-POKER CREEKS
n
U. S. ENVIRONMENTAL PROTECTION AGENCY
ARCTIC ENVIRONMENTAL RESEARCH LABORATORY
COLLEGE, ALASKA 99701
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WATER QUALITY OF THE CARIBOU-POKER CREEKS
RESEARCH WATERSHED, ALASKA
by
William M. Jinkinson
Frederick B. Lotspeich
Ernst W. Mueller
Working Paper No. 24
U.S. ENVIRONMENTAL PROTECTION AGENCY
ARCTIC ENVIRONMENTAL RESEARCH LABORATORY
COLLEGE, ALASKA
Associate Laboratory of
National Environmental Research Center
Corvallis, Oregon
Office of Research and Development
December 1973
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A Working Paper presents results of investigations which are, to some
extent, limited or incomplete. Therefore, conclusions or recommendations
expressed or implied, are tentative. Mention of commercial products or
services does not constitute endorsement.
11
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LIST OF FIGURES
FIGURE PAGE
1 Map of the Research Watershed showing the various 2
sub-watershed boundaries and water quality samp-
ling sites. Areas of sub-basins are given in
Table 1; sub-basins for Poker Creek are design-
ated in Figure 2, which shows their appearance.
2 Aerial view of the entire watershed that shows all 3
sub-basins in Poker Creek basin. Haystack Moun-
tain, 2526 feet in elevation is indicated by the
arrow with the divides delineating the outer
periphery shown by the black line.
3 Low level view of the small valley where Cl and 5
C2 converge. Low vegetation on the valley floor
is willow and dwarf birch, with black spruce
fringing the valley, taller trees on the near-
by upland are birch and aspen with intermingled
spruce on the left. Looking nearly due North.
4. View of the confluence of Poker and Caribou 6
Creeks mainstem. All of this area is underlain
by permafrost and the vegetation is scrub willow
and birch with black spruce. It is proposed to
establish a trailer field site just above this
junction within 50 - 100' of the creeks. View
is nearly due North.
5 Taxonomic distribution of macroinvertebrate fauna 19
collected during this study.
6 Distribution of macroinvertebrates in the various 21
sub-basins sampled in this study.
7 Relative distribution of macroinvertebrates be- 22
tween the total areas of Caribou and Poker Creek
basins.
m
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LIST OF TABLES
TABLE PAGE
1 Sub-Basins of Poker-Caribou Watershed 10
2 Analysis of sediment, turbidity and color--Poker- H
Caribou Creeks Watershed
3 Field Chemistry Data for Poker-Caribou Creeks 12
4 Nutrient Analyses - Poker-Caribou Watershed 14
5 Metals analyses - Poker-Caribou Watershed 16
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INTRODUCTION
Research watersheds are areas reserved for obtaining information on
relations between land, water and climate in specific environments. In
1969, the Inter-Agency Technical Committee for Alaska selected the :
Caribou-Poker Creeks Research Watershed, for study of hydrologic and
environmental parameters and processes in the upland subarctic Taiga.
Dependent on the aims of research, research watersheds (basins)
may be designated as representative or experimental (Slaughter, 1971).
Representative basins are areas set aside to permit study of the exist-
ing conditions, without major influence from man's activities. Experi-
mental basins, on the other hand, are areas in which natural conditions
are deliberately modified with the objective of quantitatively evalu-
ating the effects of these modifications on various phases of the
hydro!ogic cycle.
Within the Caribou-Poker Creeks watershed, Caribou Creek * with five
sub-basins, has been designated as representative, and Poker Creek, with
seven sub-basins as experimental. Figure 1 shows the watershed and the ,
relationships of the various sub-basins and their relative sizes. The
entire watershed contains about 40 square miles and is about 3,0 air miles
north of Fairbanks. Figure 2 is an aerial view of the entire watershed
looking to the SW with Haystack Mountain in the distance, taken from
5,000 ft. elevation in August 1971. Poker Creek basin has an area of about
24 square miles and Caribou Creek basin about 16 square miles. Slaughter
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CARIBOU-POKER CREEKS RESEARCH WATERSHED
SAMPLING SITES X
SCALE
Figure 1. Map of the Research Watershed showing the various subwatershed boundaries and water quality
sampling sites. Areas of sub-basins are given in Table 1; sub-basins for Poker Creek are
designated in Figure 2 which shows their appearance.
