The Estuary vs. the Watershed: Which Matters More for Anadromous Salmonids?

Blake Feist (NWFSC)

Richard Hicks (NWFSC)

Jonathan Hoekstra (NWFSC)

Charles Simenstad (UW Fisheries)

Question

Which is more “important” to Pacific salmon, estuarine or terrestrial habitat?

Both?

Objective

Compare the “condition” of various chinook and coho populations as a function of the “condition” of their associated estuarine and terrestrial habitats

Approach

Assess population “condition” at a local scale Annual population growth rates (Lambda)

Assess habitat “condition” at a landscape scale Estuarine: loss or gain of estuarine salt marsh

vegetation Terrestrial: loss or gain of various land cover and

land use types

Population Condition

Population Time Series

1978 – 2000 By age structure: adult, jack, sub-adult Chinook Coho Lambda

Mean yearly growth rate of a population If > 1, reproducing faster than dying If < 1, dying faster than reproducing

More on Lambda

Dennis-Holmes method based on Holmes 2001 and Dennis et al. 1991

“Markedly robust to severe sampling error” “Allows estimates of rates and risks of

population decline with a well established tool (diffusion approximations) by using age- or stage-specific censuses that are corrupted with sampling error”

Estuarine Habitat

Definition & Sources

Salt Marsh: percent habitat remaining on grassland areas bordering estuaries to landward extent of salt marsh vegetation National Wetland Inventory - estuarine vegetation classifications; Collins and Sheikh Report 2003 for NWFSC; Topographic & Hydrographic Sheets (t-sheets, h-sheets)

Intertidal: percent estuarine habitat remaining from ~EHW to ~ELW for any given delta Simenstad et al. 1982 (synthesis of several older sources); Simenstad unpubl; Bortleson et al. 1980; Good 2000 (unpubl. Estuarine Ecosystem Health Summary Report); Pacific States Marine Fisheries Commission 2003 (synthesis); Topographic & Hydrographic Sheets (t-sheets, h-sheets)

Why salt marsh & not intertidal? Intertidal describes area

of MLLW to MHHW, and accuracy of assessment was poor;

In many places true loss of vegetation is masked;

Don’t need all those damn h-sheets!

Comparison of Marsh & Intertidal Methods

Average % Loss Marsh = 70.8 ± 31.8 (n = 14) Average % Loss Intertidal = 50.5 ± 33.3 (n = 14) Relationship with methods?

r2 = 0.58

Everett Harbor

- Digital Ortho Quads (DOQ)

Everett Harbor

Current Conditions

- Digital Ortho Quads (DOQ)- National Wetland Inventory shapefiles- System: Estuarine- Subsystem: Intertidal- Class: Emergent, Scrub-shrub, Forested

Everett Harbor

Current Conditions

- Digital Ortho Quads (DOQ)- New shapefile delineating NWI classes

Everett Harbor

Historical Conditions

- Digital Ortho Quads (DOQ)- T-sheet georeferenced to DOQs

Everett Harbor

Historical Conditions

- T-sheet- Best available historical information- In this case, figure from Collins Report 2003 for NWFSC

Everett Harbor

Historical Conditions

- T-sheet- Best available historical information- New shapefile delineating historical conditions

Everett Harbor

Determining Percent Habitat Change

Percent Change = current area – historical area / historical area * 100 %

= 58.6 ac – 385.2 ac/385.2 ac* 100 %

~ 85 %

Terrestrial Habitat

Definition

Percent change in given habitat category over the catchment draining into a given estuary *

Based on Northwest Habitat Institute Wildlife-Habitat Types

* By 6-digit Hydrologic Unit Codes (HUC6) that stream flows through

Washington Northwest Habitat Institute Wildlife Types

Northwest Habitat Institute (NWHI)Agriculture, Pasture, & Mixed EnvironsAlpine Grasslands & ShrublandsBays & EstuariesCeanothus-Manzanita ShrublandsCoastal Dunes and BeachesCoastal Headlands and IsletsEastside (Interior) GrasslandsEastside (Interior) Mixed Conifer ForestEastside (Interior) Riparian WetlandsHerbaceous WetlandsLakes, Rivers, Ponds, and ReservoirsLodgepole Pine Forest and Woodlands

Marine NearshoreMontane Coniferous WetlandsMontane Mixed Conifer ForestPonderosa Pine & Eastside White Oak Forest & WoodlandsSouthwest Oregon Mixed Conifer-Hardwood ForestSubalpine ParklandUrban and Mixed EnvironsShrub-SteppeWestside GrasslandsWestside Lowland Conifer-Hardwood ForestWestside Oak & Dry Douglas-Fir Forest & WoodlandsWestside Riparian Wetlands

Historic and Current – Snohomish

HUC6 for Chinook PopulationsMontane Mixed Conifer ForestAgriculture, Pasture, & Mixed EnvironsLakes, Rivers, Ponds, & ReservoirsWestside Lowlands Conifer-Hardwood ForestUrban & Mixed EnvironsAlpine Grasslands & ShrublandsWestside Oak & Dry Douglas-Fir Forest & WoodlandsHerbaceous WetlandsBays & EstuariesWestside Riparian-WetlandsSubalpine Parkland

““Pre-Settlement”Pre-Settlement” ““Current”Current”

