Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl...
-
Upload
shannon-cullum -
Category
Documents
-
view
217 -
download
1
Transcript of Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl...
![Page 1: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/1.jpg)
Non-native fish monitoring activities in Glen and Grand Canyons during 2000
Dave Speas, AGFD
Carl Walters, UBC
Scott Rogers, AGFD
Bill Persons, AGFD
![Page 2: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/2.jpg)
Objectives: Grand Canyon
• Obtain population estimates of salmonids in Grand Canyon for use in assessing predation risks to humpback chub
• Evaluate strengths and weaknesses of longitudinal CPE/depletion/mark-recapture methods
![Page 3: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/3.jpg)
Dis
char
ge
(cfs
)
6000
10000
14000
18000
22000
26000
30000
34000
Mar Apr May Jun Jul Aug Sep Oct
Glen Canyon/Lees Ferry Grand Canyon
*December Glen Canyon trip not shown
2000 Hydrograph and Fishery Survey Trips
![Page 4: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/4.jpg)
![Page 5: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/5.jpg)
Population Estimate Approach
• Theory: CPE=q(N), or catch rate is result of catchability coefficient (q) times local fish population.
• Q derived through depletion electrofishing (multiple passes) and/or mark recapture experiments conducted at selected sites
• Calibration of CPE to local fish population via q method applied to index (single pass) electrofishing samples collected throughout entire canyon
• Resulting longitudinal curve and confidence bands were then integrated to obtain system-wide population estimates.
![Page 6: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/6.jpg)
A Typical Depletion/M-R Site
![Page 7: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/7.jpg)
Depletion Theory
A Typical RBT Depletion Sample
Example: No 98 fish (x intercept). Likelihood of No maximized given observed depletion data
0
100
200
300
400
500
40 60 80 100
Cumulative Catch
CP
E
0
1E-23
2E-23
3E-23
4E-23
5E-23
6E-23
90 95 100 105
Estimated # at start of experimentL
ikel
iho
od
![Page 8: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/8.jpg)
• 560 index electrofishing samples collected between SWCA and AGFD
• AGFD conducted 76 depletion and 20 mark/recapture experiments.
• Only 9 experiments were conducted in turbid water (information need).
• 877 salmonid stomach samples were collected (pending analysis)
Results
![Page 9: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/9.jpg)
Species-specific q Bias with Fish Density
Rainbow Trout
0
0.2
0.4
0.6
0.8
1
0 50 100 150
Est. # present
q
Brown Trout
0
0.2
0.4
0.6
0.8
1
0 10 20 30 40 50
Est. # present
q
![Page 10: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/10.jpg)
First pass CPE vs. Nearshore Fish Abundance
Rainbow Trout
0
1000
2000
3000
4000
0 50 100 150
Est. # present
CP
E
Brown Trout
0
200
400
600
800
1000
0 10 20 30 40 50
Est. # presentC
PE
![Page 11: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/11.jpg)
Longitudinal Distribution of Rainbow Trout in Grand Canyon, 2000
N 743,000 RBT
0
5000
10000
15000
20000
25000
30000
0 50 100 150 200 250
River Mile
# F
ish
/RM
Data Best Fit 95% CI
![Page 12: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/12.jpg)
Longitudinal Distribution of Brown Trout in Grand Canyon, 2000
N 57,000 BNT
0
1000
2000
3000
4000
5000
0 50 100 150 200 250River Mile
# Fi
sh/R
M
Best Fit Data 95% CI
![Page 13: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/13.jpg)
Caveat of Population Estimates from Electrofishing
![Page 14: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/14.jpg)
Summary and Conclusions I: Grand Canyon
• Longitudinal electrofishing surveys likely adequate for system wide salmonid population estimates, but variations in catchability need to be evaluated
• Minimum annual sample size for salmonids approximately 240 samples to detect 20% change in brown trout CPE over 5 years; 2 trips/yr likely depending on importance of seasonal variance in q
• Approximately 500,000-1,000,000 RBT in RM 18-225, occurring mostly in first 100 miles of river
• Approximately 20,000-100,000 BNT in RM 18-225, occurring mostly in upper-middle Granite Gorge
![Page 15: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/15.jpg)
Summary and Conclusions II: Grand Canyon
• Estimates are likely biased negatively by depletion method (M/R estimates approximately 1.5X greater), but extrapolation assuming uniform fish density in river channel likely biases estimate positively
• “Order-of-magnitude” estimates
• Information needs: variations in catchability with high brown trout density, turbidity, seasons; cross-sectional fish distribution; reconciliation of depletion and M/R estimates
![Page 16: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/16.jpg)
Glen Canyon
• Objective: Monitor rainbow trout relative density, relative condition, size distribution and proportional stock density
• Methods: Standardized electrofishing at 9 transects/trip, 4 trips (March, June, September, December)
![Page 17: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/17.jpg)
Status of Rainbow Trout Fishery in Glen Canyon
• CPE for all fish in 2000 (4.7 fish/minute) greater than 1999 (3.7 fish minute), but significance is marginal (P=0.0733)
• CPE for age 2+ fish in 2000 (2.89 fish/minute) unchanged from 1999
• Mean relative condition unchanged from 1999 (Kn=77.9), peaked during June (slightly earlier than long term average) (MO: 0.90)
• PSD (# >=406 mm/# >=305 mm) in 2000 (0.14) up slightly from 0.12 in 1999 (MO undetermined)
• Percent age-0 and age-1 among highest on record (35-40%)
![Page 18: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/18.jpg)
Length Frequencies of Rainbow Trout in Glen Canyon, 2000
Fre
qu
ency
March
0
23
46
69
92
115
138
161
184
50 100 150 200 250 300 350 400 450 500
June
50 100 150 200 250 300 350 400 450 500
September
0
23
46
69
92
115
138
161
184
50 100 150 200 250 300 350 400 450 500
December
50 100 150 200 250 300 350 400 450 500
![Page 19: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/19.jpg)
RBT Length Frequencies During April-June
1995-1999
Re
lati
ve
Fre
qu
en
cy
50100
150200
250300
350400
450 500
2000
Re
lati
ve
Fre
qu
en
cy
50100
150200
250300
350400
450 500
![Page 20: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/20.jpg)
Synthesis Model Predictions for Juvenile RBT
0
1
2
3
4
5
1994 1996 1998 2000
CP
E
020004000600080001000012000
CF
S
Pred <235 Obs <235 Flow Flux
![Page 21: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/21.jpg)
Summary and Conclusions: Glen Canyon
• Relative condition and PSD largely unchanged from 1999, seasonal variation normal
• High survival of YOY/juvenile RBT, though partially biased by electrofishing conditions (low, steady flows)
• High persistence of YOY trout during 31K, although gear saturation possible
![Page 22: Non-native fish monitoring activities in Glen and Grand Canyons during 2000 Dave Speas, AGFD Carl Walters, UBC Scott Rogers, AGFD Bill Persons, AGFD.](https://reader035.fdocuments.in/reader035/viewer/2022070307/551b8657550346d6338b596b/html5/thumbnails/22.jpg)
Number of brown trout captured in Glen Canyon during 1991-1998: 1
Number of brown trout captured in Glen Canyon during 1999-2000: 5