National Park Service 

U.S. Department of the Interior

Grand Canyon National Park 

Arizona 

_____________________________________________________________________________________________ 

FINDING OF NO SIGNIFICANT IMPACT 

Bright Angel Creek Trout Reduction Project 

 compliance with the National Environmental Policy Act (NEPA) and the National Historic Preservation 

l 

all 

urpose of and Need for the Action 

 are to benefit endangered humpback chub (Gila cypha) 

he proposed action is consistent with the 2006 NPS Management Policies that require national parks 

re with 

g 

s. 

he proposed action also conforms to the NPS Organic Act of 1916, which mandates national parks 

Grand Canyon National Park 

In

Act (NHPA), the National Park Service (NPS) prepared an Environmental Assessment/Assessment of 

Effect (EA/AEF) to examine various alternatives and environmental impacts associated with the NPS 

proposal to enhance native fish populations and restore natural ecosystem values within Bright Ange

Creek by reducing the population of non-native brown (Salmo trutta) and, coincidentally, rainbow 

trout (Oncorhynchus mykiss). Bright Angel Creek, a tributary of the Colorado River, is located within 

Grand Canyon National Park, Coconino County, Arizona. The proposal is to remove non-native fish, 

primarily trout, from the creek during their spawning season (approximately October-January) each 

year for five years. In addition, the effectiveness of the program will be assessed by monitoring 

population changes in the Bright Angel Creek fish community in early spring/summer each year; 

non-native fish captured as part of this monitoring effort would also be removed from the creek. 

P

The dual purposes of the proposed action

and other native fish species in the mainstem Colorado River, and to restore and enhance, to the 

extent possible, the native fish community that once flourished in Bright Angel Creek. The project

is needed because non-native species, primarily trout, have become dominant in Bright Angel 

Creek, and trout are also known to prey on the endangered humpback chub in the mainstem 

Colorado River. 

T

to maintain native plants and animals as parts of natural ecosystems, and to remove established 

populations of exotic (i.e., non-native) species. Specifically, Management Policies call for the 

eradication of exotic species if their control is prudent and feasible and if those species interfe

the perpetuation of native species. Total eradication of non-native trout from Bright Angel Creek will 

not be accomplished as a result of this project; however, populations of trout and other non-native fish

will be substantially reduced and maintained at low levels, thus decreasing overall competition with, 

and predation potential on, native fish. After implementation of this project, recreational trout fishin

opportunities would still be available in the creek, but at a reduced catch rate. Recreational trout 

fishing opportunities would also continue to be available in the Colorado River and other tributarie

T

conserve natural resources and manage those resources to avoid their impairment. Actions designed

to protect and restore the native species that comprise the park’s natural aquatic community further 

the intentions of that Act. Reducing threats to a federally listed species (the endangered humpback 

chub) by reducing mainstem populations of predacious non-native fishes (i.e., trout) is also consistent

with NPS directives to comply with the Endangered Species Act of 1973, as amended, and with the 

1
non-native fish control measures in the U.S. Fish and Wildlife Service (USFWS) recovery goals for the 

humpback chub (USFWS 2002a). 

Finally, the proposed action furthers Grand Canyon’s management objectives as articulated in the 

park’s 1995 General Management Plan. Specifically, the project would help the park meet the 

following objectives: 

• To the maximum extent possible, restore altered ecosystems to their natural conditions. In 

managing naturalized ecosystems, ensure the preservation of native components through the 

active management of non-native components and processes. 

• Manage ecosystems to preserve critical processes and linkages that ensure the preservation of 

rare, endemic, and specially protected (threatened/endangered) plant and animal species. 

In August 2006 the National Park Service (NPS) prepared an Environmental Assessment/Assessment 

of Effect for the Bright Angel Creek Trout Reduction Project. This EA/AEF analyzes the impacts that 

will likely result from implementation of the project. The environmental assessment evaluated two 

alternatives in detail, Alternative A, the No Action Alternative, and Alternative B, the agency’s 

preferred alternative. Several preliminary alternatives and components of alternatives that were 

initially considered during the progression through internal and external scoping and alternative 

development are described on pages 15 – 16 of the EA/AEF and were dismissed from further 

detailed analysis as discussed in the EA/AEF. 

SELECTION OF THE PREFERRED ALTERNATIVE

Alternative B was identified in the EA/AEF as the NPS preferred alternative as well as the proposed 

undertaking for §106 compliance. After consideration of public and agency comments on the 

EA/AEF, Alternative B, as modified in response to the comments, is selected as the preferred 

alternative and proposed undertaking as described in this document. 

Under Alternative B, all non-native fish, primarily brown trout and rainbow trout, would be 

mechanically removed from Bright Angel Creek using 1) a weir to capture them as they move 

upstream into the creek to spawn, and 2) electrofishing and dip netting (depletion sampling) in 

conjunction with weir use as part of fish community response monitoring to determine the effects 

of the project on the fish community in the creek. Before implementing the selected action, the 

park will ensure that it has complied with 43 CFR §24.4 regarding consultation with the state and 

application for any required state permits. 

Beginning as early as November 2006, a weir would be installed and operated throughout the trout 

spawning season (approximately October-January) for approximately 70-86 consecutive days. At the 

end of this period, the weir would be removed. The most likely location for the weir would be in the 

creek downstream of Phantom Ranch near the footbridge by the NPS river ranger station, but other 

suitable locations may be selected where stream depths are appropriate. The reduction efforts would 

continue annually for five years, with annual monitoring and evaluation of the project. Details of the 

procedures to be followed were detailed in the EA/AEF. 

To determine the effects of trout reduction on the fish community in Bright Angel Creek, population 

changes in that community would be monitored annually. Two approaches would be used: 1) 

population estimates of fish species present in the creek would be determined using electrofishing and 

the depletion survey method; and 2) a weir would be placed in the creek during early spring/summer 

(as determined to be the most effective time period each year) to capture and census native fish (e.g., 

flannelmouth and bluehead suckers) moving into Bright Angel Creek to spawn. 

To monitor spawning flannelmouth and bluehead suckers moving into Bright Angel Creek, biologists 

would install the weir at the same location identified for the trout reduction effort. For approximately 

2
45 days, during spring/summer, all large-bodied fish moving upstream would be captured in the weir 

(speckled dace would pass through). Captured fish would be removed, identified, measured, 

inspected for reproductive condition, and scanned for the presence of PIT tags. Native fish not 

previously tagged would be injected with PIT tags. Native species would be released above the weir. 

Non-native fish (e.g., trout) would be euthanized and the remains disposed of as described below. 

Following euthanization, non-native fish remains would be appropriately preserved or stored and 

transported out of the canyon (with the possible exception noted below). The fish remains would be 

made available for beneficial uses such as garden composting by Native American tribes. Final 

disposition of the remains would be determined after consultation with Native American tribes. If after 

consultation the fish remains cannot be reasonably stored and transported for beneficial uses by Native 

American tribes, the remains may be disposed of by the NPS on a case-by-case basis in a manner that 

complies with all laws and policies concerning waste disposal and/or in a manner that causes no more 

than negligible environmental impact on the park. 

ALTERNATIVES CONSIDERED

The EA/AEF evaluated two alternatives in detail for addressing the purpose of and need for action; 

the no action alternative (Alternative A) and the preferred alternative (Alternative B). The preferred 

alternative is as previously described. 

Alternative A – No Action Alternative

Under this alternative no changes would be made to the existing environment. Trout and other nonnative fish from the mainstem of the Colorado River and its tributaries would continue to be allowed 

to spawn and reside in Bright Angel Creek without human interference. This alternative would not 

address the purpose and need for the project. 

Alternatives Considered and Dismissed 

In addition, several other alternatives were identified in the EA/AEF (pages 15-16) as considered and 

dismissed from further consideration, along with the rationale for dismissing the alternatives. 

These alternatives included chemical removal, increased angling, dewatering or other flow 

modification, and alternative fish barrier structure. 

In addition, some of the comments received on the EA/AEF suggested an additional alternative: 

rather than euthanizing all non-native fish, only euthanizing brown trout and releasing unharmed 

any rainbow trout captured in the weir or by electrofishing. This suggestion was carefully 

considered, but it was dismissed because the scientific evidence currently available strongly 

supports the need to remove all non-native fish from the creek to meet the goals of the project 

(i.e., to benefit humpback chub and to restore and enhance the native fish community in Bright 

Angel Creek). 

