Embed Size (px)
Citation preview
Factors Limiting Columbia Gorge Chum Salmon
US Fish and Wildlife ServiceColumbia River Fisheries Program Office
February 2002
• Chum had widest distribution of all Pacific salmon (~ 50% of annual biomass)
• Historic chum run in the early 1900s was ~1,400,000
• By 1928, run size was ~700,000 adults
• In 1950s the run size had dropped to ~10,000
• Since 1959, the population has been relatively stable with the annual minimum run size ranging from 300 to 5,700
Brief History
Adults
Hamilton Springs Weir Hardy Creek Weir
Spawning Ground Surveys Radio Telemetry
Date
Live count and corresponding peak daily flow, 1998-2001
0
50
100
150
200
250
300
350
400
450
500
Pe
ak
Co
un
t
0
5
10
15
20
25
30
35
40
45
50
Ele
vati
on
HC Live Count
HS Live Count
Peak Elevation
-3000
-2000
-1000
0
1000
2000
3000
4000
11/20 11/25 11/30 12/5 12/10 12/15 12/20 12/25 12/30
Dis
tan
ce (
m)
fro
m R
ad
io T
ag
Sit
e
Male
Female
Typical male and female movement
[50 m]
[3600 m]
[2000 m]
Date
Hamilton Springs
Hardy Creek
Ives IslandPierce Island
3000m2
2000m2
Juveniles
D-Frame Fyke Net Floating Fyke Net
Bismark Brown Photonic Dye Injection
Smolt emigration timing, 1997-2001
0
10
20
30
40
50
60
70
80
90
100
2/4 2/24 3/15 4/4 4/24 5/14 6/3 6/23
Date
Cu
mu
lati
ve P
erc
en
t
1997
1998
1999
2000
2001
2000
2001*
*
* Indicates Hamilton Springs data
1998 1999 2000 2001
Smolt abundance estimates in Hardy Creek and Hamilton Springs, 1998- 2001
0
20000
40000
60000
80000
100000
120000
140000
160000
180000
200000 HC
HS
55*
203*
48* 50*
12*
26*
* Indicates number of females in stream previous spawning season
Redd Caps
Habitat
Piezometers
