Linking freshwater habitat to salmonid productivity Watershed Program 1 1. NW Fisheries Science...
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Transcript of Linking freshwater habitat to salmonid productivity Watershed Program 1 1. NW Fisheries Science...
Linking freshwater habitat to salmonid productivity
Watershed Program1
1. NW Fisheries Science Center 2725 Montlake Blvd. East, Seattle, WA 98112-2097
Capacity and Survival Capacity
Maximum number of fish at a life stage that can be produced under average annual environmental conditions
Total surface area Instream habitat Food supply Water quality
Survival The number of fish that live between life stages
Flows Sedimenation Pollutants Water quality
Spawner recruit relations and the effect of altered capacity or survival
Number of spawners
Nu
mb
er
of r
ecr
uits
Spawner recruit relations and the effect of altered capacity or survival
Number of spawners
Nu
mb
er
of r
ecr
uits Change in capacity
Spawner recruit relations and the effect of altered capacity or survival
Number of spawners
Nu
mb
er
of r
ecr
uits Change in survival
Carrying capacity – life stage distinctions for fall & spring
chinookSpawning Fry
(<45mm)
Parr(45-70mm)
Smolt
(freshwater)(>70mm)
Smolt
(estuary/
nearshore)(>70mm)
Total habitat area
+/-, +/- +/- +/-,+/- +/- +/-,+/-
Food supply +/- +/- +/- +/-,+/-
Total habitat area Spawning capacity example - North Fork Stillaguamish
Total habitat areaNorth Fork Stillaguamish chinook spawning capacity
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
-2.0 0.0 2.0 4.0 6.0 8.0 10.0
Range
Es
tim
ate
d #
of
sp
aw
nin
g c
hin
oo
k
Total Area (m2)
Spawn Riffle area (%)
Spawn Pool area (%)
Spawn Glide area (%)
Riffle area (%)
Pool area (%)
Glide area (%)
Redd Size (m2)
Adults per Redd
0
50
100
150
200
250
300
350
400
450
0 25,000 50,000 75,000 100,000 125,000 165,000 190,000
Chinook redd capacity
Freq
uenc
y of
est
imat
e
Estimate w data source #1
Estimate w data source #2
Total habitat areaNorth Fork Stillaguamish chinook spawning capacity
How do we compare capacities among life stages and habitat types ?
habitat area × average fish density
n
1ii
n
1jij dAN
Aij = is the sum of areas of all habitat units (j
=1 through n) of type I.
di = density of fish in habitat type i.
Habitat type preference -juvenile salmonid use
Classification of habitat types allows assessment of fish use patterns and expansion to larger aggregate units (e.g., watersheds)
tribu
tarie
sm
ains
tem
side
chan
nel
pond
s
estu
ary
chinook(0)
coho (0,+1)
steelhead (+1,+2)
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Juve
nile
sa
lmo
nid
/m2
How do we compare capacities among life stages and habitat types ?
Estimate (N) for each life stage in a given habitat
Multiply by density independent survival to smolt stage
habitat area × average fish density × survival to smolt
Smolt production potential can then be compared in terms of number of smolts ultimately produced.