ENVIRONMENTALLY PREFERABLE ALTERNATIVE

The environmentally preferred alternative is determined by applying the criteria suggested in NEPA and 

further articulated in Council on Environmental Quality (CEQ) guidelines (1981). According to those 

guidelines, “the environmentally preferred alternative is the alternative that will promote the national 

environmental policy as expressed in NEPA’s Section 101.” That policy is to: 

• Fulfill the responsibilities of each generation as trustee of the environment for succeeding 

generations; 

• Assure for all generations safe, healthful, productive, and esthetically and culturally pleasing 

surroundings; 

3
• Attain the widest range of beneficial uses of the environment without degradation, risk of 

health or safety, or other undesirable and unintended consequences; 

• Preserve important historic, cultural and natural aspects of our national heritage and maintain, 

wherever possible, an environment that supports diversity and variety of individual choice; 

• Achieve a balance between population and resource use that will permit high standards of 

living and a wide sharing of life’s amenities; and 

• Enhance the quality of renewable resources and approach the maximum attainable recycling of 

depletable resources. 

Alternative B (the preferred alternative) is also the environmentally preferred alternative. Overall, it 

more fully meets the above criteria than does Alternative A. Alternative B would meet the project’s 

purpose and objectives to enhance the natural environment of the creek, resulting in beneficial 

impacts to Grand Canyon’s native aquatic resources in both Bright Angel Creek and the Colorado 

River. It is also expected to benefit a federally listed species, the endangered humpback chub, 

although at a minor or negligible level. Alternative A, on the other hand, would proliferate the 

unnatural aspects of the environment that Alternative B seeks to correct, creating adverse effects on 

the creek’s environment and the humpback chub. 

MITIGATION MEASURES 

The mitigation measures listed below are considered part of the preferred alternative and will be 

followed during project implementation. These actions were developed to lessen the potential for 

adverse impacts from implementing the preferred alternative, and have proven to be effective in 

reducing environmental impacts on previous projects. 

To minimize potential impacts on visitor experience, native fish, human safety, and other resources, the 

following measures would be implemented as part of the preferred alternative. 

General Measures 

• Care would be taken when entering and exiting the creek to minimize impact to streambanks 

and riparian vegetation and wildlife. Unvegetated, stony banks would be used whenever 

possible to minimize erosion. 

• All project personnel would be familiar with and strictly adhere to research permit guidelines 

and limitations. 

• The NPS will conduct discussions and consultations concerning this project with other agencies 

and tribes through multiple venues, including the Glen Canyon Dam Adaptive Management 

Program. Consultation under §106 of the NHPA concerning this project with all tribes will be 

completed before a decision is made concerning this project. 

• If any cultural resources are discovered during the project, including any ethnographic 

resources/ traditional cultural properties, a park cultural resource specialist will be contacted 

immediately. All work in the immediate vicinity of the discovery will stop until the resources 

can be identified and documented and appropriate consultation and mitigation strategy is 

developed, if necessary, in accordance with the stipulations in the 1995 Programmatic 

Agreement among the NPS, the Arizona State Historic Preservation Officer, and the Advisory 

Council on Historic Preservation regarding the General Management Plan, Environmental 

Impact Statement, Grand Canyon National Park, Arizona. 

• Educational and informational measures will be instituted that encourage anglers to assist the 

project in appropriate ways; examples may include not releasing trout caught in Bright Angel 

Creek and encouraging increased fishing for trout. 

• The use of helicopters or mules in support of this project will be minimized, and existing 

procedures will be followed for review and approval of such use. Trips scheduled for other 

purposes will be utilized whenever possible. 

4
• Biologists would be sensitive to public perception and be prepared to explain weir and 

electrofishing activities to any visitor who expresses interest. 

 

Fish Handling Measures 

To minimize stress and injury to fish, capture techniques would follow Ward (2002), including: 

• Be respectful of all fish regardless of size and species. 

• Minimize the time that fish are out of the water. 

• Change water [in holding containers] frequently when fish must be held for more than a few 

minutes or if fish surface for air. Remember that handling stress increases as water 

temperature increases. 

• No more than 8-10 fish in a holding container at one time. 

• Watch straps, lapel badges and jewelry can damage fish. 

• Do not hold fish tightly around the throat and avoid touching the gills. 

• Rinse all sunscreen or lotions from hands prior to handling fish. 

• Always wet hands and equipment such as nets and fish boards before use. Dry hands and 

equipment cause damage to fish skin by removing coatings that protect fish from disease. 

Equipment such as length boards and scales become hot in the sun and can damage fish if not 

wetted prior to use. 

Electrofishing Measures 

Electrofishing would be performed in a manner that minimizes harm to native fish and ensures the 

safety of project personnel and the public. 

• All personnel involved in electrofishing would be trained in the safe and proper use of the 

backpack electrofisher to be used (e.g., Smith-Root LR24). The equipment would be kept in 

good working order, and all personnel would wear appropriate protective gear. 

• A temporary sign would be posted at the reach being electrofished, warning people to stay out 

of the creek in that location (the electrical field extends only a few feet from the anode). The 

sign would include a brief explanation of the project. 

• The minimum voltage would be used, sufficient to attract fish, but not enough to injure them. 

Biologists would observe the condition of captured fish. If signs of injury or handling stress are 

noted (dark bands on the body and longer recovery times), the settings for the electrofishing 

unit would be adjusted. 

• Fish would be removed from the electrical field immediately. Each fish would be completely 

revived before releasing it into the live-well. Care would be taken not to crowd fish in the livewell, and holding time would be minimized. Trout would be kept separate from smaller, preysized native fish to avoid predation. 

Other Measures 

• Project personnel would be instructed not to interact with California condors, bald eagles or 

osprey, and to immediately contact the appropriate Park staff if a condor, bald eagle or osprey 

appears in close proximity to project operations. If a condor, eagle or osprey is observed in the 

area, project personnel will note its behavior and report it to the Park biologist. Fish carcasses 

would be handled in such a way as not to attract condors, eagles or osprey. 

• All project equipment (including personal gear like waders) would be cleaned prior to use to 

ensure that no invasive exotic species are introduced into the project area. Project personnel 

would be instructed to look for non-native New Zealand mudsnails in particular and to ensure 

that none are brought into the area or transported from one location to another. 

5
• Special Status Species

• All actions will be consistent with the Biological Opinion issued for this project. 

• Prior to the start of the project, the park would contact personnel monitoring California condor 

locations and movement to determine condor status in or near the project. 

• If a condor occurs at the project site, operations would cease until it leaves on its own or until 

permitted personnel employ techniques resulting in the condor leaving. 

• Project workers and supervisors would be instructed to avoid interaction with condors and to 

contact the appropriate park or Peregrine Fund personnel immediately if and when condor(s) 

occur at the project site. 

• The project site would be cleaned up at the end of each work day (i.e., trash disposed of, scrap 

materials picked up) to minimize the likelihood of condors visiting the site. Park condor staff 

may complete a site visit to ensure adequate clean-up measures. 

• If condor nesting activity is known within 0.5 mile of the project area, then light and heavy 

construction would be restricted during the active nesting season, if viable nests persist. The 

active nesting season is February 1 to October 15, or until young are fully fledged. These dates 

may be modified based on the most current information, in consultation with the park biologist 

and the USFWS. 

• Biologist and biological technicians will be instructed to refrain from interacting with any eagles 

or osprey that may be present 

• If an eagle or osprey is observed in the area, biologists and technicians will note its behavior 

and report it to the Park biologist. 

• All fish will be disposed of in such a manner as to avoid creating an attractant to eagles or 

osprey. 

• In the unlikely event that a humpback chub (or even more unlikely, a razorback sucker) should 

be captured in the weir or as a result of electrofishing, it will be dealt with according to 

established protocols for handling endangered fish in Grand Canyon. If caught, individual 

endangered fish would be released into the creek upstream of the weir after being measured 

and PIT-tagged (if not already tagged). The incident will be reported to the park biologist, and 

the park biologist will notify the US Fish and Wildlife Service. 

