THESIS
FISH SPECIES DISTRIBUTION
IN DINOSAUR NATIONAL MONUMENT DURING 1961 AND 1962
Submitted by
Joe L. Banks
In partial fUlailment of the requirements
for the DEGREE OF MASTER OF SCIENCE
Colorado State UNIVERSITY
Dort COLLINS, Colorado December, 1964 COLORADO STATE UNIVERSITY
December 1964
WE HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER OUR
SUPERVISION BY JOE L. SJdJS
ENTITLED FISH SPECIES DISTRIBUTION IN DINOSAUR NATIONAL
MONUMENT DURING 1961 AND 1962 BE ACCEPTED AS FULFILLING THIS PART OF THE REQUIREMENTS FOR THE
DEGREE OF MASTER OF SCIENCE.
Committee on Graduate Work
- 1 . 4-TED-LFR ./1410-00% Z4 Major Professor
741"6,1V Head of Department
Examination Satisfactory
Committee on Final Examination
-D.
Permission to publish this report or any part of it must be obtained from the Dean of the Graduate School.
EIBRAMES (ii) COLORADO STATE UNIVERSITY, FORT COLLINS, COLORADQ, ACKNOWLED3EYENTS
The writer wishes to convey his sincere appreciation to the following persons for their part in the completion of this study:
Dr. Harold K. Hagen, the author's major professor, who rendered immeasurable assistance throughout the study and in preparation of this thesis.
The members of the writer's graduate committee, Dr. Edward
B. Reed and Dr. Harold W. Steinhoff, who critically read the manuscript and contributed many valuable suggestions for its improvement.
The staff of the National Park Service at Dinosaur National
Monument for unlimited co-operation and assistance in the field.
The students of fisheries and wildlife at COLORADO STATE
University wino assisted in the field collections.
Special acknowledgement is also due the following organizations for use of equipment and generous financial support:
The Department of Forest Recreation and Wildlife Conservation of Colorado State University, the Nations]. Park Service, and the US
Bureau of Sport FISHERIES and Wildlife.
TABLE OF CONTENTS
Chapter Page
I INTRODUCTION 1 Problem ...... 2 Problem analysis ...... 2 Delimitations ...... 2 Definitions ...... 3
II MATERIALS AND METHODS ...... 4 Environmental measuring equipment ...... 4 ThermDmeters ...... 4 Secchi disc ...... 4 Water chemistry ...... 5 Collecting equipment ...... 5 Invertebrate collecting equipment ...... 5 Fish collecting equipment ...... 5 Field operations ...... 7 The sampling effort of October, 1961 ...... 9 The sampling effort of May, 1962 ...... 9 Sumner and fall investigations of 1962 ...... 11 The sampling effort of October, 1962 ...... 12 Laboratory procedures ...... 12
III THE RIVER ENVIRONFENT ...... 13 Physiography ...... 13 Canyons and parks ...... 17 Stream gradient ...... 17 Stream-flow ...... 19 Local variation in stream-flow ...... 19 Seasonal fluctuation in stream-flow ...... 22 Yearly variation in stream-flow ...... 22 Water quality ...... 28 Water temperature ...... 28 Turbidity ...... 28 Hydrogen ion oonoentration ...... 31 Dissolved oxygen ...... 31 Phenolphthalein and methyl orange alkalinity . 32
IV PRESENTATION AND ANALYSIS OF DATA ...... 33 Fish species oomposition ...... 33 Taxonomy ...... 34 Abundance ...... 35 Effect of stream-flaw, temperature, and turbidity on fish distribution ...... 39 Effect of stream-flow ON FISH DISTRIBUTION 39 Stream temperature variations ...... 40 Stream turbidity variations ...... 40 Variations if fish faunas ...... 42
( V ) TABLE OF CONTENTS—Continued
Chapter Page
Bottom types ...... 43 Habitat preferences ...... 49 Redside shiner ...... 49 Speckled dace ...... 49 Fathead minnow ...... 51 Bonytail chub ...... 51 Colorado squawfish ...... 52 Carp ...... 53 Flannelmouth sucker ...... 53 Humpback and hybrid suckers ...... 53 Bluehead sucker ...... 54 Channel catfish ...... 55 Black bullhead ...... 55 Mottled scUlpin ...... 56 Green sunfish ...... 56 TYPES OF food ...... 57 Stomach analysis ...... 58 Bonytail chub ...... 61 Colorado squawfish ...... 61 Carp ...... 63 Flannelmouth sucker ...... 63 Humpback and hybrid suckers ...... 64 Bluehead sucker ...... 65 Channel catfish ...... 65 Black bullhead ...... 66 Records and location of fishes found after the accidental stream pollution of September, 1962 • • .66 Observations at the Gates of Lodore STUDY area • • •67 OBSERVATIONS AT downstream STUDY areas ...... 69 Sampling results of OCTOBER, 1961 and October, 1962. •71 V CONCLUSIONS AND RECOMEENDATIONS ...... 74 Recommendations ...... 76 VI SUMMARY ...... 77 APPENDICES ...... 81 APPENDIX A--WATER ANNALYSIS DATA ...... 81 Air temperature, water temperature, depth of VISIBILITY, and water chemistry measurements at Gates of Lodore ...... 81 Air temperature, water temperature, depth of visibility, and water chemistry measurements at Echo Park (Green River) ...... 82
(V) TABLE OF CONTENT3--Concluded
Chapter Page
Air temperature, water temperature, depth of visibility, and water chemistry measurements at Echo Park (Yampa River) ...... 83 Air temperature, water temperature, depth of VISIBILITY, and water chemistry measurements at Island Park ...... 84 Air temperature, water temperature, depth of visibility, and water chemistry measurements at Split Mountain ...... 84 APPENDIX 3--FISH SPECIES CAPTURE DATA ...... 85 Numbers of redside shiners collected at seven sampling areas on the dates indicated ...... 85 Numbers of speckled dace COLLECTED at seven sampling areas on the dates indicated ...... 85 Numbers of fathead minnows collected at seven sampling areas on the dates indicated ...... 86 Numbers of bonytail chubs collected at seven sampling areas on the dates indicated ...... 86 Numbers of Colorado squawfish collected at seven sampling areas on the dates indicated ...... 87 Numbers of carp collected at seven sampling areas on the dates INDICATED 87 Numbers of flannelmouth suckers collected at seven sampling areas on the dates indicated ...... 88 Numbers of humpback and hybrid sackers collected at SEVEN sampling areas on the dates indicated ...... 88 Numbers of bluehead suckers collected at seven SAMPLING areas ON the dates indicated ...... • .89 Numbers of CHANNEL CATFISH COLLECTED at SEVEN sampling areas on the DATES INDICATED 89 APPENDIX C--STOMACH ANALYSIS DATA ...... 90 FOOD OF BONYTAIL CHUB 90 FOOD OF COLORADO EQUAWFISH 90 Food of carp ...... 91 Food of nannelmouth sacker. • • • • 91 FOOD OF HUMPBACK SACKER 92 Food OF HYBRID sucker ...... 93 Food of bluehead SACKER 93 AMID OF CHANNEL CATFISH 93 FOOD OF black bullhead ...... 94
(VI)
LIST OF TABLES
Table Page
1 Stream gradient of different sections of the Green and Yampa rivers ...... 20
2 nomentary discharge of four gaging stations on the Green, Yampa, and Little Snake rivers ...... 21
3 Maxftrnun and minimum discharge of the Green, Yampa, and Little Snake rivers for the water year 1961 through 1962 24
4 Water temperature, depth of visibility, pH, dissolved oxygen, and alkalinity, July 2 through September 30, 1962 29
5 SPECIES and numbers OF FIFTH COLLECTED FROM THE Green and Yampa rivers ...... 37
Summary OF FISH SPECIES habitat preferences ...... 50
7 !umbers OF STOMACHS ANALYZED FROM EIGHT FISH SPECIES collected over three bottom types during high and law run-off periods ...... 60
8 Summary of major FOOD items of eight fish species collected over three bottom types during high and low stream-flow periods ...... 62
9 Numbers OF DEAD NTH BLAND AT FOUR LOCATIONS ON THE Green River after the accidental pollution of September, 1962 ••••• • • • • • ...... 70 10 COMPARISON OF FIT& SPECIES COLLECTED at six stations in October, 1961 and 1962 ...... 72
(VII) LIST OF FIGURES
Figure aat 1 Large seines were one of several types of collecting equipment used ...... 8
2 Location of sampling areas in Dinosaur National Monument ...... 10
3 Lodore Canyon confines the Green River as it flows southward ...... 14
4 Canyon habitat of the Green River in Whirlpool Canyon as viewed from Harper's Corner ...... 15
5 Green River at the Island Park study area ...... 16 6 Steamboat Rock near the junction of the Green and Yampa rivers in Echo Park ...... 18
7 Green River at the Gates of Lodore ...... 18
8 Fluctuations in total monthly flows on the Green, Yampa, and Little Snake rivers, October, 1961 through October, 1962 ...... 23
9 Ynnthly fluctuation and mean monthly fluctuation of the Green River during the periods indicated ...... 25
10 Monthly fluctuation and mean monthly fluctuation of the Yampa River during the periods indicated ...... 26
11 Historical flaws showing total annual disdharge at four locations ...... 27
12 One of many forms of Gila collected during the study. 36
13 Hybrid sucker collected at Gates of Lodore during September, 1962 ...... 36
14 Colorado squawfiah, the largest fish collected during the study ...... 38
1$ Humpback sacker, an endemic species of the Colorado River drainage ...... 38
16 Deviation of Yampa River temperatures from Green River temperatures during July and August, 1962 ...... 41 LIST OF FIGURES—Concluded
Figure EP_-,E12 17 Bottom type map of the Gates of Lodore study area ...... 44
18 Bottom type map of the Echo Park study area ...... 45
19 Bottom type map of the Island Park study area ...... 46
20 Bottom type map of the Split Mountain study area ...... 47
21 Bottom type map of the Castle Park study area ...... 48
22 Fish loss during the September pollution was severe in so ne areas ...... 68 Chapter I
INTRODUCTION
An act of Congress in 1956 authorized the Colorado River
Storage Project, primarily for the purposes of regulating the flow of
the Colorado River, storing of water for consumptive use, reclaiming
arid lands, and generating hydroelectric power. Four major units
were authorized by this act. These were the Navajo Unit on the San
Juan River in New lAxilico and Colorado, the Glen Canyon Unit on the
Colorado River in Arizona and Utah, the Curecanti Unit on the Gunnison
River in Colorado, and the Flaming Gorge Unit on the Green River in
Wyoming and Utah.
The completion of the Flaming Gorge Unit (Ashley Dam) on the
Green River in November, 1962, brought about a major alteration in the
downstream environment. Closure of this dam created changes in stream
turbidities and average year-round stream temperatures, and brought
an and to the characteristic patterns of high spring and early smmmer
run-off.
Prior to the upstream impoundment, the Green River within
Dinosaur National Monument contained a distinctive fish fauna. Very little was known of the ecological relationships of the various fish
species, some of which were extremely rare endemics. A pre-impoundment
study was undertaken in order to obtain a better understanding of some of the factors influencing the composition and distribution of the fish fauna before the resultant environmental modifications. 2
Problem
What WAS the composition and distribution of the fish fauna
in Dinosaur National Monument prior to the Closure of the Flaming
Gorge Dam on the Green RIVER in NOVEMBER, 1962?
Problem analysis
The PROBLEM HAS been subdivided into the following questions:
1. What apparent effect did volume of water flow, turbidity, and temperature have on the distribution of the fish fauna?
2. What relationships affecting composition and dis- tribution existed between the fish fauna and the various bottom types?
3. What relationship existed between the various fish species and the presence or absence of specific types of food?
4. What apparent effect did the accidental stream pollution by rotenone during September, 1962, have on fish species distribution?
Delimitations The thesis area was the Green River from Brown's Park Bridge,
Moffat County, Colorado, to Split Mbuntain Campground at the south boundary of Dinosaur National Monument. A 12-mile section of the Yampa River upstream from its confluence with the Green River to Castle Park was also included.
Data were taken from six study areas established within the thesis area and other accessible locations. Periodic collections of fish were made in the fill of 1961 and the spring of 1962. More extensive collections were made during the su er and fall of 1962. 3
This study is qualitative due to the selectivity of the various types of fish collecting equipment.
Definitions
Stream nollution The introduction of substances into a stream which make the waters abnormal in comparison with normal, undisturbed waters (Reid, 1961).
High water period That portion of the year beginning with the first increased spring run-off and arbitrarily ending on July 31.
Low water period That portion of the year beginning arbi- trarily on August 1 and ending with the first increased spring run-off. 4
Chapter II
MATERIALS AND METHODS
The field program consisted of measuring aquatic environ-
mental factors and collecting fish and invertebrate specimens within the thesis area.
Environmental Measuring Equipment
Environmental factors measured were water and air temper- ature, water turbidity, and general water chemistry. Field determinations for water chemistry followed Closely the procedures described by Welch (1948) and Lagler (1956).
Thermometers
A Foxboro electric resistance thermometer was employed to determine air and water temperatures during the first half of the
summer and all autumn investigations. Standardized mercury-in-glass thermometers were used during other periods of field study after they were calibrated with the electric thermometer. Electric thermometer readings were accurate to approximately one-half degree F and mercury thermometer readings were accurate to approximately one degree F.
Secchi disc
An 8-inch secchi disc was used to measure depths of visi- bility according to standard methods described by Welch (1948). All measurements were made in areas where currents were weak or lacking.
Depth of visibility was used as an index to water turbidity. 5
Water Chemistry Dissolved oxygen deteiininations were made by using the
Alsterberg modification of the Winkler method. A Helige comparator was used in the deternination of pH values. Phenolphthalein and methyl orange alkalinity was determined by standard procedures of titration after adding phenolphthalein and methyl orange indicators. For purposes of this study more involved water chemistry determinations were believed unnecessary.
Collecting equipment
Biological collections included aquatic macro-inverte- brate organisms and fishes. The large volumes of water and high turbidities made fish sampling difficult during high water periods.
Several types of collecting equipment were required so that effective sampling could be maintained during all the seasonal stream-flow conditions. A shortage of man power during the simmer investigations also placed a limitation on the types of fishing gear used.
Invertebrate collecting equipment Bottom organisms, primarily aquatic insect larvae, were collected with a Surber square foot bottom-sampler and a hand screen of number 30 mesh. SAmples were collected over bottoms varying from silt and sand to rubble and rock. All bottom fauna were placed in
50 cc glass vials containing a 75% alcohol solution.
Fish collecting equipment
Five general types of equipment were used to collect fish.
