BOARD00038 ‎(2)‎

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

Razorback Sucker Recovery Goal~ and Criteria

Objective, measurable criteria for recovery of razorback sucker in the Colorado River Basin were
developed for each of two recovery units, which are the upper basin and the lower basin.)
Recovery of the species is considered necessary in both the upper and lower basins. Without
viable wild populations, self-sustaining populations will need to be established through
augmentation with hatchery-produced fish:.

.

Downlisting

Downlisting can occur if, over a five-year period:

1. genetically and demographically viable, self-sustaining populations are maintained in the
Green River subbasin and EITHER in the upper Colorado River subbasin or the San Juan
River subbasin such that: (a) the trend in adult (age 4+;>400mm TL) point estimates for
each of the two populations does not decline significantly; (b) the mean estimated
recruitment of age-3 (300-399 mm TL) naturally produced fish equals or exceeds mean
annual adult mortality for each of the two populations; and (c) each point estimate for
each of the two populations exceeds 5,800 adults (5,800 is the estimated minimum viable
population [MVP] needed to ensure long-term genetic and demographic viability);

2. a genetic refuge is maintained in Lake Mojave in the lower basin recovery unit;

3. two genetically and demographically viable, self-sustaining populations are maintained in
the lower basin recovery unit (e.g., Colorado River mainstream and/or tributaries) such
that: (a) the trend in adult point estimates for each population does not decline
significantly; (b) mean estimated recruitment of age-3 naturally produced fish equals or .
exceeds mean annual adult mortality for each population; and (c) each point estimate for
each population exceeds 5,800 adults; and

4. certain site-specific management tasks to minimize or remove threats have been
identified, developed and implemented.

Delisting
Delisting can occur if, over a three-year period beyond downlisting:

1. genetically and demographically viable, self-sustaining populations are maintained in the
Green River subbasin and EITHER in the upper Colorado River subbasin or the San Juan
River subbasin such that: (a) the trend in adult point estimates for each of the two
populations does not decline significantly; (b) mean estimated recruitment of age-3
naturally produced fish equals or exceeds mean annual adult mortality for each of the two
populations; and (c) each point estimate for each of the two populations exceeds 5,800
adults;
2. a genetic refuge is maintained in Lake Mojave;
3. two genetically and demographically viable, self-sustaining populations are maintained in
the lower basin recovery unit such that: (a) the trend in adult point estimates for each
population does not decline significantly; (b) mean estimated recruitment of age-3

3 The upper basin includes the Green River, upper Colorado River, and San Juan River subbasins, and the lower
basin includes the Colorado River main stem and its tributaries from Glen Canyon Dam downstream to the southerly
International Boundary with Mexico.

.

22