factors limiting columbia gorge chum salmon us fish and wildlife service columbia river fisheries...

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