**Peshastin Creek Smolt Monitoring Program**

**Annual Report**

March 2004 -- December 2004

Prepared by:

Matt Cooper and Steve Mallas

Mid-Columbia River Fishery Resource Office

United States Fish and Wildlife Service

Department of Interior

Leavenworth, WA 98826

Funded by

United States Fish & Wildlife Service

Fisheries Operations Needs System

Project No. 2002-001

And

U.S. Department of Energy

Bonneville Power Administration

Division of Fish and Wildlife

Portland, Oregon 97208-3621

Project No. 2003-017-00

Intergovernmental Contract (IGC) No. 18165

**January 2004**

[]{#__RefHeading___Toc93392685 .anchor}**EXECUTIVE SUMMARY**

Beginning in 2001 and continuing each year through 2004 a portion of the
adult hatchery spring Chinook salmon that returned to Leavenworth
National Fish Hatchery (NFH) have been live outplanted to Peshastin
Creek within the Wenatchee River watershed. This outplanting effort is a
component of the Biological Opinion for Leavenworth NFH to evaluate the
natural spawning/reproductive success of hatchery adults. Outplanting is
expected to occur in 2005, however, the future of this program after
this time is uncertain.

In 2004, smolt production monitoring began in Peshastin Creek by the
USFWS, Mid-Columbia River Fisheries Resource Office (MCRFRO). The
initial purpose of this monitoring by MCRFRO was to evaluate the
productivity and progeny characteristics of outplanted spring Chinook
hatchery adults from Leavenworth NFH. This type of monitoring was
quickly recognized as critical in implementing the 2000 NMFS FCRPS
Biological Opinion RPA Actions which seeks to develop basin-scale
monitoring and evaluation programs for the Wenatchee, John Day, and
Upper Salmon River basins. Subsequently, the Peshastin Smolt Monitoring
Program was expanded in a joint effort to meet both the requirements set
forth in the Leavenworth NFH and the NMFS FCRPS BiOp's.

To meet the programs goals an instream rotary screw trap was chosen and
utilized to capture downstream migrant juvenile fishes in Peshastin
Creek. The rotary screw trap is located at river mile 6.3 (river
kilometer 10.2) near the Camas Creek confluence (47^0^ 29' 32.171"N;
120^0^ 38' 16.18"W). This report summarizes the operation of the
Peshastin Creek smolt trap from March 18 to November 21, 2004. During
this time period there were 208 days of complete sampling.

A total of 8,955 individuals were sampled throughout the trapping
season. Spring Chinook and steelhead/rainbow trout (SRT) represented
48.2% (4,319) and 48.0% (4,302) of the total catch, respectively. The
remaining catch consisted of 112 bull trout, 58 coho salmon, 155
sculpin, and 9 adult fall-back salmonids.

A total of 1,712 spring Chinook salmon juveniles captured at the trap
were PIT-tagged. An additional 314 spring Chinook were captured at the
trap site by seine net and PIT-tagged on August 20. A total of 228
spring Chinook juveniles and 100 steelhead/rainbow trout were
non-lethally tissue sampled for genetic analysis.

Trap efficiency trials were conducted throughout the season.
Emigrational spring Chinook and steelhead juveniles of varying size and
age classes were used in these efficiency trials. A total of 1,391
Chinook and 194 steelhead/rainbow trout were released for efficiency
trials with a total of 379 and 42 recaptures, respectively. A total of
61 releases were made for efficiency trials throughout the trapping
season.

The average trapping efficiency for the season was 21.4% and 15.7% for
spring Chinook and steelhead/rainbow trout juveniles, respectively. It
is estimated that 66,395 (±20,147 95%CI) sub-yearling (age 0) Chinook
and 16,082 (±3,982 95%CI) steelhead/rainbow trout, representing three
age-classes, emigrated from Peshastin Creek during the 2004 sampling
period. Steelhead/rainbow trout age-0, age-1, age-2 are estimated to
represent 52% (8,419), 42% (6,770), and 6% (893) of the population
estimate, respectively. Only one yearling (age-1) spring Chinook was
captured in the 2004 season. Therefore, a production estimate for this
age class could not be generated.

[]{#__RefHeading___Toc93392686 .anchor}**TABLE OF CONTENTS**

[**EXECUTIVE SUMMARY** i](#__RefHeading___Toc93392685)

[**TABLE OF CONTENTS** iii](#__RefHeading___Toc93392686)

[**LIST OF TABLES** iv](#__RefHeading___Toc93392687)

[**LIST OF FIGURES** iv](#__RefHeading___Toc93392688)

[**LIST OF APPENDICES** v](#__RefHeading___Toc93392689)

[**ACKNOWLEDGMENTS** vi](#__RefHeading___Toc93392690)

[**INTRODUCTION** 1](#__RefHeading___Toc93392691)

[*Background Details: Smolt Production Monitoring*
1](#__RefHeading___Toc93392692)

[*Project Purpose / Justification* 2](#__RefHeading___Toc93392693)

[**METHODS** 3](#__RefHeading___Toc93392694)

[*Methodology* 3](#__RefHeading___Toc93392695)

[*Trap Design and Study Duration* 3](#__RefHeading___Toc93392696)

[*Trap Operation* 4](#__RefHeading___Toc93392697)

[*Biological Sampling* 4](#__RefHeading___Toc93392698)

[*Age Determination* 5](#__RefHeading___Toc93392699)

[*Production Estimates* 6](#__RefHeading___Toc93392701)

[**RESULTS** 8](#__RefHeading___Toc93392702)

[*Spring Chinook* 9](#__RefHeading___Toc93392703)

[*Steelhead / Rainbow Trout* 12](#__RefHeading___Toc93392704)

[*Incidental Species* 15](#__RefHeading___Toc93392705)

[*Production Estimates* 16](#__RefHeading___Toc93392709)

[*Data Entry* 19](#__RefHeading___Toc93392710)

[*Trapping Frequency Evaluation* 19](#__RefHeading___Toc93392711)

[**DISCUSSION** 20](#__RefHeading___Toc93392712)

[**REFERENCES** 23](#__RefHeading___Toc93392713)

[]{#__RefHeading___Toc93392687 .anchor}**LIST OF TABLES**

[**Table 1.** Summary of trapping dates by strata for Peshastin Creek,
2004. 4](#__RefHeading___Toc93393115)

[**Table 2.** Peshastin Creek catch summary for 3/18/04 to 11/21/04.
8](#__RefHeading___Toc93393116)

[**Table 3.** Fork length, weight, and condition factor for sub-yearling
spring Chinook emigrating from Peshastin Creek, 2004
11](#__RefHeading___Toc93393117)

[**Table 4.** Steelhead/rainbow trout trap counts by life stage and
seasonal strata, 2004 (Fish of adequate size for PIT-tagging by strata
indicated) 12](#__RefHeading___Toc93393118)

[**Table 5.** Fork length, weight, and condition factor by age-class for
steelhead/rainbow trout juveniles emigrating from Peshastin Creek, 2004.
14](#__RefHeading___Toc93393119)

[**Table 6.** Peshastin Creek juvenile Chinook population estimate and
error by seasonal strata for 3/18/04 to 11/21/04.
17](#__RefHeading___Toc93393120)

[**Table 7.** Peshastin Creek juvenile steelhead/rainbow trout (SRT)
population and error estimate by seasonal strata for 3/18/04 to
11/21/04. 17](#__RefHeading___Toc93393121)

[**Table 8.** Alternative schedules and the estimated population
estimate for Chinook and steelhead/rainbow trout compared against the
actual 2004 trapping schedule/population estimate.
20](#__RefHeading___Toc93393122)

[]{#__RefHeading___Toc93392688 .anchor}**LIST OF FIGURES**

[**Figure 1.** Map of Peshastin Creek smolt trap location, 2004.
2](#__RefHeading___Toc93393612)

[**Figure 2.** Peshastin Creek rotary screw trap in operation during
spring, 2004. 3](#__RefHeading___Toc93393613)

[**Figure 3.** Example of various life stages of steelhead/rainbow trout
captured in Peshastin Creek, 2004. 5](#__RefHeading___Toc93393614)

[**Figure 4.** Example of a steelhead/rainbow trout monthly length
frequency graph illustrating significant changes in fish length to
determine age class. These results were confirmed with scale analysis.
5](#__RefHeading___Toc93393615)

