Oregon Sea Grant-funded Coastal Resilience Work Uncovers Rates of Sediment Supply and Blue Carbon Burial in Tidal Wetlands

In 2018, Oregon Sea Grant-supported researchers continued to investigate the factors affecting blue carbon burial in Oregon tidal wetlands. Carbon accumulation was found to be primarily controlled by sediment accretion (i.e., vertical growth), and thus accretion is an important factor in blue carbon storage. Relative sea level rise alone did not explain the sediment accretion. Instead, accretionary balance (sediment accumulation minus relative sea level rise) appeared positively correlated to river sediment supply in most Oregon tidal wetlands. However, tidal wetlands in Alsea Bay appear to be drowning, and researchers are planning future work to explore explanations. They plan to partner with U.S. Geological Survey to better estimate river sediment supply. These results will inform coastal managers about how and why Oregon estuaries changed under past conditions and could change under present and future scenarios. Results were presented to governmental, academic and community audiences, including at a meeting of the Oregon State Legislature’s Joint Interim Committee on Carbon Reduction, the American Geophysical Union’s fall meeting and Oregon Sea Grant’s State of the Coast conference.