Each type had its limitations, and all were somewhat selective as to species and size of fish captured. 6
A stream shocker was genernlly quite successful in stunning fish during low water periods. This device consisted of a combination
AC, DC, Homelite generator with an output of 230 volts and 6.3 amperes. The generator was connected to one positive and two negative electrodes by 200 feet of cord. Alternating current was found more effective in stunning fish than direct current, probably because of the turbulent water in the areas sampled.
During late spring and early summer, when water volume and turbidities were very high, throw-lines were the only effective devices found for collecting fish of larger than fingerling size. Cotton cords were cut to a length varying from 10 to 25 feet and served as the main lines. From these, 12-inch drop lines with hooks were tied at 5-foot intervals. A weight was attached to one end, and the other was anchored near the Shoreline. Throw-lines contained from two to five hooks baited with whole kernel corn or beef liver. They were usually Checked at about 7 am, 12 noon, and 6 pm. This method of collection was found selective for larger fish; usually carp Cyprinus carpio Linnaeus, channel catfish Ictalurus punctatus Rafinesque, and bonytail chubs Gila robusta Baird and Girard.
Four types of seines were used during field operations. Two-man minnow seines were successful in capturing small fish in side channels and Shallow water areas. These seines were 3 feet in depth, from 15 to 20 feet in length, and had a mesh. A small one-man push seine was made by rolling the netting around a brail until the two brails were about three feet apart. This method proved effective for capturing minnows and other small fish in small side channels during the summer investigations. Tied bag seines and tied straight seines from 40 to 60 feet in length and from 4 to 6 feet in depth were used to sample some of the slow water areas on both the Green and Yanpa rivers (Figure 1). These devices could be used only during the October field operations when manpo-,ler was sufficient to make their use practical.
Nylon experimental gill nets, 100 feet in length, 5 feet in depth, with variable 3/4 - 2-inch mesh were used when river conditions permitted. In addition, thro3 standard nylon gill nets were used during the summer investigations. One was 75 feet in length, 5 feet in depth, and had 3/4-inch mesh. The remaining two were 100 feet long, 5 feet deep, and had 1-inch mesh. Gill nets were anchored on or near the stream bank with the downstream end free, thus allowing them to lie parallel to shore. Net sets across the current were impossible because they were soon buried or broken by large quantities of silt and debris washing downstream.
Emdlsified rotenone of 5% concentration was used twice to collect fish in side channels, and at the mouth of a small tributary stream in Echo Park. Block nets increased effectiveness by eliminating routes of escape. Fish collections were also made as a result of the effects of rotenone and its oxidizer escaping from the upstream eradication project during September, 1962.
Al]. fish collected were placed in containers containing a
10% fornalin solution and transported to Colorado State University for study.
Field operations
Field operations consisted of three intensive sampling excursions by field crews from Colorado State University, and a summer Figure 1.--Large seines were one of several types of collecting equipment used. (Photograph courtesy of Harold K. Hagen) Figure 1.--Large seines werc one of several types of collecting enuipment use(1. (Fhotor ,lph courtesy of linrold K. lia o0 9
and autumn investigation of five months' duration. Dates of the
sampling excursions were October 6-M, 1961; May 9-14, 1962; and October
19-21, 1962. The summer investigations of 1962 began on June 26 and
ended on !ovember 6.
Study locations were established with the aid of contour
maps and suggestions from local Park Service personnel. The permanent
locations chosen in downstrean arrangement on the Green River were:
Brown's Park, Gates of Lodore, Echo Park, Island Park, and Split
Mountain Campground near the downstream end of Split Mountain Gorge
(Figure 2). A station was also established at Castle Park near the
Mantle Ranch on the Yampa River. Notes were made on fish species
collections from the different types of habitat following each sampling
effort.
The sampling effort of October, 1961.
Dr. Harold K. Hagen and 26 students in fisheries science
from Colorado State University traveled to the thesis area on October 7. Field crews of five men each were assigned to locations at Brown's Park, Gates of Lodore, Echo Park, Castle Park on the Yampa River, and
Split Hountain Campground. Each field crew was equipped with at least two tied bag seines or straight seines, two experimental gill nets, a square foot bottom-sampler, containers for preserving specimens, and formalin. Each crew sampled its assigned area independently.
Dr. Hagen acted as coordinator between units.
The sampling effort of May, 1962
On May 9, Dr. Hagen and six senior fisheries students returned to the thesis area for a week's sampling at the previously established DINOSAUR NATIONAL MONUMENT sampling 0 J 2 3 4 .5" area Scale in miles
cif
Island park sampli are Yo P
cho Ri t„ e r Park sampling area
Castle Park Visitor Split Mountain sampling area Centbr sampling area
Figure 2.--Location of sampling areas in Dinosaur National Lonum.lit. 11
stations. Collections were also made for the first time at Island Park,
an area approximately 13 river miles from Split Fountain Campground.
The crew was equipped with several tied straight seines, two minnow
seines, two experimental gill nets, rotenone, and stream Shocking equipment. The crew traveled from station to station, sampling each
area. Sampling methods were similar to those used during the October,
1961, effort. The rivers were in high flood stage and sampling was
difficult. Rotenone and two-man minnow seines proved the most efficient method for collecting fish.
Summer and fall investigations of 1962
From June 26 through November 6, fish and invertebrate col-
lections were made under varying water conditions along with measure-
ments of water chemistry, temperature, and depth of visibility.
Collections and measurements were made at THE PREVIOUSLY SELECTED STUDY. areas.
Equipment consisted of one experimental gill net, three
standard gill nets, two minnow seines, hook and line gear, one electric resistance thermometer, two mercury thermometers, one square foot bottom-sampler, one hand screen, one water chemistry kit, alcohol, formalin, and numerous containers for preservation OF specimens.
Hook and line proved the moat effective gear for taking large fish during the summer months; however, this method was not effective at Island Park. The one-man push seine method was successful in capturing minnows and other small fish on several occasions. When assistanoe was available, a two-man minnow SEINE captured many sm.iI1 fish. Gill nets were EFFECTIVE at Echo Park in both the Green and
Yampa rivers when water volume OF FLOW was reduced. 12
A float trip and general reconnaissance of the Green River from the Gates of Lodore to Split ibuntain Campground was made from
June 26 through June 30.
The sampling effort of October, 1962.
During the period of October 19 through 21, the collecting stations were again sampled in much the same manner. The field crew consisted of Dr. Hagen and 14 fisheries students from Colorado State
University. For convienience in sampling, the men were divided into two work crews.
Crew number one sampled stream sections at Split Mountain
Campground, Island Park, Echo Park, and Castle Park. This crew was equipped with two tied bag seines, a stream Shocker, a square foot bottom-sampler, jars, and formalin. Seining methods were discarded because the stream shocker proved much more efficient in capturing fish.
Crew number two collected at the Echo Park and Gates of Lodore study areas. They used several gill nets, a tied bag seine, rotenone, and a square foot bottom-sampler. A duplication of effort at the Echo Park station was intended because of its strategic location at the confluence of the Green and Yampa rivers.
Laboratory procedures
In the laboratory, fish were identified and stomach contents were analyzed. The digestive tract from the esophagus to the anal open- ing was removed and the contents identified. Lengths were recorded before stomachs were removed. Bottom organisms were identified as precisely as possible (Pennak, 1953) by using a binocular diEsecting microscope. 13
Chapter III
THE RIVER ENVIRONI2NT
Numerous physiographic and hydrological characteristics of the river environment exerted important influences on the fishes within the thosis area. Physical and chemical observations and measurements were essential in gaining some understanding of the effect of these factors on the fish fauna and its distribution.
Physiography
The Green River has its headwaters in the Wind River mountain range in west-central Wyoming. any tributaries add to its volume as it flows southward and into Flaming Gorge on the border of northeastern Utah and southwestern Wyoming. After entering Utah, the river tarns eastward through Brown's Park, Colorado, southward into Dinosaur National Monument, and penetrates into the steep wails of Lodore Canyon
(Figure 3). Upon reaching Echo Park, the river makes a sharp bend around Steamboat Rock, then turns abruptly westward through Whirlpool Canyon (Figure 4) and into Island Park, Utah (Figure 5). After leaving Island Park, the river flows southward through Split Mountain Canyon, and out into the relatively flat Uinta Basin.
The Yampa River has its headwaters in the Park Range of the
Rocky Mountains of northern Colorado and flows westward across the state. The river enters Dinosaur National Monument from the east, where it is soon joined by the Little Snake River at Lily, Colorado. The iigure 3.--Lodore Canyon confines the Green River as it flows southward. (Photograph courtesy of Harold K. Hagen) 3.--LO(LORE GANZ:MIL CONFINES THE GREEN ITIVR I. ;; IT FL OWS SOL; COURTESY OF HARNI.D K. ::;ICEN) FIGURE 4.--CANYON habitat of the Green River in Whirlpool Canyon as viewed from HARPER'S CORNER. (Photograph courtesy of Harold K. Hagen) -1 , Figure 5.--Green 'dyer at the Island Park study area. (Photograph courtesy of Harold K. :iagen) 10 17
Yampa River then continues to wind west through the Yampa Canyon until it merges with the Green aver near Steamboat Rock in :oho Park (Figure 6).
Canyons and parks The sandstone formations connonly found within Dinosaur
National 1,1onument are of such substance that cliffs and canyons are readily formed by erosive action. The rivers of this area are apparent- ly of earlier origin than the mountains. This is indicated by the fact
that both streams enter the cliff-lined canyon areas from lower lands
(Flgure 7). The mountains rose slowly before the stream paths, and were subsequently cut through (Woodbury and Argyle, 1963). Echo Park is the central location of the major canyons. The steep canyon wails tend to deflect river currents back and forth, thus forning pools, eddies, and backwaters. Sediments accumulate on the inner, slow-water sides of the curves while the outer areas are frequently scoured and abraded to bare rock by the swift currents. Large rapids and falls are found at intervals through- out the canyon areas. Many of the pools and back eddies that have been gouged out by the swift currents are considerably larger and deeper than any found in the open park areas.
Stream gradient
The Green River has a relatively steep gradient. Woodbury and Argyle (1963) state that from an area near the Lodore Ranger
Station to the lower end of Split Mountain Canyon, the river drops
525 feet in 42 miles. This is an average drop of about 12.4 feet per mile. Stream gradient of the Green River in this area is not consistent Figure 6.--3teamboat Rock near the junction of the Green and Yampa rivers in Echo Park.
Figure 7.--Green River at the Gates of Lodore. Figure 6.--Steamboat Rock near the junction of the Green and Yampa rivers in Echo Park.
Figure 7. --GreenGreen River at the Gates of Lodore 19
however, and ranges from about 2.5 feet drop per mile in slow water sections to more than 25 feet drop per mile in some of the steep canyon areas (Table 1). Contour maps of Dinosaur National Monument show a drop in the floor of the Yampa Canyon of 590 feet in 47 stream miles, or an average of approximately 13 feet per mile between the eastern boundary and the mouth of the river at Echo Park. Drop in this canyon also is inconsistent (Table 1). The river fnlls at a faster rate over the last 12 miles before joining the Green River at Echo Park.
Stream-flow
Stream-flow in the Green, Yampa, and Little Snake rivers was the mcst variable of all the environmental factors observed. An analysis of records compiled by the USGS during this century Shows that stream-flow was extremely variable in three respects: (1) from one location to another within the thesis AREA; (2) FROM season to season; and (3) from year to year.
Local variation in stream-flow Variation in flow from one location to another within the thesis area depended upon the amount of discharge of tributary streams.
The momentary discharge at four gaging stations on the Green, Yampa, and Little Snake RIVERS on the given dates (Table 2) dhows the effect
OF Little Snake and YAMPA RIVER RUN-OFF on the volume of the Green River between Echo Park and Jensen, Utah. 2.0
Table 1.-- Stream gradient of different sections of the Green and Yampa rivers.*
Distance Drop Drop/mile From To (=I) (ft) (ft)
Green River North boundry Lodore at Lodore rapids 6.0 15 2.5 Lodore Vouth of rapids Yampa River 13.8 251 13.2
Youth of Head of Whirl- Yampa River pool Canyon 1.0 4 4.0
Head of Whirl- End of Whirl- pool Canyon pool Canyon 7.5 90 12.0 End of Whirl- Head of split pool Canyon Mountain Canyon 7.5 25 3.3 Head of Split End of Split Eaantain Canyon Mountain Canyon _611 140 21.5 Total 42.3 525
Yampa River Eastern boundry, Castle Deer Lodge Park Park 35.0 400 11.4
Castle Mduth of Park Yampa River 12.0 122 15.8 Total 47.0 590
* Data from Woodbury and Argyle (1963) and USG'S contour maps. 21
Table 2.--Momentary discharge at four gaging stations on the Green, Yampa, and Little anake rivers.*
Little Snake Green River Green River Yampa River River Date Greendale, Utah Jensen, Utah Maybell, Colo. Lily, Colo.
Oct. 15, 1961 1,320 3,180 974 232 Nov. 15, 1961 1,050 1,930 492 120 Mar. 15, 1962 780 1,670 370 200 Apr. 15, 1962 4,670 10,600 5,470 1,700 May 15, 1962 8,650 25,000 10,400 3,870 June 15, 1962 7,180 13,500 6,350 1,660
July 15, 1962 4,330 6,200 1,570 150 Aug. 15, 1962 1,720 2,230 268 3 Sept.15, 1962 674 870 102 0
* Discharge in cfs from USGS stream,flow records.
2?
:Joasonal fluctuation in stream-flow
The general PATTERN OF SOASONAL FLUCTUATION IN STREARRFLOW was similar for all three rivers (Figure 8); however, the total volume of discharge for each river was variable. The pattern of seasonal fluctuation WAS characterized by a low flow in winter from December to February, a high in Xay and Juno, A rapid decline during the rest of the summer, and slightly increasing flow during the fall. The maximum monthly discharge on the Green diver at Greendale, Utah, (below Flaming Gorge) was reached one month later than the other stations. The extreme variation between maximum and minimum flows during the water year 1961 through 1962 is shown in Table 3. The little Snake River had no flow for many days in August and September.
In comparison with the mean maximum monthly run-off for the thirteen year period 1947 through 1959 at Jensen, Utah, the Green River during 1961 and 1962 was one month late in reaching its maxi= dis- charge (Figure 9). The maximum monthly run-off was also somewhat higher than the mean for the thirteen year period. A similar comparison for the Yampa River Moire 10) shows the maxim= monthly run-off for the two periods to be comparable in time. A comparison of total volumes can not be made since data for the 1906-1946 period were gather- ed below the mouth of the Little Snake River.