[**Figure 5.** Steelhead/rainbow trout age classes determined by monthly
length frequency graphs and scale analysis.
6](#__RefHeading___Toc93393616)

[**Figure 6.** Relative abundance of fish captured in the Peshastin
Creek smolt trap, 2004. 9](#__RefHeading___Toc93393617)

[**Figure 7.** Peshastin Creek estimated sub-yearling Chinook daily
emigration rate vs. flow, 2004. 10](#__RefHeading___Toc93393618)

[**Figure 8.** Average fork lengths of spring Chinook sub-yearlings in
Peshastin Creek, 2004. 11](#__RefHeading___Toc93393619)

[**Figure 9.** Peshastin Creek estimated juvenile steelhead/rainbow
trout daily emigration rate vs. flow, 2004.
13](#__RefHeading___Toc93393620)

[**Figure 10.** Length frequency of sub-adult bull trout captured at
Peshastin smolt trap, 2004 15](#__RefHeading___Toc93393621)

[**Figure 11.** Length frequency of sculpin captured at Peshastin smolt
trap, 2004. 16](#__RefHeading___Toc93393622)

[**Figure 12.** Peshastin Creek sub-yearling spring Chinook and
steelhead/rainbow trout catch (top) and population estimate (bottom)
with 95% CI by seasonal strata, 2004. 18](#__RefHeading___Toc93393623)

[**Figure 13.** A graphical comparison of the cumulative population
estimate and temporal migration patterns by age-class for Peshastin
Creek steelhead/rainbow trout, 2004. 19](#__RefHeading___Toc93393624)

[]{#__RefHeading___Toc93392689 .anchor}**LIST OF APPENDICES**

[**Appendix A.** Daily catch of sub-yearling spring Chinook (top graph)
and steelhead/rainbow trout (bottom graph) compared with Wenatchee River
discharge.](#__RefHeading___Toc91574898) 24

[**Appendix B.** Daily catch of bull trout (top graph) and coho (bottom
graph) compared with Wenatchee River
discharge](#__RefHeading___Toc91574899) 25

[**Appendix C.** Peshastin Creek mark-recapture efficiency trials with
trap efficiency percentages relative to
flow](#__RefHeading___Toc91574900) 26

[**Appendix D.** Peshastin Creek subyearling Chinook catch and total
number PIT-tagged by seasonal strata. Peshastin Creek steelhead/rainbow
trout catch and total numbers that were of taggable size
2](#__RefHeading___Toc91574901)8

[]{#__RefHeading___Toc93392690 .anchor}**ACKNOWLEDGMENTS**

Numerous individuals helped with the development and implementation of
this project. We thank our dedicated crew, Becky Christopherson and
Hillary Kleeb, for their hard work with trap operations and data entry.
We appreciate the support of Owen Parsley, Terry DellaPenna, and Earl
Pruitt, whose assistance made the project run smoothly. Special thanks
go to Charles Hamstreet for his expert advice, logistical support, and
assistance with data analysis. We sincerely appreciate the cooperation
and hospitality of the private landowner, Robert Graves and the entire
Drury-Graves family. We thank the biology students from Cascade High
School for assisting with data collection. Thanks go to Jim Craig for
reviewing a draft version of this report. This project was funded, in
part, by Bonneville Power Administration (Contract Agreement #00018165)
and the USFWS Fisheries Operations Needs System (FONS).

The correct citation for this report is:

Cooper, M. and S. Mallas, 2004. Peshastin Creek Smolt Monitoring
Program, Annual Report 2004. U.S. Fish and Wildlife Service,
Mid-Columbia River Fishery Resource Office, Leavenworth, WA.

[]{#__RefHeading___Toc93392691 .anchor}**INTRODUCTION**

[]{#__RefHeading___Toc93392692 .anchor}*Background Details: Smolt
Production Monitoring*

Peshastin Creek is a fifth order class I stream which originates at
Blewett Pass, Washington (T22N R17E) and runs northeast until it flows
into the Wenatchee River at river kilometer (rkm) 29 (T24N R18E S22)
(**Figure 1**). Primary discharge to Peshastin Creek comes from Ingalls
Creek (15%) a tributary entering at rkm 10.6. The Peshastin Creek
watershed encompasses 78,780 acres. The watershed is divided in
ownership with 82% (of this 29% is managed as wilderness in the Ingalls
Creek watershed) owned by the US Forest Service and 18% (primarily the
lower 12.1 km) is privately held (Cappellini, 1997). Peshastin Creek is
characterized as a high gradient, boulder cobble stream that is
potentially more suited for steelhead than Chinook. However, the stair
stepping nature of Peshastin Creek creates numerous small pools in the
upper reaches and tributaries such as Ingalls Creek. These microhabitats
are thought to have the potential to provide excellent habitat for the
rearing of small salmonids (Mullan et al 1992).

Current salmonid fish use of this system includes rainbow, cutthroat
trout and ESA listed steelhead and bull trout (Ringel, 1997). Spring
Chinook salmon historically utilized Peshastin Creek, however the best
estimates indicate this population is either very small or nonexistent.
Spawning ground surveys are conducted annually by Chelan County Public
Utility District and the Washington Department of Fish & Wildlife to
document spring Chinook and steelhead redd development. These surveys
indicate no spring Chinook redds were identified from 1997-2000 (Mosey &
Murphy 2000). It is believed spring Chinook have been extirpated from
this watershed due to irrigation diversions in the lower 7.8 km of
Peshastin Creek and these diversions may block passage during low water
periods when spring Chinook are migrating (Rife, 1999).

Only recently has spring Chinook been reintroduced to the watershed from
natural spawning by non ESA-listed Leavenworth NFH outplants. Beginning
in 2001 and continuing annually through 2004 a portion of the adult
hatchery spring Chinook that returned to Leavenworth National Fish
Hatchery (NFH) were outplanted to Peshastin Creek in a joint effort by
the United States Fish & Wildlife Service and the Yakama Indian Nation.

Although Peshastin Creek contains three "significant subwatersheds" as
identified by the Upper Columbia Regional Technical Team (RTT), little
was known about the specific life history strategies and outmigration
timing of fish utilizing this stream. In addition, landscape-level
attributes of Peshastin Creek (e.g., hydrology, topography, temperature
regime, etc.) vary significantly from other Wenatchee Subbasin
watersheds. These differences provide an important opportunity to assess
the contribution that Peshastin Creek (and other similar streams)
provides to the overall production of spring Chinook and steelhead to
the Wenatchee Subbasin.

Smolt production monitoring in Peshastin Creek was initiated by USFWS
for the first time in March, 2004. This limited monitoring program was
funded by the USFWS Fisheries Operations Needs System (FONS) Program
with a focus solely on evaluating the hatchery adult outplant program.
Additional funding from Bonneville Power Administration (BPA) was
secured to expand the scope of the Peshastin Creek monitoring program to
meet the needs of BPA Project #2003-017-00.

![](media/image1.wmf){width="7.625in" height="4.467361111111111in"}

[]{#__RefHeading___Toc93393612 .anchor}Figure 1. Map of Peshastin Creek
smolt trap location, 2004.

[]{#__RefHeading___Toc93392693 .anchor}*Project Purpose / Justification*

The Peshastin Creek smolt monitoring and evaluation program has three
primary objectives: 1) estimate the smolt production of spring Chinook
salmon and steelhead/rainbow trout 2) describe the temporal variability
of outmigrating spring Chinook and steelhead/rainbow trout, 3) evaluate
the reproductive success, productivity and performance of spring Chinook
progeny from the hatchery adult outplant program.

[]{#__RefHeading___Toc93392694 .anchor}**METHODS**

[]{#__RefHeading___Toc93392695 .anchor}*Methodology*

Technical methodologies followed protocols specified in Hillman (2004)
who developed a monitoring strategy for the Upper Columbia Basin.
Additionally, this project used the same procedures and equipment
utilized by WDFW at other smolt trapping sites within the Wenatchee
Subbasin (Murdoch et al. 1999, 1998a, 1998b, and 1997) except in certain
instances to conform to site-specific needs.

[]{#__RefHeading___Toc93392696 .anchor}*Trap Design and Study Duration*

A floating rotary screw trap (RST) was installed in Peshastin Creek at
river kilometer 10.2 (river mile 6.3) near the Camas Creek confluence
(47º 29' 32.171" N, 120º 38' 16.18" W) (**Figure 1**). This site is
situated immediately upstream of a private bridge at the head of a large
pool. The advantages to this site include ease of trap installation,
convenient access, substantial water depth throughout the trapping
season, and an adjacent eddy where extreme discharge events could be
avoided (**Figure 2**). USFWS operated the trap in accordance with all
required permits and landowner specifications.

