-POKER CREEKS n U. S. ENVIRONMENTAL PROTECTION AGENCY ARCTIC ENVIRONMENTAL RESEARCH LABORATORY COLLEGE, ALASKA 99701 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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. ------- 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. ------- (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 ------- 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. ------- 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.'/ ------- 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 ------- 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. ------- 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 ------- 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 10 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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 ------- 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. ------- 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 ------- Figure 6. Distribution of macroinvertebrates in the various sub-basins sampled in this study. ------- r>o Figure 7. Re'lative distribution of macroinvertebrates between the total areas of Caribou'and Poker Creek basins. ------- 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 ------- 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 ------- 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 ------- |