WHY THE PREFERRED ALTERNATIVE WILL NOT HAVE A SIGNIFICANT EFFECT ON THE HUMAN 

ENVIRONMENT 

As defined in 40 CFR §1508.27, significance is determined by examining the following criteria: 

Impacts that may be both beneficial and adverse. As fully discussed in the EA/AEF, the 

preferred alternative will not affect historic properties, floodplains or wetlands, Indian trust 

resources, most special status species, environmental justice, ecologically critical areas, Wild and 

Scenic Rivers, other unique natural resources, prime and unique farmland, urban quality and design 

of the built environment, energy requirements and conservation potential, public safety, geologic 

resources, water resources, air quality, soundscapes, terrestrial biological resources, invasive exotic 

species, socioeconomic resources, park operations, or recommended wilderness, so those impact 

topics were dismissed from further analysis in the EA/AEF. 

Impacts on Bright Angel Creek’s natural ecosystem values, including native fish species, would be 

moderate, direct and indirect, beneficial, and local. Impacts on non-native trout species would be 

moderate (because the impact would be largely local) and adverse. The duration of the impact 

would depend on the duration of the action. If the trout reduction program is terminated, nonnative trout would eventually re-invade from the mainstem, and the system would revert to existing 

conditions. 

6
Impacts to native fish in the mainstem are expected to be minor, direct (predation) and indirect 

(competition), beneficial, and regional. The duration of the impact would depend on the duration of 

the action. Because established protocols would be followed to minimize potential stress and injury, 

the potential impact to the native fish from handling or electrofishing would be negligible, direct, 

adverse, local, and short term. 

The combined past, present, and future non-native trout reduction programs in Grand Canyon may 

result in moderate, indirect, beneficial, and regional effects on native fish in the Colorado River. 

Impacts under the preferred alternative are primarily beneficial for special status species. The preferred 

alternative is expected to benefit humpback chub and other native fish by reducing predation and 

competition pressures from the trout that spawn and reside in Bright Angel Creek. These beneficial 

effects would be minor, with the duration of the impact depending on the duration of the action. The 

potential adverse impact of capturing individual humpback chub, flannelmouth sucker, or razorback 

sucker in the weir or by electrofishing would be negligible and short term. Utilization of appropriate 

fish handling protocols would mitigate the impact. Northern leopard frog may benefit from an 

increase in food availability and reduction in predation pressure, but effects are likely to be negligible. 

Bald eagles and ospreys may be adversely affected to a minor degree as a result of fewer trout being 

available for food, particularly in the Bright Angel Creek inflow area during the spawn. The duration 

of impact would depend on the duration of the action. The reduction in food availability for bald 

eagles and ospreys in the mainstem is expected to be negligible. 

Under the preferred alternative, the quality of angling in Bright Angel Creek would be reduced but not 

eliminated. During the trout spawn in fall/winter, the abundance of trout immediately upstream of 

the weir would diminish compared to No Action, although spawning trout typically do not feed very 

much. In the first years of the project, recreational fishing would still be productive downstream of the 

weir and along the banks of the Colorado River. Over subsequent years, as returning trout are 

eliminated, the quality of angling downstream of the weir would diminish as well. Eventually, fewer 

trout would be available anywhere in Bright Angel Creek, but some trout would always be available 

for fishing in the creek and the river. A small portion of visitors to the area would still fish as an 

incidental part of their experience, but fewer individuals would travel to the area solely or principally to 

fish. The reduction in the sport fishery could be felt by up to 2,300 visitors per year, but for the 

overwhelming majority of the Park’s 4-5 million visitors, and for most of the more than 60,000 people 

who stay overnight in the Bright Angel Creek area (i.e., Bright Angel and Cottonwood Campgrounds, 

and Phantom Ranch), the change would go unnoticed. Consequently, the impacts to visitor 

experience at Grand Canyon would be minor, indirect, adverse, and local. The duration of the impacts 

would depend on the duration of the action but is likely to be long term. 

Few visitors to Bright Angel Creek would see the weir. It would be placed in an unobtrusive location 

near the mouth of the creek, out of sight of the main trail. People crossing a footbridge to a public 

restroom and ranger station may notice the structure from the bridge. If anyone approaches the weir 

and expresses interest, the biologist on duty would explain the purpose of the project. Electrofishing 

depletion reaches upstream in the creek would be selected in part with visitor sensibilities in mind. 

Again, project personnel would take time to explain the purpose of the project to any visitor who 

notices the operation and expresses interest. Impacts on the aesthetic qualities of Bright Angel Creek 

and intrusions to visitor experience would be negligible, direct, adverse, and short term. 

Degree of effect on public health or safety. The preferred alternative involves electrofishing, which 

does have a slight potential to harm crew and park visitors. However, with the appropriate application 

of the mitigation measures for the use of electrofishing equipment, no impacts to public health or 

safety are expected. 

7
Unique characteristics of the geographic area such as proximity to historic or cultural 

resources, park lands, prime farmlands, wetlands, wild and scenic rivers, or ecologically 

critical areas. As fully discussed in the EA/AEF, the preferred alternative will not affect historic 

properties, floodplains or wetlands, Indian trust resources, most special status species, 

environmental justice, ecologically critical areas, Wild and Scenic Rivers, other unique natural 

resources, prime and unique farmland, urban quality and design of the built environment, energy 

requirements and conservation potential, public safety, geologic resources, water resources, air 

quality, soundscapes, terrestrial biological resources, invasive exotic species, socioeconomic 

resources, park operations, or recommended wilderness, so those impact topics were dismissed 

from further analysis in the EA/AEF. Mitigation measures will be implemented that minimize the 

potential for adverse impacts to natural and cultural resources. 

Degree to which effects on the quality of the human environment are likely to be highly 

controversial. As evidenced in the comments received on the EA/AEF and included in the Errata 

Sheet attached to this document, there is some disagreement associated with this project, primarily 

with including the killing of rainbow trout in the project. However, as described above, the science 

supports the project as proposed, and the disagreement does not rise to the point of being highly 

controversial. 

Degree to which the possible effects on the quality of the human environment are highly 

uncertain or involve unique or unknown risks. There were no highly uncertain, unique or 

unknown risks identified in the EA/AEF or during the public review period. Although some 

commenters questioned the scientific evidence supporting killing rainbow trout in addition to 

brown trout, the US Fish and Wildlife Service, the government authority on the subject, supports 

the preferred alternative as proposed and the level of scientific evidence supporting it. 

Degree to which the action may establish a precedent for future actions with significant 

effects or represents a decision in principle about a future consideration. The preferred 

alternative neither establishes a precedent for future actions with significant effect nor represents a 

decision in principle about a future consideration. 

Whether the action is related to other actions with individually insignificant but 

cumulatively significant impacts. Implementation of the preferred alternative will not result in 

any significant cumulative impacts. 

Degree to which the action may adversely affect districts, sites, highways, structures, or 

objects listed on National Register of Historic Places or may cause loss or destruction of 

significant scientific, cultural, or historical resources. No known ethnographic resources are 

expected to be affected by the preferred alternative in the project area (i.e., negligible impacts). If 

upon further consultation, any of the affiliated tribes subsequently identify the presence of 

ethnographic resources within the project area, appropriate mitigation measures would be undertaken 

in consultation with the tribes. The location of any ethnographic sites would not be made public. 

After applying the Advisory Council Historic Preservation’s criteria of adverse effects (36 CFR Part 

800.5, Assessment of Adverse Effects), the National Park Service concludes that implementation of 

the preferred alternative would have no affect on historic properties or on ethnographic resources. 

The State Historic Preservation Office concurred that there would be no historic properties affected 

on October 5, 2006. 

Degree to which the action may adversely affect an endangered or threatened species or 

its critical habitat. According to a Biological Opinion issued for this project on 7 November 2006 

by the US Fish and Wildlife Service, implementation of the preferred alternative is not likely to 

8
adversely affect the California condor, and is not likely to jeopardize the continued existence of the 

bald eagle and humpback chub. However, an incidental take statement, along with reasonable 

and prudent measures, were provided for the humpback chub in the Biological Opinion, in the 

unlikely, but possible, event that a humpback chub is captured during the project and suffers harm 

due to the capture. 

Whether the action threatens a violation of Federal, state or local environmental 

protection law. The preferred alternative violates no federal, state, or local environmental 

protection laws. 

IMPAIRMENT OF PARK RESOURCES OR VALUES

In addition to determining the environmental consequences of the preferred and other alternatives, 

National Park Service policy (Management Policies, 2001 and 2006) requires analysis of potential 

effects to determine whether or not actions will impair park resources. The fundamental purpose 

of the National Park System, established by the Organic Act and reaffirmed by the General 

Authorities Act as amended, begins with a mandate to conserve park resources and values. 

