The Refugia Concept: Using Watershed Analysis to Prioritize Salmonid Habitat for Conservation and Restoration

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1 The Refugia Concept: Using Watershed Analysis to Prioritize Salmonid Habitat for Conservation and Restoration Christopher May Battelle & UW Cumulative Impacts of Urbanization

2 Landscape Alterations Loss of Natural Forest Cover Loss of Wetland Storage Landscape Fragmentation Soil Compaction Impervious Surfaces

3 It s the Hydrology, stupid!

4 Impacts of Urbanization Shift in Watershed Hydrology Reduced Evapo-Transpiration Impervious Surface Generated Runoff Reduced Infiltration & GW Recharge Non-Point Source (NPS) Pollution Stream Habitat Degradation Loss of Habitat Complexity & Quality Migration Barriers (culverts, dams, etc.) Watershed Urbanization (%TIA) There is no threshold!

5 Research Findings Conserve Native Forest Cover Protect Natural Soil Structure Wetland Conservation Minimize Impervious Surfaces Riparian Conservation Floodplain & CMZ Connectivity Corridor Continuity Mature, Coniferous-Dominated Forest Active Riparian Stewardship Habitat Enhancement & Restoration Project Background Refugia Study Area: Kitsap County (WRIA-15) East Jefferson County (WRIA-16 & 17) Based on earlier work in the greater Puget Sound lowland eco-region May et al., 1997 Frissell et al., 1998 WA-SRFB Sponsored Project

6 Jefferson & Kitsap Counties Refugia Project Goals Identify and map salmonid refugia using a multi-species approach; based on best available scientific information Initial, rapid assessment of watersheds as the first step in the overall recovery process Prioritize watersheds for protection, enhancement, and restoration

7 Salmonid Refugia The last best places or habitat areas currently supporting a high level of ecological integrity and Properly Functioning Conditions (PFC) Critical habitat supportive components of salmonid life history; represent a convergence of ecological conditions that create a patch of habitat supporting the life-history of one or more salmonid populations Historically diverse & productive habitat that is currently degraded or inaccessible Biological Hot-Spots of Diversity or Productivity Refugia Identification Assumptions Wild salmonids are keystone species in the Puget Sound ecosystems, and have co-evolved with the natural, forested watershed environment (glacial history) Cumulative impacts of human activities in the watersheds & nearshore areas have contributed to the current decline Ecosystem-based approach is likely the most effective recovery strategy

8 Project Approach Fish-Centered Assessment Multi-Species Approach (not ESA driven) Based on discussions with habitat & fisheries biologists ( local knowledge ) Analysis of available salmonid population & instream habitat data Field surveys of candidate watersheds & nearshore assessments Salmon Life-Cycle

9 Meta-Population Theory Dispersed and Diverse refugia are crucial for recolonization of wild salmonid populations & support natural meta-population dynamics Salmonid Refugia

10 Project Approach Fish-Centered Analysis Components Salmonid Distribution Mapping (LFA) Salmonid Diversity (# of species) Productivity Index (based on historic data) Habitat Quality Index (HQI) Spawning Habitat Rearing Habitat Habitat Complexity (LWD) Riparian Conditions Water Quality Data The Salmon Landscape

11 Project Approach Landscape-Centered Assessment Independent of Fish-Centered approach GIS-based Watershed Analysis Assessment using Remote-Sensor Data Watershed Scale Data (LULC) Riparian Scale Data (Buffers) Nearshore Scale Data (Shore-Zone) Based on relationship between watershed conditions and salmonid habitat quality Watershed Assessment A watershed assessment is any method or collection of methods that analyzes watershed processes & attributes Identify site-specific specific causes of degradation Identify where processes are disrupted or not functioning Prioritize protection and restoration actions

12 Conceptual View of Landscape Processes Landscape Processes and Land-Use affect habitat, water quality, hydrologic regime Watershed assessment identifies causes of impacts to habitat, infrastructure, or beneficial uses Land-Use Landscape Processes Habitat, water quality Biological Response Watershed Analysis Use of GIS technology is still evolving Remote-Sensing Data Land-Sat Aerial Photos Resolution? Data Quality? Data Sources?

13 Refugia GIS Model Data DNR Hydro-Layer County Land-Use Data Shore-Zone Data Digital Elevation Model (DEM) Urban Growth Areas (UGA) Wetlands (NWI) Refugia GIS Model GIS Map Layers Watershed Forest Cover Forest Stand-Age (?) %TIA Wetland Area Agriculture Hydrologic Potential Road Density Urban Development Floodplain Modification Riparian Riparian Riparian Corridor Extent Mass Wasting Potential Riparian Vegetation Quality (Type & Maturity) Salmon Migration Barriers Fragmentation (Stream Crossings)

14 Refugia GIS Model GIS Map Layers Instream Salmonid Diversity (# Native Species) Salmonid Productivity Index Instream habitat quality (HQI) Nearshore Modification (Bulkheads) Aquatic vegetation (Type & Extent) Docks, Floats, Piers, etc. Shoreline Riparian Extent & Quality Marinas (Fueling and Sanitary) Nested-Hierarchy of Analysis Watershed Sub-Watershed Stream-Riparian Corridor Stream Segment-Reach

15 Refugia GIS Model Model Process Weighted Nonlinear Summation Map layers have different measurements Examples: acres of wetlands, number of stream crossings Convert to Synthetic Scale (1-9) Nonlinear scale, minimize variance between classes with Jenk s Natural Breaks algorithm Weight each Map Layer Compile GIS Map Layers based on Model Refugia GIS Model Refugia Metric Relative Factor Importance Instream Salmonid diversity and productivity Instream habitat quality Riparian Corridor Salmon migration barriers Riparian fragmentation Riparian corridor extent/width Riparian vegetation quality Floodplain modification Mass wasting Watershed Forest cover Total impervious surface area Wetlands Agriculture Hydrologic potential Road density Urban development 1.022

16 Refugia Categories Focal Sub-Watersheds (FSW) Nodal-Riparian Corridors (NRC) Nearshore-Estuarine (NSE) Critical Contributing Areas (CCA) Based on natural (reference) landscape characteristics & current conditions Focal Sub-Watershed

17 Nodal-Riparian Corridor

18 Refugia Quality Classification A = High-Quality, PFC, Diverse & Productive Salmonid Populations B = Moderate Degradation but still retains some natural ecological function C = Lack Quantitative Habitat Data, Hatchery Influences, Artificial Barriers D = Non-Functional, Potential Refugia, Historically Important or Future Habitat

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20 Jefferson Forest Cover Kitsap Forest Cover

21 Jefferson %TIA Kitsap %TIA

22 Jefferson Riparian Conditions Kitsap Riparian Conditions

23 Nearshore Refugia Dabob Bay & Tarboo Creek Estuary

24 Thorndyke Creek Estuary Shine Creek Estuary Fulton Creek Estuary Little Goose Creek Estuary

25 Dosewallips River Estuary Duckabush River Estuary Hood Canal Nearshore

26 Refugia Project Results Prioritized listing of: Freshwater Refugia Nearshore Refugia Jefferson & Kitsap results are consistent consistent (level playing field for funding) GIS data available for other projects Wildlife Habitat Conservation Stormwater Management Development Planning

27 Research Needs Higher resolution LULC data Standardized GIS data More complete data on forest cover Stand-Age / Species Composition Better data on nearshore conditions Salmonid Utilization? Better data on salmonid productivity Questions & Comments???