A Landscape-based Protocol to Identify Management Opportunities for Aquatic Habitats and
Native Fishes on Public Lands, Phase II: Upper Colorado River Basin
Daniel C. Dauwalter, Helen M. Neville, and Jack E. Williams
Trout Unlimited, Arlington, Virginia
Report submitted by Trout Unlimited to U.S. Bureau of Land Management per Cooperative
Agreement PAA-08-0008.
15 May 2011
Executive Summary
Effective conservation of resources managed by the Bureau of Land Management (BLM) will
require rapid, proactive and strategic approaches that incorporate landscape-scale evaluation
of management, habitat restoration, and enhancement opportunities. At present, landscapescale assessments used by the BLM, such as rapid ecoregional assessments1 or resource
management plans, may insufficiently characterize aquatic habitats and biota, partly due to a
lack of BLM fisheries and hydrology expertise available to the field and district offices
developing them. Because aquatic systems and their watersheds are naturally hierarchical,
landscape-scale planning must incorporate natural watershed boundaries to be effective. We
evaluated Trout Unlimited’s Conservation Success Index (CSI), a strategic, landscape-scale
planning tool for cold-water conservation that is focused on watersheds, for its potential as a
framework for informing BLM rapid ecoregional assessments and developing landscape-scale
aquatic conservation strategies.
The CSI synthesizes disparate bodies of information on fish populations, habitat conditions, and
future threats in a comprehensive and consistent framework that can be used across
jurisdictional boundaries. It consists of 20 indicators that describe four general categories:
range-wide conditions, population integrity, habitat integrity, and future security. Through use
of diverse information sources, the CSI can help inform management strategies, such as
protection versus restoration management, across the landscape.
Though the CSI was developed for salmonids and coldwater habitats, we show how it can be
modified to include warmwater species and used as a framework for informing BLM rapid
ecoregional assessments and developing landscape-scale aquatic conservation strategies based
on cold and warmwater habitats. In Phase I of this effort we focused on the Green River Basin
1
http://www.blm.gov/wo/st/en/prog/more/climatechange/reas.html
1
in Wyoming, Utah, and Colorado. Phase II includes a revision of Phase I and covers the entire
Upper Colorado River Basin. Thus, Phase II notably expands the number of indicators used to
characterize coldwater and warmwater fish strongholds – which together represent native fish
strongholds – but it also expands the geographic coverage of analyses. With a focus in Phase II
that includes all of the Upper Colorado River Basin, we incorporated information on sensitive
warmwater fishes (the flannelmouth sucker Catostomus latipinnis, the bluehead sucker
Catostomus discobolus, and the roundtail chub Gila robusta), as well as the Colorado River
cutthroat trout Oncorhynchus clarkii pleuriticus that often occur on lands managed primarily by
the BLM across Wyoming, Utah, and Colorado. We also show how the CSI can be expanded to
help identify areas that could potentially be managed as Native Fish Conservation Areas.
Integrating information on cold and warmwater fishes with habitat conditions and future
threats, such as climate change, energy development, and invasive species, allows management
strategies to be identified across the landscape for potential incorporation into rapid
ecoregional assessments and resource management plans. Thus, the CSI has the potential to
help inform BLM management in ways that can facilitate persistence of native fishes and
naturally functioning aquatic and riparian habitats across the West.
Introduction
The Need for a Landscape-scale Aquatic Conservation Strategy on Public Lands
The Bureau of Land Management (BLM) is charged with managing approximately 264 million
acres of public lands, primarily located in the West. This comprises one-eighth of the landmass
of the United States and includes some of the nation’s most significant biological and physical
resources. Many of these lands are targeted for energy development, will be affected by
climate change, and have experienced an influx of non-native terrestrial and aquatic species.
For example, coalbed methane production has increased dramatically in the Power River Basin
in Wyoming, and produced water can vary widely in water quality that can be detrimental to
aquatic organisms (Davis et al. 2009; Farag et al. 2010). A multitude of non-native species now
occur on public lands and threaten the viability of native species, and their invasion has been
facilitated by anthropogenic alterations of the landscape (Olden et al. 2006) and climate change
(Rahel and Olden 2008). Conserving resources on public lands will become more complex as
managers will need to anticipate the effects of future threats such as climate change that are
expected to change how ecosystems function and provide services to resource users
(Christensen et al. 2004; Williams et al. 2009).
Effective conservation of BLM resources will require rapid, proactive and strategic approaches
that enable landscape-scale strategies to guide management, restoration, and enhancement of
aquatic resources. Such approaches require the ability to synthesize and compare population
and habitat data among species and across various spatial scales to improve our understanding
of resource conditions. While rapid ecoregional assessments (REAs) are likely to provide timely
guidance for land management strategies, many fail to account sufficiently for aquatic species
2
and their habitats. Thus, despite clear direction in BLM policies and manuals, rapid ecoregional
assessments, as well as Resource Management Plans (RMPs), may not adequately address
fisheries and aquatic needs, partly due to a lack of BLM fisheries and hydrology expertise
available to field and district offices composing those plans.
Not only is it important for land managers to have an understanding of aquatic resource
conditions across broad landscapes, but it is also important to know which watersheds have the
highest aquatic values in order to tailor management for those specific watersheds. Aquatic
conservation strategies need to be focused on watersheds if they are to conserve aquatic
species and habitats effectively. River systems and their watersheds are naturally hierarchical,
and aquatic habitats and their inhabitant species are influenced by complex watershed
processes that function at both watershed and local spatial scales (Frissell et al. 1986). Thus,
land management strategies must not only consider how management decisions impact local
habitat conditions but also how they affect watershed conditions that then influence habitats
through indirect pathways. Strategies must also consider how upstream management affects
habitats downstream. Failure to incorporate watershed processes and conditions is a
commonly cited reason why stream restoration projects are often unsuccessful (Williams et al.
1997).
Watersheds managed to emphasize the conservation of aquatic resources is one strategy that
that can be used to conserve aquatic species and habitats. Native Fish Conservation Areas
(NFCAs) represent a watershed-scale approach to aquatic resource management that is
designed around natural watershed boundaries to account for the natural connectivity and
processes of river networks (Williams et al. 2011). Conservation of entire fish communities and
their supporting watersheds should provide a cost-effective approach to conservation when
compared to species-by-species approaches more typical of threatened and endangered
species conservation efforts. NFCA management should emphasize habitat diversity and
connectivity resulting from natural ecosystem processes, care for all life stages of focal species,
focus on large watersheds that facilitate long-term community persistence, and enable
sustainable long-term management. The size of watersheds managed as NFCAs should be
dependent on the specific aquatic ecosystem and native fish community rather than
jurisdictional boundaries and ownerships. While NFCAs could be managed solely for species
conservation and have a strict protective status, their practical application is likely to allow for
some management of other compatible uses, such as livestock grazing or recreational fishing, at
a level that does not inhibit conservation goals.
Trout Unlimited’s Conservation Success Index
Trout Unlimited recently developed the Conservation Success Index (CSI) to provide a strategic,
landscape-scale planning tool for cold-water conservation that is focused on watersheds (see
Williams et al. 2007a). The CSI is a geographic information system (GIS)-based, subwatershedscale (6th level hydrologic unit code) assessment that synthesizes and communicates the rangewide condition and management needs of coldwater fishes. State, federal and tribal agencies
3
have produced numerous range-wide assessments and recovery plans across the range of
aquatic species that include information on the status and trends of populations and habitat
conditions. Likewise, various geospatial datasets are also publicly available that reflect
watershed and aquatic habitat conditions. The CSI synthesizes these disparate sources of
information in a comprehensive framework across the range of focal species and across
jurisdictional boundaries. It analyzes 20 indicators of population and habitat status that can be
grouped into four general categories: range-wide conditions, population integrity, habitat
integrity, and future security (Figure 1). The aggregate structure of the CSI facilitates spatially
explicit comparisons across the landscape at several different levels: overall conditions (total
CSI scores), general population or habitat conditions (e.g., population integrity or habitat
integrity group scores), or specific conditions or threats (e.g., watershed condition indicator or
energy development indicator scores). Additional analyses related to threats such as energy
development and climate change allow for development of a conservation strategy that
provides a landscape-scale blueprint for management efforts on public lands.
Figure 1. Conservation Success Index framework and scoring structure. Each subwatershed is scored from 1 to 5 using 20
indicators within four main groups (indicator scoring details in Appendix A). Indicator scores are added per group to obtain
an overall group score. Group scores are then added to obtain a composite CSI score for each subwatershed.
4
Upper Colorado River Basin
The Colorado River heads at La Poudre Pass in Rocky Mountain National Park, Colorado and
flows for approximately 1,450 miles to the Gulf of California. The watershed encompasses
246,000 square miles in parts of seven U.S. states – Wyoming, Colorado, Utah, New Mexico,
Arizona, California, and Nevada – and part of Mexico. The largest tributary to the Colorado
River is the Green River, which was the focus of Phase I of this agreement. The Green River
originates in west-central Wyoming in the Wind River Range and flows for nearly 1,200-km to
its confluence with the Colorado River in
Utah. Other major tributaries in the Upper
Colorado River Basin, the focus of this Phase
II assessment, include the Duchesne (Lower
Green basin), Price (Lower Green basin), San
Rafael, Escalante, Dirty Devil, Yampa, White,
Dolores, Gunnison, San Juan, rivers (Figure 2).
Land ownership in the Upper Colorado River
Basin is 80% public and 20% private. Public
lands are primarily managed by the BLM
(37% of all land), the U.S. Forest Service
(19%), and Bureau of Indian Affairs (16%), but
individual states, the U.S. Bureau of
Reclamation, U.S. Fish and Wildlife Service,
and the National Park Service also manage
land in the basin.
Several factors have been implicated in the
decline of native fishes in the Upper Colorado
River Basin. Dams, introduced fishes, water
diversions, livestock grazing, and
development of sport fisheries were typically
cited as causes for these declines (Bezzerides
Figure 2. Major river basins in the Upper Colorado River Basin. and Bestgen 2002; Young 2008). For
example, the Green River was treated with
rotenone prior to filling Flaming Gorge Reservoir. The treatment was intended to decrease the
abundance of non-game fishes in order to establish a trout fishery when the reservoir was filled
(Holden 1991; Wiley 2008). Many native fish populations were decimated from the rotenone
treatment, and the changes in riverine habitat due to the dam were cited as the reason why
populations never recovered. Oil and gas exploration and development have accelerated in
recent years and threaten extant populations; bluehead sucker, for example, occur less often
when there are more oil and gas wells (Dauwalter et al. 2011b). Hybridization with non-native
species and habitat degradation are also reasons for continued declines (Bezzerides and
Bestgen 2002; Gelwicks et al. 2009; McDonald et al. 2008).
5
Evaluating the CSI as a Broadscale Aquatic Assessment Tool for Public Lands
Though the CSI was developed for salmonid fishes and coldwater habitats, we show herein how
it can be modified to include warmwater streams and species and used as a framework for
informing BLM rapid ecoregional assessments and developing landscape-scale aquatic
conservation strategies based on cold and warmwater habitats. Within a larger goal of
expanding the application of the CSI beyond coldwater resources to meet BLM needs for
landscape-scale aquatic habitat assessments, here we use the CSI to evaluate the native stream
fish community and its habitat in a focal area, the Upper Colorado River Basin in Wyoming,
Utah, and Colorado. We broaden application of the CSI from a focus on native salmonids to
include three declining warmwater fishes that occur on lower-elevation lands managed
primarily by the BLM (the flannelmouth sucker Catostomus latipinnis, the bluehead sucker
Catostomus discobolus, and the roundtail chub Gila robusta), as well as the Colorado River
cutthroat trout Oncorhynchus clarkii pleuriticus. The combined status of these four species
indicates the health of headwater and mid-elevation streams in the Upper Colorado River
Basin.
Additional native fishes, such as speckled dace Rhinichthys osculus and mountain sucker
Catostomus platyrhynchus, occur sympatrically with the three warmwater fishes but their
respective distributions are poorly known. Therefore, conservation actions for streams
containing the three warmwater fishes plus the Colorado River cutthroat trout are likely to
protect a wider community of native species than these four focal species.
By identifying remaining community strongholds as well as restoration opportunities for
degraded habitats at a landscape scale, the CSI can aid in determining management strategies
for protection, monitoring, restoration and reintroduction of focal species. The CSI also enables
inclusion of other key drivers that threaten natural resource systems across the West, such as
climate change, energy development, and invasive species. In this assessment we identify, at
the subwatershed scale (6th hydrologic unit code), areas that represent native fish strongholds
where various management actions should have the strongest collective benefit for native
fishes in the Upper Colorado River Basin. We also show how the CSI can inform identification of
watershed-scale areas with high biological value where management can benefit both cold- and
warmwater species, termed Native Fish Conservation Areas (NFCAs). As we describe below,
strongholds and NFCAs differ in the strongholds simply identify subwatersheds that have high
native fish values but do not necessarily incorporate all upstream watershed extents and both
cold and warmwater species. In contrast, NFCAs were identified through a more formal process
that incorporated known and potential species distributions, watershed connectivity, and
habitat integrity and future security that was incorporated into a tiered framework that was
vetted with agency and non-governmental organization (NGO) partners. By focusing on
strongholds or NFCAs and maintenance and restoration of natural processes, the BLM can meet
its obligation under the Federal Land Policy and Management Act to ensure species persistence
over the long-term. This integrated approach to aquatic resource conservation focused on the
6
Upper Colorado River Basin is part of a larger initiative to help provide guidance on how aquatic
needs and conditions can be integrated into REAs and RMPs developed by the BLM.
Adapting the CSI to Incorporate Cold and Warmwater Fishes and Habitats
Our goal was to adapt the CSI to
be used as a proactive,
landscape-scale tool to identify
aquatic conservation strategies
in the Upper Colorado River
Basin. This process involved
developing indicators that
describe focal cold and
warmwater fishes that can be
combined to identify areas of
overlap in the distribution of
four target species, and then
evaluating current habitat
condition and future risks to
assist in identifying
management needs in strategic
areas. Typically, the CSI is
developed only within the
historical range of the target
coldwater species. In the
Colorado River Basin this is the
historical range of Colorado
River cutthroat trout (Figure 3).