National Park Service managers must always seek ways to avoid, or to minimize to the greatest 

degree practicable, adverse impacts on park resources and values. However, the laws do give the 

National Park Service the management discretion to allow impacts to park resources and values 

when necessary and appropriate to fulfill the purposes of the park, as long as the impact does not 

constitute impairment of the affected resources and values. Although Congress has given the 

National Park Service the management discretion to allow certain impacts within parks, that 

discretion is limited by the statutory requirement that the National Park Service must leave park 

resources and values unimpaired, unless a particular law directly and specifically provides otherwise. 

The prohibited impairment is an impact that, in the professional judgment of the responsible 

National Park Service manager, will harm the integrity of park resources or values, including the 

opportunities that otherwise will be present for the enjoyment of those resources or values. 

Impairment may result from National Park Service activities in managing the park, visitor activities, 

or activities undertaken by concessionaires, contractors, and others operating in the park. An 

impact to any park resource or value may constitute impairment. An impact will be more likely to 

constitute impairment to the extent that it affects a resource or value whose conservation is: 

• Necessary to fulfill specific purposes identified in the establishing legislation or proclamation of 

the park; 

• Key to the natural or cultural integrity of the park; or 

• Identified as a goal in the park’s general management plan or other relevant NPS planning 

documents. 

Because there will be no major adverse impacts to a resource or value whose conservation is (1) 

necessary to fulfill specific purposes identified in the establishing legislation or proclamation of 

Grand Canyon National Park; (2) key to the natural or cultural integrity of the park; or (3) identified 

as a goal in the park’s general management plan or other relevant National Park Service planning 

documents, there will be no impairment of Grand Canyon National Park’s resources or values as a 

result of implementation of the preferred alternative. 

PUBLIC INVOLVEMENT

Public scoping began on December 10, 2003, with letters sent to 283 recipients, including Native 

American tribes, stakeholder groups, agencies, libraries, and private individuals who were likely to be 

interested in, or concerned about, the proposed action. The letter was also posted on the Grand 

Canyon website. Public scoping ended on January 12, 2004. Comments in the form of e-mails, 

9
letters, and phone conversations with park staff were received from 50 respondents, including 44 

individuals, 5 organizations, and 1 state agency (Arizona Game and Fish Department). 

In addition to public scoping, results of the 2003 Bright Angel Creek feasibility study and the proposed 

action were presented to stakeholder groups and the scientific community on two occasions. On 

October 1, 2003, a presentation was made to a meeting of the Glen Canyon Adaptive Management 

Program Technical Work Group (GCDAMP-TWG). 

On October 29, 2003, a similar presentation was made at a science symposium sponsored by GCMRC 

(The Colorado River: An Ecosystem Science Symposium, Tucson, Arizona, October 28-30, 2003). 

Feedback from both presentations, in addition to comments at subsequent GCMRC and GCDAMPTWG meetings, as well as public and agency comments received during the scoping period, were 

taken into account when considering alternatives and issues to be analyzed for the EA/AEF and this 

document. 

Agency Consultation 

US Fish and Wildlife Service. The Park developed a Biological Assessment (December 16, 2003) that 

was submitted to the Phoenix office of the US Fish and Wildlife Service (USFWS) on December 22, 

2003. The park requested and obtained concurrence that the proposed action (Alternative B) was 

“not likely to adversely affect” humpback chub or California condor. On February 9, 2004, the Park 

requested formal consultation for the bald eagle. On March 2, 2004, the USFWS issued a Biological 

Opinion concluding that the project, as proposed, is “not likely to jeopardize the continued existence 

of the bald eagle.” 

The USFWS provided comments on the EA/AEF in a letter dated October 12, 2006. The letter 

expressed agreement that non-native fish species are a serious threat to the native fish fauna of the 

Colorado River; confirmed that Bright Angel Creek appears to be a primary spawning habitat for 

brown trout, and that removal of this species at this location should reduce their numbers throughout 

the Colorado River in Grand Canyon benefiting all remaining native fishes; offered suggestions for the 

timing and protocols of weir operation and depletion sampling; recommended considering a 

comprehensive approach, including the use of piscicides (fish poison), to remove non-native fishes 

from the park with the goal of complete removal; and urges continued coordination with 

stakeholders, including the Arizona Game and Fish Department, and with the Glen Canyon Dam 

Adaptive Management Program. 

The USFWS also provided a Biological Opinion on November 7, 2006. The Biological Opinion states 

that implementation of the preferred alternative is not likely to adversely affect the California condor, 

and is not likely to jeopardize the continued existence of the bald eagle and humpback chub. 

However, an incidental take statement, along with reasonable and prudent measures, were provided 

for the humpback chub in the Biological Opinion, in the unlikely, but possible, event that a humpback 

chub is captured during the project and suffers harm due to the capture. 

Arizona Game and Fish Department. The Arizona Game and Fish Department provided comments 

on the EA/AEF in an October 2, 2006 letter. The letter provided detailed information supporting 

increasing the estimates of anglers that might be affected by the preferred alternative in the EA/AEF; 

concurred from their work on the Colorado River that brown trout management is likely a useful 

strategy in conservation of native fishes, but that they are less certain of the efficacy and value of 

removal of rainbow trout in contributing to conservation of native fishes; and suggested considering 

enlisting the assistance of anglers to assist in the removal of trout through recreational harvest. 

State Historic Preservation Office. Initiation of consultation with the State Historic Preservation 

Office (SHPO) occurred on 18 November 2003. In response to the park’s letter concerning the 

10
EA/AEF dated 6 September 2006, the SHPO concurred on 5 October 2006 that no historic 

properties would be affected by the project. 

American Indian Tribes. NPS initiated consultation with all affiliated tribes (Havasupai, Hopi, 

Hualapai, Kaibab Band of Paiute Indians, Navajo, Paiute Indian Tribe of Utah, White Mountain 

Apache, Yavapai Apache, San Juan Southern Paiute, Moapa Band of Paiute, Las Vegas and Pueblo 

of Zuni) as part of the review of the EA/AEF. A letter with an attached copy of the EA/AEF was 

distributed to all affiliated tribes for their review and comment. 

At a meeting with a representative of the Hualapai Tribe on 10 October 2006 where the project 

was discussed among many park issues, the representative expressed the Tribe’s continued desire 

that a beneficial use be made of non-native fish euthanized as part of projects in the canyon to 

benefit the native ecosystem and/or endangered species. From past electrofishing efforts near the 

confluence of the Little Colorado River with the mainstem Colorado River, the Hualapai Tribe 

received fish remains and used them as fertilizer in a community garden. The Tribe expressed a 

similar wish to receive and use the fish remains from this project. 

At a meeting with representatives of the Hopi Tribe on October 30, 2006, where the project was 

discussed among many park issues, the representatives discussed the Tribe’s concerns about the 

value of all life. Although they understood the purposes of the project, they had serious concerns 

about killing anything for any reason. They said that putting the trout to a beneficial use would 

reduce their concerns. 

Telephone calls were made to all the other tribes between October 20 and November 3, 2006, to 

complete consultation concerning this project. 

In response to the tribal consultation, measures were added to the preferred alternative to make 

the trout remains reasonably available for beneficial use, to carefully handle the remains, and to 

determine final disposition of the fish remains after consultation with Native American tribes. 

Comments Received on the EA/AEF 

The EA/AEF was made available for public review and comment during a 30-day period beginning 

31 August 2006 and ending 2 October 2006, through a combination of direct mailing, issuance of 

a press release and posting on the park’s Planning, Environment and Public Comment website 

(http://parkplanning.nps.gov/grca). All persons on the established park mailing list and interested 

and affected agencies, tribes and organizations received a copy of the EA/AEF during the public 

review period, including all those that commented during the scoping period. A letter was sent to 

the full 300-person park compliance mailing list, with notification that the EA/AEF was available for 

review. 

Eighteen comment letters, website submissions or e-mails were received. The majority was from 

people expressing an interest in fishing, and either supporting the No Action Alternative or 

opposing the Preferred Alternative. Some included rationale such as the project would provide too 

little benefit to justify the impacts, or there seemed to be too little difference in impacts between 

No Action and the preferred alternative to justify the project. Several suggested that more angling 

opportunities be used to reduce the number of non-native fish in Bright Angel Creek, rather than a 

weir and electrofishing. A few suggested that there were many more anglers who would be 

affected by the project than was reflected in the EA/AEF. Several suggested that the project would 

be ineffective, and a waste of effort and funds that could be better used for other purposes. 

