NUTRIOSO CREEK - CROSSWHITE PROPERTY FISH SURVEY REPORT
4-2-2000

Mike A. Lopez, Fisheries Specialist
Region I
Arizona Game and Fish Department

AMERICANS WITH DISABILITIES ACT COMPLIANCE

The Arizona Game and Fish Department complies with all provisions of the Americans with Disabilities Act. This document is available in alternative format by contacting Larry M. Riley, Fisheries Branch, Arizona Game and Fish Department, 2221 West Greenway Road WMFS, Phoenix, Arizona 85023-4399 (602) 789-3257.

CIVIL RIGHTS AND DIVERSITY COMPLIANCE

The Arizona Game and Fish Commission receives Federal financial assistance in Sport Fish and Wildlife Restoration. Under Title VI of the 1964 Civil Rights Act, Section 504 of the Rehabilitation Act of 1973, Title IX of the Education Amendments of 1972, the U.S. Department of the Interior prohibits discrimination on the basis of race, color, creed, national origin, age, sex, religion or disability. If you believe you have been discriminated against in any program, activity, or facility as described above, or if you desire further information please write to: Arizona Game and Fish Department, Office of the Deputy Director, 2221 West Greenway Road DOHQ, Phoenix, Arizona 85023-4399, and the Office for Diversity and Civil Rights, U.S. Fish and Wildlife Service, 4040 North Fairfax Drive, Room 300, Arlington, Virginia 22203.

PROJECT FUNDING

Funding for this project was provided through fishing license revenues and the Federal Aid in Sport Fish Restoration Act, a program administered by U.S. Fish and Wildlife Service, Division of Federal Aid.

TABLE OF CONTENTS

Introduction
Survey Methods and Results
Water Analysis
Habitat
Fish Population
Survey Discussion
Recommendations
Literature Cited

LIST OF FIGURES

Figure 1. Map of the Nutrioso Creek Crosswhite Property with and survey stations

LIST OF TABLES

Table 1. Limnological data summary
Table 2. GAWS station locations
Table 3. Summary of habitat conditions
Table 4. Summary of fisheries surveys
Table 5. Number, relative abundance, relative biomass, CPU of fish sampled
Table 6. Number, size, condition, and biomass (population estimates) of fish sampled
Table 7. Length frequency distribution of fish sampled

LIST OF APPENDIXES

Appendix A. General Aquatic Wildlife Survey Glossary
Appendix B. GAWS Habitat Survey Summary
Appendix C. List of fish species of Arizona and codes
Appendix D. List of plant species identified on Crosswhite Property

INTRODUCTION

Nutrioso Creek, located in southern Apache County, Arizona, is a 42.5 kilometer (28.1 mile) northerly flowing tributary of the Little Colorado River. Drainage area of the Nutrioso Creek system is approximately 411.1 square kilometers (158.7 square miles). Nutrioso Creek ranges in elevation from 2105 meters (6907 feet) at the confluence with the Little Colorado River in Springerville (T9N R29E Sec. 29 SE4NW4NE4) to a maximum of 2560 meters (8400 feet) at its origin, descending 10.7 meters/kilometer (53.1 feet/mile) over its stream course. The Strahler stream order (Strahler, 1957) of Nutrioso Creek is 6th-order, as defined by cell-based modeling (Douglas, 1986; Jenson and Dominque, 1988; Tarboton et al., 1991), or 5th-order, as defined by the conventional topographic map method (McMahon et al., 1996; Platts et al., 1983; USFS, 1985). Nutrioso Creek originates from spring flow on the southwest side of Escudilla Mountain (T6N R30E Sec. 22 NE4NE4) and flows 21.5 kilometers (13.4 miles) through the town of Nutrioso and into Nelson Reservoir. Downstream of Nelson Reservoir, Nutrioso Creek extends for another 21.0 kilometers (13.0 miles), eventually reaching the town of Springerville and its confluence with the Little Colorado River. Land ownership along Nutrioso Creek consists of private (48.6%), Apache-Sitgreaves National Forests (ASNF)(45.2%), State Trust (3.5%), and Arizona Game and Fish Department (AGFD)(2.7%). The stream's watershed consists of ponderosa pine and mixed-conifer forests in the headwaters and mid-elevations, and pinion-juniper in lower elevations.