![](media/image2.jpeg){width="5.809027777777778in"
height="3.813888888888889in"}

[]{#__RefHeading___Toc93393613 .anchor}Figure 2. Peshastin Creek rotary
screw trap in operation during spring, 2004.

[]{#__RefHeading___Toc93392697 .anchor}*Trap Operation*

The smolt trap on Peshastin Creek operated from March 18 -- November 21,
2004. Trapping occurred 24 hours per day during a regular 5-day work
week (Sunday evening through Friday morning) until BPA funding began on
June 1. From June onward, all attempts were made to operate the trap on
a continuous seven day per week schedule, excluding holidays and extreme
discharge/debris events. A total of 208 days of complete sampling
occurred in 2004, with 7 days of incomplete sampling (due to extreme
discharge/debris events) and 34 days where the trap was pulled for
holidays or weekends (**Table 1**). During days when the trap was not
operational the daily catch was estimated using an average of the two
most recent pre and post catch days.

  -------------------------------- ----------------- ----------- ----------------- ---------
  []{#__RefHeading___Toc93393115                                                   
  .anchor}**Table 1.** Summary of                                                  
  trapping dates by strata for                                                     
  Peshastin Creek, 2004.                                                           

                                                                 Number of days     

  Strata                           Dates             Complete    Incomplete        Pulled

  Spring                           Mar 17 -- Jun 21  64          5                 27

  Summer                           Jun 22 -- Sep 9   78          0                 2

  Fall                             Sep 10 -- Nov 21  66          2                 5

  Total (Percent)                                    208 (83.5)  7 (2.8)           34 (13.7)
  -------------------------------- ----------------- ----------- ----------------- ---------

[]{#__RefHeading___Toc93392698 .anchor}*Biological Sampling*

The trap was checked a minimum of every 24 hours. All fish removed from
the live box were anesthetized with tricaine methanesulfonate (MS-222),
measured to fork length, weighed, examined for identifying marks or
injuries, and assigned to an age class. Spring Chinook and
steelhead/rainbow trout juveniles were identified to age class as either
sac-fry (visible yolk, not completely buttoned), fry (\<60mm, no visible
yolk and completely buttoned), parr (≥60mm with distinctive parr marks),
transitional smolt (≥60mm with silver sheen and visible parr marks), or
smolt (≥60mm with silver sheen and partial to mostly absent parr marks).
All fish mortalities were enumerated. Incidence of mortality in excess
of 1% of the daily catch was evaluated and appropriate trap
modifications were made.

Tissue samples for genetic analysis were taken from both spring Chinook
and steelhead/rainbow trout. A portion (1mm x 1mm) of the caudal or
ventral fin tips were taken and preserved in 100% ethanol. All samples
are housed at MCRFRO until such time that a molecular analysis can be
done to characterize each population.

![](media/image3.jpeg){width="3.3444444444444446in"
height="2.4881944444444444in"}

[]{#__RefHeading___Toc93393614 .anchor}Figure 3. Example of various life
stages of steelhead/rainbow trout captured in Peshastin Creek, 2004.

[]{#__RefHeading___Toc93392699 .anchor}*Age Determination*

Various life stages of steelhead/rainbow trout were captured during the
trapping season (**Figure 3**). To determine age class, length frequency
graphs were plotted monthly. Each significant change in length indicated
a probable change in age class (**Figure 4**). Additionally, scale
samples were taken from 135 steelhead/rainbow trout of various sizes
from throughout the year. The results of this scale analysis were used
to confirm the age determinations made by the length frequency graphs.
**Figure 5** represents the sizes of steelhead/rainbow trout as age-0,
age-1, and age-2 throughout the trapping season.

![](media/image4.wmf){width="4.6722222222222225in"
height="3.1840277777777777in"}

[]{#__RefHeading___Toc93393615 .anchor}Figure 4. Example of a
steelhead/rainbow trout monthly length frequency graph illustrating
significant changes in fish length to determine age class. These results
were confirmed with scale analysis.

![](media/image5.wmf){width="5.352083333333334in"
height="3.665277777777778in"}

[]{#__RefHeading___Toc93393616 .anchor}Figure 5. Steelhead/rainbow trout
age classes determined by monthly length frequency graphs and scale
analysis.

[]{#__RefHeading___Toc93392701 .anchor}*Production Estimates*

Mark-recapture techniques were utilized in an effort to estimate the
daily abundance and total emigrant populations of spring Chinook and
steelhead/rainbow trout (**Appendix C**). Throughout the study, fish
were collected over a 72-hour period and marked prior to release. A
variety of marking methods were utilized depending on species, size of
fish, and age class. Marked groups were released along a transect 1.6
miles upstream of the trap. A successful efficiency trial was indicated
by all marked fish captured within 48 hours. Marked fish captured after
48 hours were considered non-migratory and removed from that particular
trial.

All sub-yearling spring Chinook fry (\<60mm) captured in the spring were
marked through immersion in dye (6g Bismark Brown dye in 180L aerated
water for \~30 minutes) (Todd 1994). This type of marking was utilized
only for fish deemed too small to PIT-tag or fin clip without undue harm
or handling stress. Dye marking was minimized due to limitations in
duration of mark (visible for approximately 5 days) and the inability to
differentiate between subsequent release groups. All juvenile spring
Chinook greater than 65mm were marked with a PIT-tag, providing a
permanent, individually distinguishable identifier.

Limited numbers of steelhead were available for mark-recapture
efficiency trials. Steelhead and rainbow trout data were combined due to
the inability to differentiate the two by visual examination. Migratory
fish, however, were identified by the presence of certain
characteristics (i.e., silver body sheen, faded or absent parr marks,
scale slippage, black tips on the caudal fin, and elongate body form).
During 2004, steelhead/rainbow trout were marked using a fin clip of
either the pelvic (right/left) or the caudal (upper lobe/lower lobe)
fin. Using one of the four different fin clip locations, crews were able
to differentiate between release groups upon recapture.

Trap efficiency was calculated using a method employed by Murdoch et al.
(1999) to quantify emigrant spring Chinook on the Chiwawa River. The
method borrows from Rawson (1984) and is calculated as follows:

> N~i~ = C~i~M~i~ / \[1 + M~i~ -- R~i~ / M~i~R~i~\]

Var\[N~i~\] = C~i~(C~i~ + R~i~)M~i~(M~i~ -- R~i~) / R~i~^3^

SD = sqrt(Var\[N~i~\])

95% CI for Ni = Ni1.96(SD)

N~i~ = population estimate for time period i,

C~i~ = number of fish captured during time period i,

M~i~ = number of marked fish released and assumed to have passed by the
trap for

recapture during time period i,

R^i^ = number of fish recaptured during time period i.

The above methodology assumes that all released marked fish (M~i~) incur
no mortality, have the same probability of capture as non-marked fish
(C~i~), and all pass the trap during time period i.

It is possible that regression models can be utilized to provide
estimates of daily emigration. This occurs when trap efficiency trials
exhibit a significant relationship to an independent variable collected
throughout the trapping period (e.g., stream discharge, staff gage
height). The independent variable in the model can then generate
predicted trap efficiencies at times when a trial was not conducted.
Daily emigration indices can be quantified by expanding the number of
fish trapped by the corresponding trap efficiency.

This method is currently being used by WDFW in the Wenatchee Basin and
the USFWS in the Entiat Basin to provide daily abundance and annual
population estimates with associated confidence intervals.

At the end of the study season, trap efficiency estimates were
correlated with stream discharge and staff gage height in an attempt to
create a regression model for each species and age class. Models were
only used if a significant (p\<0.05) relationship existed between
discharge/staff height and trap efficiency, the correlation coefficient
was greater than 0.5 (+ or -), and the model as fitted explains greater
than 50% of the variability.

In 2004, no models were generated that met the above criteria. In
addition, independent variables such as discharge and staff gage height
for Peshastin Creek were inconsistent in availability. The limited
numbers of available migratory spring Chinook and steelhead/rainbow
trout (primarily in the spring and summer months), forced us to pool
mark-recapture trials over periods throughout the season. With these
limitations, we generated strata for Chinook representing spring (3/17
-- 6/21), summer (6/22 -- 9/9), and fall (9/10 -- 11/21) seasonal
emigration periods. Steelhead/rainbow trout seasonal strata were very
similar except for the break between summer and fall occurred on August
26^th^ for this species. Trap efficiency trials were then grouped into
one of three strata and used to generate population estimates.