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FIGURE 2
Aerial view of the entire watershed that
shows all sub-basins in Poker Creek basin.
Haystack Mountain, 2526 feet in elevation
is indicated by the arrow with the divides
delineating the outer periphery shown by
the black line.
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(1971) gives more detail on the physical setting and some history of how
this research watershed was established.
Valley bottoms and slopes without a southern exposure are underlain
with discontinuous permafrost. Vegetation is predominantly black spruce
on colder slopes with birch and aspen on warmer slopes. Scrub willow and
arctic birch are the two important larger vegetation types on valley
bottoms. Figures 3 and 4 portray the summer appearance of this water-
shed vegetation from a lower elevation.
Numerous agencies are involved in this research watershed. The
overall plan for research is to foster a coordinated effort by these
agencies which have limited interest or responsibilities. Examples of
agency endeavors include: stream gaging by U.S. Geological Survey, soil
survey by the Soil Conservation Service, meteorological measurements by
the National Weather Service, vegetational survey by the U.S. Forest
Service, and individual research projects by graduate students at the
University of Alaska. Water quality research is being done by the U.S.
Environmental Protection Agency working out of the Arctic Environmental
Research Laboratory (AERL) on the University of Alaska campus, College,
Alaska.
A restriction to most on-going research in the watershed is the
logistical 'difficulty caused by an absence of adequate overland access
routes. Current plans by the Cold Regions Research and Engineering
Laboratory, however, are to build short sections of experimental one-
lane roads. These will be connected to form a road network to reach
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FIGURE 3
Low level view of the small valley where Cl and
C2 converge. Low vegetation on the valley floor is
willow and dwarf birch, with black spruce fringing
the valley, taller trees on the nearby upland are
birch and aspen, with intermingled spruce on the
left. Looking nearly due North.
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FIGURE 4
View of the confluence of Poker and Caribou
Creeks mainstem. All of this area is under-
lain by permafrost and the vegetation is
scrub willow and birch with black spruce. It
is proposed to establish a trailer field site
just above this junction within 50-100 feet of
the creeks. View is nearly due North.
m.
.•s^'fit yr£si'*'
KP£> • : ''' •'' -:'F.'/
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all sub-basin streams; it will permit all-season use of wheeled
vehicles, and it will accelerate the pace of research. Construction
of these roads will also offer an opportunity to monitor the effects
of construction activity on water quality, permafrost, soils and
vegetation.
AERL research in the watershed is conducted with the intent of
gaining a comprehensive understanding of the water quality prior to
and following experimental perturbations.
Research activity in the watershed during the summer of 1971
consisted of monthly sampling trips in the summer and early fall to
stations in ten sub-basins, and to one site below the confluence of
Caribou and Poker Creeks. In addition two sampling trips were made
during early summer of 1972. Because sub-basins P-3 and P-5 have a
low discharge, they were not sampled. Field measurements for pH,
alkalinity, conductivity, and temperature were made at each station,
and additional samples were collected for laboratory analysis for
nutrients, bases, suspended sediment, turbidity, color, and a few trace
metals. D.O. and TOC measurements were made, but only occasionally.
Samples of the aquatic macroinvertebrate fauna were collected, but also
on a less routine basis.
Because no perturbations are currently planned, with the exception
of the road network construction mentioned previously, it is difficult
to select those physical and chemical water quality parameters which
may be major factors in ultimately explaining the hydrologic functioning
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of subarctic watersheds. Therefore, the broad range of parameters just
noted has been selected with the objectives in mind that some may be
deleted or others added as new information and understanding accrues.