Nutrioso Creek's historic native fish population, prior to the introduction of exotic species and habitat disruption associated with man-related activity, consisted of speckled dace (Rhinichthys osculus), bluehead sucker (Pantosteus discobolus), and Little Colorado (LC) spinedace (Lepidomeda vittata). Apache trout (Oncorhynchus apache) likely occurred within the headwater portions of Nutrioso Creek and its tributaries. Museum records from the Arizona State University Vertebrate Museum include specimens of speckled dace (ASU 12003), bluehead sucker (ASU 12001), and LC spinedace (ASU 12002) collected in Nutrioso Creek near the point of confluence with Auger Creek in 1988. Rainbow trout (Oncorhynchus mykiss) was also caught during the 1988 survey (Marsh and Young 1988). Later surveys in 1990-1995 by AGFD have revealed LC spinedace, bluehead sucker, speckled dace, rainbow trout, fathead minnow (Pimephales promelas), brook trout (Salvelinus fontinalis), and brown trout (Salmo trutta)(Dorum and Young 1995). This survey on the Nutrioso Creek - Crosswhite Property documented the presence of LC spinedace, bluehead sucker, speckled dace, and fathead minnow.

Historical stocking records of the AGFD indicate that rainbow trout were stocked into the headwaters area of Nutrioso Creek in 1937. Nonnative fish have also had access into Nutrioso Creek from stockings made into Nelson Reservoir. Rainbow trout were first planted into Nelson Reservoir in 1958, channel catfish (Ictalurus punctatus) in 1975, brook trout in 1977, brown trout in 1978, and cutthroat trout (Oncorhynchus clarki) in 1987. A total of 20,000 rainbow trout are currently stocked each year into Nelson Reservoir to support an intensive-use sportfishery. Angler use at Nelson Reservoir is high, supporting an estimated 17,059 anglers and 34,380 angler hours in 1999. Angler use throughout all of Nutrioso Creek is unknown, but it is presumed to be very low. Creel surveys on public lands immediately downstream and upstream of Nelson Reservoir from 1997-1999 showed zero angler use. Nutrioso Creek is currently managed as a wild-fish water.

Comprehensive surveys of 2.038 kilometers (1.27 miles) of Nutrioso Creek located on private land (Crosswhite Property) were conducted by AGFD personnel and Jim Crosswhite (landowner) in October 1999. The Crosswhite Property is located approximately one mile North of the town of Nutrioso in Sections 20 and 29 of T7N R30E at an elevation of approximately 2304 meters (7560 feet). This report summarizes the results of the surveys of the fish population, aquatic habitat condition, riparian habitat, and water quality along that portion of Nutrioso Creek.

SURVEY METHODS AND RESULTS

WATER ANALYSIS

Basic water quality parameters were measured on the Crosswhite property in Nutrioso Creek at two locations (stations 1 and 3) on October 6, 1999. Alkalinity and dissolved oxygen were measured with a Hach model AL-36DT Ecology Combination Test Kit. Turbidity was measured with a Hach model 2100AN Turbidimeter, and pH measured with an Orion Research model 407A Ionalyzer. Results were averaged and are presented in Table 1.

Water analysis characterized Nutrioso Creek as a moderately clean stream. Moderate levels of hardness were found with total alkalinity averaging 211 mg/l and conductivity averaging 265 (mhos/cm. Hydrogen-ion (pH) concentrations were somewhat above neutral, averaging 7.9. Dissolved oxygen concentrations averaged 7.38 mg/l. The lower oxygen saturation level (88%) found at station 1 is probably due to the time of day that the sample was taken, in the morning when oxygen levels are usually at their lowest due to flora and fauna respiration and lack of photosynthesis throughout the night hours. Turbidity measurements averaged 24.5 N.T.U., with almost no difference between the upper and lower site measurements, 24.8 and 24.1 N.T.U., respectively. Stream flow measurements at the two stations ranged from 0.040 cubic meters per second (cms)(1.41 cfs) to 0.063 cms (2.22 cfs).