Total CSI scores, range-wide
condition scores, and
population integrity scores are
typically only computed for the
Figure 3. Total CSI scores for the Colorado River cutthroat trout across its
current range of the target
currently occupied range. Total scores have traditionally been developed only
species,
while habitat integrity
within the current range of the target species; habitat integrity and future
security scores are also computed for the historical range (historical range
and future security are also
shown in dark grey).
computed for the historical
range. In the Upper Colorado
River Basin this resulted in a lack of CSI coverage throughout the interior basin that comprises
most of the warmwater fish habitat, including unoccupied watersheds upstream of occupied
habitat. Adapting the CSI beyond coldwater resources and its previous single-species focus
required that the traditional Range-wide Condition and Population Integrity indicators be
modified or replaced with indicators that describe both cold and warmwater fishes and where
they occur in close proximity (see below). In Phase I this resulted in one group of five indicators
7
that represented both cold and warmwater fishes. In Phase II we continued to modify the CSI
by expanding the number of indicators by having one group of five indicators for coldwater fish
(Colorado River cutthroat trout) and one group of indicators for warmwater fishes
(flannelmouth sucker, bluehead sucker, and roundtail chub). This allowed traditional CSI
indicators to be used for Colorado River cutthroat trout, but a new suite of indicators for the
warmwater fishes. As in Phase I, adapting the CSI also required that the spatial extent of the
analysis encompassed all subwatersheds across the entire Upper Colorado River Basin.
Cold and Warmwater Fish Distributions and Native Fish Strongholds
Our first step in adapting the CSI was to
map the distributions of focal native
species. Colorado River cutthroat trout
populations were identified using the
database compiled by the Colorado
River Cutthroat Trout Recovery Team
(Hirsch et al. 2006). Only data on
conservation populations were used;
conservation populations are those
deemed important to conservation
because they are at least 90%
genetically pure (tested or suspected) or
were otherwise determined to be
important to cutthroat trout
conservation due to unique life histories
or other attributes (Hirsch et al. 2006).
The primary source for the distribution
of the warm water native fishes was a
survey of warmwater streams
conducted by Wyoming Game and Fish
Department (Gelwicks et al. 2009; Kern
et al. 2007), data from the Utah Natural
Heritage Program, and Colorado
Division of Wildlife’s fisheries database
(Figure 4).
Native Fish Strongholds
Figure 4. Populations of Colorado River cutthroat trout and sites
where flannelmouth suckers, bluehead suckers, and roundtail chubs
were collected in the Upper Colorado River Basin.
We then modified the CSI to highlight
areas that maximized both the
distribution of each species within a
subwatershed and the overlap among the four native species. In Phase I this was simply done
by deletion of Population Integrity Indicators and changing the indicators for the Range-wide
8
Condition group, renamed “Native Fish Strongholds”, to incorporate both cold- and warmwater species. However, for Phase II there are two new groups of indicators: Coldwater Fish
Stronghold and Warmwater Fish Stronghold (Figure 5). Combined, these two groups can be
used to identify Native Fish Strongholds comprised of both cold and warmwater fishes. The
Coldwater Fish Stronghold indicators accounted for the distribution and population health of
Colorado River cutthroat trout. Indicator 1 was scored from 1 to 5 based the percent of
historical habitat currently occupied by conservation populations in each subwatershed (6th
code hydrologic unit) (see Appendix A for scoring details). Indicator 2 was scored based on the
percentage of subwatersheds occupied by cutthroat trout in each subbasin (4th code hydrologic
unit). Indicator 3 was scored based on the density (fish / mile) of each cutthroat trout
conservation population. Indicator 4 was scored based the connectivity of cutthroat trout
habitat. Indicator 5 was scored based on the life history diversity of cutthroat trout
populations.
Figure 5. The CSI was modified by changing the Range-wide Condition and Population Integrity group of indicators to account
for distribution and population health of multiple target fish species. These new groups – termed Coldwater Fish Stronghold
and Warmwater Fish Stronghold – can be combined to represent Native Fish Strongholds at the subwatershed scale.
For the Warmwater Fish Strongholds group, Indicator 1 was scored based on the presence of
bluehead sucker at the subwatershed (6th code HUC), watershed (5th code HUC), and subbasin
(4th code HUC) spatial scales (again, see Appendix A for scoring details). Indicator 2 was scored
based on the presence of flannelmouth sucker at the subwatershed, watershed, and subbasin
spatial scales. Indicator 3 was scored based on the presence of roundtail chub at the
9
subwatershed, watershed, and subbasin spatial scales. Indicator 4 was scored based on the
number of warmwater species (bluehead sucker, flannelmouth sucker, and roundtail chub)
present in the subwatershed. Indicator 5 was scored based on the number of warmwater
species (bluehead sucker, flannelmouth sucker, and roundtail chub) present in the watershed.
Data limitations prohibited more extensive development of population health indicators for the
warmwater species, such as those indicating hybridization and abundance or comparisons to
historical distributions.
Figure 6. CSI Colorado River Cutthroat Trout and Warmwater Fishes Stronghold group scores for all subwatersheds in the
Upper Colorado River Basin.
Coldwater stronghold scores, based solely on Colorado River cutthroat trout, were highest in the Uinta
mountains and lower LaBarge Creek (Figure 6). Clusters of higher Coldwater Stronghold scores also
occurred in the Wyoming Range, Upper Little Snake River along the Wyoming-Colorado border, Upper
White River in Colorado, Upper White River in Utah, and other smaller clusters scattered throughout the
basin. Warmwater Stronghold scores were highest and clustered in the lower Blacks Fork, mainstem
Green River, lower White River in Colorado, Upper Muddy Creek, San Rafael River, Colorado River
mainstem, and lower Gunnison and San Miguel rivers (Figure 6). Stronghold scores, representing both
cold and warmwater species, were highest in Upper Muddy Creek, Upper Henrys Fork, Elkhead Creek,
Milk Creek, Avintaquin Creek in the Strawberry River, Garfield Creek, North Fork Gunnison River, and
Boulder Creek in the Escalante River basin. Other clusters of higher scores were also distributed across
the basin (Figure 7).
10
Habitat Integrity
In addition to adapting the CSI to identify native fish
strongholds, we analyzed Habitat Integrity and Future
Security across the Upper Colorado River Basin to
identify needed course-scale management actions
across the landscape. Habitat integrity was
summarized at the subwatershed scale (6th level
Hydrologic Unit Code; approximately 10,000 acres)
using previously-established CSI habitat integrity
indicators (Appendix A). The CSI incorporates five
indicators of habitat integrity: Land Stewardship,
Watershed Connectivity, Watershed Conditions, Water
Quality, and Flow Regime. The Land Stewardship
indictor represents the fraction of each subwatershed
with lands that have an official protected status with
high habitat integrity. Protected lands are federal or
state lands with regulatory or congressionallyestablished protections (e.g., wilderness areas,
Research Natural Areas, Areas of Critical
Figure 7. CSI Native Fish Stronghold group scores
Environmental Concern). The Watershed
for all subwatersheds in the Upper Colorado River
Connectivity indicator compares the amount of
Basin.
currently connected habitat to the amount of
historically connected habitat at the subwatershed and subbasin (4th level HUC) scales. The
Watershed Conditions indicator incorporates the amount of land that has been converted for
agriculture or pasture land in each subwatershed. The Water Quality indicator incorporates
information on 303(d) listed streams, the amount of agricultural land, number of active mines,
number of oil and gas wells, and amount of roads along stream corridors. The Flow Regime
indicator represents the number of dams in each subwatershed and subbasin, as well as the
mile of canals that divert water from streams. Detailed information for the habitat integrity
indicators is provided in Appendix A, Williams et al. (2007a), and on the CSI website:
http://www.tu.org/science/conservation-success-index.
Habitat integrity in the Upper Colorado River Basin ranged from low to high but most
subwatersheds scored as moderately high to high (Figure 8). Integrity is high in higher
elevation areas where more land is formally protected as wilderness or has not otherwise been
converted for human use. Habitat Integrity is moderate away from major streams where
water is scarce and land has yet to be converted, but is low in areas where oil and gas
development is prominent (Figure 8). Land converted to hay fields and pastures resulted in low
habitat integrity in valleys of major rivers. For example, habitat integrity was low in watersheds
between the cities of Green River and Evanston, Wyoming where the Smiths Fork of the Black
Fork is 303(d) impaired. Watershed connectivity is low in some subwatersheds where water
diversion structures inhibit fish passage (Figure 9). The lower Duchesne River, Uncompahgre
11
River near Montrose, Colorado, and upper San Rafael River have extensive canal networks and
man-made impoundments that influence the natural flow regime in those areas.
Figure 8. CSI Habitat integrity and Future Security scores for subwatersheds in the Upper Colorado River Basin. Habitat
Integrity and Future Security were determined using indicators from Trout Unlimited’s Conservation Success Index.
Future Security
The future security of subwatersheds in the Upper Colorado River Basin was summarized to
determine the future risks to extant populations, aquatic habitats, and conservation efforts
focused in each watershed. Future security was summarized at the subwatershed scale using
the five CSI indicators for future security: Land Conversion, Resource Extraction, Energy
Development, Climate Change, and Introduced Species. The Land Conversion indicator
evaluates the risk of unconverted land being converted based on private land ownership, slope
(<15%), and proximity to roads and urban areas. The Resource Extraction indicator includes
information on the amount of hard rock mineral claims and productive forest types that could
be managed for timber production. The Energy Development indicator accounts for the
fraction of subwatersheds with energy reserves or oil and gas leases and sites identified for
future hydropower development. The Climate Change indicator portrays the risk of a 3°C
12
climate warming scenario, and includes temperature warming, wildfire, winter flooding, and
drought risks (Williams et al. 2009). The Introduced Species indicator incorporates information
on the presence of introduced species deemed injurious to the target species in each
subwatershed. Detailed information for the future security indicators is provided in Appendix
A, Williams et al. (2007a), and on the CSI website: http://www.tu.org/science/conservation-successindex.
The presence of non-native species
was determined using the Colorado
River Cutthroat Trout Recovery
Team database (Hirsch et al. 2006),
the recent Green River Basin
survey targeting the three species
conducted by Wyoming Game and
Fish Department (Gelwicks et al.
2009), Utah Division of Wildlife
Resources recent fish surveys
(UDWR 2006), and the Colorado
Division of Wildlife fish database.
Figure 9. Water diversion structure on Big Sandy River. Photo by K.
Species considered injurious to
Gelwicks, WGFD.
Colorado River cutthroat trout and
the three species were: brook trout Salvelinus fontinalis, rainbow trout Oncorhynchus mykiss,
brown trout Salmo trutta, Yellowstone cutthroat trout O. c. bouvieri, white sucker Catostomus
commersonii, longnose sucker Catostomus catostomus, burbot Lota lota, smallmouth bass
Micropterus dolomieu, and northern pike Esox lucius. These species can displace native
cutthroat trout and warmwater fishes through competition and predation (Metcalf et al. 2008;
Peterson et al. 2004) as well as threaten them with extinction through hybridization (McDonald
et al. 2008; Muhlfeld et al. 2009). Where data on the presence of non-native fishes were
unavailable, information on the density of roads was used, assuming that the probability of
species introductions increases when there are more roads within watersheds providing access
points for human-mediated introductions.
Future security of watersheds in the Upper Colorado River Basin was moderately low to
moderately high (Figure 8). Most low future security scores resulted from a few primary
factors. First, climate change is expected to impact aquatic habitats and fishes through one of
three mechanisms (Figure 10). A 3°C increase in air temperatures under a climate warming
scenario is projected to cause coldwater habitats to become unsuitable for trout. Climate
warming is expected to increase the risk of uncharacteristic wildfires and drought in many parts
of the basin. At least one of these factors related to climate change posed a high risk to the
future security of most watersheds in the basin. Second, nearly all low-elevation areas in the
basin have energy reserves that could be developed in the future, and much of the basin has
been leased for oil and gas development (Figure 11). Invasive species are also present in many
parts of the basin and pose hybridization, predation, and competition risks to native species.
13
Figure 10. Climate change risk in the Upper Colorado River Basin.
14
Figure 11. Federal oil and gas leases and agreements, coal reserves, and potential hydropower sites are used in the CSI as an
indicator of the future security of fish populations and aquatic habitats related to energy development.
Using CSI Scores to Identify Broadscale Conservation Strategies Across Entire Landscapes
The Native Fish Stronghold, Habitat Integrity and Future Security Scores can be used to
highlight areas within the Upper Colorado River Basin where specific management, protection
or conservation actions may be most beneficial to native fishes. Subwatersheds with high
native fish stronghold scores (>20) and high habitat integrity scores (>20) represent good areas
for protective management (Figure 12). Where strongholds scores are high (>20) but habitat
integrity is low (≤20), habitat restoration is a logical focus for that watershed to ensure native
fishes persist into the future. In contrast, subwatersheds with high habitat integrity (>20) but
low native fish stronghold scores (≤20) may require population restoration management; where
habitat integrity is high (>20) but populations have been extirpated, reintroduction may be an
overarching management strategy. Watersheds with low stronghold and habitat integrity
scores (each ≤20) are likely to need both habitat and population restoration, and possibly
reintroductions after habitat restoration depending on the species and habitats present.
15
Figure 12. Broadscale strategies based on different components of CSI scores for primary current and historic habitats used
by target species. For example, population restoration (including reintroduction) opportunities exist where Stronghold
scores are low but Habitat Integrity scores are high. In areas with high Stronghold scores but low Habitat Integrity scores,
Habitat Integrity scores can be decomposed to determine limiting habitat factors, such as when watershed connectivity may
be poor and reconnection efforts are needed.
16
Using the CSI to Identify Native Fish Conservation Areas
Native Fish Conservation Areas represent a management approach to ensure the long-term
persistence of native fish communities at the watershed scale (Williams et al. 2011).