Yearly variation in stream-flow The variation in total annual discharge of the Green and
Yampa rivers for the period 1906 through 1962 can be seen in Figure 11. Total annual discharge for the Green River Lt Jensen, Utah, was higher during the water year 1961 through 1962 than the average for the previous 56 years. 1000- GREEN R!VER JENNCN, tih
CREEN N7, V , 900
■•■■•111
RLVER nlybell, COLO. 800- LITTLE ;:LAKC!. RIVER, LILY, COLO. 700 EET F
600 ACRE
500 4-4 C.4 0 400- 1-1 CD 0
3 J0-
20&
100.
• . . a) . 0 f, ;-■ ::-. R—I T3 D., 4 -' 0 Q .--a, 0 0 0 , A , r; I. -D 4 4 4 4 RF 1 • 11 CO 0
FIGURE 8.--FLUCTUATIONS IN total monthly flows ON THE GREEN, YAMPA, AND LITTLE Snake RDVERS, OCTOBER, 1961 THROUGH OCTOBER, 1962. USGS RECORDS. 24
Table 3.-- li-Lx.-1:71tri and :3:inimum dischruye of the Green, Yampa, and Little anake rivers for the water year 1961 through 1962. *
River Location I,Axi_mum Date !aniarun Date
Green River Greendale, Utah 15,100 3/29/62 600* mid- January
Green River Jensen, Utah 25,200 5/14/62 490 12/12/61
Yampa River nayboll, Colo. 11,300 5/14/62 93 9/18/62 Little 'Snake TAly, Colo. 9,000 3/28/62 0 August- River Sept., 1962
* Discharge in cfs from USGS stream-flow records. # Estimated volume. Figure
River duringtheperiods indicated. acre feet Argyle 1000 800 900 9.--Monthly
(1963). 1947-1959 1961-1962 Green River Green River Jensen, Jensen, fluctuation andmean monthlyfluctuationoftheGreen Utal Ut a h - i
25 USGS records andWoodbury and ▪
26
1000.
Ya!Ta River 900- ::.aybell, Colo. 1961-1962
Yampa River Lily Park, Colo. 1906-1947
700-'
4-4 a) 600. cti 0 0
500 "
CH 0
400 " A 4-1
4-) /
E-4 / 300- / / /
200-
//
/
/ /
/ 100- /
,
1 f
A ' r V/ r o
• • • 4-; • 4-) C; a. 4.3 0 0 a) a, c i ' - 0 - r p D Cl) - Figure 10.--Fonthly fluctuation and mean : onthly fluctuation of the Yampa River during the periods indicated. USGS records and Woodbury and Argyle (1963). 55)0"
\ Yampa River \ \ Green River \ \ 50)0- Lily, Colo. • • s. Jensen, Utah
45)0- Green River Yampa River Echo Park naybell, Colo. - \ 4030 4 N\ \ \ N \ \ \ \ N ■. \\ \ \ N . NN \ \ N ■ NN \ N
acre feet . 35D0- \\ \ N ''N \ \ N , N\ N \ N , NN \ \ NN \ \ N NN 1000 30)0- 'N \''. N' ''N 'N \ \ \ t. NN \ \ \ NN NN NN N NS \ N \ \ N \ \ \ \ \ N \ NN NN N \ \ NN' NN N N \ NN NN N \ NN' \ N \X. \ NN ', . N \ N• N \ 'N , \ NN \ N' NN \ NN \ 1 NSN N \ \ 'N \ SN N \ \ \ NS
Total run-off in \ \I N. , \ \ \ N N \ \ N• \ \ \ \ \ \ • NS \ \ \ \ N NN N• \ NN• \ s \ \ • 1000- 'N ' \ N \ \ \ \ \ N' ' \ \ \ N \ \ NN \N . \ NNN \ • \ \ \ N•••■ \ \ \ \ \ 500 ‚‚N N \ • \ \ \ \ N', N \ \ \ \ \ \ \ \ ' ‚N \ \
1906 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1959 1962
Figure 11.--Historical flows showing total annual discharge at four locations. USGS records and Woodbury and Argyle (1963). 28
Water quality
Leasurements of water quality were made at four locations on the Green River and one station on the Yampa River during the summer and fall of 1962.
Water temperature
Temperature ranges on the Green River at Gates of Lodore during July, and at Echo Park during August were identical. The average temperature at Echo Park was one degree higher (Table 4). The higher water temperatures found at Echo Park were probably due to the fact that measurements were made at this study area when stream- flow was reduced.
The range and average water temperature at Island Park were considerably lower than at the other stations. This would be expected since these measurements were made during late September. In Echo Park the Yampa River was found to have higher water temperatures than were found in the Green River. The studies of Bailey and Alberti (1952) confirm this observation in temperature difference. Their report indicates that Lily Park on the Yampa River was the zone of highest average temperature for that river. This influence extended downstream to the confluence with the Green River.
Turbidity
As measured by depths of visibility, turbidity was found to vary greatly. During a period of one week, depth of visibility on the 1 Green River ranged from to 9.; inches at Island Park (Table 4). The -4--inch determination was made shortly after an upstream cloudburst. Table 4.--Water temperature, DEPTH OF VISIBILITY, PH, DISSOLVED OXYGEN, AND ALKALINITY, July 2 through September 30, 1962.
Green River Green River Yampa River Green River Gates of Lodore Echo Park Echo Park Island Park July 2-25 Jay 29-August 25 July 29-August 20 Sept. 23-30 Measurement Range Average Range Average Range Average Range Average 64 Temperature (°F) 66-72 68 66-72 69 67-74 71 57- 60
DEPTH OF VISIBILITY (IN)* .25-9.25 5.25 PH 7.4-7.6 7.5 7.5-7.5 7.5 7.5_7.5 7.5 7.5-7.5 7.5 Dissolved oxygen (ppm) 6.6-7.3 7.0 6.8-8,0 7.6 6.0-8.1 7.7 8.1-8.6 8.4 Phenolphthalein ALKALINITY (PPM) 0-9 5 0-10 7 0-10 7 0-3 1 Methyl orange alkalinity (ppm) 157-165 161 121-158 139 123-146 131 128-133 133
* SECCHI DISC DEPTH 30
Turbidity on the Green River was closely related to seasonal
fluctuations in stream-flow. Daring the spring and early summer, the river was extremely turbid, in July as the high waters began to sub- side, the amount of suspended solids gradually decreased. The greatest
depth of visibility observed in the Green River during the study was
inches, measured at Split Mountain Can:pground, November 4, 1962. This pattern of gradual reduction in suspended solids during the summer
and fall was interrupted by occasional rains which caused the river to
become extremely turbid for Short periods. The water after these rains
was usually dark red in color or sometimes yellow.
Variation in turbidity in the Yampa River followed a pattern
similar to that found in the Green River. Seasonal fluctuations were
much more extreme, however. During the high water periods of spring and early summer, turbidities were comparable to those found in the Green
River. Turbidity during the low water seasons of late summer and fall was usually greatly reduced.
The possible effects of temperature and turbidity variations between the Green and Yampa rivers on distribution of the fish fauna will be discussed in the following chapter.
Apparently there is little direct effect of suspended
material on fish unless the concentration is exceedingly high (Wallen,
1951; Doudoroff, 1957; Hynes, 1960). Willen's study of the direct effect of turbidity on fish indicates that concentrations of silt particles up to approximately 20,000 ppm for prolonged periods do not produce any noticeable behaviorial reactions. The ability of fish to move through water containing suspensoids without injury to the gins has been demonstrated by Cole (1941). AN instance OF MECHANICAL INJURY through abrrsion by sharp angular particles is reported by Paul (1952). 31
Silt retards or stops aquatic plant growth by reducing the
-amount and type of light which passes into the water (Cole, 1941; Ingram
and Towne, 1959; Hynes, 1960). Settling particles blanket the stream bottom smothering plant and animal life upon which fishes are dependent
(Cole, 1941; Ingram and Towne, 1959; Hynes, 1960).
Hydrogen ion concentration
The pH values varied only slightly and only at the Sates of
Lodore study area (Table 4). Since most fishes tolerate wide ranges and rapid changes in pH (Lagler, 1956), fish distribution was probably
not affected by hydrogen ion concentration.
Dissolved oxygen
Dissolved oxygen measurements ranged from 6.6 ppm at the Gates of Lodore study area to 8.6 ppm at Island Park (Table 4).
Averages varied from 7.0 ppm (75.9% of saturation) at Gates of Lodore to 8.4 ppm (84.5% of saturation) at Island Park. The average dissolved oxygen value on the Green River at Echo Park was 7.6 ppm (84.3% of saturation). The higher values of dissolved oxygen at Echo Park may have been due to the mixing effect of the rapids and fills in Lodore
Canyon.
Island Park had the widest range and average of all the stations, probably due to the influence of rapids in Whirlpool Canyon, increased aquatic plant life, and lower water temperatures during
September when the determinations were made. All measurements of dissolved oxygen suggest that the fish fauna was not limited in distribution by this factor. 32
Phenolphthalein and methyl orange alkalinity
Phenolphthalein alkalinity ranged from 0 ppm at all stations
to 10 ppm at the Green and Yampa stations at Echo Park (Table 4).
Averages varied from 3 ppm at Island Park to 7 ppm at the Green and
Yampa stations in Echo Park. Nethyl orange values ranged from 121 ppm
on the Green River at Echo Park to 165 ppm at Gates of Lodore.
Averages varied from 131 ppm on the Yampa River to 161 ppm at Gates of
Lodore. Total alkalinity has little direct effect on fishes; however, it is usually an indicator of biological productivity (Lagler, 1956).
All values RECORDED LIE BETWEEN the expected RANGE of VALUES FOR North
American FRESH WATERS (ELLIS, Westfall and Ellis, 1946). 33
Chapter IV
PRESENTATION AND ANALYSIS OF DATA
The basic objective of this study has been the investigation of some of the factors influencing fish species composition and distribution within Dinosaur National Monument. The primary factors studied were: stream-flow, stream temperature, turbidity, habitat preferences of the fish fauna, bottom types, food types, fish species food habits, and the accidental stream pollution during September, 1962.
Fish species composition
Thirteen species of fish representing five families were collected in the thesis area. Six of the species collected were members of the family Cyprinidae, three were members of the family Catostomidae, and two species were represented in the family IctaInridae. One species from each of the families Cottidae and Centrarchidae were also collected.
The six members of the family Cyprinidae included redside shiners Aichardsonius balteatus (Richardson), speckled dace Rhinichthys osenlus (Girard), fathead minnows pimephales promelas Rafinesque, bonytail chubs Gila robusta Baird and Girard, Colorado squawfish
Ptychocheilus lucius Girard, and carp Cyprinus carpio Linnaeus. The family Catostomidae was represented by flannelmouth sackers Catostomus latipinnis Baird and Girard, bluehead suckers Pantosteus delphinus (Cope), humpback suckers Xyrauchen texanus (Abbott), and several apparent hybrid suckers Catostomus latipinnis Baird and Girard X Xyrauchen 34
texanus (Abbott). The two members of the family Ictaluridae were channel catfish Ictalurus punctatus (Rafinesque), and black bullheads
Ictalurus melas (Rafinesque). Single representatives of the families Cottidae and Centrarchidae were mottled sculpins Cottus bairdi (Girard), and green sunfish Lenomis cyanellus Rafinesque respectively. Mountain whitefish Prosopium williamsoni (Girard), rainbow trout Salmo gairdneri Richgrdson, brown trout Salmo trotta Linnaeus, and yellow walleyes Stizostedion vitreum (/'fttchill) have been collected from the Green River in or near the thesis area by some investigators
(McDonald and Dotson, 1959; Bosley, 1960; Gaufin, Smith, and Dotson, 1960; Azevedo, 1963), but were not collected during this study. These fishes were all reported as being rare in the Green River, and in most cases were collected from small tributary streams. Redside shiners, fathead minnows, carp, channel catfish, black bullheads, and green sunfish are not endemic to the thesis area.
Redside shiners, according to Simon (1946), were introduced into the Green River prior to 1942. McDonald and Dotson were the first to report fathead minnows from the Green River. Several were collected by them near Flaming Gorge in 1958. Channel catfish were introduced into the Green River in Wyoming about 1930 (Simon, 1946) and into the Colorado River in Utah in 1939 (Popov and Low, 1950).
Taxonomy
Al]. scientific and common names used are those accepted by the American Fisheries Society (1960). No attempt at identification below the species level was made. Numerous bonytail Chubs with physical characteristics often intermediate between Gila robusta robusta, 35
robusta elerans, and Gila cypha were collected. The true status
of this snecies is uncertain and is currently under study by Dr. Robert
R. 1 Mor AND associates at the University of Fichigan Musaum. Ceveral
specimens from the Green River collection of 1961 AND 1962 are included
in this study. ONO of the many forms of GILA collected during the
study is shown in Figure 12. The fish Catostomus LATININNIS
.yrauchen texanus (Figure 13) has been referred to as the Green River
hybrid sucker by other authors and will be so referred to in this study.
Simon (19)4-6) believes the Green River spring dace to be Rhinichthys
osculus yarrow' and the bigmouth sucker to be Catostomus latipinnis
discobalus.
Abundance
Species composition of the entire fish collection is pre-
sented in Table 5. A total of 2,999 fish were included in the collection.
The number of fish collected from the Green River totaled 2,573, while
426 were collected from the Yampa River at Castle and Echo parks.
Preservation of all specimens captured was impossible because some
species were taken in extremely large numbers, and some individuals
were of large size. Numerous fish observed after the accidental
stream pollution during September, 1962, were not preserved; but were
included in the collection figures since they were closely examined and
identified.
An indication of the relative species abundance in the Green
and Yampa rivers is provided by Table 5. Redside Shiners, speckled
dace, flannelmouth suckers, and bonytail chubs were the most numerous
species collected. Colorado squawfish (Figure 14), humpback suckers
(Figure 15), mottled sculpins, black bullheads, hybrid suckers, and Figure 12.--Cne of many forms of Gila collected during the study. (Photograph courtesy of Pat H. Miller)
Figure 13.---;Tbrid sucker cellectc,d, at L;ates of 1.,odere during .Jeptem- ber, 1962. (Photograph courtes of i'at E. iller) 3c
Figure 12.--One of many forms of Gila collected during the study. (Photograph courtesy Of Pat H. Miller)
Figure 13.--Hybrid sucker collected at Gates of Lodore during Septem- ber, 1962. (Photograph courtesy of Pat H. Miller) 37
Table 5.--3pecios and numbers of fish collected from the Green and Yampa rivers.