HABITAT

A survey of aquatic habitat conditions on the Nutrioso Creek - Crosswhite Property was conducted on October 7, 1999. Methods used to inventory aquatic habitats were those of the General Aquatic Wildlife Survey (GAWS) element of the U.S. Forest Service (USFS) Wildlife and Fish Habitat Relationship System (WFHRS) as described in USFS (1985). The USFS Region 3 Riparian Scorecard and the Bureau of Land Management (BLM) Proper Functioning Condition checklist were used to assess associated riparian conditions (USFS 1989a; BLM 1995).

The private lands surveyed on the Crosswhite Property were treated as one reach for sampling purposes (Figure 1). Three representative GAWS sampling stations were established to describe aquatic habitat and riparian conditions. The property was measured with a hip chain and GAWS stations permanently located by measuring distance from each station to a notable landmark (Table 2). Fence post stakes were left at each station to identify photo points and for future monitoring purposes.

Table 1. LIMNOLOGICAL DATA SUMMARY Water: Nutrioso Creek - Crosswhite Property Reference # 614.12 Date: October 6, 1999

Figure 1. Map

At each 50-meter station, numerous habitat variables were measured using the GAWS transect method with five perpendicular-to-flow transects spaced equally at 10 meter increments. From the data collected, the GAWS computer program was employed to calculate a number of habitat ratings for various stream characteristics, including a Habitat Condition Index (HCI), which is a multivariate rating of existing trout habitat. Standards and guidelines in the Apache-Sitgreaves National Forests Land and Resource Management Plan (Forest Plan) call for managing for at least 60% of potential habitat capability (60% HCI) on trout streams (USFS 1989b). A detailed explanation of GAWS data output and terminology can be found in Appendix A. Appendix B summarizes the data collected at each station and presents a mean for the reach.

Table 2. Nutrioso Creek - Crosswhite Property, GAWS Station Locations, October 1999.

The Nutrioso Creek - Crosswhite Property provides approximately 0.63 hectares (1.56 acres) of stream habitat over the 2.038 kilometer (1.27 mile) stream course surveyed with the GAWS methodology (Table 3). It was a moderate sized stream with an overall mean width of 3.1 meters (10.2 feet), a mean depth of 0.26 meters (0.85 feet), and an overall width to depth ratio of 14. Stream gradient was low, averaging 0.8 percent. The entire stream channel is downcut 6-10 feet below the surrounding valley bottom. This downcut is old and appears to be recovering, with vegetation established on the lower banks. The Nutrioso Creek - Crosswhite Property supports a riparian area that was estimated to be 1.83 hectares (4.52 acres) in size, and had an overall rating of 7.3 on the riparian scorecard which is unsatisfactory (Table 3), and a functional rating of functional-at risk, with an upward trend.

Station 1 is located 100 meters upstream of the lower property boundary fence. Stream gradient was low at 0.5 percent. Aquatic habitat consisted almost entirely of pool habitat, resulting in a poor pool-to-riffle ratio (pool measure=7.4%) and riffle rating (3.7%). The pools present were large and good quality however, rating 100% for pool structure and 96.3% for Potential Rearing Area (PRA). Bank cover, bank soil stability, and bank vegetation stability were all fair, rating 50.0%, 67.5%, and 72.5%, respectively. Water widths averaged 2.7 meters (8.9 feet), water depths averaged 0.30 meters (0.98 feet), with a good width to depth ratio of 9. Instream substrates were dominated by sand/silt (80.2%), then by gravel (15.4%) and rubble (4.4%), resulting in a poor rating for gravel bottom (19.9%). Embeddedness was poor at 60.0% and ungulate damage rated 10.0%. The Habitat Condition Index (HCI) rated below the targeted 60% minimum standard, at 52.9%, due primarily to the poor pool-to-riffle ratio and poor substrates. Station 1 supported 0.03 hectares (0.07 acres) of riparian habitat that was rated unsatisfactory (Table 3). Understory vegetation species included Carex spp., Juncus spp., Agrostis alba, Bromus spp., Equisetum spp., Rumex spp., young Salix spp., Eriogonum spp., Aster spp., Rorippa nasturtium-aquaticum, Achillea lanulosa, and Typha spp. Overstory species included Salix spp., Rhus trilobata, Alnus spp., and Elaegnus angustifolia. Common names of riparian species are listed in Appendix D.