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PHYSICAL AND CHEMICAL RESULTS
Sub-basin drainage areas and discharge measurements made to date
are listed in Table 1. Drainage area calculations are from Slaughter,
1971. These data are too preliminary to relate drainage area to dis-
charge, particularly in the various sub-basins. However, indications
are that Poker Creek's large drainage area is reflected in a higher
discharge at any one measurement period than is Caribou Creek. Mea-
surements made below the confluence of these two streams appear to
adequately verify the precision of the measurements. Because the small
sub-basins have small channels and very low discharge, these measure-
ments are not accurate, even using a "pygmy" meter. More accurate
measurements could be derived if a permanent structure such as a weir
or flume were installed in these small streams.
Because of possible increases in stream sediment concentrations
owing to erosion and stream bed disturbance resulting from watershed
management, it is important to adequately establish the sediment regime
in the stream'.s natural state. Table 2 shows total suspended sediment
concentrations, turbidity and color for the Caribou Creek and Poker
Creek main stem stations. These data indicate that the streams are quite
clear, even during high runoff periods. As might be expected, color and
suspended sediment were highest during breakup--!n this case sampled in
late May, 1972.
Table 3 shows temperature, conductivity, pH and alkalinity data for
the Poker and Caribou Creek main stem stations. Because of instrument
malfunctions, pH data was not collected at these stations at all sampling
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TABLE 1
SUB-BASINS OF POKER-CARIBOU WATERSHED
o 1
Discharge, ft°-sec
Sub-Basin
C-Main
C-l
C-2
C-3
C-4
Total
P-Main
P-l
P-2
P-3
P-4
P-5
P-6
Total
Confluence
(P-C)
Area
Mi 2*
5.3
2.6
2.0
2.2
4.4
16.5
6.8
5.7
2.6
1.1
4.3
1.1
2.7
24.3
40.8
7/20-
21/71
_ .
-
_
-
_
_
7.9
7.4
-
6.2
-
3.1
43.9
8/14/71
25.2
5.5
7.9
4.3
5.6
40.5
14.1
13.5
-
8.3
-
4.4
58.2
9/08/71
20.4
3.1
2.6
3.0
6.0
26.3
8.1
3.9
-
5.6
-
3.2
44.8
9/28-
29/71
6.4
1.8
. _
1.7
4.1
8.6
5.4
2.2
-
4.0
-
2.1
-
5/31-
6/01/72
27.7
4.9
3.4
4.1
5.5
49.3
17.6
11.2
_
9.7
-
4.3
76.4
6/29/72
9.2
2.2
1.9
1.0
2.5
17.6
4.3
2.8
_
4.1
_
2.2
27.2
*Taken from Slaughter, 1971
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TABLE 2
ANALYSIS OF SEDIMENT, TURBIDITY AND COLOR
POKER-CARIBOU CREEKS WATERSHED
Date .S
.xtlte
7/21/71
8/24/71
9/08/71
9/29/71
5/31/72
6/29/72
Susp. Sediment
mg/1
C-M P-M
4 3
6 10
7 2
2 2
27 25
4 2
Turbidity
STU
C-M P-M
7.0 6.3
0.6 0.8
0.5 0.4
0.6 0.5
1.4 2
4 2.2
Color
PCU
C-M P-M
17 13
19 14
11 7.0
8 4.8
31 31
8 8
11
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TABLE 3
FIELD CHEMISTRY DATA FOR POKER-CARIBOU CREEKS
Date >/
/Site
7/21/71
8/14/71
9/08/71
9/29/71
5/31/72
6/29/72
Temp. °C
P-M
8.6
6.2
5.3
0.0
4.5
8.5
C-M
8.6
4.9
3.9
0.1
4.2
6.2
Cond. urn ho/ cm
P-M
103
92
no
120
75
114
C-M
84
36
80
83
55
85
pH
P-M
8.2
7.1
6.7
-
-
-
C-M
7.5
7.1
6.1
-
-
-
Alk. mg/1
P-M
41
36
45
47
24
46
C-M
32
32
31
36
17
36
12
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periods. These preliminary data indicate that there are some important
differences in the chemical water quality in these two streams. Caribou
Creek is lower in conductivity and alkalinity at all sampling times.