Recognizing the importance of our initial Phase I work identifying native fish strongholds and
management opportunities for BLM, in 2009 the National Fish and Wildlife Foundation (NFWF)
adopted the NFCA framework to inform a new Keystone Initiative aimed at native fish
conservation in the Upper Colorado River Basin, focusing again on Colorado River cutthroat
trout, flannelmouth sucker, bluehead sucker, and roundtail chub. Potential NFCAs were
identified to guide a funding framework for the NFWF Keystone Initiative over the next 10+
years, where funding will be directed towards promoting long-term persistence of entire native
fish communities in watersheds identified as potential NFCAs. For the identification of NFCAs
for NFWF we used a slightly different approach than our initial efforts in Phase I of this BLM
work, so we present these modified analyses here.
The Conservation Success Index played a key role in identifying potential NFCAs for NFWF’s
Keystone Initiative. As described by Dauwalter et al. (2011a), known and potential distributions
of Colorado River cutthroat, flannelmouth sucker, bluehead sucker, and roundtail chub were
used within an integrated spatial analysis that incorporated watershed connectivity as well as
information on habitat integrity and future security - as described by the CSI - to rank all
watersheds for conservation. Watersheds of different tiers were then identified within the top
25% of ranked watersheds as potential NFCAs. Potential NFCAs were then vetted with state
and federal agencies and non-governmental organizations based on the efficacy of watershed
conservation in each potential NFCA and watershed rankings were modified accordingly.2 The
revised rankings of potential NFCAs were used to finalize potential NFCAs that are to serve as
focus watersheds for NFWF’s Keystone Initiative.
The integrated spatial analysis used to identify potential NFCAs built upon the CSI in several
ways. First, the analysis included potential species distributions (for bluehead sucker,
flannelmouth sucker, and roundtail chub) that were predicted based modeled likelihood of
occurrences based on habitat characteristics (see Dauwalter et al. 2011b). This approach was a
way to sort out sporadic occurrences of species in unsuitable habitat and the absence of species
in suitable habitat for species where information is sparse. This approach illustrates the benefit
of using what is termed ‘species distribution models’ in landscape-scale analyses (Elith and
Leathwick 2009). This contrasts, for example, the Warmwater Fish Strongholds indicators that
were only based on known occurrences of flannelmouth sucker, bluehead sucker, and roundtail
chub within subwatersheds.
2
Potential NFCAs identified in Colorado have not been vetted with agencies and are only considered to be
preliminary.
17
The spatial analysis also incorporated connectivity among watersheds. The value of individual
watersheds was adjusted based on the value of adjacent upstream and downstream
watersheds. These linkages are important to consider when identifying watersheds for
conservation because activities in the upstream watershed can influence conservation
outcomes (Moilanen et al. 2008). While the modified CSI as described above does a good job of
describing conditions within individual subwatersheds (12-digit HUCs) that are useful for broadscale landscape assessments, such as rapid ecoregional assessments or RMPs, subwatershed
values do not incorporate conditions in adjacent subwatersheds, such as cumulative impacts
from all upstream areas, that can be important to consider for some applications. For example,
although a subwatershed may have high native fish values, detrimental impacts from areas
upstream may limit the effectiveness of conservation actions in that watershed.
The Habitat Integrity and Future Security indicators were used as ‘costs’ in the spatial analysis
to identify NFCAs. Given equal biological value, conservation is more likely to be realized when
habitats are currently intact and the future of habitats and populations is secure. Therefore,
the CSI provided important background information to rank watersheds that were otherwise
equal in biological value (Figure 13).
The known and predicted species distributions, watershed connectivity, and CSI-based cost
were used in an integrated spatial analysis that ranked watersheds based on their conservation
value for the target species while accounting for connectivity and costs of conservation (Figure
13). A tiered framework was then overlain on the high-ranking watersheds to indentify
proximal cold and warmwater populations: Tier I watersheds have cutthroat trout and at least
one warmwater species (flannelmouth sucker, bluehead sucker, and roundtail chub) in the
same subwatershed (12-digit HUC), Tier II watersheds have cutthroat trout and at least one
warmwater species in the same watershed (10-digit HUC), Tier III watersheds have only
cutthroat trout or one or more warmwater species in the same watershed (10-digit HUC)
(Figure 13). These high-ranking watersheds with designated tiers were then vetted with agency
partners to determine which watershed could best serve as potential NFCAs (Figure 14).
Watersheds within a top 25% ranking were then re-ranked by partners based on local
information on the efficacy of achieving long-term conservation gains.
18
Figure 13. Watershed were ranked using a spatial prioritization that incorporated watershed connectivity, known and
predicted species occurrences, and the CSI. These were then used to identify potential Native Fish Conservation Areas
(NFCAs) (Figure 14).
19
Figure 14. Potential Native Fish Conservation Areas (NFCAs) in the Upper Colorado River Basin. NFCAs in Colorado have not
been formally vetted with agencies and are considered preliminary.
20
Last, the CSI was used to summarize current and future threats within NFCAs in addition to
broad-scale conservation strategies. Overall, potential NFCAs had habitat conditions that were
moderate to moderately-high with moderate risk to future threats (Table 1). Upper Little Snake
River, Upper White River, Escalante River Headwaters, Muddy Creek (N.F. Gunnison), and West
Fork San Juan have habitat integrity and stronghold scores across subwatersheds that suggest
they would benefit more from protective management than restoration management. In
contrast, the remaining potential NFCAs have moderate habitat conditions and are more likely
to need at least some habitat restoration to function naturally. As one example, Muddy Creek
in the North Fork of the Gunnison River has populations of Colorado River cutthroat trout in
close proximity to each other that could potentially be restored to allow natural
metapopulation dynamics to reestablish and promote long-term persistence of these
populations; restoration actions in this watershed that extend downstream could also benefit
warmwater fishes. Many watersheds will likely need proactive planning to offset the future
threats of climate change and non-native species, even in wilderness areas since these threats
don’t recognize formal land protections (Figure 11). NFCAs with lower future security should
also be the focus of monitoring efforts to determine if threats begin to manifest themselves
and impact populations and habitats. Thus, the CSI was not only incorporated into a broader
analysis to identify NFCAs, but it was used to identify place-based conditions within specific
subwatersheds and identify strategies within them, demonstrating the multifaceted utility of
the CSI for both broad-scale assessments and prioritization of specific watersheds and
identification of management needs within them.
Table 1. Overview of potential Native Fish Conservation Areas (NFCAs) for native fish
conservation in the Upper Colorado River Basin. Habitat integrity and future security scores
range from 5 to 25; mean scores across all subwatersheds are reported with ranges in
parentheses. *NFCAs in Colorado have not been formally vetted with agencies and are
considered preliminary.
Basin
Watershed
Acres
Upper
Green
Henrys Fork
337,746
Big Muddy
Creek (Blacks
Fork)
Big Sandy
Creek
128,047
Yampa
Little Sandy
Creek
107,571
Upper Muddy
Creek (Little
Snake River)
135,194
Upper L. Snake
River*
Elkhead
131,739
Warmwater
Species
Bluehead sucker,
flannelmouth
sucker
flannelmouth
sucker, roundtail
chub
Bluehead sucker,
flannelmouth
sucker
Bluehead sucker,
flannelmouth
sucker
Bluehead sucker,
flannelmouth
sucker, roundtail
chub
Bluehead sucker
142,615
Bluehead sucker,
216,862
21
Cutthroat
Populations
7
NFCA
Tier
2
Stronghold
28.7 (23 –
36)
Habitat
Integrity
17.4 (10
– 25)
Future
Security
16.2 (13
– 20)
4
2
27.0 (23 –
32)
15.8 (13
– 19)
13.2 (12
– 16)
Extirpated
3
21.5 (19 –
24)
17.6 (14
– 24)
15.3 (12
– 21)
Extirpated
3
21.3 (19 –
24)
16.3 (10
– 21)
16.0 (15
– 17)
1
1
35.5 (32 –
42)
17.0 (17
– 17)
14.8 (13
– 19)
16
1
2
1
25.6 (20 –
30)
33.1 (27 –
22.6 (20
– 25)
19.3 (13
19.0 (16
– 21)
15 (11 –
Creek*
White
Lower
Green
Upper
Colorado
Gunnison
San Juan
Deep Creek*
32,397
Milk Creek*
55,384
Upper White
River*
Piceance
Creek*
Lower White
River*
409,793
417,453
Mainstem
only
Strawberry
River
483,166
San Rafael
991,869
Escalante
Headwaters
400,704
Parachute
Creek*
126,855
Divide Creek*
128,656
Garfield
Creek*
Muddy Creek
(N.F.
Gunnison) *
West Fk. San
Juan*
28,608
164,257
43,990
flannelmouth
sucker, roundtail
chub
Bluehead sucker
39)
– 25)
17)
21.0 (17 –
25)
32.3 (27 –
36)
16.5 (15
– 18)
17.3 (14
– 20)
16.5 (16
– 17)
13.5 (12
– 15)
20.1 (17 –
29)
17.1 (15 –
26)
28.3 (23 –
30)
21.3 (12
– 25)
16.8 (13
– 19)
17.5 (16
– 20)
17.6 (14
– 20)
16.0 (14
– 18)
14.9 (13
– 17)
1
1
Bluehead sucker,
flannelmouth
sucker, roundtail
chub
Bluehead sucker
1
2
6
2
Flannelmouth
sucker
Bluehead sucker,
flannelmouth
sucker, roundtail
chub
Bluehead sucker,
flannelmouth
sucker
Bluehead sucker,
flannelmouth
sucker
Bluehead sucker,
flannelmouth
sucker
Bluehead sucker,
flannelmouth
sucker, roundtail
chub
Bluehead sucker,
flannelmouth
sucker, roundtail
chub
Bluehead sucker,
roundtail chub
Bluehead sucker,
flannelmouth
sucker
Roundtail chub
1
2
None
3
5
1
26.8 (23 –
37)
18.4 (11
– 25)
16.8 (14
– 20)
6
2
29.2 (24 –
34)
17.3 (5 –
25)
16.3 (11
– 22)
13
2
27.9 (27 –
34)
20.3 (14
– 25)
17.9 (15
– 21)
3
2
31.4 (27 –
36)
17.0 (11
– 20)
14.2 (13
– 16)
2
1
29.9 (23 –
36)
15.9 (10
– 23)
16.4 (11
– 23)
1
1
6
1
38 (38 –
38)
21.4 (17 –
37)
18 (18 –
18)
21.3 (18
– 25)
13 (13 –
13)
17.3 (13
– 24)
3
1
25.3 (20 –
29)
24.3 (23
– 25)
21.7 (19
– 23)
Discussion
Efficacy of the CSI as a Broad-scale Aquatic Assessment Tool for Public Lands
We adapted the CSI in several ways to facilitate its use as a landscape-scale aquatic assessment
tool that can be used by the BLM for landscape-level planning and resource management plan
development. This was done by modifying the original CSI Indicator Groups – Range-wide
Condition and Population Integrity – to represent Coldwater Fish Strongholds and Warmwater
Fish Strongholds, which together can be used to identify native fish strongholds. The CSI was
also modified from having the geographic coverage based solely the historical range of one
focal (trout) species to extending coverage to the entire Upper Colorado River Basin. Thus, the
22
modified CSI can be used to describe native fish strongholds, habitat conditions, and future
security of populations and habitats across the entire landscape of the Upper Colorado River
Basin, as well as identify place-based strategies at a coarse scale. Like any coarse-scale
assessment, finer-scale data and local information is also needed to identify specific
management actions within certain watersheds. Therefore, data provided by the CSI should
not be viewed as a replacement for the local knowledge and expertise that is provided by field
biologists. Ideally, the CSI is designed to be a landscape-scale compliment to local knowledge.
Nel et al. (2008) stated that networks of conservation areas should represent all target species,
promote persistence of targeted species, incorporate opportunities and constraints in each
area, and align with other conservation and planning initiatives. Formally incorporating
watershed-scale protective and restoration management strategies into landscape-level
planning by federal agencies accommodates the scale at which metapopulation dynamics
operate (Compton et al. 2008; Dunham and Rieman 1999; Hanski and Gilpin 1991; Hilderbrand
and Kershner 2000). In addition, securing populations of the various species across multiple
watersheds in the region, such as a network of Native Fish Conservation Areas, will help to
ensure that those species persist
across the landscape in the face of
stochastic disturbances in individual
watersheds that can cause local
extirpations, such as floods or
wildfires (Dunham et al. 2003a;
Williams et al. 2007b). Preserving
species in the face of local
disturbances is a main argument for
ensuring conservation areas are
distributed spatially across the region
of interest.
Figure 15. Native Fish Stronghold scores and Wyoming Game and Fish
Department Habitat Priorities identified as part of their Strategic
Habitat Plan.
23
Our native fish stronghold indicators
identify areas where multiple native
species listed as sensitive occur on the
landscape. These areas and the
potential NFCAs we identified also
align with other agency identified
priorities. For example, Wyoming
Game and Fish Department has
identified habitat priority areas based
on aquatic and combined aquatic and
terrestrial habitats. While those areas
were identified for multiple reasons,
oftentimes they were identified as
priorities based on the presence of
Colorado River cutthroat trout, flannelmouth sucker, bluehead sucker, and roundtail chub
populations. For this reason, our native fish stronghold indicators score high in many of the
areas identified as habitat priority areas in Wyoming (Figure 15). These areas of overlap can
synergize interagency coordination efforts directed at native fish conservation efforts targeting
multiple species.
Although native fish strongholds and potential NFCAs were identified using the CSI,
opportunities exist for native fish conservation outside of the network of identified watersheds.
For example, Upper Bitter Creek in Wyoming contains the only non-hybridized population of
flannelmouth sucker in Wyoming and, therefore, represents an important element of
conservation for that species despite the fact that it has no coldwater habitat nor bluehead
sucker or roundtail chub populations.
The modification and application of TU’s Conservation Success Index (CSI) in the Upper
Colorado River Basin illustrates its potential application as a rapid ecoregional assessment tool
for land managers. It provides a snapshot of aquatic ecosystem health by defining watershed
and fish community condition across multiple scales and identifies natural and anthropogenic
stressors that threaten aquatic species and their habitats. By identifying those areas that
contain complexes of native fishes, and identifying key threats to those species and habitats, it
provides needed context for informed decision-making; that is, the CSI can be used as a
decision support tool. Decision support tools are intended as a planning tool to aid decisions
regarding land-use planning and the allocation of actions and monies towards conservation of
the targeted species (Sarkar et al. 2006), and to identify actions and management practices
which are fundamentally compatible or incompatible with the species conservation objectives.
