significantly different from the control at 1% level,
cc Significantly different from the winter at 1% level.
n.d. Not determined.
109
-------
TABLE C-5. 20°C ANAEROBIC BACTERIAL COUNTS (x105/g soil) IN
OILED AND UNOILED (CONTROL)PLOTS IN 1976
Sampling
time
Julya
September
Julya
September
Control
plot
40
13
7.7
4.8
Winter
plot
AI Horizon
72*
60**
£>2 Horizon
14**
11**
Summer
plot
19**cc
1200**cc
9.9cc
21**cc
a Within 24 hours after "the summer oil spill.
* Significantly different from the control at 5% level.
** Significantly different from the control at 1% level.
cc Significantly different from the winter at 1% level.
110
-------
TABLE C-6. 20°C IN VITRO SOIL RESPIRATION RATES (mg CO /24 HR/100 g soil)
IN OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
1976
**
February
Julyb
August
September
a
February
Julyb
August
September
1977
June
July
August
June
July
August
1978
June
July
Control
plot
104.0
39.8
25.8
21.6
10.0
12.2
7.8
5.6
61.6
40.5
65.2
7.3
9.9
9.2
41.0
11.1
Winter
plot
AI Horizon
49.4**
97.4**
42.0**
48.8**
C? Horizon
3.2**
20.2**
15.4**
18.0**
AI Horizon
90.8**
55.7**
54.0**
C9 Horizon
11.4**
14.3**
15.0**
AI Horizon
68.8**
17.2**
Summer
plot
146.0**cc
88.2**cc
121.0**cc
15. Oc
9.0c
33.6**cc
223.8**cc
136.2**cc
128.7**cc
37.5**cc
17.9**cc
19.8**cc
82.5**cc
14.4*
a Within 24 hours after the winter oil spill.
b Within 24 hours after the summer oil spill.
* Significantly different from the control at 5% level.
** Significantly different from the control at 1% level.
c Significantly different from the winter at 5% level.
cc Significantly different from the winter at 1% level.
Ill
-------
TABLE C-7. pH OF SOIL COLLECTED FROM OILED AND UNOILED (CONTROL) PLOTS
Sampling
time
1976
Februarya
June
Julyb
August
September
February a
June
Julyb
Augus t
September
1977
June
July
August
June
July
August
1978
June
July
June
July
Control
plot
4.8
5.6
5.5
5.4
5.2
5.2
5.0
5.1
5.3
5.3
5.2
4.8
5.1
5.2
5.0
5.2
4.9
4.8
5.2
5.0
Winter
plot
AI Horizon
5.5
5.7
6.2
5.7
5.7
C.2 Horizon
5.2
5.5
5.2
5.5
5.6
AI Horizon
4.9
5.1
5.5
C-2 Horizon
5.2
5.2
5.2
A! Horizon
5.4
5.2
C2 Horizon
5.4
5.0
Summer
plot
6.1
5.5
5.7
5.3
5.7
5.9
5.3
5.4
5.6
5.4
5.2
5.2
5.2
5.3
5.4
5.2
a Within 24 hours after the winter oil spill.
b Within 24 hours after the summer oil spill.
112
-------
TABLE C-8. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO BACTERIAL NUMBERS IN OILED AND UNOILED
(CONTROL) PLOTS IN 1977a.
Rregression
equation b Treatment n r
4°C
Y = 6.67 + 2.06X Control 6 0.831*
Y = 8.56 + 0.04X Winter 6 0.959**
Y = 7.90 + 0.05X Summer 6 0.927**
Y = 9.31 + 0.05X All 18 0.927**
20°C
Y = 0.25 + 2.36X
Y =12.71 + 0.12X
Y = 2.28 * 0.12X
Y = 19.34 * 0.11X
Control
Winter
Summer
All
6
6
6
18
0.959**
0.938**
0.990**
0.943**
a June, July, August data in both soil horizons were used.
b Y = mg C02/24 hr/lOOg soil; X = 106 bacterial cells/g soil.
* Significant at 57. level.
** Significant at 1% level.
113
-------
TABLE C-9. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO BACTERIAL NUMBERS IN OILED AND UNOILED
(CONTROL) PLOTS IN 1976a.
