BOARD00038 ‎(2)‎

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

Hogback fish ladder allows for unobstructed movement by all fish species, including non-natives. .
Opportunistic removal of non-native fishriveIWide has also occurred during sub-adult and adult
fish monitoring trips since 1996.

Stocking of Endangered Fishes

Within the San Juan River Basin, viable wild populations of razorback sucker and Colorado
pikeminnow currently do not exist. It is recognized that self-sustaining populations need to be
established through augmentation with hatchery produced fish. The recovery plans for both
species specifically identify augmenting populations as a necessary course of action for recovery.
The following is a summary of the Program's augmentation plans for razorback sucker and
Colorado pikeminnow.

Razorback Sucker

A successful experimental stocking program for razorback sucker from 1994 to 1996 led to the
initiation of a five-year augmentation effort beginning in 1997. The five-year augmentation plan
for the species recommended stocking 73,482 razorback suckers between 1997 and 2001.
However, difficulties in obtaining enough razorback sucker stock from outside sources and the
lack of hatchery and grow-out facilities owned by the Program created large stocking shortfalls.
In order to improve the razorback sucker augmentation effort, the Program in 1997 began to
develop a series of grow-out facilities which consisted of nine grow-out ponds on Navajo Indian
Irrigation Project (NIIP) lands southwest of Farmington, New Mexico. Additionally, because of
the large stocking shortfalls, the Program amended and extended the stocking program through
2011. However, although the extended stocking program called for stocking 11,400 age-2 .
razorback suckers (> 300 mm TL) per year beginning in 2004, only a total of 2,989 razorbacks .
were stocked in that year. Causes for the shortfall from the NIIP grow-out ponds are numerous,
including lower than expected production rates, predation by birds and salamanders, and
unexpected large fish kills. The Program in 2005 funded the installation of aerators in the NIIP
grow-out ponds to eliminate fish kills resulting from low dissolved oxygen levels and the
operation of noise cannons at the ponds to deter birds from the sites.

Because of the shortfall issues encountered at the NIIP grow-out ponds, the Program diversified
its razorback production strategy in 2006 by acquiring hatchery-reared razorback sucker (> 300
mm TL) from several other facilities in addition to those raised at the ponds for stocking into the
San Juan River. Pursuant to the stocking plan and the Program's genetics management plan for
razorback sucker, the objectives for razorback sucker augmentation include:

1. producing and rearing genetically-appropriate lots of razorback sucker at the Dexter
National Fish Hatchery;

2. annually stocking grow-out ponds with 20,000 hatchery-reared fish (> 200 mm TL)
from the Dexter National Fish Hatchery;

3. annually harvesting, PIT tagging and stocking approximately 4,000 razorback sucker
(> 300 mm TL) from grow-out ponds into the San Juan River; and

4. annually procuring approximately 8,000 PIT-tagged razorback sucker (> 300 mm TL)
from other hatchery facilities and stocking them into the San Juan River.

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