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We initiated a field study to investigate the relative reproductive
success of artificially reconditioned kelt steelhead. Prior to an
implementation of a large-scale steelhead kelt reconditioning program,
it is important to evaluate the reproductive success of reconditioned
kelts relative to hatchery and natural first time spawners. To assess
kelt reproductive success, three sites (Satus Creek,WA; Omak Creek,
WA: and Shitike Creek, OR) have been chosen to replicate studies
of relative reproductive success of each variant of steelhead. Technological
advances in DNA-typing make direct measurement of reproductive success
using pedigree analysis practical. Employing these new techniques,
our study will measure the reproductive success of natural-origin,
hatchery-origin, and reconditioned kelt steelhead in natural stream
settings. This will yield quantitative data replicated geographically
and temporally that will add resolution to the issue.
The 2005 field season was the initial year of capturing, reconditioning,
and analyzing kelts in the three subbasins. While we were successful
in capturing and reconditioning kelts, the numbers and condition
of kelts was unusually poor presumably due to lower than normal
precipitation and flows. Physical evaluation and the collection
of genetic material from first time spawning adults resulted in
the capture of 113 adults at Omak Creek, 57 in Shitike Creek, and
68 from Satus Creek (retained steelhead destined for Section Corner
and South Fork Logy Creeks). We detected 34 kelts attempting to
outmigrate from Omak Creek, 39 kelts from Shitike, and 3 from Section
Corner Creek. Kelts collected at Omak Creek did not survive to be
reconditioned so post spawn steelhead from the localized broostock
program were used and three were released in October of 2005. Ten
kelts were collected for reconditioning from Shitike Creek and one
survived to release in February 2006. None of the post spawn steelhead
from Section Corner Creek survived to be reconditioned.
In 2005 we were able to collect parentage data in Section Corner
Creek, because reconditioned kelt steelhead were available and the
experiment site is analogous to a field laboratory. We released
16 steelhead into Section Corner Creek on March 9, 2005. This release
was composed of five reconditioned female kelts, six female first
time spawners, and five male first time spawners. Parentage analysis
of 159 juveniles indicated that production was from first-time spawning
females only. We believe that the reconditioned kelts were over
ripe and did not spawn. These fish were held on well water with
water temperatures that exceeded the river’s, likely accelerating
their maturation. We are implementing procedures to more closely
synchronize maturation levels from the two groups for future experiments.
Parentage analysis for Omak and Shitike Creek will begin in 2006.
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