[]{#__RefHeading___Toc93392702 .anchor}**RESULTS**

The 2004 Peshastin Creek trapping season began on March 18th and
extended through November 21st. A total of 8,955 individuals were
sampled. Spring Chinook and steelhead/rainbow trout represented 48.2%
(4,319) and 48.0% (4,302) of the total catch, respectively. The
remaining catch consisted of 112 bull trout, 58 coho salmon, 155
sculpin, and 9 adult fall-back salmonids (**Table 2** and **Figure 6**).

To aid in estimating total production of spring Chinook and
steelhead/rainbow trout (SRT), the 9-month trapping season was divided
into three strata: spring (March 18-June 21), summer (June 22-September
9), and fall (September 10-November 21). The following section details
the target catch per strata.

[]{#__RefHeading___Toc93393116 .anchor}Table 2. Peshastin Creek catch
summary for 3/18/04 to 11/21/04.

+--------------+------------+-------------+---------------+-----------+
| **SPECIES**  | **TOTAL**  | **TOTAL**   | **NUMBER      | *         |
|              |            |             | RELEASED FOR  | *NUMBER** |
|              | **         | **P         | EFFICIENCY**  |           |
|              | CAPTURED** | IT-TAGGED** |               | **REC     |
|              |            |             |               | APTURED** |
+--------------+------------+-------------+---------------+-----------+
| Spring       | 4,319      | 1,712       | 1,508         | 466       |
| Chinook      | (5,109)    |             |               |           |
+--------------+------------+-------------+---------------+-----------+
| Steel        | 4,302      | 0           | 195           | 42        |
| head/Rainbow | (4,564)    |             |               |           |
| Trout        |            |             |               |           |
+--------------+------------+-------------+---------------+-----------+
| Coho Salmon  | 58         | 2           | 0             | 0         |
+--------------+------------+-------------+---------------+-----------+
| Bull Trout   | 112        | 0           | 0             | 0         |
+--------------+------------+-------------+---------------+-----------+
| Sculpin spp. | 155        | 0           | 0             | 0         |
+--------------+------------+-------------+---------------+-----------+
| Hatchery     | 2          | 0           | 0             | 0         |
| Chinook Jack |            |             |               |           |
+--------------+------------+-------------+---------------+-----------+
| Adult        | 1          | 0           | 0             | 0         |
| Steelhead    |            |             |               |           |
+--------------+------------+-------------+---------------+-----------+
| Adult        | 6          | 0           | 0             | 0         |
| Chinook      |            |             |               |           |
+--------------+------------+-------------+---------------+-----------+
| **TOTALS**   | **8,955**  | **1,714**   | **1,703**     | **508**   |
+--------------+------------+-------------+---------------+-----------+

( ) = Estimated catch assuming continuous trapping

![](media/image6.wmf){width="5.999305555555556in"
height="4.090277777777778in"}

[]{#__RefHeading___Toc93393617 .anchor}Figure 6. Relative abundance of
fish captured in the Peshastin Creek smolt trap, 2004.

[]{#__RefHeading___Toc93392703 .anchor}*Spring Chinook*

For the trapping period of March 18 to November 21, a total of 4,319
spring Chinook were captured in Peshastin Creek. Of those, only one
yearling spring Chinook was captured (March 25), therefore no population
estimate for this life stage was generated. The remaining catch of 4,318
spring Chinook individuals were sub-yearling (**Appendix D**). This
sub-yearling Chinook migration exhibited a bi-modal timing distribution
(**Figure 7** and **Appendix A**). The first major emigration period
occurred in March and early April possibly as newly emerged fry were
being dispersed downstream as a result of high stream discharge events.
The second major emigration period occurred over a two day period in
mid-September as freshets and decreased water temperatures may have
triggered downstream movement. If the trap had operated every day
throughout the entire season we estimated a total capture of 5,109.

During the spring stratum the trap captured a total of 2,562 spring
Chinook. These sub-yearling Chinook were classified as fry. Peak fry
emigration occurred between March 18 and April 7, where 1,302 (30.1% of
total Chinook catch) sub-yearling Chinook fry were captured. Due to
their small size and the risk of undue harm or handling stress, fry
could not be PIT-tagged or fin-clipped for use in trap efficiency
trials. Instead, fry were dye-marked with a Bismark Brown solution. Four
separate dye-mark releases occurred during the spring stratum with a
total of 792 fry released. Thirty-two marked individuals were
recaptured, all within 48 hours of release, for an average efficiency of
4.0% for the stratum.

![](media/image7.wmf){width="5.127083333333333in"
height="3.7708333333333335in"}

[]{#__RefHeading___Toc93393618 .anchor}Figure 7. Peshastin Creek
estimated sub-yearling Chinook daily emigration rate vs. flow, 2004.

The total sub-yearling Chinook catch for the summer stratum was only 194
individuals (4.5% of total Chinook catch). Growth was rapid during the
summer stratum, with average lengths increasing from less than 60mm to
over 80mm (**Table 3, Figure 8**). Condition factor tended to decrease
by month throughout the trapping season. The number of PIT-tagged fish
increased from 10 to 123 from the spring to summer strata, respectively.
To supplement and increase the total number of PIT-tagged fish released
from Peshastin Creek, USFWS crews seine-netted and tagged 314 additional
sub-yearling Chinook. This tagging effort occurred at the trap site on
August 20. During the summer stratum, a total of 107 PIT-tagged fish
were released upstream of the trap for efficiency trials. Thirteen
marked individuals were recaptured, all within 48 hours of release, for
an average trap efficiency of 12.1% for the stratum.

![](media/image8.wmf){width="5.751388888888889in"
height="3.8409722222222222in"}

[]{#__RefHeading___Toc93393619 .anchor}Figure 8. Average fork lengths of
spring Chinook sub-yearlings in Peshastin Creek, 2004.

During the fall stratum, the trap captured a total of 2,353 spring
Chinook sub-yearlings. The peak of emigration occurred during a two-day
interval (September 11-12) where 1,418 individuals (32.8% of total
Chinook catch) were captured. A total of 1,505 fish were PIT-tagged
during this trapping period. During this fall stratum, 10 separate trap
efficiency trials were conducted, of which, 609 PIT-tagged fish were
released. A total of 421 individuals were recaptured, all within 48
hours of release, for an average trap efficiency of 69.1% for the
stratum.

[]{#__RefHeading___Toc93393117 .anchor}Table 3. Fork length, weight, and
condition factor for sub-yearling spring Chinook emigrating from
Peshastin Creek, 2004

  ----------- --- ------------ --- ---------- -------- --------- --- ---------- -------- --------- --- ------------- -------- ---------
                                                       * *                               * *                                  * *

  **Month**       **Total          **Fork                            **Weight                          **Condition            
                  Captured**       Length                            (g)**                             Factor**               
                                   (mm)**                                                                                     

                                   **Mean**   **SD**   ***N***       **Mean**   **SD**   ***N***       **Mean**      **SD**   ***N***

  March           886              37.9       1.1      *267*         \--        \--      \--           \--           \--      \--

  April           689              38.4       1.5      *397*         \--        \--      \--           \--           \--      \--

  May             49               43.7       5.4      *49*          \--        \--      \--           \--           \--      \--

  June            210              55.9       6.7      *151*         2.2        0.8      *151*         1.24          0.19     *151*

  July            74               71.7       9.2      *67*          4.8        1.9      *67*          1.23          0.11     *67*

  August          69               80.2       9.5      *63*          6.5        3.3      *63*          1.19          0.08     *63*

  September       2,072            89.3       6.9      *1362*        8.4        2.1      *1362*        1.16          0.07     *1362*

  October         168              91.0       6.6      *163*         8.6        1.8      *163*         1.13          0.06     *163*

  November        102              89.9       5.7      *100*         8.1        1.6      *100*         1.11          0.06     *100*

  TOTAL           4,319                                *** ***                           *** ***                              *** ***
  ----------- --- ------------ --- ---------- -------- --------- --- ---------- -------- --------- --- ------------- -------- ---------

[]{#__RefHeading___Toc93392704 .anchor}*Steelhead / Rainbow Trout*

Steelhead and rainbow trout data were combined because both forms of
*Oncorhynchus mykiss* are present in Peshastin Creek and
undistinguishable by visual examination during most of their freshwater
phase. Every effort was made, however, to determine the degree of
smoltification and their migrational propensity based upon the same
criteria used for spring Chinook salmon juveniles. Gauging the degree of
smoltification was critical in determining which fish were to be used in
trap efficiency trials. Only fish that exhibited smolt or pre-smolt
transitional characteristics were used in mark-recapture releases.

