Oregon's Blue Carbon Ecosystems: State of the Science

Summary

This report synthesizes the scientific understanding of blue carbon ecosystems along the Oregon and Pacific Northwest coast to evaluate their climate change mitigation potential. It finds that coastal ecosystems—specifically tidal wetlands (emergent marshes, scrub-shrub, and forested wetlands) and eelgrass meadows—serve as critical, durable carbon sinks where the vast majority of carbon is stored in soils and sediment. Forested tidal wetlands and scrub-shrub systems exhibit particularly high carbon density, and restoring tidal flow to historically diked and converted wetlands significantly reduces greenhouse gas emissions such as methane and carbon dioxide.

The synthesis also examines marine blue carbon pathways, including kelp forests, marine vertebrates, and aquaculture, noting that while highly productive, their net long-term carbon sequestration remains constrained by export dynamics, lack of standard accounting frameworks, and potential lifecycle emissions. The findings demonstrate that estuary conservation and restoration provide immediate, high-confidence climate and biodiversity.