Station 2 is located 741 meters upstream of station 1. Stream gradient was low, at 1.0 percent. Aquatic habitat again consisted of a preponderance of pool habitat, though not to the extent in station 1, resulting in a fair rating for pool measure (51.9%) and riffle area (25.9%). Again, the pools present were large and of good quality, resulting in good ratings for pool structure (100%) and PRA (74.1%). Water widths averaged 3.7 meters (12.1 feet), water depths averaged 0.34 meters (1.12 feet), with a good width to depth ratio of 11. Instream substrates in station 2 were dominated by sand/silt (85.4%), then by gravel (8.1%) and other (6.5%), resulting in a poor rating for gravel bottom (8.1%). Embeddedness was poor, rating 68.0%, and ungulate damage was low at 10.0%. Stream banks showed signs of recovery, resulting in fair ratings for bank cover, bank soil and vegetation stability, 50.0%, 75.0%, and 77.5%, respectively. The HCI in station 2 was just above the minimum standard, rating 60.4%. Station 2 supported a total of 0.07 hectares (0.17 acres) of riparian habitat that was rated unsatisfactory (Table 3). Understory vegetation species included Agrostis alba, Bromus spp., Scirpus spp., Juncus spp., Carex spp., Equisetum spp., Rumex spp., Rorippa nasturtium-aquaticum, and Aster spp. Overstory species included Salix spp. and Elaegnus angustifolia.

Station 3 is located 741 meters upstream of station 2 in an area characterized by a narrow downcut and considerably higher canopy coverage (29%) by alder along the lower banks. The two previous stations had practically no canopy cover, 6% and 8%, respectively for station 1 and 2. The downcuts at the previous stations were wider with the upper slopes somewhat laid back, in contrast to the mostly vertical downcut slopes at station 3. The lower banks, however, were in good condition at station 3, with bank soil stability rating 80% and bank vegetation stability rating 82.5%. Bank cover was still fair at 75.0%. Stream gradient was low, at 1.0 percent. Aquatic habitat consisted of a preponderance of glide habitat, resulting in a fair pool measure (43.5%), a high riffle rating (78.3%), and a low PRA (21.7%). Again, the pools present were good quality, resulting in a pool structure of 100%. Water widths averaged 2.8 meters (9.2 feet), water depths were shallower, averaging 0.13 meters (0.43 feet), with a fair width to depth ratio of 22. Instream substrates in station 3 were almost exclusively sand/silt (95.7%), with little rubble (2.9%) and gravel (1.4%), resulting in a poor rating for gravel bottom (4.3%). Embeddedness was poor, rating 64.0%. The HCI rated above the minimum standard, at 64.0%. Station 3 supported a total of 0.04 hectares (0.10 acres) of riparian habitat that was still rated unsatisfactory (Table 3). Understory vegetation species included Agrostis alba, Bromus spp., Carex spp., Scirpus spp., Juncus spp., Rumex spp., and Aster spp. Overstory species included Alnus tenufolia, which made up most of the increase in canopy density, and Salix spp.

Table 3. A Summary of Habitat Conditions in Nutrioso Creek - Crosswhite Property in Oct. 1999.