Substantive comments are addressed in detail in the errata sheets attached to this document. 

11

 ERRATA SHEET 

Bright Angel Creek Trout Reduction Project 

Grand Canyon National Park 

Substantive comments were considered to be comments which: 

• question, with reasonable basis, the accuracy of information in the EA. 

• question, with reasonable basis, the adequacy of environmental analysis. 

• present reasonable alternatives other than those presented in the EA. 

• cause changes or revisions in the proposal. 

In addition to the comments below, the EA/AEF did not include information concerning helicopter 

flights or mule packing that may be needed to transport equipment, trout remains, and/or people 

in and out of the canyon as part of the project. The NPS will make every effort to minimize the 

need for such use, and will comply with existing park procedures and approval processes, including 

Minimum Requirements Analysis, when such use is necessary. The park will also attempt to 

“piggy-back” onto trips scheduled for other purposes whenever possible. However, it is possible 

that some additional helicopter or mule trips will be needed to accomplish the goals of the project. 

Because such use will be in the non-wilderness Cross-Canyon Corridor using existing procedures, 

and infrequent, no new impacts are expected. The following general mitigation measure is added 

to page 17 of the EA/AEF, and also to the Finding of No Significant Impact (page 4): “The use of 

helicopters or mules in support of this project will be minimized, and existing procedures will be 

followed for review and approval of such use. Trips scheduled for other purposes will be utilized 

whenever possible.” 

 

AL1500 - Encourage Fishing to Remove Trout

 

Comment Organization: Not Specified 

 I have an idea that may appease the fishermen and biologists alike. Why not increase the bag-limit 

on both Rainbow and Brown Trout on the Bright Angel Creek alone? Perhaps even offer a bounty 

on trout caught on the river (as flyfishermen are notorious for catch-and-release). Not only will this 

solve the problem of the dwindling native species of fish, it will also save money on man-hours 

installing traps and electro-fishing the creek. 

 

 Organization: Arizona Game and Fish Department

 One component of an alternative to managing introduced trout in tributaries could perhaps 

include anglers. Perhaps some consideration should be given to enlisting the assistance of anglers 

visiting Phantom Ranch to assist in the removal of trout through recreational harvest. Anglers are 

conservationists as well, and many will embrace the conservation of not only the fishes that they 

wish to pursue but also the broader range of fishes that make up our aquatic fauna. 

 

Response: Encouraging fishing will increase the effectiveness of the preferred alternative. Therefore, the NPS 

will continue to encourage fishing in Bright Angel Creek and will take measures to educate 

fishermen not to release any fish that they catch (i.e., catch-and-keep rather than catch-andrelease); a mitigation measure has been added to the EA/AEF page 17 and to the Finding of No 

Significant Impact page 7 to address this. There have been no bag and size limits on trout in Bright 

Angel Creek for several years, and this will continue. However, as described on page 16 of the 

EA/AEF, fishing alone has not proven to be effective in reducing the numbers of non-native fish in 

the creek, so additional measures are needed. 

AL2000 - Alternatives: Alternatives Eliminated

 

Comment Organization: US Fish and Wildlife Service

13
 We note that you eliminated from further consideration the option to use piscicides to remove 

non-native fish from Bright Angel Creek ... We understand your rationale in this regard ... 

However, mechanical removal is often only effective at controlling non-native fishes over the short 

term. We recommend that you consider a comprehensive approach, using all means necessary, to 

remove non-native fishes from the park, with the goal of complete removal. This likely can only be 

accomplished with an effort that includes the use of piscicides. Thus, we urge you to continue 

consideration of the use of piscicides in Grand Canyon. 

 

Response: The use of chemicals, such as piscicides, was dismissed from further consideration for this project 

in Bright Angel Creek as described on pages 15-16 of the EA/AEF. This decision is specific to this 

project, and is not intended to affect future decisions concerning other projects in the park. Also, 

as a clarification, the fishery between Glen Canyon Dam and Lees Ferry is not in Grand Canyon 

National Park, and is not part of any current or reasonably foreseeable future effort regarding nonnative fish removal.

AL4000 - Alternatives: New Alternatives Or Elements

 

Comment Organization: Federation of Fly Fishers

 The EA/AEF does not mention that the original advice from stakeholder groups (including the 

AZGF) in 2002 was to kill migrating spawning Brown Trout ONLY! Why is the NPS ignoring the 

recommendation from stakeholders? Why is the NPS not offering an alternative that would kill 

only the migrating Brown Trout? If Rainbow Trout killing will only be "coincidental" isn't that an 

admission in the EA/AEF that killing RBT is not important but gratuitous? 

 

 Organization: Member of Northern Arizona Fly Casters

 The stated purpose of the feasibility study done in 2002-2003 (page 4) was to determine if a weir 

could be used to remove brown trout. What leap of information was used to change the scope of 

the project from brown trout to include the rainbow trout? ... Rainbow trout were not part of the 

original feasibility study and appear to have been included in Alternative B at the last minute 

because of convenience! Can't the trained biologists return the rainbow trout to the creek as was 

done in the feasibility study? 

 

Response: To determine the feasibility of using a weir to remove trout, both species of trout did not need to 

be euthanized during the feasibility study. However, after extensive consultation with the US Fish 

and Wildlife Service, both species of trout do need to be removed from the creek to meet the 

purposes of the project to restore and enhance the native fish community in Bright Angel Creek, 

and to benefit the endangered humpback chub. 

The monitoring results will be examined closely, and the project will continue to be discussed with 

stakeholders as part of the Glen Canyon Dam Adaptive Management Program, and other efforts 

as appropriate, to determine if there is any basis for modifying the project.

 

AL5510 – Insufficient Project Benefits

 

Comment Organization: Not Specified

 There are many more important projects the NPS can and should be spending time and money on 

to restore habitat and to provide a better visitor experience within the park. This project provides 

neither. 

 

 Organization: Not Specified

 Bright Angel Creek is not going to provide enough habitat to curb the possible future extinction of 

the Humpback Chub. The fact is that we have made changes to the ecosystem that will be in place 

for hundreds of years (if not thousands). Nature is still reacting and trying to cope with those 

changes. Those changes came with certain consequences, one of those being the loss of native 

14
species of fish in the Colorado River. Nature has responded to those changes and no matter how 

hard we try or how many projects we attempt to implement unless the fish manages to survive on 

its own through natures good grace it will become extinct. The only way for it not to is to 

decommission Glen Canyon Dam (which in my opinion is totally out of the question and would be 

absolutely absurd). I feel it is a waste of time and tax payers dollars to continue implementing 

programs to save these fish. I too would be sad for their loss and it truly would be a great 

misfortune but the fact is that no matter what man tries to do to save these fish we cannot change 

the course that nature is taking, to truly think that we can save the endangered fish species in the 

Colorado River is a very ignorant thought in my opinion. Please don't waste more money by doing 

something that won't matter. 

 

 Organization: Not Specified

 The fact is that you may go in and spend five years removing the trout and planting native species 

of fish in the creek, even if you are successful initially do you honestly think that the trout will stay 

out of the creek. Are you willing to spend more and more money to try to keep the trout out of 

the creek for the rest of time, because that's what will need to happen in order for you to 

accomplish your intended goal. Not to mention the other non-native species that is adapting and 

moving its way up the Colorado River, the Striped Bass. The Striped Bass is a much larger threat 

than the trout are; are you prepared to handle that issue as well? 

 

 Organization: Federation of Fly Fishers

 Even this NPS EA/AEF concludes on page 45 that with the no-action alternative "THERE WOULD BE 

NO IMPAIRMENT OF THE PARK'S RESOURCES OR VALUES" and on page 19 the EA/AEF states that 

any benefit to HBC from the Trout killing would be "minor or negligible" contradicting the NPS 

news release claim that a purpose of the project is to benefit HBC! 

 

 Organization: Not Specified

 As evidenced by the Report's own research, the Bright Angel trout are insignificant to the overall 

population of trout in the Grand Canyon system and the weir would remove an inconsequential 

number of trout. The weir that was installed in 2003 removed only 423 brown trout during the 

spawning run. That represents only 0.5% of the total estimated mainstem brown trout population 

of 84,000. For rainbow trout the numbers are even more dramatic. The 2003 weir removed 188 

rainbow trout, or 0.05% of the total estimated mainstem rainbow trout population 369,000. This 

is best summed up from the following statement in the report regarding Alternative A, "The 

intensity of impact (to the 

native species) would likely be minor because the number of trout that spawn in the creek appears 

to be small compared to the total trout population in the area." 