For the entire trapping period of March 18 to November 21, a total of
4,302 steelhead/rainbow trout were captured in Peshastin Creek (**Table
4** and **Appendix D**). If the trap had operated every day throughout
the entire season we estimated a total capture of 4,564. With such
complex and varied life history patterns, steelhead/rainbow trout did
not exhibit well-defined outmigration patterns or timing as did the
sub-yearling spring Chinook (**Figure 9** and **Appendix A**). Table 5
illustrates fork length, weight and condition factor by month for each
steelhead/rainbow trout age-class.

During the spring stratum, only 318 steelhead/rainbow trout were
captured. Emigrational steelhead and resident parr/fry represented 38.0%
and 62.0% of the catch, respectively. A total of 70 outmigrant steelhead
individuals were marked with an identifiable fin clip and released
upstream of the trap for efficiency trials. Ten marked individuals were
recaptured, all within 48 hours of release, for an average trap
efficiency of 14.3% for the stratum. Our permits do not currently allow
for tagging of steelhead, however, beginning in 2005 the Peshastin Creek
trapping operations will include the potential of PIT-tagging of *O.
mykiss* individuals. There were a total of 248 individuals large enough
(≥65mm) to PIT-tag in the summer stratum.

[]{#__RefHeading___Toc93393118 .anchor}Table 4. Steelhead/rainbow trout
trap counts by life stage and seasonal strata, 2004 (Fish of adequate
size for PIT-tagging by strata indicated)

  -------------- ----- ------- --- -------------- ------- ------- --- -------------- ------- -------
                                                                                              

  **Spring**                       **Summer**                         **Fall**               

  **3/17 -                         **6/22 -                           **9/10 -               
  6/21/04**                        9/9/04**                           11/21/04**             

  Sac Fry        1     0.3%        Sac Fry        0       0.0%        Sac Fry        4       0.2%

  Fry            63    19.8%       Fry            910     63.7%       Fry            57      2.2%

  Parr           133   41.8%       Parr           380     26.6%       Parr           1,765   69.0%

  Transitional   44    13.8%       Transitional   130     9.1%        Transitional   717     28.1%

  Smolt          77    24.2%       Smolt          8       0.6%        Smolt          13      0.5%

  Total          318               Total          1,428               Total          2,556   

                                                                                             

  PIT size       248   78.0%       PIT size       412     28.8%       PIT size       2,312   90.5%
  (≥65mm)                          (≥65mm)                            (≥65mm)                
  -------------- ----- ------- --- -------------- ------- ------- --- -------------- ------- -------

![](media/image9.wmf){width="5.959027777777778in"
height="4.385416666666667in"}

[]{#__RefHeading___Toc93393620 .anchor}Figure 9. Peshastin Creek
estimated juvenile steelhead/rainbow trout daily emigration rate vs.
flow, 2004.

A total of 1,428 steelhead/rainbow trout were captured during the summer
stratum. Newly emergent fry made up the majority (63.7%) of the catch
during this trapping period. The first fry was captured June 16. The
peak of fry movement occurred on August 25, with a total of 226 fry
captured. During this stratum, 124 steelhead/rainbow trout were marked
and released upstream of the trap for efficiency trials. Thirty-two
individuals were recaptured, all within 48 hours of release, for an
average trap efficiency of 25.8% for the stratum. There were a total of
412 steelhead/rainbow trout individuals large enough to PIT-tag during
this period.

The catch during the fall stratum totaled 2,556 steelhead/rainbow trout.
Non-migrational residents made up the majority (69.0%) of the catch for
this period. The peak of emigration for migratory fish occurred during a
two-day interval (September 11-12). A total of 379 smolts/pre-smolt
transitionals were captured during this two-day period. Since the
majority of migrational fish moved during a short window, crews were
unable to conduct any mark-recapture trials during this stratum. A total
of 2,312 steelhead/rainbow trout individuals were large enough to
PIT-tag during this trapping period.

  -------------------------------- --- ------------ --- ---------- ---------- --------- --- ---------- ---------- --------- --- ---------- ------------- ---------
  []{#__RefHeading___Toc93393119                                                                                                                         
  .anchor}**Table 5.** Fork                                                                                                                              
  length, weight, and condition                                                                                                                          
  factor by age-class for                                                                                                                                
  steelhead/rainbow trout                                                                                                                                
  juveniles emigrating from                                                                                                                              
  Peshastin Creek, 2004.                                                                                                                                 

                                                                              * *                                 * *                                    * *

                                                                   **Fork                              **Weight                            **Condition   
                                                                   Length                              (g)**                               Factor**      
                                                                   (mm)**                                                                                

  **Month**                            **Total          **Mean**   **SD**     ***N***       **Mean**   **SD**     ***N***       **Mean**   **SD**        ***N***
                                       Captured**                                                                                                        

                                                                                                                                                         

  ***Age 0 emigrants***                                                                                                                                  

                                                                                                                                                         

  March                                0                \--        \--        \--           \--        \--        \--           \--        \--           \--

  April                                0                \--        \--        \--           \--        \--        \--           \--        \--           \--

  May                                  0                \--        \--        \--           \--        \--        \--           \--        \--           \--

  June                                 163              28.5       1.4        *134*         \--        \--        \--           \--        \--           \--

  July                                 168              53.6       4.4        *14*          1.7        0.5        *14*          1.06       0.13          *14*

  August                               810              57.6       5.9        *511*         2.2        0.7        *511*         1.15       0.15          *511*

  September                            597              68.7       9.5        *308*         3.7        1.6        *308*         1.09       0.11          *308*

  October                              224              75.2       9.7        *152*         4.8        1.8        *152*         1.10       0.11          *152*

  November                             347              72.7       9.1        *341*         4.3        1.6        *341*         1.08       0.09          *341*

  **TOTAL**                            **2,309**                                                                                                         

                                                                                                                                                         

  ***Age 1 emigrants***                                                                                                                                  

                                                                                                                                                         

  March                                7                80.7       7.7        *6*           5.7        1.6        *6*           1.06       0.04          *6*

  April                                30               79.8       11.4       *30*          6.1        2.7        *30*          1.13       0.09          *30*

  May                                  55               98.6       17.8       *53*          12.5       6.9        *53*          1.17       0.09          *53*

  June                                 80               102.7      14.9       *78*          13.4       6.2        *78*          1.17       0.09          *78*

  July                                 40               139.8      27.0       *40*          35.4       18.6       *40*          1.17       0.08          *40*

  August                               204              140.5      21.9       *141*         31.7       15.6       *141*         1.06       0.07          *141*

  September                            910              140.6      19.1       *484*         29.7       13.1       *484*         1.01       0.07          *484*

  October                              363              129.4      16.9       *247*         22.8       9.5        *247*         1.00       0.06          *247*

  November                             189              130.7      19.5       *187*         23.6       11.6       *187*         0.99       0.06          *187*

  **TOTAL**                            **1,878**                                                                                                         

                                                                                                                                                         

  ***Age 2 emigrants***                                                                                                                                  

                                                                                                                                                         

  March                                11               138.7      17.6       *10*          30.4       11.0       *10*          1.11       0.22          *10*

  April                                65               166.0      24.6       *65*          51.3       22.3       *65*          1.07       0.09          *65*

  May                                  21               169.8      12.5       *21*          54.3       11.8       *21*          1.10       0.09          *21*

  June                                 4                171.8      6.4        *4*           56.3       11.2       *4*           1.10       0.14          *4*

  July                                 4                194.3      21.2       *4*           91.3       41.8       *4*           1.19       0.1           *4*

  August                               2                226.5      20.5       *2*           97.2       9.2        *2*           0.87       0.31          *2*

  September                            8                218.0      10.8       *5*           110.7      20.1       *5*           1.06       0.03          *5*

  October                              0                \--        \--        \--           \--        \--        \--           \--        \--           \--

  November                             0                \--        \--        \--           \--        \--        \--           \--        \--           \--

  **TOTAL**                            **115**                                                                                                           
  -------------------------------- --- ------------ --- ---------- ---------- --------- --- ---------- ---------- --------- --- ---------- ------------- ---------

[]{#__RefHeading___Toc93392705 .anchor}*Incidental Species*

A total of 112 bull trout (*Salvelinus confluentus*) were captured
throughout the trapping period. Juvenile bull trout (FL 39 -- 300 mm,
**Figure 10**) were captured primarily in the spring and fall, with the
majority captured from mid-September to November (**Appendix B**). All
adult bull trout (FL \>300mm) were captured in the fall, presumably as
post-spawning fluvials emigrating to the Wenatchee River. To minimize
handling stress and avoid any unintentional mortality, bull trout adults
were released directly from the trap. Fork lengths were estimated and
the fish were visually inspected for any injuries.

