History

• Listed 1967

• Critical Habitat designated in 1994

• 7 reaches totaling 379 miles

• Recovery plan in 1990

• Recovery goals in 2002: Defined recovery

• U.S. District court ruling in 2006 “lacked time and cost 

estimates”

• Draft 2009 revision: never finalized

• 2011 5-Year Review
Distribution

• 6 populations

• 5 upper Colorado 

River Basin

• 1 in lower basin

• Grand Canyon

• LCR 

• 8 mainstem

aggregations
Recovery

• Two recovery units: Upper Basin/Lower Basin

• Different recovery/conservation programs

• Covered by 3 programs

• Recovery in both units necessary

• Two types of criteria for downlisting/delisting

• Demographic (3)

• Recovery factors (minimize or remove threats)
Recovery

• Service policy (U.S. Fish and Wildlife Service 1990b) describes 

recovery as “...the process by which the decline of an endangered or 

threatened species is arrested or reversed, and threats to its survival 

are neutralized, so that its long-term survival in nature can be 

ensured. The goal of this process is the maintenance of secure, self- sustaining wild populations of species with the minimum necessary 

investment of resources.”

• The ESA’s implementing regulations (50 CFR § 402.02) define 

recovery as “...improvement in the status of listed species to the 

point at which listing is no longer appropriate under the criteria set 

out in section 4(a)(1) of the Act.” 

• Section 4(b) of the ESA suggests that a species may be delisted on 

the basis of recovery only if the best scientific and commercial data 

available indicate that it is no longer threatened or endangered. 
Downlisting

• (1) the trend in adult (age 4+; ≥ 200 mm TL) point estimates for 

each of the six extant populations does not decline significantly; 

and 

• (2) mean estimated recruitment of age-3 (150–199 mm TL) 

naturally produced fish equals or exceeds mean annual adult 

mortality for each of the six extant populations; and 

• (3) two genetically and demographically viable, self-sustaining core 

populations are maintained, such that each point estimate for each 

core population exceeds 2,100 adults; and 

• (4) when site-specific management tasks to minimize or remove 

threats have been identified, developed, and implemented.
Delisting

• (1) the trend in adult point estimates for each of the six 

extant populations does not decline significantly; and 

• (2) mean estimated recruitment of age-3 naturally 

produced fish equals or exceeds mean annual adult 

mortality for each of the six extant populations; and 

• (3) three genetically and demographically viable, self- sustaining core populations are maintained, such that each 

point estimate for each core population exceeds 2,100 

adults; and 

• (4) when certain site-specific management tasks to 

minimize or remove threats have been finalized and 

implemented, and necessary levels of protection are 

attained.
Site specific Management Actions

• Adequate habitat and range for recovered 

populations

• Protection from overutilization

• Protection from diseases and predation

• Adequate regulatory mechanisms

• Other natural or manmade factors for which 

protection has been provided
Criteria 1a: Core population maintained over a 

5 year period, adult trend does not decline

• Review: Partially met

• Justification:

• Distribution in Grand Canyon

• Analysis isn’t limited to most recent 5 years

• Downward trend in ASMR

• Uncertainty about aggregations

• How to get to “fully met”

• Continued upward and positive trend in ASMR

• See appreciable increases/expansion of aggregations

Criteria 1a: Core population maintained over a 

5 year period, adult trend does not decline

• Review: Partially met

• Justification:

• Distribution in Grand Canyon

• Analysis isn’t limited to most recent 5 years

• Downward trend in ASMR

• Uncertainty about aggregations

• How to get to “fully met”

• Continued upward and positive trend in recent ASMR

• See appreciable increases/expansion of aggregations
Criteria 1b: Core population maintained over a 5 year 

period, mean recruitment of age 3 fish equals or 

exceeds mean adult mortality

• Review: Partially met

• Justification:

• Ageing error with ASMR

• How to get to “fully met”

• Continued upward trend in recent ASMR estimates

• See appreciable increases/expansion of aggregations

• Resolve ageing errors 
Criteria 1c: Grand Canyon population is maintained 

over a 5 year period that each population exceeds 

2,100 adults

• Review: Met!