Similarly, the Report concludes that the Alternative B, the weir removal of trout, would only have a 

minor beneficial impact on, or be of little consequence to, the native fish in the mainstem. So why, 

if both Alternative A and Alternative B are of little consequence to the native species, would the 

National Park Service spend the time, effort and money on Alternative B? How can that be the 

preferred alternative? 

 

 Organization: Member of Northern Arizona Fly Casters

 Save the money, spend it on something of value. Build our park better, don't spend the money 

destroying something that costs nothing to keep. 

 

Response: Meeting the mandates described on page 3 of the EA/AEF is required, not discretionary. The 

EA/AEF discusses how the project would help to meet those NPS mandates. The NPS acknowledges 

that the project may need to continue for many years, at considerable expense. It can be very 

difficult to reverse the effects of many years of human influence on the natural ecosystem. While it 

may not be possible to immediately restore the natural ecosystem, the NPS is required to do its 

best to begin the restoration process. This project is considered to be the best option currently 

available to begin that process. The project includes monitoring to continually evaluate its 

effectiveness in achieving its purpose and goals, as well as evaluating cost effectiveness and 

15
impacts. The project may change over the years based upon the monitoring results and other 

information and techniques that may become available. 

This project focuses on Bright Angel Creek, not the mainstem Colorado River. The fact that there 

are many more trout in the Colorado River is the subject of other projects focused on the river. As 

described in the EA/AEF (e.g., page 28), Bright Angel Creek is believed to be the primary spawning 

grounds for brown trout in the canyon. 

 

CC1000 - Consultation and Coordination: General Comments 

 

Comment Organization: Federation of Fly Fishers

 The EA/AEF does not explain the delay of almost 3 years since scoping ended Jan 12th 2004. 

During the scoping period in 2003, the NPS (Jeff Cross) said that when the EA was finished public 

meetings would be held to develop public support for the project. Have any public meetings been 

scheduled? What notification methods will be used to inform the public? For a project this 

EXTREME, there has been very little public notice and only two 30 day comment periods over 

almost three years. Is this considered adequate NEPA compliance? 

 

Response: The responses received from public scoping, as well as other information available to the NPS, did 

not indicate a need for public meetings. Letters announcing the availability of the EA/AEF were 

sent to everyone who commented during the 2003 scoping period, in addition to approximately 

300 individuals and organizations on the park's mailing list. The park also sent out a press release 

and made the documents available on the NPS-wide park planning website, which is a "clearing 

house" for NPS projects at Grand Canyon as well as nationwide. None of the comments received 

on the EA/AEF, including the one above, requested public meetings or additional time for the 

comment period. 

GA1010 - Impact Analysis - Need Cost Info

 

Comment Organization: Federation of Fly Fishers

 How much money will this trout killing cost? Where will the money come from? The NPS 

complains constantly in the press about not having enough money for important things 

 

 Organization: Not Specified

 Taxpayers do not want their hard earned money spent on a costly alternative that will yield the 

same result as an alternative that will cost nothing. It is also disingenuous to make such a 

recommendation without disclosing the costs of such action. Where is the cost benefit analysis in 

the Report? What is the estimated cost to taxpayers to execute Alternative B? 

 

Response: The cost depends upon the exact methodology as well as who will implement the project. The best 

estimate is that the initial first-year implementation of the project will cost approximately 

$130,000. In response to the comment, the following text is added to the description of 

Alternative B on page 12 of the EA/AEF at the end of the third paragraph on the page providing an 

overview of Alternative B: “The cost of the project is estimated to be approximately $130,000 in 

the first year, and up to $500,000 over 5 years. However, as part of the monitoring program 

designed into the project, cost efficiencies will be constantly evaluated to get the most effective 

results with the least cost.” 

In addition, the following text is added at the end of the description of Alternative A (No Action) 

on page 12 of the EA/AEF: “There would be no new direct costs associated with implementing 

Alternative A.”

 

16
PN8000 - Purpose And Need: Objectives In Taking Action 

 

Comment Organization: Not Specified

 I'm writing to say how unusual your killing healthy trout seems to me and every other 

conservationist I know. Just finding water suitable to support trout is getting scarce, I can't 

conceive of anyone killing any of the current healthy ones. 

 

 Organization: Not Specified

 it seems to me that the [HBC] prospered when the Colorado was a warm water system 

(undammed). The Colorado has been changed and will never again be a warm water system, to 

try and artificially support a fish that won't thrive in cold water seems like an enormous waste of 

manpower and funds; only to fail in the long haul anyway. 

 

 Organization: Federation of Fly Fishers

 Even this NPS EA/AEF concludes on page 45 that with the no-action alternative "THERE WOULD 

BE NO IMPAIRMENT OF THE PARK'S RESOURCES OR VALUES" and on page 19 the EA/AEF states

that any benefit to HBC from the Trout killing would be "minor or negligible" contradicting the 

NPS news release claim that a purpose of the project is to benefit HBC! 

 

 Organization: Not Specified

 Many anglers look forward to fishing the Colorado and its side streams. The federal government 

spent much time and money making this system a prime trout fishery. Why abandon what has 

worked so well? 

 

Response: There will still be opportunities for trout fishing in Bright Angel Creek after implementation of 

this project, and as described in the EA/AEF, the project will have at most minor impacts on 

fishing in the Colorado River. The project objectives were developed to meet NPS mandates to 

protect the natural ecosystem and endangered species. In some cases, meeting those mandates 

involves attempts to reverse past decisions which caused problems not anticipated when those 

decisions were made. 

The NPS Organic Act requires NPS to avoid impairment of park resources. However, the NPS is 

also required by its mandates to maintain or reduce impacts well below the impairment level. 

SE4000 - Socioeconomics: Impact Of Proposal And Alternatives 

 

Comment Organization: Not Specified

 I for one enjoy trout fishing very much and if you diminish the trout in that area you will have a 

far more damaging impact on that community then you think. I'm sure you get a lot of tourists 

in your area due to the fishing, what would it due to the local businesses and the money that is 

generated from it. 

 

 Organization: Member of Northern Arizona Fly Casters

 I know that the money made from the fishing park visitor is small in the scope of the entire park. 

But we must consider that it is like many of the park activities ...hiking, rafting, and the tourist 

who checks out the viewscape, we are all important visitors to Grand Canyon National Park. We 

all pay the entrance fees. 

 

Response: Socioeconomics was dismissed from further consideration as an impact topic in the EA/AEF (page 

10). In that discussion, it is acknowledged that fishing is very important to some visitors, but that 

all information available to the NPS indicates that the economic impact of those visitors is 

negligible in the scope of all Grand Canyon visitation. Also, as explained in responses to other 

comments, there would still be opportunities to fish for trout in Bright Angel Creek after 

17
implementation of this project, and the project would have at most minor effects on trout 

fishing opportunities in the Colorado River. 

VE4000 - Visitor Experience: Impact Of Proposal And Alternatives

 

Comment Organization: Not Specified

 I have fished for trout numerous times in Bright Angel Creek. Fishing in Bright Angel Creek is a 

prized Grand Canyon experience for me. In fact, every time I hike in to the area I bring my 

fishing gear, and so do my friends and family. 

 

 Organization: Federation of Fly Fishers

 This project would be a gratuitous and extravagantly expensive destruction of a valuable park 

recreational fishing opportunity already diminished by government neglect and abuse, but 

appreciated by park visitors since the 1920's. 

 

 Organization: Not Specified

 ...some curtailing of trout populations might be needed but not entirely annhilating the brown 

and rainbow fishery in Bright Angel. You've already destroyed much of the trout fishery in the 

main river, Nankoweap and Thunder River. Leave it at that. Do this project as you have proposed 

and outdoor writers will have to advise against buying a fishing license for anything below Lees 

Ferry. 

 

 Organization: Member of Northern Arizona Fly Casters

 To imply in your assessment that because the number of fishermen is low and that the loss of 

this resource will not have much of an effect on the Park as a whole is a misguided concept. 

Fishing at Bright Angel Creek is one of America's great backcountry experiences. 

 

Response: The NPS will continue to encourage trout fishing in Bright Angel Creek to increase the 

effectiveness of the weir and electrofishing proposed in this project (please see the response to 

AL1500). However, the NPS will also educate anglers to catch-and-keep rather than catch-andrelease. None of these efforts are expected to completely eliminate trout from the creek, but 

they will make trout fishing more challenging and reduce catch rates. 

