Evaluating Fish Response to Habitat Restoration

1. Evaluating Fish Response to Habitat Restoration • Rationale for IMW approach • Extent of current efforts • Example of results from an IMW effort: • Fish Creek (Dr. Gordon Reeves) Overview of Intensively Monitored Watershed Research in the PNW

2. Issue Being Addressed • 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

3. 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

4. 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)

5. Scientific Support for the Concept • 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

6. WA IMW Lower Columbia Study Sites

7. Location of Some Current IMWs

8. 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?

9. Time to Detect Results WA IMW - Seabeck Creek – p=0.05

10. 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