Hence, the CSI can provide a framework for aiding managers in making land management
decisions that incorporate Colorado River cutthroat trout and the three warm-water native
species conservation needs. By stratifying the landscape under this framework, and applying
management guidance consistent with those strategies identified for each area, it will ensure
BLM meets its obligation under the Federal Land Policy and Management Act to ensure species
persistence over the long term.
Characterization of the landscape into categories of species conservation importance provides a
framework within which management direction can be developed and applied for different land
management programs. Management direction will be different within each watershed
strategy identified by the CSI (protection or restoration (including reconnection)). For example,
grazing practices which meet land health standards at local and regional scales should be
fundamentally compatible with species conservation objectives and could occur in all areas. If
grazing activities are not meeting land health objectives and impede attainment of species
conservation objectives, this information allows the decision maker to weigh the trade-offs
within this conflict. The level of management activity could also vary between watersheds and
across time. For example, watersheds that are targeted for “protection” that have a healthy
baseline may be able to sustain a higher level of management activity over a longer period of
24
time. Alternatively, watersheds that are targeted for “restoration” may require reducing
impacts in order to re-establish ecological and physical function.
In this pilot test of the CSI as a rapid ecoregional assessment (REA) tool, potential NFCAs were
also identified as watershed-scale areas that are important for native fish conservation. Under
a conservation strategy, these watersheds are those that are essential to the long-term
persistence of the species, and those with high Habitat Integrity have the highest degree of
fidelity to natural processes. In other words, they have not been impacted to a significant
degree and retain all natural ecological and physical functions. Land management actions
designed and implemented consistent with retaining ecological and physical functions would be
the most compatible for protecting those areas. Those actions which could not be mitigated or
designed to have minimal impact, would not be consistent with the conservation objectives.
This approach is consistent with current policy for Areas of Critical Environmental Concern
(ACEC), certain Natural Landscape Conservation Areas (e.g., wild and scenic rivers), wilderness,
or wilderness study areas, where only land management activities designed consistent with the
primary objectives of the area are permitted. In other words, under a multiple use doctrine the
highest value of a native fish stronghold or NFCA is for species conservation.
Confronting Future Threats
A crucial component of the CSI is that it incorporates future threats to aquatic species and
habitats. The CSI identified where three key drivers of landscape change over time are likely to
occur and have a direct impact on species survival, potentially requiring adaptations in
management strategies. These are Energy Development, Climate Change, and the continued
advance of Invasive Species (both terrestrial and aquatic). Low scores for these indicators
should not be construed as a rationale for abandoning areas as conservation targets; rather,
each of these drivers elevates the significance of future management decisions within specific
areas.
Responsible development of energy resources requires a landscape level view of conditions so
that those areas of high-energy potential (and their associated transmission corridors) can be
compared with those areas of high conservation value. Where there is overlap, conflict may
exist. This level of assessment is essential for informed decision-making, and allows the
decision maker to identify mitigation, allocate resources, or make determinations to avoid
certain areas. Within these areas of high-energy potential, the use of water to generate
renewable energy is often highly consumptive, or is managed in a manner that creates
significant impacts to aquatic species. Support of infrastructure, particularly road networks and
distribution yards will require oversight to ensure they don’t negatively impact instream habitat
structure and habitat connectivity.
Climate change will compound and exacerbate issues with water consumption and warming of
coldwater habitats. Changes in runoff patterns, loss of snowpack storage, and shifts in rainfall
patterns will all conspire to further impact water-dependent resources. Responsible
25
management of riparian areas, reconnecting channels to their floodplains, and implementation
of other management actions to ensure the storage and natural release of water will be
necessary to partially mitigate impacts and protect stream temperatures from climate change.
Focusing management towards watershed-scale areas for native fish conservation in
anticipation of these changes will be of greater value than protecting watersheds that may
quickly change from current hydrologic regimes to those that do not support targeted species
(e.g., more channels becoming intermittent or ephemeral, water temperature increases beyond
species tolerance levels, etc.).
The continued advance of invasive species, both terrestrial and aquatic, will threaten areas of
high ecologic integrity. Aquatic invasive species may rapidly expand into habitats not currently
infested, and may require special management considerations to control their spread.
Management focused on invasive species potentially reduces management flexibility. For
example, uninfected waters may need to be quarantined from uses that may potentially serve
as a vector for transmitting and spreading the invasive species. Water-based recreation uses
(boating, swimming, wading, fishing, etc.) may need to be managed closely; grazing use may
need to shift; and equipment used in construction and fire suppression may need the
application of best management practices before moving from one watershed into another.
Habitats that are less resilient to stressors due to past management practices may accelerate
the spread of these invasive species.
Regardless of the scenario that plays out, knowing the aquatic resource conditions across the
landscape, as well as within specific watersheds, provides a proactive science-based approach
for species conservation and recovery efforts. Knowledge of the conditions and trends of
watershed health can help determine the overall resilience of watersheds and their ability to
absorb and positively respond to various stressors. This knowledge creates decision space and
flexibility for managers when making decisions on resource allocation and use.
Acknowledgments
The views and conclusions contained in this document are those of the authors and should not
be interpreted as representing the opinions or policies of the U.S. Government. Mention of
trade names or commercial products does not constitute their endorsement by the U.S.
Government. We thank the Wyoming Game and Fish Department, Utah Natural Heritage
Program, Utah Division of Wildlife Resources, and Colorado Division of Wildlife for fish
distribution data and their reviews of preliminary results contained herein; especially Tyler
Abbott (BLM), Justin Jimenez (BLM), and John Sanderson (TNC). Funding was kindly provided
by the Bureau of Land Management, National Fish and Wildlife Foundation, and Trout
Unlimited’s Coldwater Conservation Fund.
26
References
Benke, A. C. 1990. A perspective on America's vanishing streams. Journal of the North American
Benthological Society 9:77-88.
Bezzerides, N., and K. Bestgen. 2002. Status review of roundtail chub Gila robusta, flannelmouth sucker
Catostomus latipinnis, and bluehead sucker Catostomus discobolus in the Colorado River Basin.
Larval Fish Lab Contribution 118, Final report to U.S. Department of the Interior, Bureau of
Reclamation, Fort Collins.
Burcher, C. L., H. M. Valett, and E. F. Benfield. 2007. The land-cover cascade: relationships coupling land
and water. Ecology 88:228-242.
Cakmakce, M., N. Kayaalp, and I. Koyuncu. 2008. Desalination of produced water from oil production
fields by membrane processes. Desalination 222:176-186.
Christensen, N. S., A. W. Wood, N. Voisin, D. P. Lettenmaier, and R. N. Palmer. 2004. The effects of
climate change on the hydrology and water resources of the Colorado River basin. Climate
Change 62:337-363.
Colyer, W. T., J. L. Kershner, and R. H. Hilderbrand. 2005. Movements of fluvial Bonneville cutthroat
trout in the Thomas Fork of the Bear River, Idaho-Wyoming. North American Journal of Fisheries
Management 25:954-963.
Compton, R. I. 2007. Population fragmentation and white sucker introduction affect populations of
bluehead suckers, flannelmouth suckers, and roundtail chubs in a headwater stream system.
M.S. thesis. University of Wyoming.
Compton, R. I., W. A. Hubert, F. J. Rahel, M. C. Quist, and M. R. Bower. 2008. Influences of fragmentation
on three species of native warmwater fishes in a Colorado River Basin headwater stream
system. North American Journal of Fisheries Management 28:1733-1743.
Dauwalter, D. C., J. S. Sanderson, J. E. Williams, and J. R. Sedell. 2011a. Identification and
implementation of Native Fish Conservation Areas in the Upper Colorado River Basin. Fisheries
36:278-288.
Dauwalter, D. C., S. J. Wenger, K. R. Gelwicks, and K. A. Fesenmyer. 2011b. Land use associations with
declining native fishes in the Upper Colorado River Basin. Transactions of the American Fisheries
Society in press.
Davies-Colley, R. J., and D. G. Smith. 2001. Turbidity, suspended sediment, and water clarity: a review.
Journal of the American Water Resources Association 37:1085-1101.
Davis, W. N., R. G. Bramblett, A. V. Zale, and C. L. Endicott. 2009. A review of the potential effects of coal
bed natural gas development activities on fish assemblages of the Powder River Geologic Basin.
Reviews in Fisheries Science 17:402-422.
27
Dunham, J. B., and B. E. Rieman. 1999. Metapopulation structure of bull trout: influences of physical,
biotic and geometrical landscape characteristics. Ecological Applications 9:642-655.
Dunham, J. B., M. K. Young, R. E. Gresswell, and B. E. Rieman. 2003a. Effects of fire on fish populations:
landscape perspectives on persistence of native fishes and nonnative fish invasions. Forest
Ecology and Management 178:183-196.
Dunham, J. B., M. K. Young, R. E. Gresswell, and B. E. Rieman. 2003b. Effects of fire on fish populations:
landscape perspectives on persistence of native fishes and nonnative fish invasions. Forest
Ecology and Management 178:183-196.
Eaglin, G. S., and W. A. Hubert. 1993. Effects of logging and roads on substrate and trout in streams of
the Medicine Bow National Forest, Wyoming. North American Journal of Fisheries Management
13:844-846.
Elith, J., and J. Leathwick. 2009. The contribution of species distribution modelling to conservation
prioritization. Pages 70-93 in A. Moilanen, K. A. Wilson, and H. P. Possingham, editors. Spatial
conservation prioritization. Oxford University Press, New York.
ESRI (U.S. Tele Atlas North America, Inc. / Geographic Data Technology, Inc., ESRI). Protected areas
(1:100,000). 2004. Redlands, California, U.S. Tele Atlas North America, Inc. / Geographic Data
Technology, Inc., ESRI.
ESRI. 2005a. Roads. Tele Atlas North America, Inc. / Geographic Data Technology, Inc.,
ESRI (ESRI). US MapData Places (2000 TIGER). (1998 - 2002). 2005b. Redlands, CA, ESRI.
Farag, A. M., D. D. Harper, A. Senecal, and W. A. Hubert. 2010. Potential effects of coalbed natural gas
development on fish and aquatic resources. Pages 227-242 in K. J. Reddy, editor. Coalbed
Natural Gas: Energy and Environment. Nova Science Publishers, Inc., Hauppauge, New York.
Fausch, K. D. 2008. A paradox of trout invasions in North America. Biological Invasions 10:685-701.
Fausch, K. D., B. E. Rieman, M. K. Young, and J. B. Dunham. 2006. Stategies for conserving native
salmonid populations at risk from nonnative fish invasions: tradeoffs in using barriers to
upstream movement. General Technical Report RMRS-GTR-174, U.S. Department of Agriculture,
Forest Service, Rocky Mountain Research Station, Fort Collins, Colorado.
Frissell, C. A., W. J. Liss, C. E. Warren, and M. D. Hurley. 1986. A hierarchical framework for stream
habitat classification: viewing streams in a watershed context. Environmental Management
10:199-214.
Gelwicks, K. R., C. J. Gill, A. I. Kern, and R. Keith. 2009. Current status of roundtail chub, flannelmouth
sucker, and bluehead sucker in the Green River drainage of Wyoming. Fish Division, Wyoming
Game and Fish Department, Laramie, Wyoming.
Gill, C. J., K. R. Gelwicks, and R. M. Keith. 2007. Current distribution of bluehead sucker, flannelmouth
sucker, and roundtail chub in seven subdrainages of the Green River, Wyoming. Pages 121-128
28
in M. J. Brouder and J. A. Scheurer, editors. Status, distribution, and conservation of native
freshwater fishes of western North America: A symposium proceedings. American Fisheries
Society, Symposium 53, Bethesda, Maryland.
Hanski, I., and M. Gilpin. 1991. Metapopulation dynamics: brief history and conceptual domain.
Biological Journal of the Linnean Society 42:3-16.
Harig, A. L., K. D. Fausch, and M. K. Young. 2000. Factors influencing success of greenback cutthroat
trout translocations. North American Journal of Fisheries Management 20:994-1004.
Hilderbrand, R. H., and J. L. Kershner. 2000. Conserving inland cutthroat trout in small streams: how
much stream is enough? North American Journal of Fisheries Management 20:513-520.
Hirsch, C. L., S. E. Albeke, and T. P. Nesler. 2006. Range-wide status of Colorado River cutthroat trout
(Oncorhynchus clarkii pleuriticus): 2005. Colorado River Cutthroat Trout Conservation Team,
Hoerling, M. P., and J. Eischeid. 2007. Past peak water in the Southwest. Southwest Hydrology 6:1819,35.
Holden, P. B. 1991. Ghosts of the Green River: impacts of Green River poisoning on management of
native fishes. Pages 43-54 in W. L. Minckley and J. E. Deacon, editors. Battle against extinction:
native fish management in the American West. University of Arizona Press, Tuscon, Arizona.
Hyndman, P. C. and H. W. Campbell (Open-File Report 99-325. Natural Resource Ecology Labaoratory,
U.S. Geological Survey). BLM mining claim recordation system: mining claim density. 1996. Fort
Collins, Colorado, Open-File Report 99-325. Natural Resource Ecology Labaoratory, U.S.
Geological Survey.
IGDC (Idaho Geospatial Data Clearinghouse (INSIDE Idaho)). Integrated Road Transportation of Idaho.
(2008-06-22). 2008. Moscow, Idaho, Idaho Geospatial Data Clearinghouse (INSIDE Idaho).
INL (Idaho National Laboratory). Hydropower Resource Assessment. 2004. Idaho Falls, Idaho, Idaho
National Laboratory.
Kern, A., R. Keith, and K. Gelwicks. 2007. Green River watershed native non-game fish species research:
phase II. Agreement Number 02-FC-40-6870, Progress report prepared by Wyoming Game and
Fish Department for U.S. Bureau of Reclamation, Green River, Wyoming.