Other riparian species observed on the property included Poa pratensis and Trifolium spp. Upland vegetation consisted of Chrysothanmnus spp., Bouteloua gracilis, Potentilla spp., Agropyron spp., Cirsium spp., Rhus trilobata, Rosa arizonica, Asclepias spp., Verbascum thapsus, Bromus spp., Iris spp., Lathyrus spp., Sitanion hystrix, Rumex spp., Achillea lanulosa, Geranium spp., and Koeleria cristata.

FISH POPULATION

Fish population surveys were conducted at each GAWS sampling station on the Nutrioso Creek - Crosswhite Property in October 1999 (Table 4). Blocking seines with 1/8 inch mesh were used at both ends of the sample area to limit the escape of fish. Three upstream depletion passes through each 50-meter station were then made with a Smith-Root model 12-POW battery powered backpack electrofisher. Fish were identified to species, enumerated, and a subsample of each species measured and weighed. Population size of each species was then estimated using the maximum likelihood method of VanDeventer and Platts (1989). Codes for fish species listed in Table 5 and 6 are identified in Appendix C.

Table 4. Summary of fisheries surveys conducted at the Nutrioso Creek - Crosswhite Property.

A total of 287 fish were sampled in the three stations surveyed. Nonnative fathead minnow were the most abundant (65.9%), with LC spinedace next abundant at 14.3% of the total (Table 5). Speckled dace (12.5%) and bluehead sucker (7.3%) composed the remainder of the catch. A total of 90.3 minutes of shocking effort was expended over the three stations.

Overall fish biomass was lower than expected, with an estimated fish population of 0.833 fish per square meter of habitat (#/m2) and a biomass of 2.124 grams per square meter of habitat (g/m2)(Table 6). However, LC spinedace were common, with 41 specimens caught over the three stations. Several size classes of spinedace were found, ranging from 35 millimeters (mm) to 101 mm total length in size, and averaging 67 mm. The numerous size classes and presence of small individuals of LC spinedace indicate that reproduction is successful (Table 7). The average weight of LC spinedace was 4 grams, and average condition factor was 1.160. Bluehead sucker had an average length of 104 mm, an average weight of 14 grams, and a condition factor of 1.085.

All four species were caught at each of the three stations, in roughly similar proportions. Fathead minnow dominated at stations 1 and 2, with LC spinedace second in relative abundance. These two stations were fairly similar, both being dominated by pool habitat. However, the third station showed minor differences. Speckled dace dominated in relative abundance, which was not surprising because of the predominance of glide and riffle habitat in station 3. Fathead minnow was second in relative abundance at station 3 and LC spinedace was third. LC spinedace biomass was at its highest at station 3 (0.500 g/m2) compared to LC spinedace biomass at stations 1 and 2 (0.370 g/m2 and 0.222 g/m2), despite being third in relative abundance. Overall biomass at station 2 was highest of all stations (3.022 g/m2), due to relatively high biomasses of fathead minnow (1.405 g/m2) and bluehead sucker (1.330 g/m2) at that station.

Calculated population estimates indicate that the 0.63 hectares (1.56 acres) of aquatic habitat on the Crosswhite Property supported a fish population of 619 LC spinedace, 360 bluehead suckers, 505 speckled dace, and 3,613 fathead minnow at the date of sampling.

Crayfish were numerous at all stations.

Table 5. Number, relative abundance, relative biomass and catch per unit effort of fish sampled by electrofishing at the Nutrioso Creek - Crosswhite Property in October 1999.

* CPUE = Number of fish per 100 meters

Table 6. Number, size, condition and biomass of fish in the Nutrioso Creek - Crosswhite Property in October 1999.

Table 7. Length frequency distribution of fish sampled by electrofishing at the Nutrioso Creek - Crosswhite Property in October 1999.

