BOARD00038 ‎(2)‎

• Board Meeting Date: 9/20/2006
• Description: WSP Section - San Juan River Recovery Implementation Program Document Revisions
• Board Meetings - Doc Type: Memo

For razorback sucker populations to be self-sustaining, reproduction and recruitment must occur .
at a rate to maintain at a minimum a population of 5,800 adults. When this occurs, the definition
of a "self-sustaining" population is met, and the "clock" starts on the downlisting and delisting
process.

Once a self-sustaining population is established, reliable population estimates, based on a
multiple mark-recapture model, are needed over a five-year monitoring period for downlisting
and over a three-year monitoring period beyond downlisting in order to achieve delisting. The
Service will assess the accuracy and precision of each point estimate in cooperation with the
respective recovery or conservation programs and in consultation with investigators conducting
the point estimates and qualified statisticians and population ecologists. The first reliable point
estimates are expected by 2015. If those estimates are acceptable to the Service and all recovery
criteria are met, including establishment of a self-sustaining population, downlisting could be
proposed in 2020 and deli sting could be proposed in 2023.

Colorado Pike minnow Recovery Goals and Criteria

Objective, measurable criteria for recovery of Colorado pikeminnow in the Colorado River Basin
were developed for the Upper Colorado River Basin (including the Green River, upper Colorado
River, and San Juan River subbasins). Recovery of the species is considered necessary only in
the upper basin because of the status of populations and because information on Colorado
pikeminnow biology support application of the metapopulation concept to extant populations.
The need for self-sustaining populations in the lower basin and associated site-specific
management actions and tasks necessary to minimize or remove threats will be reevaluated at the .
status review of the species.

Downlisting
Downlisting can occur if, over a five-year period, the upper basin metapopulation is maintained
such that:
1. a genetically and demographically viable, self-sustaining population is maintained in the
Green River subbasin such that: (a) the trends in separate adult (age 7+; >450 mm TL)
point estimates for the middle Green River and the lower Green River do not decline
significantly; (b) the mean estimated recruitment of age-6 (400-449 mm TL) naturally
produced fish equals or exceeds mean annual adult mortality for the Green River
subbasin; and (c) each population point estimate for the Green River subbasin exceeds
2,600 adults (2,600 is the estimated minimum viable population [MVP] needed to ensure
long-term genetic and demographic viability);
2. a self-sustaining population of at least 700 adults (number based on inferences about
carrying capacity) is maintained in the upper Colorado River subbasin such that: (a) the
trend in adult point estimates does not decline significantly; and (b) the mean estimated
recruitment of age-6 naturally produced fish equals or exceeds mean annual adult
mortality;
3. a target number of 1,000 age-5+ fish (>300 mm TL; number based on estimated survival
of stocked fish and inferences about carrying capacity) is established through
augmentation and/or natural reproduction in the San Juan River subbasin; and
4. certain site-specific management tasks to minimize or remove threats have been .
identified, developed and implemented. .

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