Change in historic v. current coho smolt potential production
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
Skagit Stillaguamish
Co
ho
sm
olt
s Trib Loss
Mainstem Loss
Slough Loss
Pond Loss
Current
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
Skagit Stillaguamish
Co
ho
sm
olt
s Trib Loss
Mainstem Loss
Slough Loss
Pond Loss
Current
Range of current estimated v. measured coho smolt potential production
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
Stillaguamish(Pess
estimate)
Stillaguamish(Nelson
measuredCWT)
Skagit(Beechieestimate)
Skagit (Seilerscrewtrap)
Maximum
Mean
Minimum
Habitat preference – a change in freshwater rearing quality
There are 5.4 times as There are 5.4 times as many juvenile chinook many juvenile chinook salmon in natural wood salmon in natural wood banks as hydromodified banks as hydromodified banksbanks
Beamer et. al., 1998Beamer et. al., 1998
Expected change in juvenile salmonid abundance normalized to abundance in riprap (always = 1.0)
02468
101214161820
no c
over
boul
der
cobb
le
plan
ts
ripra
p
rubb
le
woo
d
w-
bank
root
sw
- deb
rispi
les
w-s
ingl
elo
gs w-
root
wad
s
Ele
ctiv
ity in
dex
Chinook (0+)
Summer rainbow (0+)
Summer coho parr
Winter rainbow (0+)
Beamer et. al., 1998Beamer et. al., 1998
From Beamer, From Beamer,
unpublished dataunpublished data
Habitat preference Chinook spawning
0
20
40
60
80
100
120
0 10 20 30 40
Pool spacing (Bankfull channel widths per pool)
Ch
ino
ok
sa
lmo
n r
ed
ds
pe
r k
m Forced pool-riffle
Plane-bed
Pool-riffle
Carrying capacity – Food supply and habitat capacity
Slaney and Northcote (1974) -Rainbow trout (0+) High prey density, less change in territory size
Giannico (2000) – Coho (0+) Food supply high – found in pools with little wood
cover Food supply low – found in pools with abundant wood
A small change in food supply can effect capacity by altering territory size and density of salmonids
Survival – life stage distinctions for fall & spring chinook
Egg to fry Fry to parr Parr to smolt Freshwater to estuarine/
nearshore
Temperature +/- +/- +/- +/-
Sedimentation +/- +/- +/- +/-
Food supply +/- +/- +/-
Flows +/- +/- +/- +/-
Water quality +/- (?) +/- (?) +/- (?) +/-
Peak flows and egg to migrant fry survival estimates - Skagit Chinook (1989-1996)
(Seiler & others 1998).
y = -4E-05x + 0.1745
R2 = 0.86
0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
0 1000 2000 3000 4000 5000
Annual maximum discharge (cms)
Est
imat
ed e
gg t
o m
igra
nt
fry
surv
ival
Peak flow recurrence interval and egg to migrant fry survival estimates - Skagit Chinook
(1989-1996)
egg to fry survival = 0.1284e-0.0446(flood recurrence interval)
R2 = 0.97
0%2%4%6%8%
10%12%14%16%18%
0 20 40 60 80
Flood reccurence interval (years)
Est
imat
ed e
gg t
o m
igra
nt
fry
surv
ival
Chinook recruits/spawner v. flood recurrence interval
0
1
2
3
4
5
6
7
0 50 100 150Flood recurrence interval (FRI) (years)
Chi
nook
rec
ruits
per
spa
wne
r
Cascade summer runLower Skagit fall runUpper Skagit summer runUpper Sauk spring-runLower Sauk summer-runSuiattle spring-runStillaguamish summer-run
A change in peak flows in the North Fork Stillaguamish
y = 180.82x - 331389
R2 = 0.29p < 0.001
0
200
400
600
800
1000
1200
1920 1940 1960 1980 2000
Year
An
nu
al m
axim
um
d
isch
arge
(cm
s)
A change in peak flows in the North Fork Stillaguamish
0
200
400
600
800
1000
1200
1 10 100
Recurrence interval (year)
An
nu
al m
axim
um
d
isch
arge
(cm
s)
1972 to 19951950 to 19711928 to 1949
Sensitivity of regression to changes in peak flows in the North Fork Stillaguamish
0%
2%
4%
6%
8%
10%
12%
14%
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
Recurrence interval (year)
Est
imat
ed e
gg to
fry
surv
ival
Survival for 1928 to 1949 flow conditions
Survival for 1950 to 1971 flow conditions
Survival for 1972 to 1995 flow conditions
Survival – Scour? Entombment? Oxygenation?
Downstream displacement?
0
0.2
0.4
0.6
0.8
1
0 10 20 30 40 50
Scour depth (cm)(could also be fines %, peak flows (cms))
Est
imat
ed e
gg
to
fry
su
rviv
al (
%)
Survival – peak flow caveats
Cannot break down survival by mechanism Keep mechanisms lumped
Egg to fry Entombment Scour Oxygenation
Fry to smolt Predation Downstream displacement
Different relationship in Columbia River Basin Rain-on-snow v. snow-dominated
Survival – Food supply
Slaney & Ward (1993) – Steelhead (1+,2+) Increase in phosphorus & nitrogen
Increase in smolt to adult survival (1+) - +62% Smolts – +30% to 130%
Being clear about assumptions and model choice
Do a sensitivity analysis where possible
Run multiple scenarios with different datasets
Many relationships are not universal Puget Sound v. Columbia Basin flow example
Keep it simple Do not assume cause and effect mechanism unless it is clear
Egg to outmigrating fry example
Keep numbers local where possible
Check model numbers against real fish numbers