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This presentation by Peter Hummel, ASLA, explores the nearshore ecosystem and its essential roles in coastal landscapes. It covers the interplay between human activities and ecological necessities, highlighting examples of nearshore projects. Key topics include sediment supply, habitat modifications, and the needs of juvenile salmonids. The discussion emphasizes the importance of blending restoration and enhancement strategies to maintain ecological functions while accommodating human uses. Questions and insights will foster discussion about future nearshore management practices.
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Living with the Nearshore: Beaches, Seawalls and What lies in Between Presented to University of Washington Department of Landscape Architecture Prepared by Peter Hummel, ASLA, Anchor Environmental May 13, 2005
Presentation Overview • Understanding the Nearshore • Blending Human Uses with Habitat • Nearshore Project Examples • Summary-Key Questions • Questions and Discussion
Understanding the Nearshore • What is the Nearshore • Nearshore Physical Processes • Ecological Functions of the Nearshore • Location in the Landscape • Habitat Modifications and Effects
Understanding the Nearshore Source: King County Department of Natural Resources
Nearshore Physical Processes Source: http://meted.ucar.edu/marine/ripcurrents/NSF/print.htm
Understanding Waves Source: http://meted.ucar.edu/marine/ripcurrents/NSF/print.htm
Sediment Supply • Drift cell based • Sediment supply potential • none ● high • low ● exceptional • moderate • Sediment supply connectivity • none ● moderate • low ● high
Essential Functions of Nearshorefor Juvenile Salmon • Food Production • Predator Refuge • Physiological Refuge • High-energy Refuge • Migratory Corridor
Notes:* This attribute only applied for shoreline segments identified as having exceptional or high sediment supply potential Yellow text Habitat parameters that receive a weighting factor
Nearshore Habitat Modifications & Effects: Conceptual Model Impacts Controlling Factors HabitatStructures HabitatProcesses Juvenile Salmonid Needs • Shoreline modifications • Pollution • Depth • Substrate • Slope • Light • Salinity • Vegetation • Vegetation density • Vegetation biomass • Diversity • Patch size and shape • Landscape position • Production • Shading • Sediment flux • Nutrient flux • Food production • Predator Refuge • Physiological Refuge • Energy Refuge • Migratory Corridor Source: Williams and Thom (2001)
Blending Human Uses with Habitat • Habitat Perspective: • How Good and How Altered • Human Use Perspective: • Existing & Proposed Uses and Facilities • Space and Property Lines • Cost/Benefits • Feasibility: • Restoration Versus Enhancement of Specific Ecological Functions
Restoration Prioritization Site Features Habitat Opportunities Habitat Constraints Site Location Habitat Improvement Potential Landscape Considerations No Action- Conserve Site Park Use Constraints Park Use Opportunities Combined Improvement Potential Restoration Feasibility • Reach Restoration Priority • No Action- Conserve Site • High Priority • Medium Priority • Low Priority • No Action- Use Conflict Source: Seattle Parks Shoreline Inventory and Habitat Assessment
Restoration Example: Martha Washington Park Existing Conditions
Restoration Example: Seahurst Park • Microcosm of Puget Sound Shoreline Habitats • Habitat Forming Processes Restoration Opportunity • Shoreline and Park Master Plan
Shoreline Restoration Goals • Preserve existing functioning nearshore habitats • Remove existing shoreline protection structures • Model restored beach slopes and substrates after natural on-site and adjacent reference beaches • Replenish gravel and sand lost to bulkhead induced erosion • Restore and protect the natural hillside sediment delivery paths
Lower Beach Rock Removal Mid Project After Mid Project Before
Beach Monitoring Initial Results Beach Profiles: 1973, 2004, 2005 Beach Sediment Sample Source: Johannessen, Coastal Geologic Services, 2005
Required Biological Monitoring Pre-Project Initial Results Eelgrass Survey Forage Fish Monitoring
Desirable Biological Pre-Project Monitoring Initial Results Location Comparisons Epibenthic On-Site Sampling Source: Toft, UW Wetland Ecosystem Team, 2005
Restoration Example: Squalicum Waterway Existing Conditions