A total of 58 coho salmon juveniles were captured during the trapping
season. Eight newly emerged fry (FL 37 -- 52 mm) were captured between
April 1 and June 6. The remaining 50 individuals were sub-yearling fall
emigrants (FL 67 -- 110 mm) captured from September 13^th^ - November
19^th^ (**Appendix B**).

A total of 155 sculpin individuals were captured ranging in size from FL
17 -- 120 mm (**Figure 11**). There was no apparent pattern to
emigration; sculpin were common throughout the entire trapping season.
The movement of sculpin may be the result of a redistribution or
displacement of these stream residents.

The remaining catch of incidentals consisted of adult post-spawned
salmonids. One adult male steelhead was captured on May 21. Six adult
and 2 jack spring Chinook were captured between July 18 and September 2.
These eight fish were all tagged, indicating they were outplanted from
the Leavenworth National Fish Hatchery on July 12^th^ -- 14^th^, 2004.

![](media/image10.wmf){width="5.999305555555556in"
height="3.5930555555555554in"}

[]{#__RefHeading___Toc93393621 .anchor}Figure 10. Length frequency of
sub-adult bull trout captured at Peshastin smolt trap, 2004

![](media/image11.wmf){width="5.999305555555556in"
height="3.5930555555555554in"}

[]{#__RefHeading___Toc93393622 .anchor}Figure 11. Length frequency of
sculpin captured at Peshastin smolt trap, 2004.

[]{#__RefHeading___Toc93392709 .anchor}*Production Estimates*

Regression models can be used to estimate fish production when trap
efficiency trials exhibit a significant relationship to an independent
variable (e.g., stream discharge, gage height). In 2004, the
construction of daily emigration estimates using regression modeling was
not possible due to extended periods of limited fish availability for
trap efficiency trials and intermittent Peshastin Creek discharge data
throughout the season.

Estimates of population size for both sub-yearling Chinook and
steelhead/rainbow trout were conducted by combining daily catch into
seasonal strata (**Tables 6 and 7, Figure 12**). These strata were
identified and chosen by combining similar trap efficiencies, with
similarity in flow and catch by species size classes. An estimated
66,395 (±30%) spring Chinook juveniles and 16,082 (±25%)
steelhead/rainbow trout are estimated to have emigrated from Peshastin
Creek in 2004. Estimated daily emigration rates were generated for
Chinook (**Figure 7**) and steelhead/rainbow trout (**Figure 9**) using
catch as an estimated proportion of the population estimate by strata.

[]{#__RefHeading___Toc93393120 .anchor}Table 6. Peshastin Creek juvenile
Chinook population estimate and error by seasonal strata for 3/18/04 to
11/21/04.

> ![](media/image12.wmf){width="5.996527777777778in"
> height="1.5277777777777777in"}

[]{#__RefHeading___Toc93393121 .anchor}**Table 7.** Peshastin Creek
juvenile steelhead/rainbow trout (SRT) population and error estimate by
seasonal strata for 3/18/04 to 11/21/04.

> ![](media/image13.wmf){width="5.995138888888889in"
> height="1.5402777777777779in"}

![](media/image14.wmf){width="4.584027777777778in"
height="6.383333333333334in"}

[]{#__RefHeading___Toc93393623 .anchor}Figure 12. Peshastin Creek
sub-yearling spring Chinook and steelhead/rainbow trout catch (top) and
population estimate (bottom) with 95% CI by seasonal strata, 2004.

Estimates of population size for each age-class of steelhead/rainbow
trout were conducted by expanding the daily catch proportions of each
age into the population estimate for each stratum (**Figure 13**). In
2004, steelhead/rainbow trout age-classes 0, 1, and 2 represented 52%,
42%, and 6%, respectively of the population estimate. Age-2 dominated
early production and exited the system primarily in the spring, peaking
in migration by late-April. Age-1 steelhead/rainbow trout was present
throughout the trapping season and primarily dominated the summer catch
but did not peak in migration until mid-September, the latest of all
age-classes. Age-0 steelhead/rainbow trout began to appear as fry in
trap catches in mid-June and quickly dominated the catch composition by
late-summer/early fall and peak migration occurred in late-August. This
age-class went on to provide the greatest proportion of the
steelhead/rainbow trout population estimate.

![](media/image15.wmf){width="5.627083333333333in"
height="3.790277777777778in"}

[]{#__RefHeading___Toc93393624 .anchor}Figure 13. A graphical comparison
of the cumulative population estimate and temporal migration patterns by
age-class for Peshastin Creek steelhead/rainbow trout, 2004.

[]{#__RefHeading___Toc93392710 .anchor}*Data Entry*

All data for the 2004 Peshastin Creek Smolt Monitoring Program has been
validated, quality-controlled and is housed both on the common and
network computer drives at the USFWS Mid-Columbia River Fishery Resource
Office. All PIT files have been validated and submitted to Pacific
States Marine Fisheries Commission (PSMFC). Daily catch by species and
life stage can be found on the internet at:
[*http://www.fpc.org*](http://www.fpc.org/) or
*<http://www.cbr.washington.edu/mcpud/>.*

[]{#__RefHeading___Toc93392711 .anchor}*Trapping Frequency Evaluation*

As previously mentioned, 2004 was the first year of trapping operations
on Peshastin Creek. Efforts were made to operate the trap during as much
of the estimated migration season as possible to document periods of
fish movement. It was an aim of the project to evaluate trapping
frequency and in subsequent years limit operation during anticipated
times of little or no fish movement to reduce project costs. The 2004
catch and population estimates of Chinook and steelhead/rainbow trout
under the actual trapping schedule (5 day/wk spring and 7-day/wk
summer-fall) were compared against a variety of alternative schedules
(**Table 8**). The best alternative schedules included a 5-day/week
spring and summer with a 7-day/week fall or a 5-day/week spring with a
7-day/week fall (omit summer = greatest cost savings) schedule. Although
both schedules estimate approximately 98-100% of the actual 2004 Chinook
population estimate they underestimate the steelhead/rainbow trout
population by 29-36%. Due to the actual 5-day/week sampling in the
spring, no schedule comparisons were made to include a spring 7-day/week
schedule.

[]{#__RefHeading___Toc93393122 .anchor}Table 8. Alternative schedules
and the estimated population estimate for Chinook and steelhead/rainbow
trout compared against the actual 2004 trapping schedule/population
estimate.

![](media/image16.wmf){width="5.979861111111111in"
height="1.5347222222222223in"}

[]{#__RefHeading___Toc93392712 .anchor}**DISCUSSION**

Prior to 2004, little was known about the production or temporal
migration of juvenile salmonids from the Peshastin Subbasin. The
Peshastin Smolt Monitoring Program was successful in determining
relative abundance, production and migrational timing of Chinook and
steelhead within this system. Additionally, trapping was successful in
capturing and PIT tagging a substantial number of juvenile Chinook for
future analysis of survival and migrational timing through the Columbia
River hydro-corridor. The analysis of these marked Chinook will also
provide the USFWS and others a performance comparison of naturally
reared hatchery progeny against traditional hatchery programs at
Leavenworth NFH and elsewhere in the Upper Columbia. Overall trap
operation in 2004 provided data towards many "unknowns" that previously
existed and many obstacles were overcome. As in any first year study,
methodology was modified to provide greater site specific efficiency in
an effort to generate greater consistency during future operations.
However, challenges still exist and the remaining discussion will focus
on identifying each obstacle and recommendations for improvement.