Fish Total Total Total Green and species Green River Yampa River Yampa rivers
Cyprinidae Redside Shiner 1502 33 1535 Lipeckled dace 322 174 496 Fathead minnow 18 21 39 Bonytail chub 183 90 273 Colorado squawfish 35 3 38 Carp 92 5 97 Catostomidae Flannelnouth sacker 277 70 347 Humpback sucker 10 0 10 Hybrid sacker 5 0 5 Bluehead sucker 25 17 42 Ictaluridae Channel catfish 97 6 • 103 Black bullhead 6 6 Cottidae Aottled sculpin 1 6 7 Centrarchidae Green sunfish o 1 1 Total 2573 426 2999 Figure 14.--Colorado squawfish, the largest fish collected during the study. (Photo courtesy of Pat H. lidller)
Figure 15.--Humpback sucker, an endemic species of the Colorado River drainage. (Fhoto courtesy of Pat H. 1:.iller) Figure 14.—Colorado squawfish, the largest fish collected during the study. (Photo courtesy of Pat H. Miller)
Figure 15.--Humpback sucker, an endemic species of the Colorado River drainage. (Photo courtesy of Pat H. Miller) 39
green sunfish were rarely taken. The figures in Table 5 however, are
biased due to selectivity of the sampling gear, extreme fluctuation in
water volume of flow, variable water turbidity, and limited access
within the canyon areas.
Effect of stream-flow, temperature, and turbidity
on fish distribution
Stream-flow, temperature, and turbidity were the major
factors INFLUENCING fish distribution in both the Green and Yampa rivers. Volume of flow affected SEASONAL distribution in both rivers,
while differences in temperature and turbidity between the two rivers
may have caused some of the observed variation in fish faunas.
Effect of stream-flow on fish distribution
During spring and early mummer, run-off in both Green and
Yampa rivers was extremely high, and caused fast, turbulent currents in the MID-CHANNEL areas. Even though the deep, fast waters of the main channels were DIFFICULT TO sample, numerous collecting efforts in these areas were made. They produced Almost no fish. Throw-lines set during these periods took fig' only Close to Shore. Beyond the third hook, or about 10 TO 15 feet from the bank, no fish were ever taken. Seining also produced many more fish in protected backwaters and areas near the shoreline where the current was not as strong.
This wctld suggest that most FLAB DID NOT VENTURE FAR INTO THE SWIFT, turbulent currents.
Collecting efforts were mach more productive in the mid- stream areas during late gmmmer and fell when stream-flow was greatly reduced. Although most young fish were still found in the Shallow 40
areas with little or no current, many larger fish were collected in mid-channel with electro-fishing gear, seines, and gill nets.
Stream temperature variations
Major differences in stream-flow patterns of the Green River at Greendale, Utah, and the Yampa River at laybell, Colorado, during
1961 and 1962 are shown in Figure 8. Volume of water flow was con- siderably greater in the Green River during the months of June, July, and August. The earlier reduction in run-off in the Yampa River resulted in higher water temperatures for a greater portion of the year.
This variation in water temperatures between the Green and
Yampa rivers was measured at Echo Park during the month of August, 1962 (Figure 16). The average of the temperature measurements in the Green River during this month was found to be two degrees cooler than the average of those in the Yampa River. All comparative temperature
MEASUREMENTS WERE MADE within one hour of each other, and were made nearly everyday. Temperature OOMPARISONS WERE MADE AT DIFFERENT HOURS on different days.
Stream turbidity variations Turbidity was observed greater in the Green River than in the Yampa during the law run-off seasons. The Yampa River was characterized by very glow currents during low water periods, while currents in the Green River were moderate to fast in most places.
Observations of the variation in turbidity (indicated by variable depths of visibility) were made in Echo Park during August, 1962.
Maximum depth of visibility in the Green River WAS never observed to be greater than one foot. In the Yampa River however, maximum depth Yampa River
+4
+ 3
+ 2.
+ 1
Orcen River no deviation
Temperature difference in decrees F 31 1 2 3 4 9 10 11 12 13 14 15 16 20 July August
Figure 16.--Deviation of Yampa River temperatures from Green River temperatures during July and August, 1962. All paired temperature measurements were made within one hour of each other. 42
of visibility was observed consistently greater than one foot. In many instances, objects were visible at depths greater than three feet.
Variations in fish faunas
The fish faunas of the two rivers were found to differ in several respects. Three species of fish, the humpback sucker, hybrid sucker, and black bullhead were collected only from the Green River.
Only two records of the capture of these fish from the Yampa River are known. Azevedo (1963) reported the capture of one humpback sucker in the Yampa River a few yards from its oonfluenoe with the Green River in Echo Park. Bailey and Alberti (1952) collected several black bullheads from the Yampa River at the mouth of the Little Snake River in Lily Park. In both instances, these fish were collected near other rivers. Gaufin, et Al. (1960) reported the mottled aculpin to be oommon in the upper Green River in Wyoming; however, Only a single specimen was collected from the Green River within Dinosaur National Monument during 1961 and 1962. Several specimens were captured at Castle Park on the Yampa River. Another observed variation between the faunas of the two rivers concerned the bonytail chub. Although many individuals were collected from the Yampa River, the humpbacked form was not found among them. Environment, possibly, is an important factor influencing nuchal hump formation on these fish. If the humpbacked forms are a distinct species, they apparently do not select the Yampa River environment. Bluehead suckers were also oollected more often in the
Yampa River at Castle Park than at any of the other study areas.
Although many factors or oombinations of factors may have been responsible for the observed differences in the fish faunas of the L3
two rivers, the greatest environmental variations observed were water
temperature and turbidity during the low water seasons. Additional year-round measurements of these variations along with studies of the
preferred habitats of the fish faunas may aid in understanding the reasons for their distribution.
Bottom types
TWO obvious differences in bottom type were observed in the
Green and Yampa rivers. The most common type typical of the slower sections with reduced gradients consisted predominantly of very fine silt and sand which was oontinually Shifting and abrading, expecially during the high run-off seasons. This bottom type contained some small areas; however, which were hard-packed and stable. Partin:11y buried sticks and snags were distributed throughout most of the stream sections which had this bottom type. A few smill isolated areas of rubble and rook were also found at some of these locations. The second DISTINCTIVE bottom TYPE OBSERVED PRIMARILY IN steep-walled canyon areas WAS composed of small pebbles, rabble, rocks, and boulders.
The sampling areas at Brown's Park Bridge and Gates of Lodore
(Figure 17) had primarily type 1 substrates. The Echo Park (Figure 18) and Island Park (Figure 19) sampling areas were COMPOSED MOSTLY OF TYPE
2 substrates. A third type, arbitrarily called a combination type, was recognized at 3plit Mountain (Figure 20) and Castle Park on the
Yampa River (Figure 21). This third bottom type consisted of alternating stretches of silt and sand and rubble and rock. L 4
Brown's Park Flow
Cottonwoo Silt and sand Creek
Rubble
Sampling area
Diamond 0 Mountain Douglas Mountain
(1)
0
0 Scale: I in.= 1 000 ft.
GATES OF LODORE STUDY AREA
FIGURE 7.--BOTTOM TYPE MAP OF THE GATES OF LODORE STUDY AREA. ECHO PARK STUDY AREA -
Figure 18.--Bottom type map of the Echo Park study area. 46
Silt and sand
Rubble
EIMMO CA.4 Rock
ampling area
Flow
Rainbow Park
Scale: I in.=I000 ft.
-ISLAND PARK STUDY AREA
Figure 19.--Bottom type map of the Island Park study area. 147
Silt and sand
Split Mountain Campground
Scale: I in. = 50 ft.
SPLIT MOUNTAIN STUDY AREA
Figure 20.--Bottom type map of the Split Mountain study area. L5
Silt and sand
Scale: in.= 40 ff.
Castle Rock
CASTLE PARK STUDY AREA
Figure 21.--Bottom type map of the Castle Park study area. 14-9
Habitat preferences
The habitat preference of each fish species was an important
factor determining distribution. Some species were commonly found in
association with particular bottom types. Some were usually found in
riffle areas, while others were often captured from areas lacking a
strong current. Nearly all immature fishes were collected in Shallow
backwater areas where there was no current.
Redside shiner
Collection records show that red side Shiners were commonly
collected in association with the silt and sand bottom types found at the Brown's Park Bridge and Gates of Lodore sampling areas (Table 6). Many specimens were collected at the mouth of Beaver Creek in Brown's
Park, Cottonwood Creek near the Gates of Lodore, and Pool Creek in
Echo Park. This species was observed in large schools at the mouth of
Jones Creek in June, 1962. Redside Shiners were also commonly oollected
from shallow, quiet areas near the main channel of the Green River and
from email side channels.
Bodley (1960) odllected this species only from the trib-
utaries of the Green River. McDonald and Dotson (1959) and Gaufin
et Al. (1960) found the redside Shiner to be the most oommon species in THEIR collections from the Green River near the Flaming GORGE AREA.
All investigators agreed that this fish preferred a Slow, shallow
habitat*
Speckled dace
Speckled dace WERE found more abundant in the Yampa River at
Castle Park than at any of the stations ON THE GREEN RIVER. THIS species apparently preferred shallow riffle areas and small, swift 50
TABLE 6.--Summary OF FISH SPECIES habitat PREFERENCES.
Bottom Mouths of RIVER type Current tributaries
o ccil
Ti an A Cree E nwoc nati d R FA Creek s
Cd 0 T4 0 0
- one
4EA 1 G J Common name
Red aide shiner X X X 2( X X X XX
Speckled dace X i X X
FATHEAD MINNOW X X X X X X
Bonytail CHUB XXX XXAJJ
Colorado squawfish X X X X J J
CARP X X X X XXXJ
Flannelmouth sacker X X X X X AJJ
HUMPBACK SUCKER A A A
HYBRID SACKER A A A
Bluehead sucker X X X A J
CHANNEL CATFISH X X X X X
BLACK BULLHEAD X X
MOTTLED scUlpin X X X )
X ADULTS AND JUVENILES
A ADULTS
J JUVENILES 51 side channels (Table 6). Although individuals were collected over all bottom types, they appeared to select those areas with rubble and rock bottoms. Only a few specimens were captured in areas lacking a current. Miller (1952) stated that this fish has adapted to a wide range of habitats. McDonald and Dotson (1959) and Gaufin at al. (1960) collected MANY SPECIMENS near the Flaming Gorge area from island channels, along the Shoreline of the MAIN channel, in most tributary
STREAMS, and to a lesser extent in the deep water of the main channel.
MCDONALD and Dotson (1959) observed these fish spawning in gravel at the end of a riffle area in the Green River.
Fathead minnow Most fathead minnows were collected from the Yampa and Green rivers in Echo Park. This SPECIES APPARENTLY PREFERRED areas with
LITTLE or no current and silt and sand substrates (Table 6). Several
FISH WERE ALSO COLLECTED AT THE MOUTHS OF Beaver and Cottonwood Creeks.
Fathead minnows were captured by MCDONALD AND DOTSON (1959) IN the MUDDY backwaters at the mouths of canyons near Flaming Gorge. Gaulin at al. (1960) captured specimens from two island Channels in the same area.
Bonytail chub
Numerous bonytail chubs were collected over ALL BOTTOM TYPES (Table 6). During low stream-flow seasons, larger specimens were most often collected from the main CHANNEL OF both rivers where there was a moderate to swift current. Numerous larger fish (10 to 15 INCHES) were collected Close to Shore at the Gates of Lodore study area during 52
high water periods. Young FISH APPEARED TO favor quiet, shallow areas with silt and sand bottoms and reduced currents during both high and low run-off seasons.
MCDONALD AND Dotson (1959) collected bonytail chubs in the
Green River primarily from the main channel. A FEW SMALL SPECIMENS were taken along the shoreline. Bosley (1960) COLLECTED THIS species most OFTEN IN AREAS OF moderate to slow stream-flows over silt and sand bottoms. Bosley also noted an apparent change in physical character- istics in the extreme lower section of his study area. Many of the individuals taken in and near the Flaming Gorge Canyon had a very pro- nounced hump back. Gaufin et al. (1960) captured what they considered
Gila robasta elegans only in the canyon areas near the Flaming Gorge.
Colorado solaawfish
Of a total collection of 38 squawfish, only six specimens were of larger than fingerling size. Bost fish were Sound Above rubble and rock and combination bottom types (Table 6). They were taken in small numbers from all the study areas except near Brawn's Park Bridge where no fish appeared in the collections.
Sigler and Miller (1963) reported that this filth has been taken only in or near big rivers, where there is a strong current, turbid water, a bottom of mud, stones, and sand, and water three or more feet in depth. Miller (1961) stated that these fish lie in deep holes, especially below riffles, and move in Close to shore to feed on drift materials when the river level rises. He stated that the young are often found where the current is slight or absent, and in water less than two feet deep. 53
Carp
Carp were captured from a great variety of habitats in all
study areas (Table 6). Specimens wore comnonly collected and observed in quiet pools, and in moderate to swift currents. Small fish were
taken in some of the deeper backwater areas and isolated pools near
the Yampa River in Echo Park.
Several small specimens were captured by Gaufin et al. (1960)
in isolated side channels within the Flaming Gorge Canyon area. Simon
(1946) stated that, in rivers, this species will usually seek quiet
waters and deep holes, and avoid swift water except during spawning runs.
Flannelmouth sacker
Flannelmauth suckers were collected in approximately equal numbers over 411 bottom types (Table 6). Larger individuals were taken from nearly all habitats in both Green and Yampa rivers. Young fish
were most often oollected from Shallow, quiet areas and from Shallow
side channels with Slow to moderate currents.
This species was found to be the most widely distributed
fish in the Green River by McDonald and Dotson (1959). Gaufin et al.
(1960) considered the flannelmouth sacker the dominant fish species
in the Flaming Gorge area.
Humpback and hybrid sackers
Al]. ten humPback suckers collected during the study were
taken from the Green River Shortly after the accidental stream pollution
of September, 1962. Limited data suggest that this species selects areas with silt and sand substrates (Table 6). Eight of the ten individuals captured were taken above the silt and sand bottoms at the 54
Lrown's Park Bridge and Gates of Lodore study areas. Two specimens were captured over a combination bottom type at Split Mountain. No
young fish were taken during the STUDY.
Adults are usuAlly collected in areas where there is a strong current, while the young are usually found in shallows along the river
margins (Sigler and Miller, 1963). TWO immature specimens 1.5 inches in length were collected by McDonald and Dotson (1959) in a backwater area in Glen Canyon. No records of the occurence of young further upstream were found. McDonald and Dotson (1959) and Gaufin et al. (1960) each collected one adult fish in the Flaming Gorge area. Azevedo (1963)
captured one adult fish in the Yampa River from a deep, quiet pool near
the junction of the Green and Yampa rivers.