Lee, D. C., J. R. Sedell, B. E. Rieman, R. F. Thurow, and J. E. Williams. 1997. Broadscale assessment of
aquatic species and habitats. Pages 1057-1496 in T. M. Quigley and S. J. Arbelbide, editors. An
assessment of ecosystem components in the Interior Columbia Basin and portions of the
Klamath and Great Basins: Volume III. USDA Forest Service, General Technical Report PNW-GTR405, Portland, Oregon.
Lloyd, D. S. 1987. Turbidity as a water quality standard for salmonid habitats in Alaska. North American
Journal of Fisheries Management 7:34-45.
29
McAda, C. W., C. R. Berry, Jr., and C. E. Phillips. 1980. Distribution of fishes in the San Rafael River system
of the Upper Colorado River Basin. Southwestern Naturalist 25:41-50.
McDonald, D. B., T. L. Parchman, M. R. Bower, W. A. Hubert, and F. J. Rahel. 2008. An introduced and a
native vertebrate hybridize to form a genetic bridge to a second native species. Proceedings of
the National Academy of Sciences 105:10842-10847.
Metcalf, J. L., M. R. Siegle, and A. P. Martin. 2008. Hybridization dynamics between Colorado's native
cutthroat trout and introduced rainbow trout. Journal of Heredity 99:149-156.
Moilanen, A., J. Leathwick, and J. Elith. 2008. A method for spatial freshwater conservation
prioritization. Freshwater Biology 53:577-592.
Muhlfeld, C. C., S. T. Kalinowski, T. E. McMahon, M. L. Taper, S. Painter, R. F. Leary, and F. W. Allendorf.
2009. Hybridization rapidly reduces fitness of a native trout in the wild. Biology Letters 5:328331.
Murray-Gulde, C., J. E. Heatley, T. Karanfil, J. H. Jr. Rodgers, and J. E. Myers. 2003. Performance of a
hybrid reverse osmosis-constructed wetland treatment system for brackish oil field produced
water. Water Research 37:705-713.
Nel, J. L., D. J. Roux, R. Abell, P. J. Ashton, R. M. Cowling, J. V. Higgins, M. Thieme, and J. H. Viers. 2008.
Progress and challenges in freshwater conservation planning. Aquatic Conservation: Marine and
Freshwater Ecosystems in press.
Olden, J. D., N. L. Poff, and K. R. Bestgen. 2006. Life-history strategies predict fish invasions and
extirpations in the Colorado River Basin. Ecological Monographs 76:25-40.
Palmer, W. C. 1965. Meteorological drought. Research Paper No. 45, U.S. Weather Bureau,
Peterson, D. P., K. D. Fausch, and G. C. White. 2004. Population ecology of an invasion: effects of brook
trout on native cutthroat trout. Ecological Applications 14:754-772.
Poff, N. L., J. D. Allan, M. B. Bain, J. R. Karr, K. L. Prestegaard, B. D. Richter, R. E. Sparks, and J. C.
Stromberg. 1997. The natural flow regime. BioScience 47:769-784.
PRISM Group (Oregon State University). PRISM 800m Normals (1971 - 2000). 2008. Corvallis, Oregon,
Oregon State University.
Quist, M. C., M. R. Bower, and W. A. Hubert. 2006. Summer food habitats and trophic overlap of
roundtail chub and creek chub in Muddy Creek, Wyoming. Southwestern Naturalist 51:22-27.
Rahel, F. J. 2004. Unauthorized fish introductions: fisheries management of the people, for the people,
or by the people. Pages 431-443 in M. J. Nickum, P. M. Mazik, J. G. Nickum, and D. D. MacKinlay,
editors. Propagated fish in resource management, 44 edition. American Fisheries Society
Symposium 44, Bethesda, Maryland.
30
Rahel, F. J., and J. D. Olden. 2008. Effects of climate change on aquatic invasive species. Conservation
Biology 22:521-533.
Rahn, P. H., A. D. Davis, C. J. Webb, and A. D. Nichols. 1996. Water quality impacts from mining in the
Black Hills, South Dakota, USA. Environmental Geology 27:38-53.
Rice, C. A., M. S. Ellis, and J. H. Jr. Bullock. 2000. Water co-produced with coalbed methane in the
Powder River Basin, Wyoming: preliminary compositional data. Open-File Report 00-372, U.S.
Department of the Interior, U.S. Geological Survey, Denver, Colorado.
Roberts, J. J., and F. J. Rahel. 2008. Irrigation canals as sink habitat for trout and other fishes in a
Wyoming drainage. Transactions of the American Fisheries Society 137:951-961.
Sarkar, S., R. L. Pressey, D. P. Faith, C. R. Margules, T. Fuller, D. M. Stoms, A. Moffett, K. A. Wilson, K. J.
Williams, P. H. Williams, and S. Andelman. 2006. Biodiversity conservation planning tools:
present status and challenges for the future. Annual Review of Environment and Resources
31:123-159.
Schrank, A. J., and F. J. Rahel. 2004. Movement patterns in inland cutthroat trout (Oncorhynchus clarki
utah): management and conservation implications. Canadian Journal of Fisheries and Aquatic
Sciences 61:1528-1537.
Shepard, B. B., R. Spoon, and L. Nelson. 2002. A native westslope cutthroat trout population responds
positively after brook trout removal and habitat restoration. Intermountain Journal of Sciences
8:191-211.
Stephens, S. E., J. A. Walker, D. R. Blunck, A. Jayaraman, D. E. Naugle, J. K. Ringelman, and A. J. Smith.
2008. Predicting risk of habitat conversion in native temperate grasslands. Conservation Biology
22:1320-1330.
Sweet, D. E. 2007. Movement patterns and habitat associations of native and introduced catostomids in
a tributary system of the Colorado River. M.S. thesis. University of Wyoming.
Sweet, D. E., and W. A. Hubert. 2010. Seasonal movements of native and introduced catostomids in the
Big Sandy River, Wyoming. Southwestern Naturalist 55:382-389.
UDWR. 2006. Conservation and management plan for three species in Utah. Publication Number 06-17,
Division of Wildlife Resources, Utah Department of Natural Resources, Salt Lake City, Utah.
USACE (U.S. Army Corps of Engineers). National Inventory of Dams. 2008. U.S. Army Corps of Engineers.
USBLM (USBLM and USFS). Geocommunicator. 2008. USBLM and USFS.
USDA Forest Service (Geospatial Service and Technology Center, U.S. Department of Agriculture, Forest
Service). National inventoried roadless areas (IRAs). 2008. Salt Lake City, Utah, Geospatial
Service and Technology Center, U.S. Department of Agriculture, Forest Service.
31
USEPA (U.S. Environmental Protection Agency). 303(d) listed waters. (2002). 2002. Washington, DC, U.S.
Environmental Protection Agency.
USEPA and USGS (U.S. Environmental Protection Agency and U.S. Geological Survey). National
Hydrography Dataset Plus - NHDPlus (1:100,000 scale). 2005. Sioux Falls, South Dakota, U.S.
Environmental Protection Agency and U.S. Geological Survey.
USFS (Wildland Fire Leadership Council and U.S. Forest Service). LANDFIRE. (Rapid Refresh). 2008.
Wildland Fire Leadership Council and U.S. Forest Service.
USGS (U.S. Geological Survey). National Land Cover Database. 2001. Sioux Falls, South Dakota, U.S.
Geological Survey.
USGS (Sage-grouse rangewide conservation assessment, Snake River Field Station, U.S. Geological
Survey). Land Ownership in Western North America, 180 m. (1986-2003). 2004. Boise, Idaho,
Sage-grouse rangewide conservation assessment, Snake River Field Station, U.S. Geological
Survey.
USGS (U.S. Geological Survey). Mineral Resources Data System (MRDS) (Active). (2005). 2008a. Reston,
Virginia, U.S. Geological Survey.
USGS (USGS EROS Data Center). National Elevation Dataset (30m) (1:24,000). 2008b. Sioux Falls, SD,
USGS EROS Data Center.
Waters, T. F. 1995. Sediment in streams: sources, biological effects, and control. American Fisheries
Society Monograph 7, Bethesda, Maryland.
Westerling, A. L., H. G. Hidalso, D. R. Cayan, and T. W. Swetnam. 2006. Warming and earlier spring
increases western U.S. forest wildfire activity. Science 313:940-943.
White, S. M., and F. J. Rahel. 2008. Complementation of habitats for Bonneville cutthroat trout in
watersheds influenced by beavers, livestock, and drought. Transactions of the American
Fisheries Society 137:881-894.
Wiley, R. W. 2008. The 1962 rotenone treatment of the Green River, Wyoming and Utah, revisited:
lessons learned. Fisheries 33:611-617.
Williams, J. E., A. L. Haak, N. G. Gillespie, and W. T. Colyer. 2007a. The Conservation Success Index:
synthesizing and communicating salmonid condition and management needs. Fisheries 32:477492.
Williams, J. E., A. L. Haak, H. M. Neville, and W. T. Colyer. 2009. Potential consequences of climate
change to persistence of cutthroat trout populations. North American Journal of Fisheries
Management 29:533-548.
Williams, J. E., A. L. Haak, H. M. Neville, W. T. Colyer, and N. G. Gillespie. 2007b. Climate change and
western trout: strategies for restoring resistance and resilience in native populations. Pages 23632
246 in R. F. Carline and C. LoSapio, editors. Wild Trout IX: Sustaining wild trout in a changing
world. Wild Trout Symposium, Bozeman, Montana.
Williams, J. E., R. N. Williams, R. F. Thurow, L. Elwell, D. P. Philipp, F. A. Harris, J. L. Kershner, P. J.
Martinez, D. Miller, G. H. Reeves, C. A. Frissell, and J. R. Sedell. 2011. Native Fish Conservation
Areas: a vision for large-scale conservation of native fish communities. Fisheries 36:in press.
Williams, J. E., C. A. Wood, and M. P. Dombeck. 1997. Watershed restoration: principles and practices.
American Fisheries Society, Bethesda, Maryland.
Wyoming Oil and Gas Conservation Commission. Wyoming Active Oil and Gas Wells. 9.
Young, M. K. 2008. Colorado River cutthroat trout: a technical conservation assessment. General
Technical Report RMRS-GTR-207-WWW, USDA Forest Service, Rocky Mountain Research
Station, Fort Collins, Colorado.
33
Appendix A. Modified Subwatershed Scoring and Rule Set for Trout Unlimited’s Conservation
Success Index.
The modified CSI consists of three main groups of indicators:
1.
2.
3.
4.
Native coldwater fish strongholds
Native warmwater fish strongholds
Habitat integrity
Future security
Below is an overview of each CSI group and the indicators within each group. Each section
contains an overview of the group indicators
Native Coldwater Fish Strongholds: Indicators used to identify native fish strongholds:
Overview:
1. Percent historic habitat occupied in subwatershed (6th level HUC)
2. Percent of subwatersheds (6th level HUC) occupied by cutthroat trout within
subbasin (4th level HUC)
3. Native trout population density
4. Native trout population extent
5. Life history diversity in native trout populations
Indicator: 1. Percent historic Colorado River cutthroat trout habitat occupied in subwatershed
Indicator Scoring:
Occupied stream habitat
0%; Non-historic habitat
1 – 15%
16 – 30%
31 – 50%
51 – 100%
CSI Score
1
2
3
4
5
Explanation: Percent of historic Colorado River cutthroat currently occupied in subwatershed
(6th code hydrologic unit)
Rationale: Subwatershed is a better candidate as a native fish stronghold when more historic
Colorado River cutthroat habitat is currently occupied
34
Data Sources: The presence of cutthroat trout populations was based on the Colorado River
cutthroat trout Recovery Team database (Hirsch et al. 2006)
Indicator: 2. Percent historically occupied subwatersheds currently occupied within subbasin.
Indicator Scoring:
Percent subwatersheds
occupied by subbasin
0%; Non-historic habitat
1-25%
26-50%
51-75%
76-100%
CSI Score
1
2
3
4
5
Explanation: The percentage of historically occupied subwatersheds that are currently occupied
by cutthroat trout within each subbasin. The percentage is the same for all subwatersheds
within a subbasin.
Rationale: Species that occupy a larger proportion of subwatersheds are likely to be more
broadly distributed and have an increased likelihood of persistence.
Data Sources: The presence of cutthroat trout populations was based on the Colorado River
cutthroat trout Recovery Team database (Hirsch et al. 2006).
Indicator: 3. Native trout population density.
Indicator Scoring:
Fish per mile
0
1 - 50
51 - 150
151 - 400
>400
CSI Score
1
2
3
4
5
Explanation: Population density expressed as number of adult fish per mile.
Rationale: Subwatershed is a better candidate as a native fish stronghold when native trout are
more abundant.
35
Data Sources: Density of cutthroat trout populations was based on the Colorado River
cutthroat trout Recovery Team database (Hirsch et al. 2006).
Indicator: 4. Native trout population extent.
Indicator Scoring:
Degree of connectedness
No population
4 (Population Isolated)
3 (Weakly Connected)
2 (Moderately Connected)
1 (Strongly Connected)
CSI Score
1
2
3
4
5
Explanation: The linear miles of habitat occupied by native trout population.
Rationale: Populations occupying larger extents of habitat have increased likelihood of
persistence.
Data Sources: Extent of cutthroat trout populations was based on the Colorado River cutthroat
trout Recovery Team database (Hirsch et al. 2006).
Indicator: 5. Life history diversity in native trout populations.
Indicator Scoring:
Conservation population
No population
One life history form present:
Resident only
Two life histories present: Fluvial
and Resident with historic lakes but
no current adfluvial forms
CSI Score
1
2
3
4
Two or three life histories present:
Fluvial and resident with no lake
populations;
Any combination with Adfluvial
present
36
5
Explanation: Life history diversity expressed as resident, fluvial, and adfluvial life history forms.
Rationale: Populations with fluvial and adfluvial life histories have increased likelihood of
persistence.
Data Sources: Life history diversity of cutthroat trout populations was based on the Colorado
River cutthroat trout Recovery Team database (Hirsch et al. 2006).
