salmon and steelhead conservation through adaptive ... · salmon caught in river annually in late...
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Salmon and Steelhead Conservationthrough adaptive management ofwater levels in the Jenner estuary
NOAA’S National Marine Fisheries Service
STEELHEAD COUNTS, ESTIMATES AND RETURNS
2000
800010000
15,000 15,000
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
50,000
55,000
60,000
1926 1936 1957 1972 1980 1990 2000
Fis
h
ESTIMATED
Wild
57,000
HATCHERY STEELHEAD
WILD HARVEST COUNTS
ESTIMATED
WILD
5,000
WILD STEELHEAD
0
5,000
10,000
15,000
20,000
1880's to 1920's 1930's to 1950's 1960's to 1970's 1970's to 1980 1980'S to 1990's
Nu
mb
er
of
Fis
h
ESTIMATED
20,000
8,000
TO
15,000
SALMON
CAUGHT
IN RIVER
ANNUALLY
IN LATE
1800'S
CHINOOK
AND
COHO
COMBINED
ESTIMATED 5,500
TO 7,500
MOSTLY
COHO
ESTIMATED 5,000
TO 6,000
ESTIMATED
15,000
Figure 1: Hypothetical escapements to the Russian River for all species of salmon. [Estimates based on conservative
expansion of U.S. Bureau of Fish and Fisheries (1888), Warm Springs Hatchery return numbers, anecdotal CDFG
reports, and CDFG Hatchery Returns.]
MOSTLY
DRY CREEK
COHO
ESTIMATED 500
TO 1,500
HATCHERY
SALMON
Warm Springs Hatchery COHO Returns
0 4
986
9
76
0
472
576
534
140
277
162
578
449
765
62
148
4 8 10
100
200
300
400
500
600
700
800
900
1000
1100
80/8
1
81/8
2
82/8
3
83/8
4
84/8
5
85/8
6
86/8
7
87/8
8
88/8
9
89/9
0
90/9
1
91/9
2
92/9
3
93/9
4
94/9
5
95/9
6
96/9
7
97/9
8
98/9
9
99/0
0
00/0
1
Water Year
Nu
mb
er
of
Fis
h R
etu
rned
Returns
Trend
Pacific Ocean
Conceptual Map of the Russian River watershed
Why the decline in salmon and steelhead populations?
Habitat Degradation
Sedimentation
Water Diversions
Channelization
Water Quality Impairment
Ocean Warming
Impaired estuary function
• Roads
• Agriculture
• Timber Harvest
• Rural and Urban Development
• Dams
• Flood Control Projects
• Climate Change
Causes
Estuary Dynamics and Management
Ocean Estuary
1. In Mediterranean climates, barrier beaches naturally close estuaries to
form lagoons
Estuary Dynamics and Management
Ocean Estuary
Sand
1. In Mediterranean climates, barrier beaches naturally close estuaries to
form lagoons
Estuary Dynamics and Management
Ocean Estuary
1. In Mediterranean climates, barrier beaches naturally close estuaries to
form lagoons
Flow
Estuary Dynamics and Management
2. When barrier beaches close, estuaries become freshwater lagoons or low
salinity brackish systems (oligohaline)
Freshwater
High Salinity
InflowLow Salinity
Flow
Estuary Dynamics and Management
2. When barrier beaches close, perched estuaries become primarily
freshwater lagoons…
High Salinity
Inflow
Low Salinity
Freshwater
Flow
Estuary Dynamics and Management
2. When barrier beaches close, perched estuaries become primarily
freshwater lagoons…
High SalinityLow Salinity
FreshwaterInflow
Flow
Estuary Dynamics and Management
3. Given moderate natural inflows, lagoons form highly productive rearing habitats for steelhead and salmon
In Scott Creek:
“While comprising less than 5% of the total stream area, the estuary may be the most important habitat for steelhead growth in this watershed“ (Hayes et al. 2008)
In Pescadero, San Gregorio, and Waddell Creeks:
“The high numbers and/or large sizes of steelhead reared in the lagoons during years of freshwater conversion demonstrate that these lagoons can potentially contribute the majority of steelhead smolts produced in these small coastal watersheds.” (Smith 1990)
River/Creek Estuary Type Area
(1000 m2)
Steelhead
Density (#/m2)
Reference
Scott Freshwater 8 0.25 Bond 2006
Mattole Freshwater 180 0.15 Zedonis 1992
Pescadero Freshwater/
Stratified
30 0.30 Smith 1990
San Gregorio Freshwater 43 0.25 Smith 1990
Waddell Freshwater 18 0.67 Smith 1990
Navarro* Stratified 377 0.024 Cannata 1998
Russian Managed as
open – saline
585 Very low SCWA 2006
Garcia* Open – largely
saline
200 Very low Higgins 1995
Albion Open – largely
saline
160 Very low Maahs and Cannata
1998
Smith Open – largely
saline
1,171 0.005-0.01 Quinones and
Mulligan 2005
Estuary Dynamics and Management
4. A disproportionately large number of adult steelhead returning from the ocean are reared in freshwater lagoons.
In Scott Creek:
“Estuary reared steelhead show a large survival advantage and comprise 85% of the returning adult population, despite being between 8% and 48% of the juvenile population” (Bond 2006)
“The majority of fish reaching typical steelhead ocean entry sizes were estuary-lagoon reared, which indicates a disproportionate contribution of this habitat type to survival of Scott Creek steelhead.” (Hayes et al. 2008)
Recovery of Species
Restoration of Viable Populations
Viable populations:Good AbundanceGood population growth rateGood population spatial structurehealthy genetic & ecological diversity