Tidal wetlands provide critical benefits to Pacific Northwest communities and wildlife: they help reduce storm impacts, store carbon, improve water quality and provide habitat for fish and birds. Many tidal wetlands have been lost or altered by development, including agriculture, dikes and levees, roads, residential and commercial buildings and port facilities. As sea levels rise, tidal wetlands and other coastal habitats may try to adapt by migrating inland. However, dikes and other barriers can physically prevent this inland migration, a challenge known as coastal squeeze. Restoring tidal flow to former wetlands can help rebuild these habitats and support their ability to adapt to climate change.

Drew Burke’s project studies vegetation development at zis a ba II, a recently restored tidal marsh site in the Stillaguamish River estuary. The site was reconnected to tidal waters after dikes were removed as part of a larger restoration effort led by the Stillaguamish Tribe in partnership with The Nature Conservancy. Drew will map native and non-native plant communities across the site and evaluate how their distribution relates to elevation, salinity and distance from tidal channels. He will also compare observed vegetation patterns with predictions from a local vegetation model.

Through this project, Drew will provide the Stillaguamish Tribe with detailed maps, a predictive vegetation model and early indicators of whether the site is developing as expected. These results can support adaptive management at zis a ba II, help guide planning for the nearby zis a ba III restoration area and inform future estuary-restoration projects. By identifying where native marsh vegetation is establishing successfully, and where non-native plants or unsuitable conditions may limit recovery, the project will help tribal resource managers design and maintain tidal wetlands that can provide salmon habitat, flood protection and other ecosystem benefits as sea levels rise.