Faux of the five adult hybrid suckers collected in the Green
River were also taken SHORTLY after the accidental stream pollution of
September, 1962. TWO SPECIMENS were oollected above a silt and sand
bottom at THE Gates of LODORE STAFTR AREA, AND TWO were found at split
Mountain above a combination bottom TYPE. ONE FISH WAS captured at the
mouth of Pool Creek during Nay, 1962.
No prior records of the hybrid SUCKER collected in or near
the thesis area were found. This fish was first described by Hubbs and
MILLER (1953). They commented that great reductions in humpback
sucker populations have probably increased the incidence of hybridization.
BLUEHEAD SUCKER
Adults of this species were usually captured in the swift riffle areas with rubble and ROCK substrates (Table 6). More bluehead suckers were taken at Castle Park in the Yampa River area than at any of 55 the stations on the Green River. Young fish were most often captured in quiet, shallow areas near shoreline. Fingerling fish were usually collected along with small flannelmouth suckers; however, they were never as common. McDonald and Dotson (1959) and Gaufin et al. (1960) collected larger specimens from the deeper waters within the Flaming Gorge Canyon.
Bosley (1960) found this fish more abundant upstream from the Flaming
Gorge area.
Channel catfish
Channel catfish were commonly collected above all bottom types; however, they appeared most abundant where the substrate consisted of rubble and rock (Table 6). Larger fish were often captured from stream sections having a moderate to fast current. During high water at the Gates of Lodore study area, this species was collected from the same habitat as the bonytail chub. No fish were taken from the swift currents more than 10 to 15 feet from shore. Most young fish were captured near the shoreline in slow to moderate currents. Very few young fish were found in quiet backwater areas. Bosley (1960) and Gaufin et al. (1960) stated that channel catfish preferred the swifter waters in and near the Flaming Gorge
Canyon.
Black bullhead
The six individuals collected during the study were all taken from quiet backwaters or isolated pools (Table 6). Three fish were captured from an isolated pool near the main channel of the Green River at Split Mountain. Two were collected in a shallow, quiet area 56
near the shoreline at Echo Park. No black bullheads were taken in the
Yampa River.
Simon (1946) reported that, in streams, the black bullhead prefers to lie in deep pools and in the more quiet, turbid areas. Thirty specimens were collected from an isolated, stagnant pond near the Green River by McDonald and Dotson (1959) in Brown's Park. Dailey and Alberti (1952) collected black bullheads from a quiet pool at the junction of the Yampa and Little Snake rivers.
l'ottled sculpin
Of the seven sculpin specimens captured during the study, six
were collected at Castle Park on the Yampa River. One fish was captured
at Island Park on the Green River. All fish were taken from Shallow, swift-water areas above rubble and rock substrates (Table 6). The mottled sculpin was taken quite often from the Rha11ow
waters in the Flaming Gorge impoundment area by lioDonald and Dotson (1959). Gaufin et al. (1960) stated that this species was not common in the
Flaming Gorge study area, but Showed the broadest ecological tolerance of any species collected.
Green sanfish
One green sunfish was captured from the Yampa River at Castle Park during October, 1961. Bailey and Alberti (1952) collected occasional
green sunfish from the Yampa River above Lily Park. They conaluded that these fish were probably washed downstream during high water periods from numerous farm ponds upstream. No records of the collection of this species from the Green River in or near the study area were found. 57
Troes of food
The different foods and their distribution were closely dependent upon bottom types and stream-flow. Substrates of silt and sand supported a bottom fauna differing both qualitatively and quantitatively from that found on the rubble and rock bottoms.
Silt and sand substrates supported less dense populations of aquatic plants and invertebrates. The continually shifting sand in most places and the hard-packed sand in others provided few places of attachment for bottom flora or fauna. Sampling in these areas with a square foot bottom-sampler seldom captured any form of aquatic insect larvae. Collections made from occasional submerged limbs and roots with a hand screen produced numerous mayfly nymphs, primarily of the FAMILY
Baetidae, and Trichoptera larvae, mainly Brachyoentrus. Burrowing dragonfly larvae (Ophiogomnhus) were collected in areas with weak or no currents. Although the scouring action and blockage of sunlight from turbidity on this bottom type decreased considerably during low water seasons, very little seasonal variation in available food was observed.
Greater seasonal variation in food was found on the rubble and rock substrates. During high run-off periods these bottom types were subjected to extreme scouring action. An average of 2.6 aquatic insect larvae per square foot was found for 21 square foot bottom samples taken in Lodore Canyon during June 26 through 28, 1962. Compressed forms of
Ephemeroptera larvae of the family Heptageniidae were oommon1y found beneath the rubble and small rooks in swift water. Mayfly nymphs of the family Baetidae were found in lesser numbers. The caddisfly larvae, Brachycentrus, was also found on this bottom type attached to 59
submerged plant debris and rocks. A few specimens of the Plecoptera
nymphs believed to be Acroneuria were also collected.
During seasons of low run-off and reduced turbidity, scouring
action on rubble and rock substrates was considerably reduced. Mats of
filamentous algae developed on the ex-posed rubble and rock surfaces.
An average of 16.9 aquatic insect larvae per square foot was found for
18 square foot bottom samples taken at Island Park and Split Mountain on
October 28 and November 4, 1962, respectively. The order Trichoptara
was represented by larvae of livdropsyche and Brachycentrus. Nymphs of
families of mayflies, Baetidae, Heptageniidae, and Ephemeridae, were
also found along with large plecopterans keyed as Acroneuria.
Stomach analysis
Fish stomach analyses were conducted to deterialine relation-
ships between fish distribution, food, and substrates. A total of 20$
fish stomachs were examined, 16 of which were empty. The fish species analyzed included bonytail chubs, carp, flannalmouth sackers, channel catfish, Colorado squawfish, humpback suckers, hybrid suckers, bluehead
suckers, and black bullheads. Only a limited examination of the stomach contents of the latter five species was accomplished; however, because these fish were rarely collected or were seldom of larger than fingerling size.
Comparisons were made of the food eaten by each fish species in relation to bottom types during high and low stream-flow periods.
These comparisons were made by determining the per cent frequency of occurrence of each food catagory found in the stomachs of each fish species collected from the different identifiable ecosystems. 59
The fish collections of October 7-8, 1961, and August 1 through November 6, 1962, were made during periods of greatly reduced stream-flow. The collections of May 9-14, 1962, and July 1-31, 1962, were made during periods of very high run-off. An arbitrary date of
August I was established to separate high and low water seasons. Little intraspecific variation in foods was found for fish collected over similar substrate types during comparable stream-flow periods. Therefore, even though only limited numbers of stomachs were analyzed from many of the different environmental situations (Table 7), it is believed that the foods found are representative of the particular length ranges of the individuals examined. The following food groups or catagories were established: algae, terrestrial seeds, horsetail stems (Eouisetum), plant debris,
Ephemeroptera, Flecoptera, Trichoptera, Hemiptera, Coleoptera, Diptera, terrestrial insects, unidentified insects, fish remains, feathers, and inorganic material.
Algae consisted almost entirely of Spirogyra. Plant debris consisted of broken parts of terrestrial plant stems, roots, and woody fragments. Nearly all insects of the orders Ephemeroptera, Fleooptera,
Trichoptera, and Diptera were larval forms. Henipterans were mostly water boatmen (COrixidae), and coleopterans were usually adult aquatic beetles. Most terrestrial insects observed were ants. Two species of fish, speckled dace and redside Shiners, were identified in the stomachs of bonytail chubs and channel catfish on several occasions. Feathers were found in the stomach of one large channel catfish. Inorganic material consisted of silt and fine sand particles. 6o
Table 7.--Numbers of stomachs analyzed from eight fish species COLLECTED over three bottom TYPES DURING high and low run-off periods.
Bottom type Fish SPECIES Silt and sand Rubble and rock Combination
1 Bonytail chub A 3 A 4 A 3 B 13 B 2 D O
Colorado squawfish A O A 2 AO D O B O B 0
Carp A 10 A 5 A 25 13 3 B 3 B 2
Flannelmouth sucker A 15 A 6 AU B 3 B 11. D l
Humpback sucker A 4 A 0 A L DO B O D O
Hybrid sucker A2 A0 AO BO D l B O
Bluehead sucker AO A2 A2 BO BO BO
Channel catfish A 4 A23 A 9 B ? B8 B 7
Black bullhead A 3 AO AO B 1 DO B O
A Low water periods B High water periods 61
Bonytail chub
The stomach contents of 25 bonytail chubs were analyzed.
Sixteen stomachs were from specimens captured over silt and sand bottoms, six were from fish collected above rubble and rock substrates, and three were from fish taken from areas with combination bottom types (Table 7). Lengths varied between 10 and 16 inches. The length average was 12.2 inches. The presence of large quantities of horsetail stems (Scuisetum
Ea.) in fish collected during high water periods (Table 8) suggests that, during this season, bonytail chubs were often found foraging for food in shallow water near the shore line where currents were reduced. Horsetail stems were not available during low run-off seasons. Large quantities of terrestrial seeds and insects were eaten during low flaw periods. It would appear that bonytail chubs commonly fed at the surface and at mid-water depths in these seasons. Feeding habits of the bonytail chub are probably more dependent upon volume of flow than upon substrate type.
Colorado squawfish
Only two of the five Colorado squawfish stomachs examined contained food. These were from fish approximately 9 inches in length captured above a rubble and rock bottom (Table 7). Fish remains were found in one stomach, and small numbers of Trichoptera and Diptera larvae were found in the other (Table 8). Simon (1946), Beckman (1952), and
LaRivers (1962) reported this fish to be a carnivore. small specimens were known to feed on insects and insect larvae. Fishermen have sucessfUily used fish, mice, birds, and rabbits as bait for large individuals (Beckman, 1952). 62
TABLE 8.--SUMMARY OF MAJOR FOOD ITEMS OF EIGHT FISH SPECIES COLLECTED OVER three BOTTOM TYPES DURING HIGH AND LOW STREAM-FLOW PERIODS.
0 4-) 0 0 TL G RI
6 W
W A 0 W P4 II) 4 3 P 1) 4 TRL .4S D + 0 0 4-) P. F-4 LI A O 0 0 '5 CJ .0 4 48.. 1. 1 G 8 8 tn COMMON NAME BOTTOM TYPE
I
BONYTAIL CHUB SILT and sand A X B B
Rubble and rock tr1 A X X B Combination B B
Colorado squawfidh Silt and sand B B B
Carp Silt and sand tr1 X X B B
RUBBLE AND ROCK tx1 A X B
Combination tri A X B
Flannalmauth sucker Silt and sand tr1 A X B B
RUBBLE AND rook trl A X B B A
Combination td A X B B
Humpback sucker Silt and sand tr1 B B
Combination td B B B
Hybrid sucker Silt and sand bri B B B RUBBLE and rock A A
Bluehead sucker RUBBLE and rock
Combination ww B
Channel catfish Silt and sand A X - X B i Rubble and rock tr AXBBA B Combination X BXBX X
Black bullhead Silt and sand B B B Rubble and rock A
X High and low stream-flow periods A High stream-flow periods B Low stream-flow periods 63
Carp
Of a total of 48 carp stomachs analyzed, 13 were taken from
fish captured above silt and sand bottoms, six were from rubble and
rock substrates, and 27 were from combination bottom types (Table 7).
Lengths ranged from 7 to 20 inches, and averaged 11.3 inches.
Large quantities of seeds and plant debris found in carp
stomachs (Table 8) indicates that this species was probably not limited
to any particular bottom type for food. Large quantities of filamentous
algae and dipterans found in the stomachs of carp collected during low
water periods indicates that this species often fed above rubble and rock
substrates where these foods were abundant. Mau carp were observed and
collected over silt and sand bottom types at the Brown's Park Bridge
and Gates of Lodore study areas during low water seasons. Their food
habits indicate however, that they move into rubble and rock areas to feed. Marly carp were observed congregated near the small rubble area
at the Gates of Lodore study area during a low water period in
September, 1962.
Flannelmouth sucker
The stomach contents of 40 flannelmouth sackers were analyzed.
Eighteen stomachs were taken from fish captured over silt and sand
substrates, ten were from fish collected in areas with rubble and rock
substrates, and 12 were from fish taken above combination bottom types
(Table 7). Lengths of fish examined ranged from 8 to 21 inches. The average length was 13.8 inches.
Flannelmouth sackers in both the Green and Yampa rivers appear to have food habits similar to those of carp (Table 8). Large 64
quantities of terrestrial seeds and plant debris were consumed during
the high run-off seasons. The distribution of this species was probably
not limited by their food habits during the high water seasons because
large quantities of terrestrial seeds and plant debris were consumed.
Large quantities of algae and Diptera larvae in fish collected during
low water periods indicate that these fish often fed near areas with
rubble and rock bottom types. Flannelnouth suckers may not have been
as restricted by their food habits as carp since Ephemeroptera and
Trichoptera larvae were important foods consumed over silt and sand
bottoms during low water periods. These two foods were abundant on the
partiAlly buried sticks, snags, and plant debris which were distributed
over the silt and sand substrates.
Humpback and hybrid suckers
The stomach contents of five humpback and three hybrid suckers
were analyzed (Table 7). Four of the humpback suckers were collected
from areas having silt and sand bottom types. One humpback sacker was
captured above a combination bottom type. Two of the hybrid sackers
were taken over silt and sand substrates, and the third hybrid was
collected from an area with a rubble and rock bottom. Lengths of the
humpback suckers varied from 16 to 17 inches. Hybrid sackers ranged in
length between 19 and 22 inches.
Very lirrited data obtained from these fish suggest that their
food habits are similar to those of carp and flannelnouth suckers
(Table 8). Larger quantities of Ephemeroptera larvae and Trichoptera larvae were eaten by humpback and hybrid suckers than were consumed by
carp or flannelmouth suckers. Apparently, the relationships between 65
distribution and food habits of these fish are similar to those of carp
and flannolmouth suckers. Other investigators reported that algae and
midge larvae were the primary foods of humpback suckers (Dill, 1944;
Simon, 1946; McDonald and Dotson, 1959).
Bluehead sucker
The stomach contents of two bluehead suckers collected above
a rubble and rock bottom and two individuals captured over a combination
substrate were analyzed (Table 7). All specimens were captured during law water periods. The lengths of these fish varied between 9 and 10 inches.