Number of Fish*

SURVEY DISCUSSION

Nutrioso Creek is managed under the "Wildfish" concept of Arizona's Wildlife 2000 Strategic Plan (AGFD 1995). Sustained viable populations depend on natural reproduction of wild fish, which require that stream habitat be maintained in a high quality state. The neighboring Apache-Sitgreaves National Forests recognized the importance of aquatic habitat and riparian areas when developing their Forest Plan and set standards and goals for management of stream and riparian habitat (USFS 1989b). These standards call for a minimum of 60% of potential habitat capability (60% HCI) when managing streams on the Apache-Sitgreaves National Forests. The Nutrioso Creek - Crosswhite Property rated just below this standard, averaging 59.2% HCI over the stream course surveyed, although two stations did rate slightly above the standard. The below-standard average HCI rating was due primarily to deficiencies in riffles, resulting in poor pool-to-riffle ratios (pool measure = 34.2%). The preponderance of silt substrates (gravel bottom=10.8%) and a fair rating on bank cover (58.3%) also contributed in the low HCI rating. In contrast, bank soil stability and bank vegetation stability were near good, rating 74.2% and 77.5%, respectively.

The old downcutting of the stream channel is the result of historic impacts, both locally (overgrazing) and throughout the watershed. Large raw banks, some of which continue to be eroded, are currently present, however the channel shows overall signs of improvement and recovery. Banks are becoming stable, with a fair amount of vegetation growth along the banks and instream. The presence of sedges, rushes, and small willows are a good sign of an upward trend. The channel is attempting to restore its natural sinuosity, which will continue to contribute to erosion until channel migration stabilizes. Woody vegetation such as alder and willow appear to be establishing new areas, and sedges and rushes are present also. These components should continue to improve and contribute to bank stabilization as long as they are protected from being grazed and browsed too heavily.

The poor pool-to-riffle ratio probably cannot be improved significantly. The observed ratio is the natural result of the low gradient of the stream. The low gradient is tied to the flat valley bottom and open meadow geology of the area. Likewise, the substrates probably cannot be significantly improved either, due to the naturally fine composition of the soils in the immediate area. Improvements in the watershed and establishing vigorous vegetation on stream banks will minimize erosion, which only contributes more silt to the system. As conditions improve, instream aquatic vegetation should increase and hold fine sediments together, as well as providing cover not provided by the absence of larger substrates. Greater stability in the fine substrates by vegetation should also improve turbidity somewhat, however, significant improvements may never be realized because of the natural predominance of fine sediments, which stay suspended longer than larger sediments.

Pool habitats and silt substrates alone are poor producers of aquatic insects. However, an increase in instream and bank vegetation should increase aquatic insect production within the stream, providing more food for fish. Instream vegetation provides food and cover for aquatic insects, as well as for the fish themselves. Bankside vegetation produces terrestrial insects that provide food to fish as the insects fall into the stream and also provide food and cover to "shredding" aquatic insects as leaves and grasses fall into the stream.

RECOMMENDATIONS

1. Improve bank stability and riparian vegetation vigor through strict grazing management.

2. Survey permanent stations again in 3-5 years to evaluate changes/improvements in stream channel conditions, riparian vegetation, and fish populations.

LITERATURE CITED

AGFD (Arizona Game and Fish Department). 1995. Wildlife 2000 Strategic Plan. Arizona Game and Fish Department. Phoenix, AZ. 97p.

BLM (Bureau of Land Management). 1995. Riparian Area Management: Process for Assessing Proper Functioning Condition. Technical Reference 1737-9. Denver, Colorado. 51 p.

Dorum, D.B. and K.L. Young. 1995. Little Colorado spinedace project summary report. Nongame and Endangered Wildlife Program, Technical Report 88. Arizona Game and Fish Department, Phoenix, Arizona.

Douglas, D.H. 1986. Experiments to locate ridges and channels to create a new type of digital elevation model. Cartographica 23(4):29-61.

Jenson, S.K. and J.O. Dominque. 1988. Extracting topographic structure from digital elevation data for geographic information system analysis. Photogrammetric Engineering and Remote Sensing 54(11):1593-1600.

Marsh, P.C. and K.L. Young. 1988. Fish Survey of Nutrioso Creek, Apache County, Arizona. Report submitted to Dames and Moore. Center for Environmental Studies, Arizona State University. Tempe, AZ. 10p.