This may also be true of pH. Although the data are not complete, pH
generally follows the same trends as alkalinity. These differences in
alaklinity, conductivity and pH may be related to variations in the
geological formations within the aquifers and to differences in the
drainage area, stream velocities, and stream-bed composition and con-
figuration.
Temperature is also frequently lower in Caribou Creek than in Poker
Creek. However, because these are grab samples, the temperatures may not
be truly indicative, because of diurnal variations, although they were
taken within a few hours of one another. On trips where biological sam-
ples were not collected all water quality measurements were completed in
an 8 hour day, using helicopter transportation.
Table 4 lists some of the nutrient chemistry data collected from the
main stations on Poker and Caribou Creeks, and are representative of a
larger mass of similar data collected at all eleven sampling sites. These
nutrient data are typical of relatively unpolluted streams, in that most
inorganic nitrogen is in the form of nitrate, the highest oxidized form.
Streams polluted with organic wastes generally have high ammonia nitrogen
relative to nitrate. Nitrate-nitrogen analyses of these streams (data
not shown) was low, being very near the limit of detection. Total
phosphate-phosphorus data are low—again typical of unpolluted free-
flowing streams. Ortho-phosphate data (not shown) were from 50 - 75
13
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TABLE 4
NUTRfENT ANALYSES - POKER-CARIBOU WATERSHED
Date /
./Site
7/21/71
8/14/71
9/08/71
9/29/71
5/31/72
6/29/72
Total PO,-P
mg/T *
C-M
.021
.08
.08
.07
.09
.06
P-M
.021
.07
.07
.06
.07
.05
NHo-N
mg/1
C-M
.01
.01
.09
.02
.03
.01
P-M
.01
.04
.08
.02
.03
.01
N03"-N
mq/1
C-M
.26
.26
.28
.27
.24
.29
P-M
.26
.30
.26
.28
.34
.34
Si Do
mg/1
C-M
6.8
4.4
7.6
8.4
2.1
3.5
P-M
6.6
6.1
7.8
8.0
2.6
3.8
14
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percent of the total phosphate. Dissolved silica concentrations appear
to be typical of streams in this area—which generally range from 3-15
mg/1 in summer. Although these data are preliminary, they do not appear
to be directly related to hydrologic events such as high-runoff or break-
up. Of course, one would expect seasonal changes to be demonstrated in
samples collected in winter.
Table 5 lists major metal analyses, again at the two main stations.
The low ratio of sodium-potassium to calcium-magnesium concentrations is
typical of streams draining formations of primarily sedimentary or meta-
morphlc rather than igneous origin. As might be expected, the differences
between Poker Creek and Caribou Creek generally follow the same trends as
the conductivity. A general inverse relationship with discharge is demon-
strated, suggesting that most of the metals are derived from groundwater
sources.
In summary, the two streams are of good general chemical water quality,
at least as indicated by the summer and fall sampling periods. The
differences between Caribou and Poker Creeks, particularly in major metal
concentration and temperature, are important to know in advance of any
planned perturbations that might be applied to a Poker Creek sub-basin.
15
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TABLE 5
METALS ANALYSES - POKER-CARIBOU WATERSHED
Date >X
X^Site
7/21/71
8/14/71
9/08/71
9/29/71
5/31/72
6/29/72
Ca
C-M
12.4
3.4
5.7
12.3
7.1
17.1
P-M
16.1
5.6
9.4
16.6
10.5
18.4
Mg
C-M
2.5
2.4
2.8
2.5
2.1
2.8
P-M
3.3
3.8
3.9
3.4
2.7
3.3
Na
C-M
1.0
0.2
0.8
0.1
1.2
2.0
P-M
0.8
0.3
0.8
0.1
1.2
1.7
K
C-M
0.4
0.5
0.6
0.8
0.8
0.6
P-M
' 0.4
0.7
0.7
0.8
1.1
0.6
16
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MACROINVERTEBRATE FAUNA
Biologically, the water quality of a stream is manifested in its
biotic community—the bacteria, algae, macrophytes, invertebrates and
vertebrates. The structure of natural biotic communities, i.e., the
complex of individuals which belong to the species of the biota, is
characterized by some species with many individuals, some species with
few individuals, and a range of intermediates between the two extremes.