Historic and Current – Everett Harbor

Snohomish, Snoqualmie, Skykomish, Pilchuck, & Wallace Rivers

Agriculture, Pasture, & Mixed EnvironsAgriculture, Pasture, & Mixed Environs 65.9%

Urban & Mixed EnvironsUrban & Mixed Environs 33.0%33.0%

Montane Mixed Conifer ForestMontane Mixed Conifer Forest 29.5%

Subalpine ParklandSubalpine Parkland 2.4%

Montane Coniferous WetlandsMontane Coniferous Wetlands 1.0%

Bays & EstuariesBays & Estuaries 0.3%

Westside Oak & Dry Douglas-Fir Forest & WoodlandsWestside Oak & Dry Douglas-Fir Forest & Woodlands 0.0%

Lakes, Rivers, Ponds, & ReservoirsLakes, Rivers, Ponds, & Reservoirs -2.2%

Alpine Grasslands & ShrublandsAlpine Grasslands & Shrublands -5.4%

Westside Lowlands Conifer-Hardwood ForestWestside Lowlands Conifer-Hardwood Forest -22.1%

Herbaceous WetlandsHerbaceous Wetlands -49.8%

Westside Riparian-WetlandsWestside Riparian-Wetlands -53.4%

Results:Terrestrial Habitat

-15

-10

-5

0

5

10

15

Wests ideLowlandsConifer-

HardwoodFores t

Wests ideOak & Dry

Douglas-firFores t &

Woodlands

MontaneMixed

ConiferFores t

LodgepolePine Fores t

&Woodlands

SubalpineParklands

AlpineGrass lands

&Shrublands

Wests ideGrass lands

Agriculture,Pasture, &

MixedEnvirons

Urban &Mixed

Environs

Lakes,Rivers ,

Ponds, &Reservoirs

HerbaceousWetlands

Wests ideRiparian-Wetlands

MontaneConiferousWetlands

NWHI Wildlife Category

Me

an

Ch

an

ge

Change in Wildlife-Habitat Types

All Chinook Populations in Washington

Chinook & Coho Lambda vs. Change in Agriculture, Pasture, & Mixed Environs

R2 = 0.001

R2 = 0.0077

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0% 5% 10% 15% 20% 25% 30%

Agriculture, Pasture, & Mixed Environs Change

Mea

n P

rob

abili

ty L

amb

da

< 1

Mean Probability Chinook Lambda < 1Mean Probability Coho Lambda < 1Linear (Mean Probability Chinook Lambda < 1)Linear (Mean Probability Coho Lambda < 1)

Chinook and Coho Lambda vs. Change in Herbaceous Wetlands

R2 = 0.0129

R2 = 0.0371

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-50% -40% -30% -20% -10% 0% 10%

Herbaceous Wetlands Change

Mea

n P

rob

abili

ty L

amb

da

< 1

Mean Probability Chinook Lambda < 1Mean Probability Coho Lambda < 1Linear (Mean Probability Chinook Lambda < 1)Linear (Mean Probability Coho Lambda < 1)

Chinook and Coho Lambda vs. Change in Urban & Mixed Environs

R2 = 0.007

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0% 10% 20% 30% 40% 50% 60%

Urban & Mixed Environs Change

Mea

n P

rob

abili

ty L

amb

da

< 1

Mean Probability Chinook Lambda < 1

Mean Probability Coho Lambda < 1

Linear (Mean Probability Chinook Lambda< 1)

Chinook & Coho Lambda vs. Change in Westside Lowlands Conifer-Hardwood Forest

R2 = 0.0666

R2 = 9E-05

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-60% -50% -40% -30% -20% -10% 0% 10% 20% 30% 40% 50% 60%

Westside Lowlands Conifer-Hardwood Forest Change

Mea

n P

rob

abili

ty L

amb

da

< 1

Mean Probability Chinook Lambda < 1Mean Probability Coho Lambda < 1Linear (Mean Probability Chinook Lambda < 1)Linear (Mean Probability Coho Lambda < 1)

Chinook and Coho Lambda vs. Change in Westside Riparian Wetlands

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-40% -30% -20% -10% 0% 10% 20%

Westside Riparian Wetland Change

Mea

n P

rob

abili

ty L

amb

da

< 1

Mean Probability Chinook Lambda < 1

Mean Probability Coho Lambda < 1

Results: Estuarine Habitat

Chinook and Coho Lambda vs. Estuarine Habitat Loss

R2 = 0.0472

R2 = 0.0887

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Estuarine Habitat Loss

Mea

n P

rob

abili

ty L

amb

da

< 1

Mean Probability Chinook Lambda < 1Mean Probability Coho Lambda < 1Linear (Mean Probability Chinook Lambda < 1)Linear (Mean Probability Coho Lambda < 1)

Estuarine Habitat Loss and Lambda

R2 = 0.0438

0

1

2

3

4

5

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Estuarine Habitat Loss (%)

Lam

bd

a

Conclusions

Amount of remaining estuarine habitat seems important

Terrestrial habitat does not appear to be as important

Next Steps

Finish estuarine habitat loss assessment Finish assessing terrestrial habitat “condition”

at local scale Assess terrestrial habitat “condition” using

static categories Run appropriate statistical tests for

significance