McMahon, T.M., A.V. Zale, and D.J. Orth. 1996. Aquatic habitat measurements. Pages 83-120 in B.R. Murphy and D.W. Willis, editors. Fisheries Techniques, 2nd Edition. American Fisheries Society, Bethesda, Maryland.

Platts, W.S., W.F. Megahan, and G.W. Minshall. 1983. Methods for evaluating stream, riparian, and biotic conditions. U.S. Forest Service, Intermountain Forest and Range Experiment Station. General Technical Report INT-138. 70p.

Strahler, A.N. 1957. Quantitative analysis of watershed geomorphology. Transactions of the American Geophysical Union. 38:910-920.

Tarboton, D.G., R.L. Bras, and I. Rodriguez-Iturbe. 1991. On the extraction of channel networks from digital elevation data. Hydrological Processes 5:81-100.

USFS (United States Forest Service). 1985. Fisheries Habitat Survey Handbook. U.S. Forest Service. Region 4-2609.23.

USFS (United States Forest Service). 1989a. Riparian Analysis. Coconino & Apache-Sitgreaves National Forests. U.S. Forest Service. Southwestern Region.

USFS (United States Forest Service). 1989b. Apache-Sitgreaves National Forests Land and Resource Management Plan. Amendment No. 1. U.S. Forest Service. Southwestern Region.

Van Deventer, J.S. and W.S. Platts. 1989. Microcomputer Software System for Generating Population Statistics from Electrofishing Data -- User's Guide for MICROFISH 3.0. U.S. Forest Service. Intermountain Research Station General Technical Report INT-254. 15p.

APPENDIX A
GENERAL AQUATIC WILDLIFE SURVEY (GAWS) GLOSSARY

Bank Angle - The average of angles formed between the downward sloping streambanks and the water surface. If the stream bank is undercut, the angle is always less than 90 degrees, otherwise the angle is 90 degrees or greater. Valuable rearing habitat is lost if the bank has been cut away and moved back from the water column. Fish often congregate near undercuts and vertical banks.

Bank Cover - A rating of streambank vegetation types. Brush is considered optimal and assigned the highest rating of 4. Forested is rated a 3, grass and forbs is rated a 2, and exposed (rock or soil) is assigned the lowest rating of 1. The ratings are converted to a percentage of the maximum possible.

Bank Soil Stability - A rating of the streambank's soil characteristics and ability to resist erosion. Plant density, rootmass, particle size composition, rawbanks and extent of erosion are considered in the rating of each bank. The ratings are converted to a percentage of the maximum possible.

Bank Vegetation Stability - A rating of the streambank's vegetation density and ability to resist erosion. Streambank vegetation provides cover, shade, and a terrestrial food source for fish, as well as rootmass and soil cover to resist erosion from flowing water. The ratings are converted to a percentage of the maximum possible.

Canopy Density - The percentage of sky over the stream channel, which is blocked out by vegetation. A canopy provides shading of the stream, which helps prevent water temperatures from increasing to critical levels for trout. Leaf drop in the fall can be a major energy source to the stream's aquatic food web when a healthy canopy is made up of deciduous trees and shrubs.

Embeddedness- A rating of the amount of surface area of large size particles (gravel, rubble, and boulder) on the streambottom which is covered by fine sediments. High silt levels inhibit successful spawning of trout, production of streambottom macroinvertebrates, and primary production of attached algae by covering rocky substrate. High embeddedness is also an indicator of unstable conditions upstream. The ratings are converted to a percentage of the maximum possible.

Gravel Bottom (Streambottom) - The percentage of the streambottom composed of gravel and rubble. These size particles are necessary for spawning and are the most productive in producing food (aquatic macroinvertebrates) for fish.

