Modeling sea level rise impacts to Oregon’s tidal wetlands : Maps and prioritization tools to help plan for habitat conservation into the future

• Main Authors: Brophy, Laura S., Ewald, Michael J.
• Other Authors: Recht, Fran, College of Earth, Ocean, and Atmospheric Sciences
• Format: Report
• Language: English; unknown
• Published: MidCoast Watersheds Council
• Subjects: Wetland mapping > Oregon; Estuaries > Oregon; Sea level > Oregon; Habitat conservation > Oregon; Wetlands > Oregon; Elk River; Pacific; Rogue River; Beaver Creek
• Online Access: https://ir.library.oregonstate.edu/concern/technical_reports/tt44ps38k

Background: Tidal wetlands are important habitats for salmon and a diversity of other fish and wildlife species. They also trap sediment, buffer coastal communities from flooding and erosion, and perform other valued ecosystem services. Tidal wetlands currently exist just at and above sea level, and healthy tidal wetlands are able to adapt to slow sea level changes. But if sea level rises too fast, tidal wetland plant communities may not be able to persist at their current locations. To survive, these plants may have to move to areas of higher elevation. These higher areas are called “landward migration zones” ("LMZs"); they are potential future tidal wetlands under sea level rise ("SLR"). This project modeled and prioritized these LMZs. It was sponsored and supported by the MidCoast Watersheds Council (MCWC) and the Pacific States Marine Fisheries Commission and funded by the Oregon Watershed Enhancement Board and the U.S. Fish and Wildlife Service's Coastal Program. Geographic scope: This project mapped LMZs for 23 estuaries on Oregon's coast south of the Columbia River. From north to south these are: Necanicum River, Nehalem River, Tillamook Bay, Netarts Bay, Sand Lake, Nestucca Bay, Salmon River, Siletz Bay, Yaquina Bay, Beaver Creek, Alsea Bay, Yachats River, Siuslaw River, Umpqua River, Coos Bay, Coquille River, New River Area, Sixes River, Elk River, Rogue River, Pistol River, Chetco River, and Winchuck River. Modeling approach: This project used an elevation-based method (modified bathtub approach) to map current and future tidal wetlands. Elevation was obtained from LIDAR; projected SLR was obtained from recent, authoritative, and region-specific scientific literature. LMZs were modeled for six SLR scenarios that could be expected between now and the year 2160, but this study did not assume any specific timeframe for the scenarios modeled. Both lower and upper boundaries for LMZs were mapped, to allow determination of areas that would be lost due to conversion to mudflat under each SLR scenario. Wetland ...