Native Warmwater Fish Strongholds: Indicators used to identify native fish strongholds:
Overview:
1. Presence of bluehead sucker at multiple scales
2. Presence of flannelmouth sucker at multiple scales
3. Presence of roundtail chub at multiple scales
4. Number of three species present in subwatershed (6th level HUC)
5. Number of three species present in watershed (5th level HUC)
Indicator: 1. Presence of bluehead sucker at multiple scales
Indicator Scoring:
Presence
Not present in HUC 4
Present in HUC 4
Present in HUC 5
Present in HUC 6
CSI Score
1
2
4
5
Explanation: Presence of bluehead sucker at multiple scales
Rationale: Subwatershed is a better candidate as a warmwater stronghold bluehead sucker are
present, but subwatershed is also valuable as a stronghold when bluehead sucker are present
in watershed or subbasin.
Data Sources: Wyoming Game and Fish Department database, Utah Natural Heritage Program
database, and Colorado Division of Wildlife database.
Indicator: 2. Presence of flannelmouth sucker at multiple scales
37
Indicator Scoring:
Presence
Not present in HUC 4
Present in HUC 4
Present in HUC 5
Present in HUC 6
CSI Score
1
2
4
5
Explanation: Presence of flannelmouth sucker at multiple scales
Rationale: Subwatershed (HUC 6) is a better candidate as a warmwater stronghold
flannelmouth sucker are present, but subwatershed is also valuable as a stronghold when
flannelmouth sucker are present in watershed (HUC 5) or subbasin (HUC 4).
Data Sources: Wyoming Game and Fish Department database, Utah Natural Heritage Program
database, and Colorado Division of Wildlife database.
Indicator: 3. Presence of roundtail chub at multiple scales
Indicator Scoring:
Presence
Not present in HUC 4
Present in HUC 4
Present in HUC 5
Present in HUC 6
CSI Score
1
2
4
5
Explanation: Presence of roundtail chub at multiple scales
Rationale: Subwatershed (HUC 6) is a better candidate as a warmwater stronghold roundtail
chub are present, but subwatershed is also valuable as a stronghold when roundtail chub are
present in watershed (HUC 5) or subbasin (HUC 4).
Data Sources: Wyoming Game and Fish Department database, Utah Natural Heritage Program
database, and Colorado Division of Wildlife database.
Indicator: 4. Number of three species present in subwatershed (6th level HUC)
Indicator Scoring:
38
Number of three species
0
1
2
3
CSI Score
1
2
4
5
Explanation: The number of three species (bluehead sucker, flannelmouth sucker, and
roundtail chub) in the subwatershed (HUC 6).
Rationale: Subwatershed (HUC 6) has higher value was a warmwater stronghold when more
species are present.
Data Sources: Wyoming Game and Fish Department database, Utah Natural Heritage Program
database, and Colorado Division of Wildlife database.
Indicator: 4. Number of three species present in watershed (5th level HUC)
Indicator Scoring:
Number of three species
0
1
2
3
CSI Score
1
2
4
5
Explanation: The number of three species (bluehead sucker, flannelmouth sucker, and
roundtail chub) in the watershed (HUC 5).
Rationale: Subwatershed has higher value was a warmwater stronghold when more species are
present in the watershed (HUC 5).
Data Sources: Wyoming Game and Fish Department database, Utah Natural Heritage Program
database, and Colorado Division of Wildlife database.
Habitat Integrity: Indicators for the integrity of aquatic habitats.
Overview:
1. Land stewardship
2. Watershed connectivity
39
3. Watershed conditions
4. Water quality
5. Flow regime
Indicator: 1. Land stewardship.
Indicator Scoring:
Protected stream
habitat
none
1 – 9%
1 – 9%
10 – 19%
10 – 19%
20 – 29%
20 – 29%
≥30%
Subwatershed
protection
any
<25%
≥25%
<25%
≥25%
<50%
≥50%
any
CSI Score
1
1
2
2
3
4
5
5
Explanation: The percent of stream habitat AND percent subwatershed that is protected lands.
Protected lands are federal or state lands with regulatory or congressionally-established
protections, such as: federal or state parks and monuments, national wildlife refuges, wild and
scenic river designations, designated wilderness areas, inventoried roadless areas on federal
lands, Research Natural Areas, Areas of Critical Environmental Concern, others areas of special
protective designations, or private ownership designated for conservation purposes (e.g.,
easements).
Rationale: Stream habitat and subwatersheds with higher proportions of protected lands
typically support higher quality habitat than do other lands.
Data Sources: Protected areas data were compiled from the ESRI, Tele Atlas North American /
Geographic Data Technology dataset on protected areas (ESRI 2004) and the U.S. Department
of Agriculture, Forest Service’s National Inventoried Roadless Areas dataset (USDA Forest
Service 2008). Stream habitat was determined using all streams in the National Hydrography
Dataset Plus (USEPA and USGS 2005).
Indicator: 2. Watershed connectivity.
Indicator Scoring:
Number of
CSI Score
40
stream/canal
intersections
≥12
8 – 11
5–7
1–4
0
1
2
3
4
5
Explanation: The number of stream-canal intersections.
Rationale: Increased hydrologic connectivity provides more habitat area and better supports
multiple life histories, which increases the likelihood of persistence (Colyer et al. 2005).
Diversions, when they do not directly inhibit fish passage, can represent false movement
corridors, cause fish entrainment, and act as population sinks (Roberts and Rahel 2008; Schrank
and Rahel 2004).
Data Sources: Connectivity was determined using all streams was determined using all streams
in the National Hydrography Dataset Plus (USEPA and USGS 2005).
Indicator: 3. Watershed condition.
Indicator Scoring:
Land
conversion
≥30%
20 – 29%
10 – 19%
5 – 9%
0 - 4%
CSI
Score
1
2
3
4
5
CSI score is downgraded 1 point if road density is ≥1.7 and <4.7 mi/square mile.
If road density is ≥4.7 mi/square mile it is downgraded 2 points.
Explanation: The percentage of converted lands in the subwatershed, and the density of roads.
Rationale: Habitat conditions are the primary determinant of persistence for most populations
(Harig et al. 2000). Converted lands are known to degrade aquatic habitats (Shepard et al.
2002; White and Rahel 2008). Road density is computed for the subwatershed; roads are
41
known to cause sediment-related impacts to stream habitat (Eaglin and Hubert 1993; Lee et al.
1997; Waters 1995). Lee et al. (1997) recognized 6 road density classifications as they related
to aquatic habitat integrity and noted densities of 1.7 and 4.7 mi/mi2 as important thresholds.
Data Sources: Converted lands were determined using the National Land Cover Database (USGS
2001), with all Developed, Pasture/Hay, and Cultivated Crops land cover types considered to be
converted lands. Road density was determined using Integrated Road Transportation of Idaho
data (IGDC 2008).
Indicator: 4. Water quality.
Indicator Scoring:
Miles 303(d)
Streams
Agricultural Land
>0
58-100%
28-57%
16-27%
6-15%
0-5%
Number
Active
Mines
Number
active
oil/gas
wells
≥10
≥400
7-9
300 - 399
4-6
200 - 299
1-3
50 - 199
0
0 - 49
Score for worst case.
Road mi/
Stream mi
CSI
Score
0.5 – 1.0
0.25 – 0.49
0.10 - 0.24
0.05 – 0.09
0 – 0.04
1
2
3
4
5
Explanation: The presence of 303(d) impaired streams, percentage agricultural land, number of
active mines, number of active oil and gas wells, and miles of road within 150 ft of streams in
the subwatershed.
Rationale: Decreases in water quality, including reduced dissolved oxygen, increased turbidity,
increased temperature, and the presence of pollutants, reduces habitat suitability for salmonids
and other native fishes. Agricultural land can impact aquatic habitats by contributing nutrients
and fine sediments, and deplete dissolved oxygen. Mining activity can deteriorate water
quality through leachates and sediments. Oil and gas development is associated with road
building, water withdrawals, and saline water discharge (Cakmakce et al. 2008; Murray-Gulde
et al. 2003; Rice et al. 2000). Roads along streams can also contribute large amounts of fine
sediments that smother benthic invertebrates, embed spawning substrates, and increase
turbidity (Davies-Colley and Smith 2001; Lloyd 1987).
Data Sources: 303(d) impaired streams was determined using U.S. Environmental Protection
Agency data (USEPA 2002). The National Land Cover Database (USGS 2001) was used to
42
identify agricultural lands; Hay/Pasture and Cultivated Crops were defined as agricultural land.
Active mines were identified by using the Mineral Resources Data System (USGS 2008a). Active
oil and gas wells from Wyoming Oil and Gas Conservation Commission (Wyoming Oil and Gas
Conservation Commission 9 A.D.). Road density within a 150 ft buffer was computed using ESRI
roads (ESRI 2005a) and the National Hydrography Dataset Plus (USEPA and USGS 2005).
Indicator: 5. Flow regime.
Indicator Scoring:
Number of
dams
≥5
3–4
2
1
0
Miles of
Storage (acreCanals
ft)/stream mile
≥20
≥2,500
10 – 19.9
1,000 – 2,499
5 – 9.9
250 – 999
1 – 4.9
1- 249
0 – 0.9
0
Score for worst case.
CSI Score
1
2
3
4
5
Explanation: Number of dams, miles of canals, and acre-feet of reservoir storage per perennial
stream mile.
Rationale: Natural flow regimes are critical to proper aquatic ecosystem function (Poff et al.
1997). Dams, reservoirs, and canals alter flow regimes (Benke 1990). Reduced or altered flows
reduce the capability of watersheds to support native biodiversity and salmonid populations.
Data Sources: The National Inventory of Dams (USACE 2008) was the data source for dams and
their storage capacity. Data on canals were obtained from the National Hydrography Dataset
Plus (USEPA and USGS 2005). Perennial streams were obtained from the National Hydrography
Dataset Plus (USEPA and USGS 2005).
Future Security Indicators for the future security of populations and aquatic habitats.
Overview:
1.
2.
3.
4.
5.
Land conversion
Resource extraction
Energy development
Climate change
Introduced species
43
Indicator: 1. Land conversion.
Indicator Scoring:
Land Vulnerable to Conversion
81 – 100%
61 – 80%
41 - 60%
21 - 40%
0 – 20%
CSI Score
1
2
3
4
5
Explanation: The potential for future land conversion is modeled as a function of slope, land
ownership, roads, and urban areas. Land is considered vulnerable to conversion if the slope is
less than 15%, it is in private ownership and not already converted, it is within 0.5 miles of a
road, and within 5 miles of an urban center.
Rationale: Conversion of land from its natural condition will reduce aquatic habitat quality and
availability (Burcher et al. 2007; Stephens et al. 2008).
Data Sources: Slope was computed from elevation data from the National Hydrography Dataset
Plus (USEPA and USGS 2005). Land cover was determined from the National Land Cover
Database (USGS 2001), and all land cover classes except developed areas, hay/pasture, and
cultivated crops cover types were considered for potential conversion. Urban areas were
determined using 2000 TIGER Census data (ESRI 2005b), roads from ESRI Roads (ESRI 2005a),
and land ownership using USGS data on Land Ownership in Western North America (USGS
2004).
Indicator: 2. Resource extraction.
Indicator Scoring:
Forest
Hard Metal
management
Mine Claims
51-100%
51 -100%
26 – 50%
26-50%
11 – 25%
11-25%
1 – 10%
1 – 10%
0%
0%
Score for worst case.
44
CSI
Score
1
2
3
4
5
Explanation: Percentage of subwatershed available for industrial timber production and the
percent of subwatershed with hard metal mining claims (assuming an average of 20 acres per
claim) outside of protected areas. Protected lands were removed from availability and include:
federal or state parks and monuments, national wildlife refuges, wild and scenic river
designations, designated wilderness areas, inventoried roadless areas on federal lands,
Research Natural Areas, Areas of Critical Environmental Concern, others areas of special
protective designations, or private ownership designated for conservation purposes.
Rationale: Productive forest types have a higher likelihood of being managed for timber
production than unproductive types, and, hence, future logging poses a future risk to aquatic
habitats and fishes (Eaglin and Hubert 1993). Areas with hard metal claims pose a future risk to
mining impacts than areas without claims. Claims indicate areas with potential for hard mineral
mining, and mining can impact aquatic habitats and fishes (Rahn et al. 1996).
Data Sources: Timber management potential identifies productive forest types using the
existing vegetation type in the Landfire dataset (USFS 2008). The number of mining claims was
determined using Bureau of Land Management data (Hyndman and Campbell 1996), and each
claim was assumed to potentially impact 20 acres. Protected areas data were compiled from
the ESRI, Tele Atlas North American / Geographic Data Technology dataset on protected areas
(ESRI 2004) and the U.S. Department of Agriculture, Forest Service’s National Inventoried
Roadless Areas dataset (USDA Forest Service 2008).
Indicator: 3. Energy Development.
Indicator Scoring:
Leases or
reserves
51-100%
26 – 50%
11 – 25%
1 – 10%
0%
CSI Score
th
New Dams 4
New Dams 6
≥4
≥1
3
2
1
0
Score for worst case
th
1
2
3
4
5
Explanation: The acreage of oil, gas, and coal reserves and the number of dam sites located for
potential development outside of protected areas within each subbasin and subwatershed.
Rationale: Increased resource development will increase road densities, modify natural
hydrology, and increase the likelihood of pollution to aquatic systems. Changes in natural flow
45
regimes associated with dams are likely to reduce habitat suitability for native salmonids and
increase the likelihood of invasion by non-native species(Fausch 2008). If lands are protected
then the watersheds will be less likely to be developed.
Data Sources: Oil and gas leases and agreements from BLM Geocommunicator (USBLM 2008).
Potential dam sites are based on Idaho National Laboratory (INL) hydropower potential data
(INL 2004). Protected areas data were compiled from the ESRI, Tele Atlas North American /
Geographic Data Technology dataset on protected areas (ESRI 2004) and the U.S. Department
of Agriculture, Forest Service’s National Inventoried Roadless Areas dataset (USDA Forest
Service 2008).
Indicator: 4. Climate change.