The primary challenge throughout the spring and summer months of the
monitoring program was in capturing sufficient numbers of migratory fish
to conduct efficiency trials. Trap efficiency testing throughout the
spring stratum (March 18 -- June 21) was limited to the quantity of
species and life stages available. The vast majority of trap catch was
newly emerged Chinook fry most likely displaced by spring discharge
events. Consistent catch of fry appeared to occur coinciding with times
of increasing discharge (**Appendix C**) possibly indicating forced
rather than volitional migration. Additionally, small sized fry and parr
are highly susceptible to within live box predation when bull trout and
steelhead are present. These predators can quickly bias a recapture
event when few marked fish are recaptured. During the summer, error in
population estimates may have been the result of utilizing primarily
Chinook fry/parr and rainbow trout parr. These larger life stages were
less susceptible to within trap predation but may also have not been
truly migratory. Marked groups possibly resided upstream of the trap
following release and merely dispersed downstream seeking favorable
habitat and did not pass the trap until much later. This is indicated by
some pit-tagged release groups captured several weeks to a month
following release 1.6 miles upstream of the trap. Similarly, it is
suspected that the transitional pre-smolt steelhead may not be migratory
(although not validated with pit tags in 2004) and that this biased
recapture rates. In September, however, Chinook numbers increased
markedly associated with stream cooling and increased discharge
following an early fall rain event. During the month of September a
total of 2,415 Chinook were captured. The increased Chinook catch
exhibiting "true" migratory behavior gave us the opportunity to conduct
several quality trap efficiency trials. This resulted in Chinook
population error rates dropping substantially compared to spring/summer
estimates. In contrast, the increased fall catch of steelhead/rainbow
trout did not help in reducing error to a significant degree.

Lack of true migrational tendencies and loss of marked fish to predators
is thought to have caused some inconsistency in recapture rates and
subsequent error in population estimates. Recommendations to improve
future trap efficiency testing include: 1) release of Chinook and
steelhead/rainbow fry/parr within 300 meters of trap (ODFW
recommendation) to mimic within stream migration behavior of non-marked
population, 2) create a refuge for captured fry within live box to avoid
predation, 3) conduct upstream releases using differentially segregated
transitional/smolt groups and parr type groups of Chinook and steelhead
to determine migrational tendencies.

During 2004, salmonid production was most effectively quantified on a
seasonal basis. An effort has been made to identify periods of the year
where reduced trapping efforts could occur without significantly
impacting population estimates. This has proved difficult as our target
species (Chinook and steelhead) exhibited differing periods of
substantial contribution to productivity estimation. Based on
estimation, Chinook fry captured in the spring contributed \~93% of the
productivity, while steelhead in this same time accounted for only 13%
of the populations estimate. Conversely, during the summer, Chinook
production accounted for only 2% of the population estimate while
steelhead accounted for 36% of their production estimate. The fall
provided the highest capture and lowest population error rates for both
species. However, the estimated contribution for production contrasted
for each species with over 50% of steelhead versus only 5% of the
Chinook population estimate attributable to the fall stratum. In all
there was little evidence to eliminate a particular trapping window if
precise production of both species is desired. A better approach may be
to reduce the number of sample days during times of consistent
catch/discharge such as in the summer to reduce program effort and
expense.

Another issue of concern in the 2004 season was the relative lack of
yearling Chinook or age-1+ steelhead smolt observed exiting the system
during the spring. Only one yearling Chinook was captured (no population
estimate for this life stage generated) and as previously mentioned only
13% of the steelhead were estimated to have emigrated during the spring
of 2004 (mostly age-2). It seems most likely that the absence of
yearling Chinook and the extensive migration of age-0 steelhead/rainbow
trout in the summer/fall may indicate that Peshastin Creek does not
provide adequate over wintering habitat. However, it is also possible
that the March 18 start date in 2004 missed early migration or the five
day a week trapping schedule (until June) missed substantial emigration
pulses by these older age-classes.

Recommendations to improve future trap operation include: 1) Begin
trapping in early-March to document low over-winter emigration rates
prior to prevalence of spring conditions 2) Operate the trap seven days
a week during the spring and fall to capture all potential pulses in
emigration. 3) Conduct or acquire consistent and reliable monitoring of
stream characteristics to provide greater precision in which to relate
trap efficiency tests towards generating sound daily emigration
estimates.

[]{#__RefHeading___Toc93392713 .anchor}**REFERENCES**

Cappellini M.M.J. 1998. Peshastin Creek Washington -- 1997 Stream Survey
Report. US Fish and Wildlife Service Mid-Columbia River Fishery Resource
Office Report pp. 19.

Hillman, T.W. 2004. Monitoring strategy for the Upper Columbia Basin:
Draft report February 1, 2004. Prepared for Upper Columbia Regional
Technical Team, Wenatchee, Washington.

Mosey, T.R., and L.J. Murphy. 2000. Spring and summer chinook spawning
ground surveys on the Wenatchee River Basin, 2000.Chelan County Public
Utility District. Wenatchee, WA. pp. 33.

Mullan, J.W., Williams, K.R., Rhodus, G., Hillman, T.W., and J.D.
McIntyre. 1992. Production and habitat of salmonids in Mid-Columbia
River tributary streams. U.S. Fish and Wildlife Service, Monograph 1,
Leavenworth, Washington.

Murdoch, A., K. Petersen, A. Mikkelsen, and M. Tonseth. 1997. Freshwater
production and emigration of juvenile spring Chinook salmon form the
Chiwawa River in 1995. Report No. H97-02. Washington Department of Fish
and Wildlife, Olympia, WA.

Murdoch, A., K. Petersen, A. Mikkelsen, and M. Tonseth. 1998a.
Freshwater production and emigration of juvenile spring Chinook salmon
form the Chiwawa River in 1996. Report No. H98-01. Washington Department
of Fish and Wildlife, Olympia, WA.

Murdoch, A., K. Petersen, M. Tonseth, and T. Miller. 1998b. Freshwater
production and emigration of juvenile spring Chinook salmon form the
Chiwawa River in 1997. Report No. H98-05. Washington Department of Fish
and Wildlife, Olympia, WA.

Murdoch, A., K. Petersen, T. Miller, M. Tonseth, and T. Randolph. 1999.
Freshwater production and emigration of juvenile spring Chinook salmon
form the Chiwawa River in 1998. Report No. SS99-05. Washington
Department of Fish and Wildlife, Olympia, WA. pp. 57.

Rawson, K. 1984. An estimate of the size of a migrating population of
juvenile salmon using an index of trap efficiency obtained by dye
marking. Alaska Department of Fish and Game, Division of Fisheries and
Rehabilitation, Enhancement, and Development. Report Number 28. Juneau,
Alaska.

Rife, D.W. 1999. Lower Peshastin ecosystem restoration project.
Leavenworth Ranger District, Wenatchee National Forest, Fisheries
Biological Evaluation. August 18, 1999. pp.50.

Ringel, B. K. 1997. Analysis of fish populations in Icicle Creek, Trout
Creek, Jack Creek, Peshastin Creek, Ingalls Creek, and Negro Creek,
Washington 1994 and 1995. US Fish and Wildlife Service Mid-Columbia
River Fishery Resource Office Report pp. 49.

Todd, G. 1994. A lightweight, inclined-plane trap for sampling salmon
smolts in rivers. Alaska Fishery Research Bulletin. 1(2): 168-175.

Appendix A. Daily catch of subyearling spring Chinook (top graph) and
steelhead/rainbow (bottom graph) compared with Wenatchee River
discharge, 2004.

![](media/image17.wmf){width="5.999305555555556in"
height="6.847222222222222in"}

Appendix B. Daily catch of bull trout (top graph) and coho (bottom
graph) compared with Wenatchee River discharge, 2004

![](media/image18.wmf){width="5.999305555555556in"
height="6.847222222222222in"}

Appendix C. Peshastin Creek mark-recapture trials with trap efficiency
percentages relative to flow, 2004.

