Evaluating Fish Response to Habitat Restoration Overview of Intensively Monitored Watershed

Research in the PNW

•Rationale for IMW approach•Extent of current efforts•Example of results from an IMW effort:

Fish Creek (Dr. Gordon Reeves)

• Many millions of $$$ have been spent in the PNW on salmon habitat restoration and protection

• Expectation that these actions will increase the productivity of fish populations

• Little direct evidence that these efforts have been effective• This knowledge is essential to:

– Effectively allocate restoration resources– Estimate the contribution to recovery of tributary habitat actions

Issue Being Addressed

Relationship between Freshwater Habitat

Condition and Salmon Productivity • Relationship is difficult to quantify • Variability in fish populations due to factors other than

freshwater habitat • Year-to-year variation in climate• Data on fish populations is lacking• Each species requires a suite of habitat types to

complete freshwater life rearing• The relative importance of each type of habitat varies

spatially and temporally

IMW Concept

• IMW approach based on the premise that watershed-scale experiments are an effective means to study salmon-habitat relationships

• Quantification of salmon response to habitat actions requires assessment at appropriate scales of space and time

– Experimental unit large enough to include all the habitats required for freshwater rearing

– Unit small enough so a high proportion of the habitat can be treated– Evaluation over sufficient time to be able to detect a response

• Expense requires that IMWs occur at relatively few locations• Various designs have been employed

– Long-term, paired-watershed experiments– BACI design– Single watershed – quantify ecological processes

• Most IMWs collect data on a basic set of parameters– Habitat (physical, chemical)– Fish populations (fry, parr, smolts, adults)

• Number of regional science panels have recommended this type of approach – NOAA Fisheries SRSP - grand experiments – ISAB/ISRP- intensive watershed monitoring advocated in numerous

reports– Monitoring design for WA forest practices identified IMW as a

component of effectiveness monitoring – WA ISP has reviewed the WA IMW program twice and concurred with

the approach

Scientific Support for the Concept

0 1 2 3 Kilometers

N

Mill Cr

Abernathy Cr

Germany Cr

WA IMW Lower Columbia Study Sites

Lower Columbia

GermanyAbernathy

Mill

coho steelheadChinook

forestry - private and stateagriculture in lower valleys

206 km2

(57, 73, 75 km2)

flow basalt w/ interbedded sandstone

160 cm/yr

Lemhi R

Lower SF John Day R

Upper MF John Day R

Lower Entiat R

Libby, Gold and Beaver Cks - Methow R.

Nason, Peshastin and Chiwawa Cks - Wenatchee R

East/West Twin, Deep Cks

Germany, Mill, Abernathy Cks

Skagit R Estuary

Little Anderson,Seabeck, Stavis,Big Beef Cks

Touchet R

Scappoose R

EF Lobster CkCummins,Tenmile Cks

Hinkle Ck

WF Smith R

NF Nehalem R

Winchester Ck

Mill Ck – Siletz RMill Ck – Yaquina R

Cascade Ck

EF Trask R

Hollow Tree Ck – SF Eel R

Yakima tribs

Location of Some Current IMWs

Issues Raised about IMWs

• Time required to detect a response– Long studies traditionally required owing to interannual variation

in salmon abundance and climate– Difficult to obtain consistent funding for long-term studies

• Transferability of results– Are results of an IMW study only applicable to the watersheds

where the studies were conducted?

Time to Detect Results

5 10 15 20 25Years

0

10

20

30

40

50

60

70%

of m

ea

n p

rod

uctio

n

BACI w/ covariatesBACIBefore-After

WA IMW - Seabeck Creek – p=0.05

Transferability of Results• Large number of watershed-scale manipulative studies established in last 5 years

– Increased sample size (comparable questions and data collection methods)– Comparison of results will provide indication of generality

• Expect like responses from watersheds with comparable conditions– Classification of watersheds across the region being conducted by NOAA-Fisheries

• IMWs provide understanding of processes governing relationships between habitat and fish population response

– Many of these relationships will be broadly applicable– Greatly improve our ability to parameterize predictive models currently in use

• IMWs will help to identify habitat parameters most relevant to fish – Useful in gauging watershed condition regionally– Provides direct linkage between the IMW efforts and status and trend monitoring

being conducted at broader scale