Only two food groups, filamentous algae and Diptera larvae
(primarily chironomids), were found in the stomachs of these fish (Table
8). Very little information concerning the relationships between food
habits and distribution of bluehead sackers is provided by the few fish examined. The main food of this fish in other areas was reported to be algae (Fnlis, 1914; Simon, 1946; BECKMAN, 1952; Miller, 1952; Sigler and
Miller, 1963). Miler (1952) reported that this fish scrapes algae from rooks and boulders with the chisel-like ridge found inside each lip.
Simon (1946) stated that bluehead sackers feed as readily upside down as upright, and can easily feed on the underside of boulders.
Channel CATFISH
Of a total of 58 channel catfish STOMACHS analyzed, 11 were taken from fish captured above silt and sand bottoms, 31 were from fish collected over rubble and rock substrates, and 16 were FROM FISH captured in areas with combination bottom types (Table 7). Lengths ranged from
8 to 19 inches, with an average length of 10.5 inches. 66
The food habits of this species appeared similar to those of the bonytail chub (Table 8). Eauisetum was an important food item during high run-off seasons over silt and sand and rubble and rock bottom types. During high water, this species also apparently foraged for food in the shallow areas near the shoreline where submerged horsetai]s were available. Channel catfish consumed the greatest variety of food groups of any of the fishes studied. They did not feed heavily on algae during low water periods as did carp and suckers. They are probably not greatly limited in distribution by their food habits.
Black bullhead
Stomach contents from four black bullheads captured in backwater areas and isolated pools with sand and mud bottoms were analyzed (Table 7). The lengths of all specimens ranged from 5 to 6 inches. Plant debris was the most common food substance found in all stomachs (Table 8). Trichoptera larvae, Diptera larvae, and Hemiptera
(water boatmen) were found in the stomachs of the three fish collected during low water periods.
Records and location of fishes found after the accidental stream pollution of September, 1962 An eradication project covering approximately 450 stream miles was conducted under the joint efforts of the Wyoming and Utah fish and game departments and the US Bureau of Sport Fisheries and Wildlife in order to enhance the sport fishing potential of the reservoir to be created by Flaming Gorge Dam. Approximately 20 rotenone stations were established at various locations through Wyoming and Utah so that a level of toxin of 5 ppm could be obtained. A neutralizing station consisting 67
of four dispensers for potassium permanganate was established at the
Brown's Park Bridge for detoxification of rotenone and protection of the
downstream fish fauna within Dinosaur National 1.;onument.
Despite the precautions taken at Brown's Park Bridge, fish
were killed within Dinosaur National Nonunent (Figure 22). The following
observations were made during and after the accidental pollution of the
Green River within the thesis area.
Observations at the Gates of Lodore study area
Chloroform tests carried out at the Gates of Lodore study
area on September 9, 1962, indicated a concentration of approximately
.25 ppm rotenone at 6:00 am. A mortality of approximately 80% was
found in two live boxes containing redside Shiners and speckled dace
which had been placed in the Green River the previous evening.
Speckled dace and small flannelmouth sackers were first
observed in distress at approximately 7:00 am, September 9. Numerous
fish were found near the water's edge a Short distance upstream from the
Lodore Ranger Station. Six humpback sackers, three bonytail chubs, one
channel catfish, and several carp were collected. Very few of the fish
observed were dead.
On September 10 at approximately 8:00 am, chloroform tests
Showed a concentration of rotenone of approximately .25 ppm. Speckled
dace, flannelmouth suckers, carp, two humpback sackers, two hybrid
suckers, and two large Colorado squawfish (approximately 9 pounds) were
collected from sandbars near the Shoreline. Many more flannelmouth
suckers were observed than on the previous day.
No fish were observed in distress on the morning of September
11; however, many carp and a few channel catfish were found in distress oftwamma
FIGURE 22.--FISH LOS DURING THE SEPTEMBER POLLUTION WAS SEVERE IN SOME AREAS. (PHOTO- GRAPH COURTESY OF HAROLD E. HAGEN Figure 22.--Fish loss during the September pollution was scvere in..3 o!rie (Photo- graph courtesy of Harold K. Hagen) 69
during the afternoon. .)maller numbers of channel catfish and a few
FLANNELMOUTH SUCKERS were observed in distress on :Aptember 12.
seining with a 23-foot minnow seine from 3eptember 13 THROUGH
16 for a distance of approximately one-half mile within the Sates of
Lodore study area produced only one speckled dace FROM an isolated pool
near the main channel. Two gill nets set on September 15, approximately
one mile apart, also captured no fish. !:any redside shiners, speckled
dace, and small flannelmouth suckers were found dead in shallow backwater
areas.
Approximately 200 redside shiners and speckled dace were
captured one day prior to the accidental stream pollution with a 20-foot
minnow seine at the Gates of Lodore study area. This sampling effort
lasted approximately two hours. Seines, gill nets, and hook and line
were also successful in capturing numerous fish during the previous
collecting efforts at Gates of Lodore.
Observations at downstream study areas
Additional observations were made at the Echo Park, Island
Park, Rainbow Park, and Split Mountain study areas as a result of reports
by Park Service personnel of downstream fish kills. Numbers of dead
fish found at each of these stations are Shown in Table 9. Observations of fish apparently not in distress were also made at each of these
stations.
Approximately one mile of stream at the Echo Park, Island
Park, and Split Mountain study areas was examined. Approximately
one-half mile of stream at Rainbow Park was examined. Four small fish,
apparently in good condition, were observed in the Green River at Echo
Park. Many small fish were observed in the Yampa River near its junction :!!
70
Table 9.--Nunbers of dead fish found at four locations on the Green . River after the accidental pollution of September, 1962*
Fish ECHO ISLAND Rainbow Split SPECIES PARK Park Park, Mountain
REDSIDE shiner 4 0 0 0
Speckled DACE 6 1 0 0
Bonytail chub 5 0 0 0 Colorado squawfish 1 0 0 0
Carp 3 1 0 1 Flannelmouth sucker 25 46 7 18 Humpback sucker 0 0 0 2
Hybrid sucker 2 0 0 0
Channel catfish 1-7. 1 1 I TOTAL 25 49 8 22
* COUNTS OF DEAD FISH WERE MADE AT SPLIT MOUNTAIN AND ECHO PARK ON SEPTEMBER 17 and at Rainbow and Island parks ON SEPTEMBER 18.
# Approximately 2 RIVER MILES below IsIand Park. 71
with the Green River. None of these fish appeared to be in distress.
Two flannelmouth suckers and several smaller fish were found in shallow water apparently in good condition at Rainbow Park. any carp were noticed feeding on the surface and near the shoreline at Island Tark, and a large school of srall fish was observed in shallow water.
Numerous fish were seen risini7 to the surface for insects at Split lountain.
Sampling results of October, 1961 and October, 1962
A comparison was made of the results of the October, 1961 and 1962 sampling efforts in order to determine changes in the dis- tribution of the fish fauna brought about principally by the accidental stream pollution. In attempting to duplicate the two collecting efforts, the size and location of the areas sampled, the dates of the collections, and the amount of effort expended at each sampling area were held as closely similar as possible. Stream turbidity in 1961 linlited the type of equipment used and its effectiveness. Bag seines, gill nets, and rotenone were the most effective equipment for taking fish in 1961. In
1962, when stream turbidity was reduced, stream Shocking equipment proved the moat effective method of collecting fish.
The greatest reduction in the number of species captured was at Gates of Lodore where no fish were found in 1962 (Table 10). At
Echo Park in 1962 only three of the eleven species recorded in 1961 were found. The fathead minnow was found in 1962 at Echo Park, but not in 1961. Eight of the nine species captured at Split Mountain in 1961 were found again in 1962.
The methods used certainly do not guarantee that sampling was representative of the fish present within the areas sampled. 72
Table 10.--Comparison of fish species collected at six stations in October, 1961 and October, 1962.
Station Station Fish species 1961 1962
Redside shiner 2, 3, 4, 6 6
Speckled dace 2, 3, 4, 6 3, 4, 5, 6
Fathead minnow 1 4 Bonytall chub 2, 3, 4, 6 3, 4, 6
Colorado squawfish 2, 3, 4, 6 6
Carp 2, 3, 4, 6 3, 5, 6 Flannelmouth sucker 2, 3, 4, 6 3, 4, 5, 6 Bluehead sucker 2, 3, 4, 6 3 Channel catfish 2, 3, 4, 6 3, 5, 6 Black bullhead 4, 6 6
Mottled sculpin 3 3 Green sunfish 3
1 Brown's Park Bridge 2 Gates of Lodore 3 Castle Park (Yampa River) 4 Echo Park 5 Island Park 6 Split Mountain 73
. The contrast between the numbers of fish taken in 1961 and 1962 however,
was very apparent. Many more fish were collected in 1961 with less
effective equipment in higher, more turbid water. In Echo Park, the
1961 crew took hundreds of fishes in a single "hole" near the entrance
of Pool Creek. In 1962, this hole plus the entire section of the Green
River produced only 26 fish. A total of 269 fish were collected during
the entire 1962 sampling effort. In view of the change found in 1962,
it is regrettable that no attempt was made to count total numbers of
fish collected in 1961. 74
Chapter V
CONCLUSIONS AND RECOIYENDArIONS
1. Dissolved oxygen, pH, phenolphthalein alkalinity, and methyl orange alkalinity appeared to have little effect on the dis- tribution of fishes within the thesis area.
2. Of all the environmental factors investigated, stream- flow exerted the greatest influence on seasonal distribution of fishes within the thesis area. The fish fauna was limited primarily to backwaters and to less turbulent areas near shoreline during high run- off seasons. Fish distribution was not as limited during the low stream-flow periods. Many large fish were collected from mid-stream areas during this season; however, smaller fish preferred backwaters, shallow side channels, and areas near the Shoreline. 3. Differences in run-off, temperature, and turbidity between the Green and Yampa rivers during the low run-off seasons were possibly responsible for variations in the fish faunas of these rivers. Humpback and hybrid suckers, humpback forms of the bonytail chub, and black bullheads appeared to select the Green River environment, while mottled scUlpins and bluehead suckers were usually restricted to the
Yanpa River,
4. Redside shiners and fathead minnows were found to select shallow, quiet areas with silt and sand bottoms and habitats at the mouths of small tributary streams. Speckled daoe, mottled scUlpins, and bluehead suckers appeared to prefer shAllow riffle areas with 75 rubble and rock substrates. lost Colorado squa.,:fish were found near rubble and rock substrates. Adult bonytail chubs apparently preferred areas with moderate to fast currents and silt and sand bottoms, while the young were usually captured in areas with little or no current. The majority of hympback and hybrid suckers were collected in areas with silt and sand bottom types; however, they appeared most abundant where the substrate consisted of rubble and rock. Elack bullheads preferred quiet areas with silt, sand, and said bottoms. Carp and flannelmouth suckers were abundant in areas with currents varying from swift to none over bottom types varying from silt and sand to rubble and rock.
5. The presence of Ecuisetum in the stomachs of bonytail chubs and channel catfish captured during high run-off periods indicates that during these seasons, both species foraged for food near the shoreline. The distribution of these fishes was not greatly affected by the presence or absence of specific food types during low stream-flow periods. Large quantities of filamentous algae and Diptera larvae were found in the stomachs of carp and flannelmouth suckers captured during low water periods. This would indicate that, during low stream-flow seasons, both species often fed over rubble and rock substrates where these foods were most abundant. The distribution of these two species was not affected extensively by food or bottom types during high water periods. Very limited data obtained from the stomach analyses of humpback and hybrid suckers suggest that their food habits were similar to those of carp and flannelmouth sackers.
6. A partial fish kill by rotenone occurred throughout the length of the Green River portion of the thesis area following com- pletion of the upstream eradication project during September, 1962. 76
The apparent effects of the accidental stream pollution within the thesis area were a decreaso in abundance of the fish fauna and a decrease in their distribution. Mortality was severe at Gates of Lodore; however, it appeared to decrease as the pollutant moved downstream.
7. The data gathered and the conclusions drawn from this study are not necessarily representative of conditions in the steep and nearly inaccessible canyons within Dinosaur National Monument.
Recommendations
Three recommendations are submitted for future investigation based on data and observations from this study:
1. That additional studies of fish species composition, distribution, and abundance be conducted within Dinosaur National
Monument so that changes in the fish fauna following closure of the
Flaming Gorge Dam may be determined.
2. That life history studies of the rare endemic fishes of the Green and Yampa rivers be conducted.
3. That additional studies of the fish fauna be conducted in the remote canyon areas of Dinosaur National Monument with boat shockers supplying rectified current. 77
Chapter VI
summikay
1. A study of the conposition and distribution of the fish faunas in the Green and Yampa rivers in and near Dinosaur National
1.1onument, Colorado and Utah, was conducted during the fall periods of 1961 and 1962, and the spring and summer of 1962.
2. Fish collections were made with stream Shockers, gill
nets, beach seines, minnow seines, rotenone, hook and line, and as a
result of the after effects of the accidental stream pollution during
September, 1962. Collections of bottom fauna were made with square
foot bottom-samplers and a hand screen. Water temperatures were measured
WITH electric and mercury thermometers. Depth of visibility into the
water was measured with a SECCHI DISC.
3. The Green and Yampa rivers within THE THESIS AREA are
bordered BY STEEP canyons in MOST locations. Run-off in both rivers is characterized by extreme seasonal fluctuations in volume. During high
water periods, rapid currents create high turbidities and subject the shifting silt and sand and heavy rubble and rock bottoms to intensive
scouring. During low water seasons, current velocity, turbidity, and scouring action are greatly reduced.
4. Dissolved oxygen, pH, phenolphthalein alkalinity, methyl orange alkalinity, were within the usual range of values encountered in most North American fresh waters, and did not vary greatly. These 78
factors probably had little if any effect on fish species distribution within the thesis area.
5. Several thousand fish representing thirteen species were collected during the study. These included: redside shiners, speckled dace, fathead minnows, bonytail chubs, Colorado squawfish, flannelmouth suckers, bluehead suckers, humpback suckers, hybrid suckors (flannel- mouth sucker X humpback sucker ), channel catfish, black bullheads, mottled sculpins, and green sunfish.
6. Of the environmental factors investigated, stream-flow appeared to exert the greatest influence on seasonal distribution of fishes. The extremely swift currents during the high water season of spring and early smmmer apparently limited fish distribution primarily to backwaters and other less turbulent areas near the shoreline. Throw- lines, set during the high water season, took fish only next to the shore. Beyond the third hook, or about 10 to 15 feet from the bank, no fish were ever taken. Seining in the shallow, less turbulent areas also produced by far the greatest numbers of fishes, even though considerable effort was spent in sampling the swift mid-stream areas. During the low water periods of late smmmer and fall, many adult fish were captured in deep pools and mid-stream areas with bag seines, gill nets, and stream Shockers, while small fish were usually collected from Shallow aide channels and backwaters.