• Justification:

• Estimate of adults is above 2,100 per ASMR

• Accept estimates as far back as they have been 

calculated

• Future goal revision to include updated MVP 

number per Dexter project
Recovery Factor A: Adequate habitat and range

Criterion 1: life stages and habitats of HBC in the mainstem

identified and the relationship between the LCR/mainstem

determined

• Review: Met!

• Justification:

• Site fidelity

• Monitoring information
Recovery Factor A: Adequate habitat and range

Criterion 2: Continue GCD operations to benefit spawning, 

nursery, juv/adult habitat

• Review: Partially met

• Justification:

• Used 2008 BO

• Mainstem habitat and flow relationships still unclear

• Outcome of key conservation measures unclear

• How to get to “fully met”

• Implement the conservation measures/RPM’s in 2011 

BO

• Development of flow options for nonnative fish control

• Progress on demographic criteria
Recovery Factor A: Adequate habitat and range

Criterion 3: Effects and feasibility of a Temperature control 

device

• Review: Met!

• Justification:

• Risk assessment (2004)
Recovery Factor B: Protection from overutilization

Criterion 4: Commercial, recreational, scientific or education

• Review: Met!

• Justification:

• No commercial harvest

• CRMP

• Grand Canyon Handling Protocol
Recovery Factor C: Protection from diseases/predation

Criterion 5: Asian Fish tapeworm

• Review: Met!

• Justification:

• Methods for controlling tapeworm are known

• Cold mainstem temps interrupt life cycle

• No evidence that disease impacts lifecycle
Recovery Factor C: Protection from diseases/predation

Criterion 6: Procedures developed to minimize escapement of 

nonnative fish species into the Colorado river/tribs

• Review: Not been Met

• Justification:

• No procedures developed

• Poor understanding of where problematic fish occur

• Unlikely to detect new nonnatives if they did occur

• How to get to fully met:

• Identify sources of nonnative fish 

• Plans in place to minimize watershed level 

introductions

• Better monitoring to detect rare/new species
Recovery Factor C: Protection from diseases/predation

Criterion 7/8: Nonnative control programs should be 

developed/implemented

• Review: Partially met

• Justification:

• Nonnative fish in the LCR appear low..sampling doesn’t 

target these species

• Levels of control necessary to maintain low trout are 

unknown

• Effects of mechanical removal unclear

• How to get to fully met:

• Response program developed to address nonnative fish

• Identify levels necessary to maintain low predation

• Develop a nonnative control program
Recovery Factor D: Adequate regulatory mechansims

Criterion 9: Legal protection of habitat 

• Review: Met!

• Justification:

• Grand Canyon Protection Act

• Grand Canyon National Park

• LCR watershed plan

• Development of Navajo Watershed Plan for LCR
Recovery Factor D: Adequate regulatory mechansims

Criterion 10: Conservation plans identified to provide for longterm management and protection of HBC populations

• Review: Not been met

• Justification:

• Conservation plans have not been developed

• How to get to fully met:

• Develop conservation plans that cover HBC and their 

habitats beyond down/delisting
Recovery Factor E: Natural or manmade factors 

Criterion 11/12: Hazardous materials spill response plans and 

measures identified to minimize

• Review: Not been met

• Justification:

• Hazardous material spill plans have not been developed

• No measures identified to minimize risk on Hwy 89

• How to get to fully met:

• Emergency response plans for spills and other 

watershed level catastrophes

Factor A: Flows

• Appear to be met given status/trend of HBC

• Need to relate flow to habitat conditions

• LCR watershed planning (1995 BO)

• Changes in LCR hydrograph difficult to detect
Factor B: Overutilization

• Some HBC are killed via field work activities, 

regulated under Section 10a 1a permits

• Overall increase in population 
Factor C: Predation/Competition

• Nonnative fishes are low in abundance in LCR

• No target level identified in recovery goals

• Nonnative fish stocking has been evaluated

• Asian fish tapeworm, effects unknown
Factor D: Existing Regulatory 

Mechanisms

• Appear to be met in the LCR

• Still need model that defines instream flow 

needs
Factor E: Natural and man-made 

factors

• Minimize the risk of hazardous chemical spill

• Part of HBC comprehensive plan