  ------------- ------------- ------------- -------------- ----------- ----------- ---------- ---------------
  **RELEASE**   **SPECIES**   **MARK**      **NUMBER**     **RECAP**   **RECAP**   **T.E.**   **WENATCHEE**

  **DATE**                    **TYPE~1~**   **RELEASED**   **DAY 1**   **DAY 2**   **(%)**    **RIVER
                                                                                              (CFS)^2^**

  3/24/2004     Chinook fry   DM            300            21          1           7.3        3570.0

  3/31/2004     Chinook fry   DM            223            8           1           4.0        3510.0

  4/7/2004      Chinook fry   DM            191            1           0           0.5        4690.0

  4/14/2004     Steelhead     UC            4              0           0           0.0        7380.0

  4/21/2004     Steelhead     LC            6              2           0           33.3       4370.0

  4/28/2004     Steelhead     RV            30             5           0           16.7       6260.0

  5/12/2004     Steelhead     LC            2              1           0           50.0       5840.0

  5/19/2004     Steelhead     RV            6              2           0           33.3       6890.0

  5/26/2004     Steelhead     LV            2              0           0           0.0        6720.0

  6/3/2004      Steelhead     UC            7              0           0           0.0        5370.0

  6/6/2004      Steelhead     LC            7              0           0           0.0        7330.0

  6/8/2004      Chinook fry   DM            78             0           0           0.0        5680.0

  6/13/2004     Steelhead     RV            4              0           0           0.0        4920.0

  6/16/2004     Steelhead     LV            2              0           0           0.0        4160.0

  6/30/2004     Chinook       PIT           3              0           0           0.0        3700.0
                smolts                                                                        

  6/30/2004     Steelhead     UC            1              0           0           0.0        3700.0

  7/3/2004      Chinook       PIT           2              0           0           0.0        3050.0
                smolts                                                                        

  7/3/2004      Steelhead     LC            2              0           0           0.0        3050.0

  7/5/2004      Chinook       PIT           1              0           0           0.0        2670.0
                smolts                                                                        

  7/6/2004      Steelhead     RV            2              0           0           0.0        2530.0

  7/7/2004      Chinook       PIT           1              0           0           0.0        2490.0
                smolts                                                                        

  7/7/2004      Steelhead     RV            1              0           0           0.0        2490.0

  7/9/2004      Chinook       PIT           24             0           0           0.0        2030.0
                smolts                                                                        

  7/10/2004     Chinook       PIT           4              0           0           0.0        1840.0
                smolts                                                                        

  7/13/2004     Chinook       PIT           1              0           0           0.0        1560.0
                smolts                                                                        

  7/13/2004     Steelhead     RV            1              0           0           0.0        1560.0

  7/19/2004     Chinook       PIT           3              0           0           0.0        1560.0
                smolts                                                                        

  7/19/2004     Steelhead     LV            2              0           0           0.0        1560.0

  7/21/2004     Chinook       PIT           3              0           0           0.0        1430.0
                smolts                                                                        

  7/21/2004     Steelhead     RV            3              0           0           0.0        1430.0

  7/24/2004     Steelhead     UC            4              1           0           25.0       1210.0

  7/25/2004     Chinook       PIT           1              0           0           0.0        1190.0
                smolts                                                                        

  7/25/2004     Steelhead     LC            2              0           0           0.0        1190.0

  7/26/2004     Chinook       PIT           1              0           0           0.0        1170.0
                smolts                                                                        

  7/29/2004     Steelhead     RV            1              0           0           0.0        1040.0

  7/31/2004     Steelhead     LV            4              1           0           25.0       1000.0

  8/2/2004      Steelhead     UC            2              0           0           0.0        907.0

  8/3/2004      Steelhead     LC            2              0           0           0.0        873.0

  8/4/2004      Steelhead     LC            1              0           0           0.0        842.0

  8/5/2004      Chinook       PIT           1              0           0           0.0        843.0
                smolts                                                                        

  8/7/2004      Steelhead     RV            7              1           0           14.3       894.0

  8/7/2004      Chinook       PIT           3              0           1           33.3       894.0
                smolts                                                                        

  8/8/2004      Chinook       PIT           4              0           0           0.0        923.0
                smolts                                                                        

  8/9/2004      Steelhead     LV            2              0           0           0.0        848.0

  8/12/2004     Chinook       PIT           1              0           0           0.0        766.0
                smolts                                                                        

  8/13/2004     Steelhead     UC            2              0           1           50.0       758.0

  8/16/2004     Chinook       PIT           1              0           0           0.0        739.0
                smolts                                                                        

  8/16/2004     Steelhead     LC            3              0           0           0.0        739.0

  8/20/2004     Steelhead     LV            3              0           0           0.0        725.0

  8/24/2004     Chinook       PIT           1              0           0           0.0        835.0
                smolts                                                                        

  8/25/2004     Steelhead     UC            22             5           1           27.3       1320.0

  8/25/2004     Chinook       PIT           31             7           2           29.0       1320.0
                smolts                                                                        

  8/26/2004     Steelhead     LC            14             4           3           50.0       1580.0

  8/26/2004     Chinook       PIT           9              0           0           0.0        1580.0
                smolts                                                                        

  8/27/2004     Steelhead     RV            7              0           0           0.0        1430.0

  **RELEASE**   **SPECIES**   **MARK**      **NUMBER**     **RECAP**   **RECAP**   **T.E.**   **WENATCHEE**

  **DATE**      ** **         **TYPE^1^**   **RELEASED**   **DAY 1**   **DAY 2**   **(%)**    **RIVER
                                                                                              (cfs)^2^**

  8/27/2004     Chinook       PIT           3              0           0           0.0        1430.0
                smolts                                                                        

  8/28/2004     Chinook       PIT           1              0           0           0.0        1220.0
                smolts                                                                        

  8/29/2004     Steelhead     LV            4              3           0           75.0       1100.0

  8/29/2004     Chinook       PIT           1              0           0           0.0        1100.0
                smolts                                                                        

  9/2/2004      Steelhead     UC            5              2           0           40.0       942.0

  9/3/2004      Steelhead     LC            8              2           0           25.0       976.0

  9/4/2004      Steelhead     LV            8              3           0           37.5       884.0

  9/4/2004      Chinook       PIT           4              2           0           50.0       884.0
                smolts                                                                        

  9/7/2004      Steelhead     UC            3              0           0           0.0        725.0

  9/7/2004      Chinook       PIT           2              0           1           50.0       725.0
                smolts                                                                        

  9/8/2004      Steelhead     LC            4              2           1           75.0       685.0

  9/8/2004      Chinook       PIT           1              0           0           0.0        685.0
                smolts                                                                        

  9/9/2004      Steelhead     RV            4              2           0           50.0       669.0

  9/9/2004      Chinook       PIT           2              1           0           50.0       669.0
                smolts                                                                        

  9/10/2004     Chinook       PIT           101            62          0           61.4       657.0
                smolts                                                                        

  9/11/2004     Chinook       PIT           93             58          0           62.4       780.0
                smolts                                                                        

  9/12/2004     Chinook       PIT           71             60          5           91.5       1120.0
                smolts                                                                        

  9/15/2004     Chinook       PIT           66             50          0           75.8       1810.0
                smolts                                                                        

  9/18/2004     Chinook       PIT           113            86          0           76.1       2560.0
                smolts                                                                        

  9/22/2004     Chinook       PIT           46             19          0           41.3       1570.0
                smolts                                                                        

  10/16/2004    Chinook       PIT           16             11          0           68.8       765.0
                smolts                                                                        

  10/16/2004    Steelhead     UC            1              0           0           0.0        765.0

  10/20/2004    Chinook       PIT           56             46          0           82.1       1260.0
                smolts                                                                        

  11/6/2004     Chinook       PIT           45             22          1           51.1       2260.0
                smolts                                                                        
  ------------- ------------- ------------- -------------- ----------- ----------- ---------- ---------------

**[^1^MARK TYPE]{.underline}:** DM = Bismark brown dye-marked; UC =
Upper caudal lobe fin-clip; LC = Lower caudal lobe fin-clip; LV = Left
ventral fin-clip;

RV = Right ventral fin-clip; PIT = Tag code and injection scar were used
as identifiers.

**[^2^Wenatchee River (CFS)]{.underline}:** Discharge taken from USGS
Gauging Site #12459000 Wenatchee River at Peshastin, Washington.
Available online

at: <http://waterdata.usgs.gov/wa/nwis/uv?12459000>.

> ;

![](media/image19.wmf){width="5.999305555555556in"
height="4.090277777777778in"}

Appendix D. Peshastin Creek subyearling Chinook catch and total number
PIT-tagged by seasonal strata. Peshastin Creek steelhead/rainbow trout
catch and total numbers that were of taggable size.

![](media/image20.wmf){width="6.0in" height="3.34375in"}

![](media/image21.wmf){width="6.25in" height="3.6458333333333335in"}