Rainbow Trout Early Life Stag

(RTELSS): 2006 Project U

•Comparison of Redd Counts 2003-2006•Comparison of 2004-2006 Fry Catch•Integrated Stock Assessment Model for evaleffects of experimental flows and other GCD •Future Field Work, Analysis, and Documen
0

200400600800

10001200

2003 2004 2005 2006

Peak Redd Count

0

200400600800

10001200

Nov-01 Dec-01 Dec-31 Jan-30 Mar-01 Mar-31 Apr-30 May-30 Jun-29 Jul-29

Redd Count

02-0303-04Mar. 0505-06
Comparison of Fry Catches: 200

0

100200300400500600700800900

1000

1-Mar 31-Mar 30-Apr 30-May 29-Jun 29-Jul 28-Aug 27-Sep 27-Oc

Catch Per Trip

LSLLS

Low Steep

2006/2004 Ratio

Spawn 0.04

10-Jun 0.09

9-Jul 0.43 0.72

Compensation Ratio

10-Jun 2.21 ?

9-Jul 8.5 14.4
Evaluation of 2003-2005 Ja

Experimental Flows Compl

Compensatory Surviv

Egg Depositi

GCD Impact On Incubation Survival

Low

(06)

H

(0

(

ROD (control)Low (06/07)

ExperimentalModerate (03/04)
Egg 

# Em

Food Availability

Competition

Mortality rate

Growth rate

Habitat Use

Ontogenetic Habitat Shifts

Predation risk

Hydrograph

Integrated Juvenile Stock Assessm

Estimates Demographic Parameters th

Recruitment Rate to Adult Pop

Incubation 

mortality

Spawning site selection

Spawn timing

Intergravel temperature

# by age 

Low Angleshallower /slowerLower predationPoorer energetics

# by age # by age # by age 
Data for Integrated Model

• Redd counts (Jan – Jun, monthly, every 2 w• Redd hypsometry and intergravel temperatu

– Determines timing of hatch and predicts relative 

survival

• Abundance of fry in low and steep angle hab

(monthly)

• Length-frequency in low and steep angle ha

(monthly)

• Length-at-age (otoliths)
Integrated Model Estimate

• Spawn magnitude (# redds) and timing• Relative incubation survival rate (by year and season)• Survival rate of fry from emergence to ca. 8 months

• Annual or seasonal by habitat type

• Growth rate of fry• Habitat use and movement• Parameters of model are jointly estimated via maximum l

• Most likely estimates• Confidence limits (posterior distributions)• How MLE’s and confidence changes with increasing• Interaction of model parameters (confounding)
0 10 20 30 40 

0

200400600800

1000

Weeks from Dec. 1

Redds

Integrated Assessment Model Fit to 2004 

Redd Counts
Integrated Assessment Model Fit to 2004 

Catch By Trip and Habitat Type

20 25 30 35 40 45 

0

200400600800

Sample Week

Low Angle Catch

20 25 30 35 40 45 

0

200400600800

S l

W

k

Steep Angle Catch
0 10 20 30 

0

20406080

100120

Age (wks)

Length (mm)

Low AngleSteep AngleEstimated

Integrated Assessment Model Fit to 2004 

Length-at-Age Otolith Data
Integrated Assessment Model: Fit to 20

Low Angle Proportions-by-Leng

20 40 60 80 100 120

0.00.10.20.30.40.5

week= 18 n= 17

Low Angle

20 40 60 80 100 120

0.00.10.20.30.4

week= 23 n= 115

20 40 60 80 100 120

0.000.050.100.150.200.250.30

week= 28 n= 413

20 40 60 80 100 120

0.000.050.100.150.200.25

week= 31 n= 402

20 40 60 8

0.000.050.100.150.200.25

week= 36 n= 

20 40 60 8

0.000.050.100.150.20

week= 41 n= 

20 40 60 8

0.000.050.100.150.20

week= 49 n

20 40 60 8

0.00.10.20.30.40.5

week= 52 n

Length (mm)

Fish
Integrated Assessment Model: Fit to 20

Steep Angle Proportions-by-Leng

20 40 60 80 100 120

0.00.10.20.3

week= 18 n= 19

Steep Angle

20 40 60 80 100 120

0.000.050.100.150.200.250.30

week= 23 n= 24

20 40 60 80 100 120

0.000.050.100.150.20

week= 28 n= 179

20 40 60 80 100 120

0.000.050.100.15

week= 31 n= 573

20 40 60 8

0.000.050.100.15

week= 36 n= 

20 40 60 8

0.000.050.100.15

week= 41 n= 

20 40 60 8

0.000.020.040.060.080.100.120.14

week= 49 n= 

20 40 60 8

0.000.050.100.15

week= 52 n= 

Length (mm)

Fish
Utility of RTELSS Pro

1. Original intent

– Evaluation of 2003-2004 experimental flows on incubati

monitoring used to verify model-based estimate of treatm

2. Potential to evaluate processes driving recruitment to adult p

– Estimate annual and seasonal variation in age-0 mortalit

• High summertime daily fluctuations (10-18 kcfs)• Sept. min. flow change (10-18 kcfs to 5-10 kcfs)• 2004 flood• Sunday steady (2003) vs. unsteady (2004+) flows during s

– Evaluate compensatory growth and mortality response a

data: stocking in 06 not necessary, reducing incubation soffset by strong compensation-target later life stage to re

3. Long-Term monitoring of Lee’s Ferry trout population to lin

changes in the abundance of adult population

– Spawning intensity– Age-0 abundance– Annual and in-season incubation and Age-0 growth, surv

4. Useful conceptual model for juvenile native fish studie

approaches)
Future Project Activiti

• Complete FY06 proposed age-0 sampling (

FY06).

• Finalize integrated model and document mo

in primary literature (partially funded from 

• Review assessment at FY07 PEP:

– Assessment of 03-05 experimental flows (?)– As a long-term monitoring strategy for Lee’s Fe

model to evaluate alternate designs (not funded)

• Field assessment of 2007 age-0 cohort (not 
Glen Canyon 2003 + 2004

0

20406080

100120

0 30 60 90 120 150 180 210 2

Age from Hatch (days)

Forklength (mm)

20042003MLE

Compensatory Growth Response to L

Have good age-length at high density to compare with 

Fish size for July is bigger or same, but spawning is latgrowth. Need decent otolith sample size to evaluate.