The NPS acknowledges the great value of the fishing experience to some park visitors, but must 

also consider the value of visitor experiences in the context of its other mandates, some of which 

are reflected in the purpose and goals of this project. Please also see the response to VU2000. 

VU2000 - Visitor Use: Methodology And Assumptions 

 

Comment Organization: Not Specified

 The overall statistics the researchers provide regarding the number of anglers may be vastly 

underestimated. Over the past 28 years, I've probably fished Bright Angel Creek 35 or more 

times. Counting friends and family who do the same, I would attribute just to people I know 

some 250 angler days over this period. Using the statistics in this EA, just myself and the people I 

know would represent an major chunk of all fishing activity in Bright Angel Creek in close to 3 

decades, which is of course very hard to believe. 

Our experience is reason to suspect the methodology the researchers used to determine the 

frequency and number of anglers is inadequate or seriously flawed. In my experience, never once 

have I encountered a ranger or anyone else who appeared to be tracking the number of anglers 

on the creek. To the extent the number of anglers is underestimated, therefore, this then draws 

into question some the underlying reasons for the recommendations of the EA. 

 

18
 Organization: Arizona Game and Fish Department

 We believe the angler use estimates ...on Page 43, Table 4 are low. Angler use was not 

extrapolated to the entire year or period of use by anglers, it was only reported for the period of 

time that creel surveys were conducted. In the 1977-78 data, an average of 6.3 anglers were 

counted each day, over 20 days. Total use extrapolation in the EA only included the number of 

days that creel counts were conducted. From our reading, it implied that was total use. Total use 

should be estimated using the total number of days in the year or season of fishing use 

multiplied by the average number of anglers per day. 

For example, in your Table 4 the EA/AEF reported 6.3 anglers/day * 20 days that anglers were 

counted = 126 anglers for 1977-78. A more applicable extrapolation is probably closer to 6.3 

anglers/day * 365 days/year = 2,300 anglers. If angler counts were only conducted during peak 

use periods, the extrapolation should be weighted by the average number of anglers each 

month. Similar errors in extrapolation are apparent for the 1989-90 data also. Data from 

Appendix 7-1 in Carothers and Minckley (1981) show an estimated 951 anglers during the 

months that anglers were counted (November-March). Assuming similar use patterns during the 

rest of the year, we would estimate that up to 2,283 anglers fished Bright Angel creek in 12 

months during 1977-78. While the order of magnitude difference in the estimates may seem 

minor, we would hold that it is important to reflect the relatibve value placed on the activity by 

visitors to the best of our abilities. Angler use of Bright Angel creek may not seem large, avid 

anglers who visit Bright Angel Creek and other tributaries within Grand Canyon National Park 

will view trout fishing as an important issue. We suggest that you reassess angler use estimates 

for Bright Angel Creek so that annual angler use can disclosed and assessed in the context of 

overall use of the creek. 

 

 Organization: Member of Northern Arizona Fly Casters

 Fishing licenses are most likely to be purchased in Flagstaff ... This makes counting the licenses 

sold at the park an unreliable way to guage the number of anglers. 

 

Response: Estimates for the number of anglers fishing in Bright Angel Creek are included in the EA/AEF 

primarily on pages 42-45. The above comments question the numbers, and suggest increasing 

the estimates. The EA/AEF simply reported the numbers available to the NPS; use was not 

extrapolated to an entire year because the NPS did not believe it had sufficient basis for such an 

extrapolation. 

The underlying reasons for the recommendations (in the Purpose and Need section on EA/AEF 

page 1) are not affected by angler use estimates. However, the extent of impact on anglers is 

called into question by these comments. 

In response to the comments. the NPS is revising the language in the EA/AEF on page 45 to 

indicate that “up to 2,300 visitors per year” rather than “an estimated 200 visitors per year” 

may be adversely affected by the project. However, even if the suggested figure of 

approximately 2,300 anglers per year is used, that number would compare to approximately 

36,000 people who camp each year at Bright Angel and Cottonwood Campgrounds, and 

approximately 25,000 people who stay overnight at Phantom Ranch (plus over 22,000 river 

runners who currently pass through the area). Therefore, although more people may be 

affected than originally portrayed in the EA/AEF, the conclusion on page 45 is still accurate that 

the proportion is very small and the impacts to the visitor experience at Grand Canyon would still 

be minor, indirect, adverse, and local as stated (EA/AEF page 45). 

WH2000 - Wildlife And Wildlife Habitat: Methodology And Assumptions 

 

Comment Organization: Not Specified

 Representative Quote: In reference to the non-native species removal, I must say I do not 

agree. Nature has a way of selecting species through several methods. There are storms, changes 

in climate, food, or water. Nature is a dynamic force, dynamic in that it is constantly changing 

19
and adapting. It is arrogant to decide that "we" can decide how nature should look and what 

species should survive or not survive. 

 

 Organization: Not Specified

 Bright Angel Creek is not going to provide enough habitat to curb the possible future extinction 

of the Humpback Chub. The fact is that we have made changes to the ecosystem that will be in 

place for hundreds of years (if not thousands). Nature is still reacting and trying to cope with 

those changes. Those changes came with certain consequences, one of those being the loss of 

native species of fish in the Colorado River. Nature has responded to those changes and no 

matter how hard we try or how many projects we attempt to implement unless the fish manages

to survive on its own through natures good grace it will become extinct. The only way for it not 

to is to decommission Glen Canyon Dam (which in my opinion is totally out of the question and 

would be absolutely absurd). I feel it is a waste of time and tax payers dollars to continue 

implementing programs to save these fish. I too would be sad for their loss and it truly would be 

a great misfortune but the fact is that no matter what man tries to do to save these fish we 

cannot change the course that nature is taking, to truly think that we can save the endangered 

fish species in the Colorado River is a very ignorant thought in my opinion. Please don't waste 

more money by doing something that won't matter. 

 

 Organization: Not Specified

 The fact is that you may go in and spend five years removing the trout and planting native 

species of fish in the creek, even if you are successful initially do you honestly think that the trout 

will stay out of the creek. Are you willing to spend more and more money to try to keep the 

trout out of the creek for the rest of time, because that's what will need to happen in order for 

you to accomplish your intended goal. Not to mention the other non-native species that is 

adapting and moving its way up the Colorado River, the Striped Bass. The Striped Bass is a much 

larger threat than the trout are; are you prepared to handle that issue as well? 

 

 Organization: Federation of Fly Fishers

 HBC do not live in BA creek because the water is too cold! Even John Wesley Powell in the 

1860's thought BA creek was a trout stream! Historically, native Apache Trout or native 

Colorado River Cutthroat Trout could have been present in BA creek! Would minnows and 

suckers alone constitute a balanced fish population in BA creek? 

 

 Organization: Federation of Fly Fishers

 The EA/AEF does not mention that just last year, 2005, the trout fishery through out the Grand 

Canyon again suffered at least a 50% decline likely due to destruction of the food supply for fish 

resulting from the November 2004 high flow (flood) experiment intended to increase the size of 

camping beaches in the Grand Canyon. It is LIKELY that there would be very few Trout to catch 

with the weir if it is used in November 2006 as planned since the trout population in the Grand 

Canyon is currently at very low numbers. 

 

 Organization: Federation of Fly Fishers

 The EA/AEF does not mention that the GCMRC trout killing project and the NPS BA creek trout 

killing project were drastic emergency responses to what was an inaccurately low estimate of 

only 1000 HBC in 2002. Also the estimate of 8,000 HBC in the 1980s is now thought by the 

USFWS to have been inaccurately high! It seems that HBC probably have been stable at about 

5,000, which coincidentally may be about the carrying capacity of the LCR even with all the 

warm water non-native fish living in the LCR! 

 

 Organization: Federation of Fly Fishers

 The EA/AEF does not mention that the NPS drastically reduced the quality of BA creek fish 

habitat in 1991 by removing beavers, beaver dams and beaver ponds in the lower 2 miles to 

protect trees they planted to shade their buildings. This seriously reduced fish habitat quality and 

recreationally fishing quality for park visitors. The NPS did not notify the public or do any NEPA 

20
compliance before removing the beavers and when questioned now they claim (Jeff Cross) the 

beavers were washed away by flash floods. However, several anglers witnessed the NPS 

destroying beaver dams. Several of the beaver dams were very large, beautiful park features, and 

resistant to flash flooding. See photos included! 