Regression
equation b
Treatment
n
4°C
Y = 2.27 + 1.72X
Y = 7.10 + 0.03X
Y = 8.60 + 0.05X
Y = 6.09 + 0.05X
Control
Winter
Summer
All
6
6
6
18
0.892*
0.863*
0.860*
0.858**
20°C
Y = 0.05 + 1.45X
Y = 10.20 + 0.17X
Y =49.19 *- 0.05X
Y = 30.51 + 0.08X
Control
Winter
Summer
All
6
6
6
18
0.980**
0.952**
0.466
0.566*
a July, August and September data in both soil horizons were used.
b Y = mg CO /24 hr/lOOg soil; X = bacterial cells x 106/g soil.
* Significant at 52 level.
** Significant at 1% level.
114
-------
TABLE C-10. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO FILAMENTOUS FUNGI PROPAGULE COUNTS IN
OILED AND UNOILED (CONTROL) PLOTS IN 1976a-
Regression
equation b Treatment n r
4°C
Y = 3.47 + 0.04X Control 6 0.724
Y = 5.47 + 0.53X Winter 6 0.822*
Y = 7.52 + 0.30X Summer 6 0.806
Y= 7.37O.15X All 18 0.504*
20°C
Y = 6.13 + 0.21X Control 6 0.980**
Y = 34.91 + 0.25X Winter 5 0.277
Y = 47.86 + 0.17X Summer 6 0.500
Y = 28.39 + 0.21X All 17 0.520*
a July, August, and September data in both soil horizons were used.
b Y = mg C07/24 hr/100 g soil; X = 104 filamentous fungal propagules/g soil.
* Significant at 52 level.
** Significant at 1% level.
115
-------
TABLE C-ll. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO FILAMENTOUS FUNGI PROPAGULE COUNTS IN
OILED AND UNOILED (CONTROL) PLOTS IN 1977a.
Regression.
equation b Treatment
4°C
Y = 2.82 * 0.17X Control 6 0.980**
Y = 10.01 + 0.78X Winter 6 0.933**
Y = 1.14 + 1.58X Summer 6 0.906*
Y = 15.50 + 0.18X All 18 0.283
20°C
Y = 6.72
Y = -4.44
Y = 7.80
Y * 15.20
+ 0.23X
+ 1.77X
+ 0.68X
+ 0.46X
Control
Winter
Summer
All
6
6
6
18
0.894*
0.843*
0.995**
0.794**
a June, July and August data in both soil horizons were used.
b Y = mg CO-/24 hr/100 g soil; X = 10^ filamentous fungal propagules/g soil.
* Significant at 5Z level.
** Significant at 1Z level.
116
-------
TABLE C-12. -CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO YEAST NUMBERS III OILED AND UNOILED
(CONTROL) PLOTS IN 1976a.
Regression
equation b Treatment
4°C
Y = 1.91 + 4.26X Control 6 0.710
Y = 6.89 + 0.25X Winter 6 0.792
Y = 7.45 + 0.04X Summer 6 0.853*
Y = 7.62 + 0.04X All 18 0.837**
20°C
Y = 14.26 + 1.12X
Y = 29.47 + 0.09X
Y = 48.67 + 0.03X
Y = 31.12 + 0.04X
Control
Winter
Summer
All
6
6
6
18
0.374
0.382
0.412
0.545*
a July, August and September data in both soil horizons were used.
b Y = mg C02/24 hr/100 g soil; X = 105 yeast cells/g soil.
* Significant at 52 level.
** Significant at 1Z level.
117
-------
TABLE C-13. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO YEAST NUMBERS IN OILED AND UNOILED
(CONTROL) PLOTS IN 1977a.
Regression
equation b
Treatment
Y = 5.49 + 3.46X
Y = 9.03 + 0.72X
Y = 8.19 + ).51X
Y = 9.96 + 0.50X
4°C
Control
Winter
Summer
All
20°C
6
6
6
18
0.781
0.964**
0.985**
0.964**
Y = 6.04
Y = 8.52
Y = 21.44
Y = 31.43
+ 11.01X
+ 0.20X
+ 0.03X
+ 0.03X
Control
Winter
Summer
All
6
6
6
18
0.800
0.768
0.768
0.775**
a June, July and August data in both soil horizons were used.
b Y = mg O>2/24 hr/100 g soil; X = 105 yeast cells/g soil.
** Significant at 12 level.
118
-------
TABLE C-14. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO OIL CONCENTRATIONS IN OILED PLOTS IN 1976a.