Indicator Scoring:
TU Climate Change Analysis
Climate Risk Factors
CSI Score
High, High, Any., Any
1
High, Any, Any, Any
2
Mod., Mod., Mod, (Mod or Low)
3
Mod, Mod, Low, Low
4
Low, Low, Low, (Mod or Low)
5
Explanation: Climate change is based on TU Climate Change analysis, which focuses on 4
identified risk factors related to climate change:
a. Increased Summer Temperature: loss of lower-elevation (higher-stream order)
habitat impacts temperature sensitive species
b. Uncharacteristic Winter Flooding: rain-on-snow events lead to more and larger
floods
c. Uncharacteristic Wildfire: earlier spring snowmelt coupled with warmer
temperatures results in drier fuels and longer burning, more intense wildfire
d. Drought: moisture loss under climate warming will overwhelm any gains in
precipitation and lead to higher drought risk
46
Each of the four factors is ranked as low, moderate, or high. Increased summer temperature
due to climate change was modeled as a 3°C increase. Uncharacteristic winter flooding can
result from basins transitioning from snow dominated to rain-on-snow dominated with
increased winter flooding. Uncharacteristic wildfires result from changes in climate and fire
fuels. Drought risk is based on the Palmer Drought Severity Index, but was adjusted for
elevation and precipitation.
Rationale: Climate change is likely to threaten most salmonid populations because of warmer
water temperatures, changes in peak flows, and increased frequency and intensity of
disturbances such as floods and wildfires (Williams et al. 2009; Williams et al. 2007b). A 3°C
increase in summer temperature has the potential to impact coldwater species occupying
habitat at the edge of their thermal tolerance. Increased winter flooding can cause local
populations to be extirpated. Wildfire can change aquatic habitats, flow regimes,
temperatures, and wood inputs that are important to salmonids (Dunham et al. 2003b).
Drought is expected to reduce water availability (Hoerling and Eischeid 2007; Westerling et al.
2006) and the availability of aquatic habitat. These risks are further discussed by Williams et
al.(2009)
Data Sources: Temperature and precipitation data were obtained from the PRISM Group(PRISM
Group 2008). Elevation data was obtained from the National Elevation Dataset (USGS 2008b),
and LANDFIRE data for the Anderson Fire Behavior Fuel Model 13 (USFS 2008) was used as
input for wildfire risk. The Palmer Drought Severity Index was used for drought risk (Palmer
47
1965), but was adjusted for elevation (elevations above 2690 have lower risk (Westerling et al.
2006)) and the deviation from mean annual precipitation (areas with more precipitation on
average have lower risk).
Indicator: 5. Introduced species.
Indicator Scoring:
If introduced species have been documented in a subwatershed
Present in
Present in
Road Density CSI Score
4th
6th
Yes
Yes
Any
1
Yes
No
>4.7
2
Yes
No
1.7 - 4.7
3
Yes
No
<1.7
4
No
No
Any
5
Score worst case.
If introduced species have not been documented in a subwatershed
Present in
4th
Yes
Yes
Yes
Yes
No
Road Density
CSI Score
>4.7
3.7 – 4.7
2.7 – 3.7
<2.7
any
Score worst case.
1
2
3
4
5
If introduced species have not been documented in a subwatershed or subbasin
Road Density CSI Score
>4.7
1
3.7 – 4.7
2
2.7 – 3.7
3
1.7 – 2.7
4
<1.7
5
Score worst case.
48
Explanation: The presence of introduced, injurious species in a subbasin and subwatershed and
road density. Road density is the length of road per subwatershed area, and represents the
potential for future introduction of non-native species into the subwatershed.
Rationale: Introduced species can reduce native fish populations through predation,
competition, hybridization, and the introduction of non-native parasites and pathogens (Fausch
et al. 2006). In the absence of data on presence of non-native species in a subwatershed or
subbasin, road density can be used as a surrogate for risk of non-native fish introductions by
perpetrators (Rahel 2004).
Data Sources: Data on non-native, injurious species were obtained from a variety of sources.
Wyoming Game and Fish Department considers white sucker, longnose sucker, and burbot to
be the non-native species of highest concern to the flannelmouth sucker, bluehead sucker, and
roundtail chub (K. Gelwicks, Wyoming Game and Fish Department, personal communication).
The non-native white sucker hybridizes readily with the flannelmouth sucker and bluehead
sucker (Gill et al. 2007; McDonald et al. 2008), and burbot are suspected to prey on native
warmwater fishes (Sweet 2007). Non-native trout can also cause population declines or
extirpation of Colorado River cutthroat trout through competition, predation, and
hybridization. Information on the presence of non-native species was obtained from recent
Wyoming Game and Fish Department stream surveys targeted at the three warmwater species,
recent surveys by Utah Division of Wildlife Resources, and Colorado Division of Wildlife fish
database, and the geodatabase associated with the Colorado River cutthroat trout range-wide
assessment (Hirsch et al. 2006). Although Quist et al.(2006) found that non-native creek chubs
had high diet overlap with roundtail chub in Muddy Creek, Wyoming, creek chub were
considered to have minimal impacts on native fish populations. The longnose sucker has also
been found to hybridize with native suckers (Gelwicks et al. 2009).
49
Appendix B. Detailed second-tier analysis of identified NFCAs using CSI data. *NFCAs in
Colorado have not been formally vetted with agencies and are considered preliminary;
therefore, they are not included here.
Upper Muddy Creek
The Upper Muddy Creek watershed is in the Yampa River Basin southwest of Rawlins,
Wyoming. Muddy Creek is a tributary to the Little Snake River, and Upper Muddy Creek is one
of two streams sampled by Wyoming Game and Fish Department where all three warmwater
fishes – flannelmouth sucker, bluehead sucker, and roundtail chub - were collected at the same
sampling location (Figure 1B). There is also a conservation population of genetically pure
Colorado River cutthroat trout in Littlefield Creek in the Upper Muddy Creek watershed. This
population now overlaps in distribution with native warmwater fishes. The Upper Muddy Creek
watershed was proposed as an Area of Critical Environmental Concern in the revised Resource
Management Plan for the Rawlins Field Office, Bureau of Land Management due to the
presence of native cold and warmwater fishes and presence of critical winter habitat for big
game.
Figure 1B. The Upper Muddy Creek watershed.
50
Brook trout and white suckers are non-native species that also occur in the Upper Muddy Creek
watershed. Hybridization is occurring in Upper Muddy Creek (Compton 2007; Gelwicks et al.
2009). There is concern that hybridization between white sucker and flannelmouth sucker have
allowed introgression between flannelmouth sucker and bluehead sucker – two species
previously isolated by reproductive barriers (McDonald et al. 2008). The presence of these
injurious non-native species may lower the success of other conservation activities focused in
the watershed, but their presence also indicates that directed non-native fish removal is a much
needed conservation action. Although not considered as large a threat as the other non-native
species, the creek chub Semotilus atromaculatus is another non-native species that occurs in
Muddy Creek and has been shown to potentially compete with roundtail chubs for food
resources (Quist et al. 2006).
The Upper Muddy Creek watershed has moderate habitat integrity with no protected lands,
poor water quality, and poor connectivity. Land ownership is a checkerboard mix of private
land (35%), U.S. Bureau of Land Management (55%), and State of Wyoming (10%) land but
none of the watershed has an official protected status. Water quality is impaired, with almost
one-half of the Upper Muddy Creek watershed is 303(d) listed for habitat degradation; a
portion of Littlefield Creek also received a PFC rating of ‘non-functional’. Muddy Creek has
several barriers that prevent fish from moving freely within the watershed (Figure 2B)
(Compton et al. 2008).
Figure 2B. Rock gabion in Upper Muddy Creek. Photo by R. Beatty.
51
The future security of the Muddy Creek watershed is high with a few exceptions. There is very
high risk of further energy development throughout the watershed, including recent plans to
develop wind power in the McKinney Creek area. Non-native species injurious to cutthroat
trout and native warmwater fishes, as discussed above, occur in the watershed and have the
potential to out-compete native fishes and cause extinction through hybridization. There is low
risk for lands being converted for agriculture. There is also low risk for future flow modification
and climate change in the watershed. Conservation opportunities in the watershed include
restricting energy development and implementing land protection measures, as well as removal
of non-native fishes.
Potential conservation activities in Upper Muddy Creek include habitat restoration, non-native
fish removal, barrier removal and management, proactive protective measures. Habitat
restoration includes grazing management and restoration of riparian vegetation and stream
morphology to natural conditions, including McKinney Creek, and Muddy Creek above
Littlefield Creek. Wyoming Game and Fish Department recently worked with a local landowner
to develop an off-stream watering site for cattle (R. Compton, Wyoming Game and Fish
Department, personal communication). A small section of Littlefield Creek also received a nonfunctional PFC rating. Non-native fish removal would benefit cold and warmwater natives.
Brook trout occupy McKinney Creek. Although brook trout are isolated from Colorado River
cutthroat trout are isolated by a barrier, their presence in the watershed does increase the risk
of future colonization of Littlefield Creek. Removal of white sucker, hybrid suckers, and creek
chubs would also benefit native warmwater fishes. Mechanical removal (e.g., electrofishing)
can be effective in reducing non-native fish populations, but it is not 100% effective and would
need to be conducted periodically over time. A fish weir at the confluence of McKinney Creek
could be used to capture non-native fishes moving upstream to spawn. Chemical treatment is
also an option but would need to be planned in accordance with private landowners, and native
fishes would need to be held off site while piscicides are applied. The Weber headcut structure
would need to be maintained as a fish barrier to prevent non-native fishes from colonizing from
downstream, and other structures within Muddy Creek could be removed or retrofitted to
facilitate fish passage and allow native fishes access to the entire watershed to complete their
life cycles. Wind power development is forecasted near McKinney Creek, and oil and gas
development is ongoing in portions of the watershed and active measures should be taken to
ensure development does not impact aquatic habitat. The Rawlins Field Office of the Bureau of
Land Management proposed upper Muddy Creek as an Area of Critical Environmental Concern
to afford the watershed more protection from future threats to the native fish community (P.
Lionberger, Bureau of Land Management, pers. comm.). Although the ACEC designation was
not adopted, Upper Muddy Creek will be managed by the Bureau of Land Management as a
Wildlife Habitat Management Alternative.
Big Muddy Creek
Big Muddy Creek originates in the Uinta Mountains in Utah on the Wasatch National Forest and
flows north into Wyoming east of Evanston where it joins with the Black Fork of the Green
52
River. Colorado River cutthroat trout inhabit the headwaters, whereas flannelmouth suckers
and roundtail chubs occupy the lower watershed near I-80 (Figure 3B).
Figure 3B. Big Muddy Creek watershed.
Rainbow trout have been introduced into the watershed, and non-native white suckers are also
present. Rainbow trout hybridize with native cutthroat trout (Young 2008) and were stocked
into Vacher Reservoir in the 1990’s. Cutthroat trout were also stocked into West Muddy Creek
in 1950 and 1962. Populations are somewhat introgressed with non-native cutthroat trout and
rainbow trout, except in some isolated headwater reaches. White suckers are found
throughout the lower watershed and white sucker x flannelmouth hybrids were collected
during recent fish surveys (Gill et al. 2007).
The Big Muddy Creek watershed has moderate-high habitat integrity. The creek itself is largely
in private ownership (Figure 6B), and there is a checkerboard ownership pattern between
private landowners (71%) and the Bureau of Land Management in the lower watershed (21%).
The State of Wyoming owns several sections throughout the watershed (5%), and the Forest
Service owns a small portion of the headwaters (2%). No part of the watershed has a formal
protected status. Connectivity is generally good, but a culvert at I-80 and a diversion structure
53
with an approximate 3 ft. drop, both in the lower watershed, appear to limit the upstream
extent of flannelmouth suckers and roundtail chubs. There are also several private stock ponds
on streams tributary to Big Muddy Creek that do not appear to affect native cutthroat trout or
warmwater fishes. Watershed conditions are good as very little of the watershed has been
converted for human use; only land along lower Big Muddy Creek as been converted to
hay/pasture. Roads along streams in the lower watershed offer the only potential water quality
problem, and stock ponds and canals that divert water affect streamflows along the mid-course
of Big Muddy Creek.
Big Muddy Creek has low-moderate security from future risks. Approximately 50% of the
watershed is amenable to being converted for human use, and the proximity to Evanston
increases the risk of land conversion. Approximately one half of the watershed has been leased
for oil and gas development. Climate change is expected to have moderate to high impact on
the watershed. East Muddy Creek has a high risk for uncharacteristic wildfire, whereas the rest
of the Muddy Creek watershed has a moderate risk to wildfire. The entire watershed has a low
risk to winter flooding under a changing climate, but the lower watershed has a moderate risk
to warming temperatures that could be unsuitable for cutthroat trout. The presence of nonnative cold and warmwater fishes threatens the future security of both native cutthroat trout
and warmwater fishes.
Big Muddy Creek has several conservation opportunities. Providing fish passage in the lower
watershed at the I-80 culvert and a diversion structure would likely allow roundtail chubs and
flannelmouth suckers to extend their distribution further into the watershed. Protective
measures that restrict oil and gas development would benefit native fish populations into the
future. Ensuring ample streamside vegetation in the upper watershed would mitigate the
potential impacts of climate warming on cutthroat trout populations.
Henrys Fork
The Henrys Fork of the Green River is a large watershed that flows directly into Flaming Gorge
Reservoir along the Wyoming-Utah border. Most perennial tributaries originate on the north
slope of the Uinta Mountains. Colorado River cutthroat trout occupy headwater streams at
higher elevations. Bluehead suckers and flannelmouth suckers have recently been collected on
the mainstem Henrys Fork and Burnt Fork (Figure 4B).
54
Figure 4B. The Henrys Fork watershed.
Non-native cutthroat trout and non-native suckers occupy portions of the Henrys Fork
watershed. Yellowstone cutthroat trout were stocked into the upper Henrys Fork and have
introgressed with native Colorado River cutthroat trout. Brook trout are also in several
tributary streams and are known to outcompete cutthroat trout (Peterson et al. 2004). White
suckers have also been found to be hybridizing with native suckers in the lower portion of the
Henrys Fork (Gill et al. 2007).