7. Differences in stream-flow, temperature, and turbidity between the Green and Yampa rivers may have been responsible for observed variations in the fish faunas of the two rivers. High water subsided approximately one month earlier in the Yampa River than in the
Green. Water temperatures and maximum depths of visibility were also 79
found higher in the Yampa River for prolonged periods during the low water seasons. Humpback suckers, hybrid suckers, humpback forms of
the bonytail chub, and black bullheads were not collected from the Yampa
River, while mottled sculpins appeared to be primarily restricted from the Green River. 8. Distinctive habitat preferences were found for some
fishes. Redside shiners and fathead minnows were most often collected from shallow, quiet areas over silt and sand bottoms or at the mouths of small tributary streams. Speckled dace, mottled sculpins, and bluehead
suckers were usually captured in shallow riffle areas with rubble and rock substrates. Colorado SQUAWFISH WERE found in small numbers, usually
ABOVE rubble and ROCK substrates. Adult bonytail chubs apparently pre-
ferred areas with moderate to fast currents with silt and sand bottoms.
Young bonytails were usually captured in areas with reduced currents.
Most humpback and hybrid suckers were collected in areas with silt and
sand substrates. Memel catfish were captured over all bottom types; however, they appeared to be most abundant where the substrate consisted
of rubble and rock. All black bullheads were collected over silt, sand, or mud bottoms where there was little or no current. Carp and flannel-
mouth suckers appeared to be abundant above all bottom TYPES in currents varying from SWIFT TO none.
8. The different food TYPES found were closely associated with bottom types. Scouring action and turbidity reduced the numbers of invertebrates and limited algal growth on all bottom types during high water periods. Growths of algae, resulting in the formation of algal mats, were much more prominant on rubble and rock substrates during low run-off seasons. NUMBERS OF insect larvae, closely associated with
80
these algal mats, also increased. Little seasonal change in food type was found in areas where the substrate consisted of silt and sand.
9. Data obtained from stomach analyses indicated that, in most cases, the presence or absence of specific food types had little effect on the distribution of bonytail chubs, carp, flannelmouth suckers, humpback and hybrid suckers, and channel catfish. During high run-off seasons, the foods of bonytail chubs and channel catfish indicated that they were primarily limited to areas near the shoreline. The foods of carp and flannelmouth suckers during low water periods indicated that these fishes were drawn to areas of rubble and rock to feed. Very limited data from the stomach analysis of hybrid and humpback suckers suggested that these species had food habits similar to flannelmouth suckers. Stomach analyses of Colorado squawfish, bluehead suckers, and black bullheads were too limited to determine the effects of food types on distribution.
10. Falowing the upstream eradication project of September,
1962, a partial fish kill by rotenone occurred throughout the length of the Green River portion of the thesis area. The apparent effects of the accidental stream pollution were a decrease in abundance and dis- tribution of the fish fauna. Mortality at the Gates of Lodore study area was severe; however, it appeared to decrease as the pollutant moved downstream. No fish were encountered for a period of more than a month following the observed loss of fish life at Gates of Lodore.
Sampling in October, 1962, at other study areas also indicated a de- crease in abundance of some species.
U. Recommendations were made for future studies of fish species composition, distribution, abundance, and life histories within
Dinosaur National Monument.
APPENDICES 81
APPENDIX. A
Air temperature, water temperature, depth of visibility and water chemistry measurements at four study areas during 1962
Gates of Lodore
Air Water Depth of hydrogen Dissolved Alkalinity temp temp visibility ion oxygen phth. mo. Date Time F F (in.) concn (PPm) (PPm) (PPm)
July 2 9:00 AM -- 66 1 7.4 3 9:30 AN -- 67 1 7.5 ___ -- 4' 1:30 PM -- 69 2 7.4 6.8 0 5 11:30 AM -_ 68 2 7.4 6.6 33 6 11:00 An 91 69 2 7.5 6.8 0 7 9:30 AM 89 70 3 7.4 7.0 O 8 12:45 PM 82 68 3 7.4 6.8 0 9 10:30 AN 91 68 3 7.5 7.0 O LO 11:45 AM 96 69 3 7.5 6.9 41 -- U 11:00 AM 92 70 3 7.5 6.8 41 12 4:00 Pm 86 71 3 7.5 7.0 18 13 4:15 PM 77 70 3 7.5 7.0 23 OM ••••■••
17 4:45 PM 89 67 2 7.5 7.0 25 •••11••••• 18 4:15 PM 81 68 2 7.5 7.0 25 19 3:55 PM 87 69 3 7.5 6.8 31 ---- 20 4:15 PM 87 69 3 7.5 7.2 9 165 21 4:15 PM 92 72 3 7.5 6.9 o 157 22 6:00 PM 88 72 4 7.5 7.1 0 161 23 2:00 PM 72 69 4 7.6 7.1 __ 24 11:15 AM 85 69 4 7.5 7.3 9 165 25 4:30 PM 74 69 4 7.5 7.3 9 162.
Sept. 16 8:45 AM 69 60 7.5 6 143 32
APPENDI A--Continued
Air temperature, water temperature, depth of visibility, and water chemistry measurements at four study areas during 1962
Echo Park (Green River)
Air Water Depth of HYDROGEN Dissolved ALKALINITY temp temp visibility ion oxygen PHTH. MO. Date Time F F (in.) concn (PPm) (PPM) (PPM)
JULY 29 11:30 AM 70 6 7.5 7.7 9 151 30 9:45 AM 68 6 7.5 7.8 10 158 31 11:15 AM 70 6 7.5 7.7 6 121
Aug. 1 2:15 PM -- 72 7 7.5 7.8 10 133 2 10:30 AM 85 69 7 7.5 7.8 6 133 3 4:45 PM 80 70 8 7.5 7.9 6 134 4 1:15 PM 87 71 8 7.5 8.0 9 138 5 11:45 AM 86 68 2 7.5 7.8 8 141 6 3:15 PM 88 70 5 7.5 7.8 8 142 9 9:45 Am 77 66 7 7.5 7.8 7 139 10 4:00 PM 79 68 8 7.5 7.7 7 137 11 5:30 Pm 81 68 8 7.5 7.8 7 139 12 6:30 Ph 84 69 9 7.5 7.8 8 138 13 7:00 PM 87 67 9 7.5 7.4 9 136 14 4:45 PM 90 69 9 7.5 7.6 5 140 15 5:30 PM 87 70 9 7.5 7.7 4 134 16 5:00 PM 90 69 9 7.5 7.7 8 136 20 5:15 PM 82 70 2 7.5 6.8 0 148 21 5:00 pm 76 69 1 7.5 6.8 6 148 33
APPENDIX A--Continued
Air temperature, water temperature, depth of visibility, and water chemistry measurements at four study areas during 1962
Echo Park (Yampa River)
Air Water Depth of Hydrogen Dissolved Alkalinity temp temp visibility ion oxygen phth. mo. Date Time F F (ft.) concn (PPm) (PPm) (PPm)
July 29 9:45 Al: 3.5 7.5 7.8 o 141
31 9:45 AM 69 3.5 7.5 7.8 6 146
Aug. 1 12:30 pn -- 72 3.5 7.5 7.8 8 127 2 10:30 An 83 70 3.5 7.5 7.8 7 123 3 415 Pm 82 73 3.5 7.5 7.9 9 124 4 12:30 PM 87 71 3.5 7.5 7.8 10 129 5 11:00 AM 86 67 3.5 7.5 7.8 6 131 6 3:15 PM 88 72 4.0 7.5 7.8 9 128
9 9:45 AM 77 68 4.0 7.5 7.8 9 127 10 3:30 Pm 85 72 4.0 7.5 7.8 10 132 11 4:45 PM 87 72 4.0 7.5 7.8 5 131 12 6:00 Pm 87 72 4.0 7.5 7.8 7 127 13 6:00 PM 87 70 4.0 7.5 7.8 9 128 14 4:15 PM 90 70 4.5 7.5 7.8 5 138 15 4:30 PM 90 73 4.5 7.5 7.9 4 127 16 4:30 Pm 90 73 4.5 7.5 8.1 8 134 20 4:45 Pm 85 74 4.5 7.5 6.0 7 137 84
APPENDIX: A--Concluded
Air temperature, water temperature, depth of visibility, AND water chemistry measurements at four study areas during 1962 ISLAND Fark
Air Water Depth of F;ydrogen Dissolved Alkalinity temp temp visibility ION OXYGEN phth. mo. Date Time F F (IN.) concn ( PM) (on) (PPm) Sept. 23 10:30 A 70 62 .25 25 4:30 PM 81 64 2.00 I 26 3:30 PE 72 62 4.00 7.5 8.1 3 138 28 6:00 PM 57 58 6.00 7.5 8.7 29 10:00 AM 60 57 9.75 7.5 8.6 30 11:00 AL 68 57 9.25 7.5 ___ 0 128 Oct. 28 2:45 PM 63 48 13.00 7.5 10.6 5 161
Split /,;ountain
Air Water Depth of gydrogen Dissolved Alkalinity temp temp visibility ion oxygen phth. mo. Date Time F F con= (j:71Dra) tni3m) (rmen) Oct. 7 11:45 AM 64 55 13.25 7.5 9.2 0 137 Nov. 4 2:45 PM 48 48 18.25 7.5 10.7 0 140 85
APPENDIX B
Numbers of redside shiners collected at different stations on the dates indicated. Collection Brown's Park Gates of Echo Echo Island Split Castle date Bridge Lodore Park* Park# Park Mtn. Park 10/7-8/61 0 6+ 8+ 7+ 10+ 5/9-14/62 403 751 188+ 74 10+
7/2-8/25/62 29 23 0 -- + 9/8-18/62 21 0 4 0 0 10/20-21/62 0 0 0 0 1 0
Total 424 786 23 200+ 74 18 10+
* Collected in the YAMPA River
# Collected in the Green River
+ Numerous additional SPECIMENS were released without counting
Numbers of speckled dace collected BY sampling date and station. Collection Brown's Park Gates of Echo Echo.1 Island pplit Castle date Bridge Lodore Park* Pare Park Mtn. Park + 10/7-8/61 0 11+ - 22+ -- 36+ 65 5/9-14/62 0 14t - 8+ 32 26+ _- 7/2-8/25/62 __- 1 6 18 ------9/8-18/62 1254- 3+ - 6 1 0 -- 10/20-21/62 ___ 0 - 2 15 2 122 + Total 125 29+ 6 56+ 48 64+ 168+
* Collected in the YAMPA River
# Collected in the Green River
+ Numerous additional specimens were released without counting 86
APPENDIX B--Continued
NUMBERS OF fathead minnows collected by sampling date and station.
' Collection Brown s Park Gates of Echo Echo Island Split Castle
* date Bridge Lodore PARK PARK PARK Mtn. Park
10/7-8/61 0 0 - 0 0
5/9-14/62 4 3 o o
7/2-8/25/62 0 21 0
- 9/8 18/62 0 0 -- 0 0 0
10/20- 21/62 0 11 0 0 0
Total 4 3 21 11 0 0 0
* COLLECTED in THE YAMPA RIVER
COLLECTED IN the GREEN RIVER
NUMBERS OF bonytail CHUBS COLLECTED BY SAMPLING DATE and STATION. Collection Brown's Park Gates of Echo. Echo., Island Split Castle - DATE BRIDGE Lodore Park Parkr Park Mtn. PARK 10/7-8/61 _- 9+ -- 16+ - 9+ 14+ 5/9-14/62 0 3.5+ __ 2,<4- 9 3+ __ + 7/2-8/25/62 __ 16 74 6 - EV ■•=41=
9/8".18/62 30+ 2 6 o o --
l0/D-21/62 __ o -- 12 0 I 2 TOTAL 30+ 62+ 74t 65+ 9 17+ 16+
* Collected in the Yampa River
# Collected in THE GREEN RIVER
+ NUMEROUS additional specimens were released without oounting
, :Y F1 87
APPENDIK B--Continued
Numbers of Colorado squawfish collected by sampling date and station. Collection Brown's Park Gates of Echo Echo s Island 3plit Castle date Bridge Lodore Park* Park Park Mtn. Park
10/7-8/61 - 2 4 - 3 2
5/9-14/62 o 1 - 6 9 4 - 7/2-8/25/62 - o 1 1
9/8-18/62 o 2 - 1 0 0 -
10/20-21/62 0 o o 2 0
Total 0 5 1 12 9 9 2
* Collected in the Yampa River
i Collected in the Green River
Numbers of carp collected by sanpling date and station. Collection Brown's Park Gates of Echo Echo/ Island Split Castle date Bridge Lodore Park* Park' Park Mtn. Park
4 + + 10/7-8/61 111•1•■•■ 3 - 2+ -- 1 1
5/9-14/62 6 2 3 -- 2
7/2-8/25/62 4 3 5 M1,1•10 1••■■
+ 9/8,18/62 LE 1 - 3 1 1
10/2o-21/62 o o o lo .... . 1 Total 10+ 3 13+ n 4o+
* Collected in the Yampa River
# Collected in the Green River
+ Numerous additional specimens were released without counting F!' L 8
APPENDIX B --CONTINUED
NUMBERS OF FLANNELMOUTH SUCKERS collected by sampling data AND STATION. Collection Brown's Park GATES OF ECHO,* ECHO Island Split Castle date Bridge LODORE Park Park Park 'tn. Park
10/7-8/61 19+ 5+ -- 14+ 14+
5/9-14/62 o 26+ le lo 1+ + 7/2-8/25/62 5 44 8
9/8-18/62 44+ 5+ 25 53 18 --
10/20-21/62 0 1 8 2.2 12 + Total 44 55+ 44+ 49+ 71 53 26+
* Collected in the Yampa River
# Collected in the Green River
+ Numerous additional specimens were released without counting
Numbers of humpback and hybrid suckers collected by sampling date and station. Collection Brown's Park Gates of Echo* Echo s Island SPLIT Castle date Bridge Lodore Park Park' Park An. Park 10/7-8/61 - 0 - 0 - 0 0 5/9-14/62 0 0 - 1+ 0 0 - 7/2-8/25/62 - 0 0 0 - - -
+ + 9/8-18/62 1 7, 2 - 2 0 2 4PD ;1
10/20-21/62 .. 0 - 0 0 4••■■•■■•• 0 0
K Total 1 7,2 0 3+ 0 2 0
* Collected in the Yampa River
# Collected in the Green River
+ Hybrid sucker kPFE!TDIX B--Concluded
NunIce7.5 OF TUEHEAD SUCKERS collected by SAMPLING date and station. COLLECTION BROWN'S PARK Gates of Echo Echo,, Island Split Castle date Bridge LODORE PARK * PARK PARK MTN. PARK
10/7-8/61 4+ - 2+ - 1+ 6+
5/9-14/62 0 3+ 9+ 4 0
7/2-8/25/62 0 0 1 -
9/8-18/62 1 0 - 0 1 0
10/20-21/62 0 0 0 0 10 + Total 1 74. 0 12t 5 1' 16
* Collected in the Yampa River
Collected in the Green River
+ Numerous additional specimens were released without oounting
Numbers of channel catfish collected by sampling data and station. Collection Brown's Park Gates of Echo* Echoi, Island Split Castle date Bridge Lodore Park Parkr Park Mtn. Park + 10/7-8/61 2 4+ 2+
5/9-14/62 0 2 9 11
7/2-8/25/62 13 3 20 • ■•••••
9/8-18/62 2 1 17 2 1 .11.110
10/20-21/62 0 0 2 2 1
+ Total 2 18 3 554 4 18 3+
* Collected in the Yampa River
# Collected in the Green River
+ Numerous additional specimens were released without counting
V,
90
APPENDIX C
Food item per cent frequency of occurrence for eight fish species collected over three bottom types during high and low water SEASONS.