Regression
equation b Treatment
4°C
Y = 5.58 + 1.53X Winter 6 0.879*
Y = 9.85 + 1.84X Summer 6 0.607
Y = 7.13 + 1.84X All 12 0.643*
20°C
Y = 2.71 + 10.21X Winter 6 0.990**
Y = 14.36 + 11.92X Summer 6 0.958**
Y = 6.19 + 11.72X Both 12 0.945**
a July, August and September data in both soil horizons were used.
b Y = mg C02/24 hr/100 g soil; X = % oil in soil.
* Significant at 52 level.
** Significant at 1% level.
119
-------
TABLE C-15. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING IN VITRO
SOIL RESPIRATION RATES TO OIL CONCENTRATIONS IN OILED PLOTS IN 1976a,
Regression
equation b
Treatment
n
Y = 5.62 + 2.17X
Y = 11.29 + 2.85X
Y = 6.60 + 2.89X
4°C
Winter
Summer
Both
20°C
6
6
12
0.980**
0.970**
0.949**
Y = 5.52
Y = 29.39
Y = 12.80
+ 7.33X
f 8.53X
* 8.82X
Winter
Summer
Both
6
6
12
0.917**
0.943**
0.922**
a June, July and August data in both soil horizons were used.
b Y = mg C02/24 hr/100 g soil; X = % oil in soil.
** Significant at 1% level.
120
-------
TABLE C-16. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING BACTERIAL
NUMBERS TO OIL CONCENTRATIONS IN OILED PLOTS IN 1976a.
Regression
equation b Treatment n
4°C
Y = -51.29 + 54.11X Winter 6 0.997**
Y = 161.37 + 9.06X Summer 6 0.164
Y = 80.34 * 23.04X Both 12 0.421
20°C
Y = -30.90 + 56.08X Winter 6 0.980**
Y = 259.92 + 22.46X Summer 6 0.210
Y = 124.15 + 35.14X Both 12 0.359
a July, August and September data in both soil horizons were used.
b Y = 106 bacterial cells/g soil; X = % oil in soil.
** Significant at 1% level.
121
-------
TABLE C-17. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING BACTERIAL
NUMBERS TO OIL CONCENTRATIONS IN OILED PLOTS IN 1977a.
Regression
equation b Treatment n r
4°C
Y = -56.40 + 47.76X Winter 6 0.975**
Y = 108.04 + 55.20X Summer 6 0.964**
Y = -4.70 + 57.30X Both 12 0.938**
20°C
Y = -62.69 + 63.35X Winter 6 0.980**
Y = 222.43 * 69.21X Summer 6 0.949**
Y = 40.30 + 73.38X Both 12 0.917**
a June, July and August data in both soil horizons were used.
b Y = 106 bacterial cells/g soil; X = % oil in soil.
** Significant at 1% level.
122
-------
BACIESIAL
Regression
equation b Treatment
4°C
Y = 12.77 + 21.05X Winter 4 0.995**
Y = -7.64 + 36.56X Summer 4 0.889
Y = -4.48 + 29.79X Both 3 0.854**
20°C
Y = -8.98
Y = 4.35
Y = -8.47
+ 41.92X
+ 58.40X
+ 50.96X
Winter
Summer
Both
4
4
8
1.000**
0.975*
0.943**
a June and July data in both soil horizons were used,
b Y = 106 bacterial cells/g soil; X = % oil in soil.
* Significant at 5% level.
** Significant at 1Z level.
123
-------
TABLE C-19. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING BACTERIAL
NUMBERS TO OIL CONCENTRATIONS IN OILED PLOTS IN 1978a.
Regression
equation b Treatment n r
4°C
Y = -4.20 + 2.49X Winter 6 0.938**
Y = 8.37 + 1.55X Summer 6 0.922**
Y = 2.61 + 1.82X Both 12 0.889**
20°C
Y = 8.71 + 3.30X
Y = 35.65 « 11.95X
Y = 3.08 + 11.73X
Winter
Summer
Both
6
6
12
0.812*
0.911*
0.831**
a June, July and August data in both soil horizons were «£
b Y = 10* filamentous fungal propagules/g soil; X = /» oil in sou.
* Significant at 51 level.
** Significant at 1% level.
124
-------
TABLE C-20. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATION
FILAMENTOUS FUNGAL PROPAGULE COUNTS TO OIL CONCENTRATIONS
IN OILED PLOTS IN 1978a.