Habitat integrity is moderately high to high throughout the watershed except in Birch Creek
where it is moderately low. Much of the Henrys Fork heads in the Uinta Mountains (40%),
although several tributaries arise in more arid lands (Figure 7B). The Bureau of Land
Management owns the lower elevation shrublands (32%), and private lands encompass much
of the perennial streams and mainstem Henrys Fork. The States of Wyoming and Utah own
sections throughout the watershed (6%), while private landowners own tracts along the larger
streams (22%). The headwaters of the Henrys Fork are largely protected as wilderness,
whereas the lower watershed has no formal protection. Much of the watershed is
interconnected, except for the upper Henrys Fork where there are several barriers and on Birch
Creek where several canals intersect streams. Watershed conditions are good, except in Birch
55
Creek and Wildhorse Draw where some land has been converted to hay/pasture. Water quality
is moderate in Birch Creek because of road along streams, but otherwise should be good
throughout the Henrys Fork watershed. Streamflows in Burnt Fork, Louse Creek, and Birch
Creek are moderately impacted by water diversions.
The future security of the Henrys Fork watershed is moderate overall but slightly higher at
higher elevations. There is low risk to future land conversion or resource extraction, but the
northern portion of the watershed is at high risk to energy development and climate change; a
warming climate poses a moderate risk of wildfires and drought.
Conservation measures include protecting the watershed from energy development and
climate change risk, as well as non-native fish management. Protection from oil and gas
development would benefit native fishes from potential water quality impacts associated with
well drilling and watershed disturbances associated with infrastructure. Restoring and
maintaining healthy riparian vegetation and maintaining sufficient streamflows would reduce
the impacts of climate warming and drought. The existing dam in the lower watershed could
be managed as a fish barrier to prohibit recolonization of non-native fishes if the Henrys Fork is
to be the focus of non-native fish removal efforts; however, the large size of the watershed
require substantial resources to remove non-native fishes.
Big Sandy River
The Big Sandy River watershed is located north of Rock Springs, Wyoming and east of US 191.
Big Sandy River heads in Wyoming’s Wind River Range on the Bridger National Forest. Big
Sandy River is historical habitat for Colorado River cutthroat trout that have since been
extirpated (Figure 5B). Flannelmouth suckers and bluehead suckers occur in Big Sandy Creek,
and roundtail chub historically occurred in Big Sandy Creek but were not documented in recent
surveys (Gill et al. 2007).
Several non-native fish species occur in the Big Sandy watershed. Brook trout, brown trout, and
rainbow trout occur in the upper watershed, whereas white suckers, longnose suckers, and
burbot are found in the lower watershed. White suckers and longnose suckers threaten the
flannelmouth sucker and bluehead sucker with hybridization (Gill et al. 2007; Sweet 2007),
although some spatial segregation is evident during the spawning season (Sweet and Hubert
2010). Burbot have been suspected to be predatory on native juvenile suckers and limit their
recruitment to the adult population (Sweet 2007).
56
Figure 5B. The Big Sandy River and Little Sandy Creek watersheds.
The habitat integrity of Big Sandy River watershed is moderately high to high, except for the
Potson Reservoir subwatershed. The Forest Service owns the upper watershed (23% total)
(Figure 5B). The Bureau of Land Management owns a majority (65%) of the watershed at lower
elevations, except where the State of Wyoming owns several land parcels (6%) scattered
throughout the watershed and along Big Sandy River where ownership is predominantly private
(4%). The Bureau of Reclamation (2%) owns land around Big Sandy Reservoir, which is located
just above the confluence with Little Sandy Creek. The only protected habitat is upstream in
the Bridger Wilderness. Connectivity of the watershed is largely intact. Watershed conditions
are good since little land has been converted for human use, but roads along streams are a
factor potentially impacting water quality. Canals diverting water along the midcourse of Big
Sandy River impact streamflows.
The Big Sandy watershed is largely secure from future threats. The primary threat is from oil
and gas development in the lower watershed; almost the entire lower one half of the
watershed is leased. Non-native trout, suckers, and burbot pose additional threats to the
future security of native suckers. There is a low threat of future land conversion. Projected
57
climate change poses only a moderate threat of uncharacteristic wildfires and no threat due to
winter flooding or temperature warming. Only future drought poses a serious risk in the lower
watershed under a changing climate.
There are several conservation opportunities in the Big Sandy River. One is to remove nonnative suckers through mechanical or chemical removal. Mechanical removal is not 100%
efficient, and would need to be done periodically over time. Chemical removal is more
effective but would entail creating some type of fish-holding facility for native fishes during
treatment. Another opportunity is to create a fish barrier above Big Sandy Reservoir to limit
upstream movement of burbot and white suckers that reside in the reservoir. There is a large
concrete water diversion structure near the midcourse of Big Sandy Creek that is a potential
barrier to movement. While cutthroat trout are extirpated from the watershed, the presence
of non-native trout is a potential problem for cutthroat trout restoration. Removal of nonnative trout is not likely to be feasible since the high elevation, remote headwater lakes in the
Bridger Wilderness would need to be treated prior to cutthroat trout restoration. Meeks Lake,
another high elevation lake, contains a population on non-native longnose sucker that likely
seed downstream populations (Sweet 2007). In addition, private landowners stock trout into
Big Sandy River, which would make native trout restoration, and even chemical treatment,
difficult.
Little Sandy Creek
Little Sandy Creek is adjacent to Big Sandy River to the south, north of Rock Springs, Wyoming
and west of US 191. Colorado River cutthroat trout were native to Little Sandy Creek but have
since been extirpated (Figure 5B). Flannelmouth suckers and bluehead suckers are found in
Little Sandy Creek above the Eden Diversion.
Non-native trout and suckers are found in Little Sandy Creek. Brook trout and brown trout
have been documented in the upper Little Sandy watershed, whereas rainbow trout have been
collected in the lower watershed. White suckers have also been collected in lower Little Sandy
Creek and threaten native suckers with hybridization (Gill et al. 2007).
Habitat integrity is high in the headwaters of Little Sandy Creek but low-moderate downstream.
Like Big Sandy River, the Forest Service owns the upper watershed (Bridger National Forest;
11%), and the Bureau of Land Management own most of the lower watershed (69%). Most of
Little Sandy Creek is privately owned (12%), especially along its lower reaches, but the State of
Wyoming also owns land sporadically along the creek and across the watershed (6%). The
Bureau of Reclamation owns part of Little Sandy Creek watershed near Big Sandy Reservoir
(3%). Part of the upper watershed is protected as Bridger Wilderness on the Bridger National
Forest. Connectivity of the lower watershed is interrupted by water diversion structures and a
small reservoir. Watershed conditions are good upstream but moderate below where land has
been converted for hay/pasture. There are no threats to water quality in the watershed, but
58
water diversions alter streamflow patterns in downstream reaches and portions of Mitchell
Slough received a ‘non-functional’ PFC rating.
The future security of Little Sandy Creek is moderately high in the upper watershed but
moderately low in the lower watershed. There is low risk of land being converted for human
use, but there is a high risk of oil and gas development because most of the lower watershed
has been leased. There is a moderate risk throughout the watershed for uncharacteristic
wildfires and high risk of drought under a climate change, and the lower watershed has a
moderate risk for temperature warming should attempts be made to restore native cutthroat
trout.
Conservation opportunities in Little Sandy Creek center on non-native fish removal. Non-native
white suckers and white sucker-native sucker hybrids comprise approximately 80% of all
catostomids in Little Sandy Creek, despite high abundance of flannelmouth suckers. Although
mechanical removal of non-native suckers is possible, it is not 100% efficient. Chemical
treatment of Little Sandy Creek would require off-channel holding facilities for native fishes
during treatment. Restoration of Mitchell Slough might also benefit native fishes downstream
of its confluence with Little Sandy Creek. Ensuring sufficient streamflows would buffer native
sucker populations from future droughts that are projected under a warming climate.
Strawberry River
The Strawberry River and its tributaries between Strawberry Reservoir and Starvation Reservoir
contains populations of Colorado River cutthroat trout, flannelmouth sucker, and bluehead
sucker (Figure 6B). Ownership 13% Tribal, 32% Forest Service, 19% State of Utah, 36% Private,
and very little BLM land.
The Strawberry River has non-native species that could impede native fish conservation. Brown
trout are naturalized in the Strawberry River mainstem, and Colorado River cutthroat trout
have introgressed with non-native rainbow trout, with Strawberry Reservoir being a premier
rainbow and cutthroat trout and kokanee salmon fishery.
Habitat integrity is moderate, with scores ranging from 14 to 20. Streamflows in the mainstem
are regulated by flow releases from Strawberry Reservoir. Likewise, Current Creek reservoir
alters streamflows and isolates cutthroat trout populations above the reservoir with those
downstream. Lake Canyon and Red Creek have lands converted for agriculture and poor water
quality, whereas the headwaters of Avintaquin Creek are in good condition.
59
Figure 6B. The Strawberry River watershed, and its tributaries, between Strawberry Reservoir
and Starvation Reservoir.
The future security of populations and habitat in the Strawberry River is moderately high. Most
subwatersheds score low for presence of non-native species. Climate change is a high risk to
some watersheds, particularly for uncharacteristic wildfires and drought under a warming
climate. Tabby Swale in the Red Creek drainage also has high risk for future energy
development.
Native fish conservation efforts in the Strawberry River area include strategic non-native fish
management, especially with regard to maintaining the genetic purity of conservation
populations of cutthroat trout. There are also opportunities for improving water quality.
Although oil and gas development has occurred in the watershed, there are opportunities for
mitigation, as well as protecting areas that have been leased for development. Maintaining or
restoring healthy stream systems will help to offset future climate change impacts from
droughts and fires.
60
San Rafael River
The San Rafael River is a tributary to the Green River that arises in the Wasatch Plateau region
of Utah. It is approximately 90 miles in length, with its major tributaries being Ferron,
Cottonwood, and Huntington creeks, flowing through the San Rafael Swell and San Rafael
Gorge. Headwater streams have populations of Colorado River cutthroat trout, and
flannelmouth sucker, bluehead sucker, and roundtail chub occur sporadically in the San Rafael
mainstem to its confluence with the Green River. Several fishes listed as Endangered under the
Endangered Species Act also use the lower San Rafael near its confluence with the Green River.
Land ownership is 34% Forest Service, most of which is in the upper watershed, and 43% BLM,
10% State of Utah, and 13% private (Figures 7B, 8B).
Figure 7B. The Upper San Rafael basin that includes Huntington Creek, Cottonwood Creek, and
Ferron Creek.
Like other rivers and streams in the Colorado River Basin, non-native fishes are found
throughout the watershed. Red shiners, fathead minnows, black bullheads, and channel catfish
have all been collected, as have non-native trouts in tributary streams. Popular sport fisheries
exist, for example, in Huntington Creek that prohibit native fish conservation in some areas.
61
Habitat integrity ranges from poor to good in the upper San Rafael basin. Watershed
conditions, connectivity, water quality, and flow regime have all been impacted where the
headwater tributaries converge to form the San Rafael River. However, Miller Fork Canyon
(Huntington Creek), Big Bear Creek (Ferron Creek), and the middle San Rafael mainstem have
relatively intact habitat conditions aside from somewhat altered flow regimes.
Figure 8B. The Lower San Rafael basin.
Future security of habitats and native fish populations is relatively high in headwater
tributaries. However, lower Huntington Creek has high risk for energy development, and much
of the lower portions of Huntington Creek, Ferron Creek, and Cottonwood Creek have high risk
for drought and stream temperature warming under climate warming scenarios. Non-native
species pose a risk to future populations throughout the San Rafael watershed.
Many opportunities exist for native fish conservation in the San Rafael watershed. Strategic
barrier management is needed to reconnect fragmented native fish populations but also
prohibit upstream invasion by non-native warmwater fishes. Non-native warmwater fishes
have occupied the lower San Rafael for some time (McAda et al. 1980), and suppression of non62
native fishes could benefit natives in this area. Ensuring adequate streamflows and healthy
riparian areas would help offset drought and stream temperature risks due to increasing global
temperatures. Protecting existing habitats and populations for energy development is also a
key strategy.
Upper Escalante River
The Escalante River forms at the confluence of North and Birch creeks near the town of
Escalante. Headwater streams originate on the Aquarius Plateau, and the Escalante River flows
through sandstone gorges, including Grand Staircase-Escalante National Monument, before
entering Lake Powell. Land ownership in the watershed is BLM (33%), Forest Service (62%),
with state and private lands comprising less than 5% each.
The Upper Escalante watershed contains multiple populations of Colorado River cutthroat
trout, and flannelmouth sucker, bluehead sucker, and roundtail chub have been collected
around the town of Escalante, as well as some bluehead suckers further upstream in tributaries.
Several lake populations of Colorado River cutthroat trout also occur in the watershed (Figure
9B).
Habitat integrity is generally good throughout the watershed, aside from some local but specific
threats. Water development infrastructure influences streamflows in a few places in the
watershed. For example, Upper North Creek has several dams, as do the Boulder Creek
headwaters. The mainstem Escalante River is also 303(d) listed due to temperature impairment
and dewatering. Roads along riparian areas also influence habitat integrity in some parts of the
watershed.
Land conversion and resource extraction pose little risk to the future security of aquatic
habitats and fish populations in the Escalante River headwaters. Rather, climate change, nonnative fishes, and energy development – in that order – pose the biggest future risks. Drought
related to climate change poses the biggest risk, but there is also moderate risk due to
uncharacteristic wildfire, water temperature warming, and winter flooding due to rain-on-snow
events. Coal reserves pose a potential future energy risk in Birch Creek and North Creek
watersheds. Non-native salmonids and warmwater fishes also pose competition, predation,
and hybridization risks to native fishes.
There are several opportunities for native fish conservation in the Escalante River headwaters.
Cutthroat trout populations could be expanded and reconnected in Boulder and North creeks
to increase their likelihood of persistence. Warmwater fishes in the mainstem would benefit
from streamflow restoration that limited low flow periods and dewatering. Both of these
would increase the resilience of native fishes in the face of future disturbances driven by land
uses or climate change.
63
Figure 9B. Escalante River headwaters.
64