 

 Organization: Federation of Fly Fishers

 The EA/AEF does not mention that the U.S. Geological Survey's Grand Canyon Monitoring and 

Research Center (GCMRC) found only 1 percent of the 20,000 Rainbow Trout (RBT) they killed in 

the Grand Canyon in the past four years had fish in their stomachs and those were mostly either 

common suckers or baby trout. 

 

 Organization: Federation of Fly Fishers

 The EA/AEF references high numbers of anglers fishing BA creek ("20 or more anglers per day", 

page 43) in the 1980's when trout fishing was phenomenal and coincidentally HBC numbers 

were thought to be at their highest. Fishing quality as referenced in the EA/AEF has been poor in 

the last decade and a half and the HBC have been thought to have declined also in the last 15 

years 

 

 Organization: Federation of Fly Fishers

 Why is the NPS not asking to kill the "monster Carp" (USFWS observations) and other warm 

water non-native fish (Channel Catfish, Green Sunfish, Black Bullheads, fathead minnows, Red 

Shiners etc.) residing in the Little Colorado River (LCR), the warm water home of the endangered 

Humpback Chubs (HBC) in the Grand Canyon? Trout do not live in the warm water of the LCR!

 

 Organization: Not Specified

 John Wesley Powell's journals indicate the presence of fish in Bright Angel. These could well be 

Colorado River cutthroat. How can you prove there were not trout native to this system? Why 

not consider restoring cutthroats? 

 

 Organization: Not Specified

 What proof is there that trout far downstream from the Little Colorado (prime humpback chub 

habitat) at Bright Angel prey on or bother the chubs? 

 

 Organization: Not Specified

 Admittedly, I am fisherman and whole heartedly agree with the statement in the report that 

"angling in the spectacular setting at the bottom of Grand Canyon is a unique and prized 

experience." Why deny me and others that opportunity based on incomplete evidence and 

flawed conclusions. It's clear that if the humpback chub populations have stabilized then both 

trout and native species can co-exist. 

 

 Organization: Arizona Game and Fish Department

 We concur from our work on the Colorado River that brown trout management is likely a useful 

strategy in conservation of native fishes. We are less certain of the efficacy and value of removal 

of rainbow trout in contributing to the conservation of native fishes. ... We do place emphasis on 

conservation of native fishes in the Colorado River through Grand Canyon below the Lees Ferry 

Reach down to the Lake Mead influence and believe that it is a focal area for native fish 

conservation. 

 

 Organization: Member of Northern Arizona Fly Casters

 Removal of the rainbow and brown trout will not correct the removal of the beaver ponds. The 

flannel mouth sucker needs slack water to spawn; the beaver ponds did provide that habitat. 

Competition for space with trout did not drive them out of the creek. The Park Service removal 

of the beaver habitat to protect the new trees at Phantom Ranch did. 

 

21
 Organization: US Fish and Wildlife Service

 The EA/AEF currently calls for two methods to assess weir effectiveness. First, the weir will be 

operated in early spring from April to May to catch native suckers migrating into Bright Angel 

creek. Second, the EA/AEF describes depletion sampling in Bright Angel Creek during the same 

period. We recommend that sampling be scheduled later in the year, from mid- to late-summer 

(prior to the monsoon season), to minimize the potential impact on spawning fish, primarily the 

suckers that the weir will be catching in the spring. Additionally, if sampling is pushed back until 

late July, hoopnets could also be used to catch young of the year which may provide a better 

overall index of how the native fishes are potentially benefiting from removal of non-native 

salmonids. While depletion sampling has merit, especially in December/January when native fish 

densities are likely at their lowest, because depletion sampling can be very hard on non-target 

species, a better measure of the benefit of the weir is how it affects recruitment in the spring. 

Also, ... reduces manpower needed ... during weir operation ... five days should be an 

appropriate amount of time to accomplish monitoring objectives. We also recommend that the 

45-day weir operation scheduled for spring remain as fluid as possible ... factors are 

unpredictable ... starting day and ending day can be tailored around fish movement ...We 

further recommend that all biologists on the project be educated in existing protocols for 

conducting fish research in Grand Canyon, that fish of any species larger than 150 mm be 

scanned for a passive integrated transponder (PIT) tag, and that all unmarked native fish larger 

than 150 mm be marked with a PIT tag. 

 

Response: The above responses to AL5510, PN8000, and VE4000 address most of the issues raised in these 

comments. 

Additional issues include: 

If striped bass or other non-native fish are caught during this project, they will be euthanized. 

Comprehensive efforts to address non-native fish in other parts of the Colorado River system are 

outside the scope of this project. 

While beaver dams and ponds were removed by the NPS in Bright Angel Creek, the NPS has 

nothing but anecdotal evidence of their value (either positive or negative) to the native fish 

community. Similarly, any correlation between fishing quality and humpback chub populations 

are at this time hypothetical or anecdotal. 

As discussed in the EA/AEF (e.g., pages 26-29), the proportion of fish in the diet of brown and 

rainbow trout varies by many factors, including whether they are spawning as many of the fish 

were in the study cited in the comment (they usually eat very little when spawning). 

Powell did not specify what species of fish he found in the creek. There is insufficient basis to 

consider any species of trout as native in Bright Angel Creek, and no evidence that brown or 

rainbow trout are anything but non-natives. 

On pages 3-4 of the EA/AEF, GCMRC 2006 is cited indicating that the humpback chub 

population in Grand Canyon may be stabilizing. The reference also acknowledges that the exact 

causes of stabilization, and the relative importance of the various factors (including non-native 

fish removal) that may be contributing to it cannot be specified at this time. This issue does not 

affect the need to take action to benefit the chub, nor does it affect the other project purpose to 

restore the native fish community in the creek. 

Changes to the methodology such as those suggested in the comment are of a level of detail 

that do not affect the impacts or decision. Such changes may be made as a result of the 

monitoring program in future years as well. The suggested changes are reflected in the 

description of the preferred alternative in the Finding of No Significant Impact.

22
WH4000 - Wildlife And Wildlife Habitat: Impact Of Proposal And Alternatives 

 

Comment Organization: Not Specified

 No evidence was presented that the native species would benefit, particularly the humpback 

chub, from the removal of trout via a weir placed in Bright Angel Creek. In fact, the report 

concludes that the benefit to the native species from Alternative B would be of little 

consequence. 

 

 Organization: Not Specified

 The Assessment Report is glaring in its omission of an analysis of the relative contributing factors 

to the decline of the native species. What impact have various other environmental factors, like 

pollution and water flows, had on the native species? Are trout 1%, 5%, 50%, 80% responsible 

for the decline? Where is the data or the discussion? 

Although this information is not presented directly, the Report's own words indicate that trout, 

or at least the trout spawning in Bright Angel, have very little to do with the decline of the native 

species. The Assessment Report states that the No Action alternative would have a minor adverse 

impact on the humpback chub and flannelmouth sucker and no effect, or negligible adverse 

effect, on the razorback sucker. Minor is defined in the Report as "measurable but small and 

localized and of little consequence". 

 

 Organization: Not Specified

 The Report states that "it appears that the humpback chub population in Grand Canyon may be 

stabilizing." If that is the case, why kill one species, trout, for the alleged benefit of another 

species, humpback chub, that may not even be in decline? Shouldn't an assessment be made of 

the true current status of the native species before another species is destroyed? Seems like 

good common sense to me. 

 

 Organization: US Fish and Wildlife Service

 As you have clearly identified, non-native fish species are a serious threat to the native fish fauna 

of the Colorado River. A suite of non-native fishes prey on and compete with native fishes in the 

mainstem Colorado River, and are considered a prime cause in their decline. ...Because Bright 

Angel Creek appears to be a primary spawning habitat for brown trout (Salmo trutta)in Grand 

Canyon, removal of this species at this location should reduce their numbers throughout the 

Colorado River in Grand Canyon and should benefit all the remaining native fishes (humpback 

chub, speckled dace (Rhinichthys osculus), flannelmouth sucker (Catostomus latipinnis), and 

bluehead sucker (Catostomus discobolus)). 

 

Response: The comment by the Fish and Wildlife Service answers most of the criticism evident in the other 

comments. While the relative importance of all factors in the decline of the native species is not 

known, it is well established that trout predation and competition plays an important part. The 

EA/AEF, on pages 31-32, indicates a moderate benefit to the creek's natural ecosystem. 

23