Regression
equation b
Treatment
Y = 3.29 + 1.66X
Y = 7.05 + 4.55X
Y = 4.14 + 3.23X
4°C
Winter
Summer
Both
20°C
4
4
8
0.990**
0.990**
0.762*
Y = -68.76 + 57.57X
Y = 33.54 * 43.63X
Y = -22.62 + 50.70X
Winter
Summer
Both
4
3
7
0.985*
0.990
0.975**
a June and July data in both soil horizons were used.
b Y = 10^ filamentous fungal propagules/g soil; X = % oil in soil.
* Significant at 5% level.
** Significant at LZ level.
125
-------
TABLE C-21. CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATION
YEAST NUMBERS TO OIL CONCENTRATIONS IN OILED PLOTS IN 1977a.
Regression
equation b
Y = -4.22 +
Y = 5.25 +
Y = -5.44 +
2.92X
5.56X
5. SIX
Treatment
4°C
Winter
Summer
Both
n
6
6
12
r
0.980**
0.995**
0.938**
Y = 88.42 + 14.56X
Y = 1274.73 + 118.41X
Y = 366.12 * 129.73X
20°C
Winter
Summer
Both
6
6
12
0.480
0.574
0.538
a June, July and August data in both soil horizons were used.
b Y = 105 yeast cells/g soil; X = % oil in soil.
** Significant at 1Z level.
126
-------
TABLE C-22.
CORRELATION COEFFICIENTS AND REGRESSION EQUATIONS RELATING
YEAST NUMBERS TO OIL CONCENTRATIONS IN OILED PLOTS IN 1978a.
Regression
equation b
Treatment
n
Y = 5.62 + 2.73X
Y = -3.30 + 22.72X
Y = -7.27 + 13.37X
4°C
Winter
Summer
Both
20°C
4
4
8
0.894
0.889
0.616
Y = -312.54
Y = 78.97
Y = -72.12
+ 377. 99X
+ 304. 45X
+ 334. 38X
Winter
Summer
Both
4
4
8
0.998**
0.998**
0.992**
a June and July data in both soil horizons were used.
b Y = 10^ yeast cells/g soil; X = % oil in soil.
** Significant at 1% level.
127
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/3-80-040
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
The Fate and Effects of Crude Oil Spilled on Subarctic
Permafrost Terrain in Interior Alaska
5. REPORT DATE
March 1980 issuing date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
L.A.Johnson, E.B.Sparrow, T.F.Jenkins, C.M.Collins,
C.V.Davenport, T.T.McFadden
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S.Army Cold Regions Research and Engineering
Laboratory
Fairbanks, Alaska 99703
10. PROGRAM ELEMENT NO.
1BA820
11. CONTRACT/GRANT NO.
Grant # EPA-IAF-D7-0794
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research LaboratoryCorvallis, OR
Office of Research and Development
Environmental Protection Agency
Corvallis, Oregon 97330
13. TYPE OF REPORT AND PERIOD COVERED
final 1975-1979
14. SPONSORING AGENCY CODE
EPA/600/02
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This study was conducted to determine both the short- and long-term effects of spills
of hot Prudhoe Bay crude oil on permafrost terrain in subarctic interior Alaska. Two
experimental oil spills of 7570 liters (2000 gallons) each on 500m^ test plots were
made at a forest site underlain by permafrost near Fairbanks, Alaska. The oil spills,
one in winter and one in summer, were conducted to evaluate their effect during these
two seasonal extremes. Oil movement, thermal regime, botanical effects, microbiologi-
cal responses, permafrost impact, and composition of the oil in the soil were monitor-
ed for two years.
The results indicate that oil movement during the winter spill occurred within the
surface moss layer beneath the snow. In the summer spill, movement of the oil was
primarily below the moss in the organic soil. The oil movement in the summer spill
was more rapid, moving 30 m downslope in the first 24 hours and 41 m total through the
summer. The oil in the winter spill moved only 18 m downslope in the first day and
stopped. Remobilization occurred in the spring allowing the oil in the winter spill
to move an additional 17 m. The total area affected by the summer spill was nearly
one and one-half times as large as the winter spill (303 m^ Vs 188 m^ or 40 m^/nP of
oil ;vs 24 m2/m3 of
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. cos AT I Field/Group
Alaska
Oil spill
Permafrost
Subarctic
06/C
06/F
08/L
18. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (ThisReport)
unclassified
21. NO. OF PAGES
142
20. SECURITY CLASS (Thispage)
unclassified
22. PRICE
EPA Form 2220-1 (Key. 4-77) PREVIOUS EDITION is OBSOLETE
U. S. GOVERNMENT POINTING OFFICE: 1980-698-311 /I34 REGION 10
128
------- |