Further, organisms in natural biotic communities have adapted over
geologic time to the physical, chemical, and biological conditions with-
in their environment. Since it took a long period of time to become
adapted to these conditions, it is understandable that in many cases,
organisms cannot tolerate or readily adapt to rapid changes, if these
changes are not within the limits and timing of the natural variations
that occur, either within a season or annually.
Alteration of the aquatic environment by the activities of man may
represent these changes. Changes in natural water qualities such as
increased suspended sediment from poorly constructed logging roads, in-
creased water temperature from shade removal, or introduced toxic sub-
stances may result in subsequent detectable alterations of the community
structure. Subject to the severity of the disturbance, some species may
be reduced in abundance or disappear, while others may increase or become
established. Moreover, changes in composition of aquatic life, caused by
subtle modifications of their environment can be detected before physical
*
or chemical changes become apparent.
Ideally, all components of the biota should be analyzed in a water
17
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quality survey, but this usually is not practicable. The^macroinverte-
brate fauna is one component of the community that is commonly employed,
as is the case in this survey. Their relative low mobility does not
allow them to readily avoid an area of perturbation, their life cycles
are generally convenient to study in relation to disturbances, they are
relatively easy to sample quantitatively, are conducive to classification
after preservation, and are useful for assessment of mild pollution of all
kinds. They are also important in the trophic structure of the aquatic
ecosystem and are directly important to species of interest to man—namely
fish. Water quality alterations that affect the macroinvertebrates (e.g.,
alter life cycles, decrease abundance or diversity) may be reflected in
the fish which rely heavily on this segment of the community for food.
Investigation of the macroinvertebrate fauna within Caribou-Poker
Creeks watershed has preceded mainly on a qualitative basis. The effort
has been to document the kinds of organisms within the sub-basins, and
basins, and to relate these areas taxonomically. Some quantitative in-
formation is available but will not be presented here. The number of
trips to all stations has not been consistent, ranging from two visits at
one station to six visits at others. All stations but P-C have been
sampled in late May or early June, July, August, and late September or
early October.
Figure 5 indicates the taxonomic treatment of the collections and
gives a general overview of the organisms present. At this point, classi-
fication is fairly coarse, although the majority are identified to the
generic level or below. Thirty-four taxa have been collected from the
18
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PHYLUM 1
CLASS....; 3
ORDER 4
FAMILY 8
GENERA 15
SUBGENERA......2
SPECIES 1
TOTAL TAXA....34
28
INSECTA
NEMATODA
OLIGOCHAETA, GASTROPODA,
TURBELLARIA
AMPHIPODA, ACARINA
25
DIPTERA
EPHEMEROPTERA
PLECOPTERA
TRICHOPTERA
COLLEMBOLA
HEMIPTERA
LEPIDOPTERA
Figure 5. Taxonomic distribution of macroinvertebrate fauna collected during this study.
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entire watershed and these run the gamut from phylum to species. Twenty-
eight of the 34 taxa are included with the Class Insecta and represent
the lower taxonomic levels. The remaining six represent most of the higher
taxonomic categories and are also generally the fewest in numbers of indi-
viduals: the phylum nematoda, the classes of fresh-water annelids, snails,
and flatworms, and the orders of scuds and water mites. Of the insect
groups, 25 occur within 4 orders—the two-winged flies, mayflies, stoneflies,
and caddisflies. These are the creatures that pass their immature stages
in the water and are of great importance in fish foodwebs. Within the
confines of taxonomic treatment, they make up the bulk of the taxa pre-
sent and are also the most abundant in numbers of individuals. The re-
ami ning three insect groups are the order of springtails, a family within
the true-bugs, and the order of butterflies and moths. Taxonomic work is
expected to continue mainly within the Class Insecta, and consist of re-
ducing certain families to the generic level or below.
