ESTUARINE WETLAND Coho salmon life history/estuarine residence - PDF document

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Outline • Orientation/Coos estuary alterations ESTUARINE WETLAND • Coho salmon life history/estuarine residence RESTORATION • Restoration Approach Lessons Learned at the • Demonstration projects: South Slough National Estuarine Research Reserve Coos Bay, OR Kunz Marsh: subsidence adjustment Dalton Creek Marsh: tidal channel restoration Craig Cornu Stewardship Coordinator South Slough NERR Anderson Creek Marsh: non-tidal channel restoration Winchester Creek : large wood South Slough WA National Estuarine Research Reserve OR North Bend Portland Charleston CA Coos Bay Coos Bay Eugene Oregon South Slough NERR South Slough Watershed ~80% Loss of Earth Levees Estuarine Wetlands (Scranton 2002) Earth Levees Constructed Ditches Constructed Ditches Coos Bay 1900 Coos Bay 1900 Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 1

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation South Slough Coho Salmon Watershed South Slough Watershed South Slough NERR Admin. Boundary Winchester Creek Fry/Age 0 Smolts/Age 1 Movement Migration (March-October) (Feb-June) Lower estuary: 5-8 days Upper estuary Upper estuary: rearing: 3 weeks 4-8 months Spawning habitat Source: Miller and Sadro 2003 and Source: Miller and Sadro 2003 and Koehler and Miller 2003 (report) Koehler and Miller 2003 (report) mark-recapture/acoustic tagging mark-recapture/acoustic tagging South Slough South Slough Watershed Watershed Winchester Stream-Estuary Tidelands Ecotone Restoration Project Area Rearing/Foraging Habitats: • Main channel • Marsh channels Winter salinity: 0.0 ppt. • Marsh plain Summer salinity: • Tributary streams ~20 ppt. • Beaver ponds Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 2

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Winchester Creek Kunz Marsh Kunz Marsh Dalton Creek Marsh (1996) (1998) Fredrickson Marsh Dalton Creek (1998) Marsh Anderson Creek (2002/2003) Cox Canyon Marsh (1996) Fredrickson Marsh Winchester Creek (2004) Cox Canyon Marsh 1991 Aerial Photo Winchester Tidelands Restoration Project Approach Earth Levees Constructed Ditches LWD Removed • Estuarine Wetland Advisory group • Informal Information Gaps Assessment • Demonstration projects • Advisory Group/Coastal Decision Maker and Restoration Practitioner Workshops • Publications/Outreach Documents 1991 Aerial Photo Restoration Approach � Use Reserve as outdoor lab to test innovative restoration techniques � Restore to pre-contact conditions as represented by relatively undisturbed reference sites in Reserve � Self design methods used (manipulate key site attributes and allow natural processes to do the rest of the work) � Demonstrate “accessible” restoration methods- methods within reach of most restoration practitioners (e.g., watershed associations) Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 3

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Restoration Approach (cont.) Restoration Approach (cont.) � � Approach is largely focused on “single family”: Projects are adaptive on multiple levels: salmonidae a.k.a. salmonids � Take corrective actions at sites based on project monitoring information � Apply lessons learned from each project to future projects in Reserve � Projects contribute to broader regional/national efforts to improve the practice of habitat restoration by testing and evaluating experimental or innovative methods Kunz Marsh Kunz Marsh Restoration Project 1991 Aerial Photo Kunz Earth levee Marsh Kunz Marsh Ditches Major Issues: � Subsided marsh surface (0.80 m) � Little or no salmonid access to marsh plain/edge � Tidal channel network reduced to linear ditches � Little or no connection with rest of estuary (nutrient exchange) Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 4

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Kunz Marsh Kunz Marsh Profile 3.3 Kunz Marsh Dike Danger Point Marsh Profile 2.8 Elevation (m NAVD) Danger Point Marsh Surface 2.3 Subsided Kunz Marsh Surface 1.8 1.3 0.8 0 10 20 30 40 50 60 70 80 90 Distance Along Transect (m) Kunz High Kunz Mid Kunz Low 1 Kunz Low 2 Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 5

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation High- 2.2 m Mid- 1.8 m Low 1- 1.5 m Low 2- 1.5 m Elevations tied to NAVD ‘88 Kunz Mid Marsh Cell- 1996 Emergent Vegetation Kunz Mid Marsh Cell- 1999 Kunz Marsh 2003 Kunz Mid Marsh Cell- 2002 Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 6

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Tidal Channels Flotsam Cove Low Marsh (Reference Site) Winchester Creek Danger Point High Marsh (Reference Site) Kunz Kunz Low 2 Marsh Kunz Low 1 Kunz Mid Developing Tidal Channels Kunz High Tom’s Creek High Marsh Figure 3 50 m (Reference Site) N Number Evolution of Tidal of Tidal Channels: Channels: • 23 in 2005 • Channels not evolving at high • 7 in 1999 elevation • More • 71% channels developing developing at lower order lower channels elevations Evolution of Tidal Channels: Elevation isn’t everything • Channels dimensions ~increasing in Kunz Mid and Kunz Low 2 • Channel dimensions decreasing in Kunz Mid Kunz Low 1 Kunz Low 1 Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 7

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Lessons Learned Other Monitoring 1. Manipulating the marsh surface to mid � Sediment dynamics using feldspar marsh elevations provided conditions horizon markers, surface elevation favorable for relatively rapid emergent tables (SETs) marsh vegetation colonization while allowing channel development over � Fish use of research cells using time. winged fyke nets 2. Manipulating the marsh surface to low � Invertebrate community abundance marsh elevations resulted in slower vegetation community development but and species composition using allowed channel development and sediment cores and fallout traps benefited more fish in the early stages of marsh recovery. Lessons Learned 3. Manipulating the marsh surface to high marsh elevations sacrificed channel Dalton Creek development for rapid vegetation colonization. Restoration Project 4. Channels developed initially by erosion/headcutting at different rates depending on marsh elevation, gradient and path of small tributary creek 5. Fill material at the project site consolidated as predicted and did not get exported off-site Tidal High Low Channel Gradient Gradient Dalton Creek Non-Tidal Non-Tidal Marsh Channel Channel Dalton Creek Lower Watershed and Floodplain- 1991 1991 Aerial Photo Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 8

Adaptive Restoration of the West Coast's Tidal Wetlands Craig Cornu Presentation Ditches Earth Levees Dalton Creek Lower Watershed and Floodplain- 1991 Dalton Creek Lower Watershed and Floodplain- 1991 Dalton Creek Marsh Major Issues: � Tidal channel network reduced to linear ditches � Little or no salmonid access to marsh plain/edge � Little or no connection with rest of estuary (nutrient 1991 1999 exchange) � Logistical: No access to marsh surface for excavating equipment except tracked vehicles between muted tides 2005 1. 2. 4. 3. Dalton Creek Tidal Channel Blast Sequence 5. Coastal Training Program Elkhorn Slough & SF Bay National Estuarine Research Reserve January 12, 2006 9