HCI - The Habitat Condition Index (HCI) is a multivariate rating of existing trout habitat quality. It is computed using Pool Measure (PM), Pool Structure (PS), Gravel Bottom (GB), Bank Cover (BC), Bank Soil Stability (BSS) and Bank Vegetation Stability (BVS) ratings. The HCI increases as habitat quality increases.

HCI % = PM + PS + GB + BC + BSS + BVS
6

HVI - The Habitat Vulnerability Index (HVI) is a rating that predicts the vulnerability of stream habitat to management activities and natural occurrences. It is computed using Valley Bottom Width (VWC), Stream Gradient (SGC), Side-Slope Gradient (SSC), Lower Bank Type (LBC), Bank Stability (CSC), and Indicators of Potential Sediment Production (SPC) coefficients. The HVI increases as the stream's susceptibility to damage increases.

HVI % = VWC + SGC + SSC + LBC + CSC + SPC
3 + 4 + 4 + 3 + 4 + 4

Pool Measure - A rating of the pool-riffle ratio of the sample area. A fifty-fifty pool-riffle ratio is assumed to be the most productive. Pools provide resting and rearing habitat for fish, whereas riffles produce food and support trout spawning. The pool measure rating decreases as the pool-riffle ratio deviates either direction from a fifty-fifty ratio.

P = Total Pool Widths x 100
Total Water Widths

where P = 50, the Rating is 100%

where P < 50, solve:
Pool Measure % = 100 - [(50-P) x 2]

where P > 50, solve:
Pool Measure % = 100 - [(P-50) x 2]

Pool Structure - A rating of pool quality, which reflects the percentage of high-rated pool widths out of the total pool widths measured. Pools are rated by size, depth, and fish cover available. A good relationship exists between high quality pools and high fish standing crops.

PRA - Potential Rearing Area (PRA) is the percentage of stream area with water velocities < 1 foot per second (pools). Small trout require these pool areas for rearing.

PSA - Potential Spawning Area (PSA) is the percentage of streambottom area composed of 1/8" to 3" diameter gravel. Trout require these gravels for spawning and embryo incubation.

Riffles - The percentage of stream area where water velocity is fast, stream depth is shallow and water surface gradient is steep. Riffles are the food (aquatic macroinvertebrate and periphyton) producing areas of a stream.

Riparian Condition - A rating of existing riparian conditions using the USFS Region 3 Riparian Scorecard. Overstory, midstory, and understory conditions are all rated. Riparian vegetation is important in stabilizing streambanks, filtering eroded soil, blocking solar radiation, providing cover and a source of terrestrial insects for fish, as well as providing organic input to the stream's aquatic food web.

Shore Depth - The average of water depths measured at the shoreline or at the edge of a bank overhanging the shoreline. Shore depth is critical for young-of-the-year fish. Valuable rearing habitat is lost when the banks have been cut away and there is zero shore depth.

Undercut Banks - The average of all undercut widths (the distance from the furthest point of protrusion of the bank to the furthest undercut of the bank) measured at each station. If no undercut is present at the transect, the undercut measurement is recorded as a zero. Undercut banks provide valuable cover for fish and provide conditions favorable to producing high trout biomass.

Ungulate Damage - A rating of observed bank damage caused by ungulates including trampling, removal of streambank riparian vegetation, sloughing, and bank erosion. The ratings are converted to a percentage of the maximum possible. Excessive ungulate damage destroys riparian vegetation, causes bank sloughing, increases sedimentation and embeddedness, causes the stream to widen and shallow, resulting in an increase of water temperature.

APPENDIX B Stream: Nutrioso Creek GAWS HABITAT SURVEY SUMMARY

Appendix C. Alphabetically sorted list of abbreviations (codes) for fish species of Arizona. Codes are derived from the first two letters each of the genus and specific epithet.

NONNATIVE FISHES BY SCIENTIFIC NAME

NATIVE FISHES BY SCIENTIFIC NAME

Appendix D. Scientific and common names of vegetation species observed within the riparian zone on Nutrioso Creek - Crosswhite Property in October 1999.

Riparian Understory

Riparian Overstory

Upland

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