The sector diagrams in Figure 6 numerically illustrate the taxa found
at each station. The entire circle represents the 34 total taxa and the
number found at a station is the sum of the lined and shaded areas (P-M for
example). Taxa per station ranged from 15 to 24, but most were nearer 20.
The lined area in each diagram indicates the taxa common to each of the
11. Those found in common are the fresh-water annelids, and representa-
tives from each of the 4 major insect orders previously noted.
An examination of the data from the two basins (Figure 7) shows that
27 of the 34 taxa are held in common. Here the shaded areas indicate that
Poker basin has 4 unique taxa and Caribou has 3. Those unique to Poker
20
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Figure 6. Distribution of macroinvertebrates in the various sub-basins sampled in this study.
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r>o
Figure 7. Re'lative distribution of macroinvertebrates between the total areas of Caribou'and Poker Creek
basins.
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Basin are a species and genera of mayflies, and two genera of caddisflies.
Unique taxa in Caribou Creek are three families of two-winged flies. The
sub-basin and basin areas certainly are not dissimilar to any great
degree as indicated by the taxa held in common. One would expect that
over a long period of time, and within the limits of habitat differences
such as stream order and chemistry, that the organisms would readily in-
habit the streams in this small area.
Conversely, differences between the areas are indicated. With the
fairly sporadic data gathered thus far, however, these may not represent
actual differences. The unique taxa in each basin area, for example, were
derived from only one or two stations and on only one or two occasions,
and may be the consequence of relatively few sampling trips. Although similar
habitats were sampled at each station, differences such as the size of
stream bed rocks and water velocity may be a factor. Also, consistent
physical and chemical differences were noted earlier between the two basins.
The information in the sector diagrams reflect, it seems, the general
structure of natural communities in general; that some organisms are abun-
dant, some are rare, with a range of intermediates. The work cited here,
of course, is just a beginning. To properly understand the complexities
of the aquatic environment and stream biota in these watersheds will take
a variety of approaches, and many years.
Future work is planned to conduct a series of winter samplings
similar to those made in the summer. It may not be possible to sample
all stations, particularly those in the higher elevations, because of
reduced stream flow in winter. However, the two major stations and the
23
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station below the confluence can probably be sampled. Sampling of the
macroinvertebrate fauna will likely be restricted to the few areas where
open water persists throughout the winter. Because grab samples do not
properly evaluate short-term changes, particularly diurnal fluctuations
in such parameters as dissolved oxygen, temperature, pH and discharge,
future plans call for the installation of an automatic recording data
network. This network will include an automatic water quality monitor-
ing system, a climatological data gathering system, and a 24-point
profile of soil and water temperature.
No firm plans presently exist for expanded biological research,
except for the winter sampling just mentioned. Greater emphasis, however,
should be directed toward this segment of the research since pollution is
essentially a biological phenomenon. Approach currently utilized, for
example, should be intensified to resolve the doubts raised by the rela-
tively few samples collected thus far. Also, mild pollution may only affect
macroinvertebrates quantitatively, so additional information should be
gathered in this regard. Moveover, the biological consequences on streams
from watershed management may be initially more subtle and affect the very
basis of the trophic structure. The phytoplankton, therefore, should be
studied, and estimates made of primary production. These, of course, are
a very few of the possibilities that exist to reach the eventual goal of
understanding watershed management techniques and their inter-relationships
to the aquatic biological community.
24
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LITURATURE CITED
Slaughter, C. W. 1971. Caribou-Poker Creeks Research Water. Interior
Alaska; Background and Current Status. Corps of Engineers, CRREL, Rept.
157. 11 pp.
25
U. S. GOVERNMENT PRINTING OFFICE: 1974—79S-474 (93 REGION 10
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