Bonvtail chub
BOTTOM TYPE Food item Per cent frequency OF occurrence
high water Low water
Silt and sand SQUISETUM PL. 61.53 0.00 Plant debris 61.53 66.66 Plecoptera 7.69 0.00 Trichoptera 15.38 0.00 COLEOPTERA 15.38 0.00 UNIDENTIFIED INSECTS 0.00 33.33 Fish 15.38 33.33 Inorganic material 7.69 0.00
Rubble and rock Algae 0.00 100.00 Eouisetum AR. 50.00 0.00 Plant debris 100.00 50.00 Trichoptera 100.00 50.00 Terrestrial insects 0.00 50.00 Unidentified insects 50.00 0.00 Fish 50.00 0.00
Combination Algae ------66.66 Plant debris 100.00 Trichoptera ------33.33 Diptera 33.33 Terrestrial insects ------33.33 UNIDENTIFIED insects ------66.66
Colorado equawfish
Bottom type Food item Per cent frequency of occurrence
High water Law water
RUBBLE AND ROCK Trichoptera 50.00 Dipt era 5040 Fish 50.00 0--ontinued
Food item ner cent frequency of occurrence for eight fish species collected over three bottom tynes durin7, hiqh and low water seasons.
Oarr
bottom type Food item :er ccnt frequency of occurrence liRh water Low water out and sand aae 0.00 70.00 lerrestr4 a1 seeds 100.00 40.00 Plant debris 100.0) 60.00 :yohererontera 0.00 20.00 Trichoptera 0.03 50.00 Coleoptera 0.00 20.00 Diptera 0.00 60.00 Unidentified insects 0.00 10.00 Inorganic material 33.33 0.00 Hubble and rock Algae 0.00 60.00 Terrestrial seeds 100.00 40.00 Plant debris 100.00 100.00 Trichoptera 33.33 20.00 $i Diptera 0.00 40.00 f.4 Inorganic material 66.66 0.00
Combination Algae 0.00 88.00 Terrestrial seeds 100.00 12.00 Plant debris 100.00 84.00 Hemiptera 0.00 8.00 Coleoptera 0.00 12.00 Diptera 0.00 80.00 Unidentified insects 0.00 44.00 Fish 0.00 4.00 Flannelmouth sucker Bottom type Food item Per cent frequency of occurrence ti High water Low water A Silt and sand Algae 0.00 73.33 il Terrestrial seeds 100.00 26.66 k.r■ Plant debris 100.00 100.00 Ephemeroptera 0.00 66.66 Trichoptera 0.00 66.66 Diptera 0.00 26.66 Unidentified insects 0.00 20.00 Inorganic material 33.33 0.00
92
APPWM C--CONTINUED
FOOD ITEM per cent frequency of occurrence for eipht fish species collected over three bottom types during high and low water seasons.
Flannelmouth sucker
Bottom type Food item Per cent frequency of occurrence
High water Low water
Rubble and rock Algae 0.00 100.00 Terrestrial SEEDS 100.00 0.00 Plant debris 75.00 33.33 Ephemeroptera 0.00 16.66 Trichoptera 25.00 33.33 Diptera 0.00 50.00 Unidentified insects 50.00 16.66
Combination Algae 0.00 90.90 Terrestrial seeds 100.00 9.09 Plant debris 25.00 45.45 Ephemeroptera 0.00 18.18 TriChoptera 0.00 45.45 Coleoptera 0.00 9.09 Diptera 0.00 90.90 Unidentified insects 0.00 27.27
Humpback sucker
Bottom type Food item Per cent frequency of occurrence
High water Low water
Silt and sand Algae 75.00 Terrestrial seeds • ■••■•■•■•■■ 25.00 Plant debris 100.00 Ephemeroptera 50.00 Tridhoptera 50.00 Coleopt era 50.00 Diptera 11•■■•••■••■•■••• 25.00 Unidentified insects 25.00
Combination Algae 100.00 Ephemeroptera 100.00 Trichopt era 100.00 Diptera 100.00 93
17"1 )TX C--CONTINUED
Food item per cent frequency of occurrence for eir;ht fish species collected over three bottom types during high and low water seasons.
- Hybrid sucker
Bottom type Food item Per cent frequency of occurrence
High water Low water
Silt and sand Algae 50,00 Plant debris 50,00 Ephemeropt era 100,00 Trichoptera 100,00 Inorganic material 50,00
Hubble and rock Terrestrial seeds 100.00 Plant debris 100.00
Bluehead sucker
Bottom type FOOD ITEM Per cent frequency of occurrence
High water Law water
Rubble and rock Algae 100.00
Combination Algae 100.00 Diptera 100.00
Channel catfish
Bottom type FOOD ITEM Per cent frequency of occurrence
High water Low water
Silt AND SAND Algae 0.00 25.00 Terrestrial seeds 42.85 25.00 ECUISETUM JER. 57.14 0.00 Plant debris 57.14 75.00 Ephemeroptera 50.00 Trichoptera 14.2 100.00 Coleoptera 42.85 0.00 UNIDENTIFIED INSECTS 28.57 25.00 Fish 14.28 Inorganic material 14.28 0.00
94
r,-Concluded
FOOL ITEM PER CENT FREQUENCY of OCCURRENCE for eight fish species collected over three bottom types during high and low water seasons.
Channel catfish
Bottom type Food item Per cent frequency of occurrence
HiRh water Low water
Rubble and rock Algae 37.50 43.47 Terrestrial seeds 25.00 8.69 Equisetum a. 50.00 4.34 Plant debris 75.00 78.26 Ephemeroptera 25.00 43.47 Trichoptera 37.50 60.86 Hemiptera 0,00 8.69 Coleoptera 87,50 26.08 Diptera 0.00 26.08 Terrestrial insects 12.50 4.34 Unidentified insects 37.50 43.47 Fish 12.50 21.73 Feathers 0.00 4.43 Inorganic material 0.00 4.43 Combination Algae 0.00 33.33 Terrestrial seeds 14.29 0.00 Plant debris 85.71 44.44 Ephemeroptera 28.57 44.44 Trichoptera 5704 33.33 Hemiptera 0.00 33.33 Coleoptera 42.85 33.33 Diptera 0.00 11.11 Unidentified insects 57.14 33.33 Fish 14.29 11.11 Inorganic material 42.85 0.00
Black bullhead
Bottom type Food item Per cent frequency of occurrence
High water Low water
Silt and sand Plant debris 100.00 Trichoptera 100.00 Hemiptera 100.00 Fish 33.33 Rubble and rock Plant debris 100.00 LITE'RATtaE, CIT3D--Concluded
, Hynes, H. 5. 1960. The biolor- of polluted waters. Liverpool Univ. ?ress, Liverpool, England. 202 p.
Ingram, W. M., and W. W. Towne. 1959. Stream life below industrial outfalls. U.S. Public Health Rep. 74:1059-1070.
Lagler, K. F. 1956. Freshwater fishery biology. 2nd. ed. Wm. C. :rown Company, Dubuque, Iowa. 421 p.
LaRivers, I. A. 1962. Fishes and fisheries of Nevada. Nevada State Fish and Game Comm., Carson City. 782 p.
McDonald, D. B., and P. A. Dotson. 1959. Pre-impoundment investigations of the Green River and Colorado River developments. Utah Dep. of Game and Fish, job No. 5, Dep. Bull. No. 60-3. 70 p.
Miller, R. R. 1952. Bait fishes of the lower Colorado River from Lake Mead, Nevada to Yuma, Arizona, with a key for their identification. Calif. Fish and Game 38:7-42.
1961. Man and the changing fish fauna of the American Southwest, Michigan Acad. Sc., Arts, and Letters 46:365-404.
Paul, P. M. 1952. Water pollution: a factor modifying fish populations in Pacific Coast streams. Scientific Monthly 74:14-17.
Pennak, R. W. 1953. Fresh-water invertebrates of the United States. The Ronald Press Company, New York. 769 p.
Popov, B., and J. B. Low. 1950. Game, fur animal and flail introduction into Utah. Pdb. NO. 4. Utah Fish and Game Dep., Salt Lake City. 36 p.
Reid, G. K. 1961. Ecology of inland waters and estuaries. Reinhold Publishing Corporation, New York. 375 p.
Sigler, W. F., and R. R. Miller. 1963. Fishes of Utah. Utah State Dep. of Fish and Game, Salt Lake City. 203 p. Simon, J. R. 1946. WyorirT fishes. Bull. Wyo. Game and Fish Dep. 4:1-129.
Wallen, I. E. 1951. The direct effect of turbidity on fishes. Bull. Oklahoma Agr. and Mech. Coll., Biol. Ser. 2. 48:1-27.
Welch, P. S. 1948. Limnological methods. McGraw-Hill Book Company, Inc., New York. 381 p.
Woodbury, L. Ms, and D. W. Argyle. 1963. Ecology and limnology of the Green River, p. 9-48. In A. 14 Woodbury (ed.) Studies of biota in Dinosaur National Monument, Utah and Colorado. Univ. of Utah Div. of Biol. Sci. Misc. Paper No. 1. !!' 95
LITERATUR CITED
American Fisheries Society. 1960. A list of common scientific names of fishes from the United States and Canada. Amer. Fisheries Soc. Spec. Publ. No. 2. 102 p. Azevedo, R. 1963. Dinosaur National Monument - Green River fish collections. Report of the Green River ecology studies conference, Sept. 4, 1963. 6 p. (In files at Dinosaur National Monument Headquarters, Artesia, Colorado). Bailey, C., and R. Alberti. 1952. Lower Yanpa River and tributaries study. Colorado Dep. of Game and Fish, job completion rep. No. 2. p. 160-180. Beckman, W. C. 1952. Guide to the fishes of Colorado. Leaflet No. 11, Univ. of Colorado, Boulder. 110 p. Bosley, C. E. 1960. Pre-impoundment study of the Flaming Gorge Reservoir. Fisheries Tech. Rep. No. 9, Cheyenne. 81 p. Cole, E. A. 1941. The effects of pollutional wastes on fish life, p. 241-259. In A symposium on hydrobiology, Univ. of Wisconsin Press, Madison.
Dill, W. A. 1944. The fishery of the lover Colorado River. Calif. Fish and Game 30:109-211.
Doudoroff, P. 1957. Water quality requirements of fishes and effects of toxic substances. 2:403-430. In M. E. Brown (ed.) The physiology of fishes. Acad. Press, Inc., New York.
Ellis, M. M. 1914. Fishes of Colorado. Univ. of Colorado Studies. 11:1-136.
Ellis, M. M., B. A. Westfal, and M. D. Ellis. 1946. Determination of water quality. U.S. Fish and Wildlife Service Res. Rep. No. 9. 122 p.
Gaufin, A. R., G. R. Smith, and P. A. Dotson. 1960. Aquatic survey of the Green River and tributaries within the Flaming Gorge Reservoir Basin, P. 139-175. In C. B. Dibble (ed.) Ecological studies of the flora and fauna of Flaming Gorge Reservoir Basin, Utah and Wyoming. Univ. of Utah Anthropological paper No. 48. Hubbs, C. L., and R. R. Miller. 1953. Hybridization in nature between the fish genera Catostomus and Xyrauchen. Michigan Acad. Sei., Arts, and Letters 38:207-233. 1
ABSTRACT OF THESIS
FISH SPECIES DISTRIBUTION
IN DINOSAUR NATIONAL MONUMENT
DURING 1961 AND 1962
Submitted by
Joe L. Banks
In partial fulfillment of the requirements
for the Degree of Master of Science
Colorado State University
Fort Collins, Colorado
December, 1964 FISH SPECIES DISTRIDUTI N IN DINOSAUR NATIONAI MoNUMENT
DURING 1961 AND 1962
A study of fish species distribution in the Green
and Yampa rivers as related to stream-flow, water temperature,
turbidity, bottom types, tynes of food, and the accidental
stream Pollution of SePtember, 1Q62, was conducted in Dinosaur
National Monument, Utah and Colorado. Collections and obser-
vations were made at six study areas during the fall of 1961
and 1962 and the spring and summer of 1962. aithin the thesis
area, these rivers were subjected to extreme seasonal fluctu-
ations in run-off.
Of the environmental factors investigated, variations
in stream-flow exerted the greatest influence on fish distri-
bution. During high run-off seasons, the fish fauna was pri-
marily limited to backwaters and to less turbulent areas near
the shoreline. Many fishes of larger than fingerling size were
collected in mid-stream areas during low run-off seasons.
Differences in stream-flow, temperature, and turbidity
between the Green and Yampa rivers during the low water seasons
were possibly responsible for variations in the fish faunas of these rivers.
Types of food were dependent on bottom types and had little if any effect on the distribution of bonytail chubs and channel catfish of the size ranges studied. Carp and flannel- mouth suckers within the size ranges analyzed were apparently drawn to rubble and rock substrates for food during low water neriods.
Redside shiners, soeckled dace, fathead minnows, bonytail chubs, bluchead suckers, mottled sculpins, and black bullheads were the most snecific in habitat selection. No narticular habitat preferences were observed for carp, flannel- mouth suckers, and channel catfish.
Environmental factors of pH, dissolved oxygen, phenol- phthalein alkalinity, and methyl orange alkalinity did not noticably influence fish snecies distribution.
The fish fauna within the study areas decreased in abundance and distribution after completion of the upstream fish eradication project during September, 1962.
Joe L. Banks
Department of Forest Recreation and Wildlife Conservation
Colorado State University
December, 1964