POSTER SESSION 1
15:30–17:30, Monday, September 14
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1358 | POSTER 73
OPTICAL REMOTE SENSING REVEALS A WEAKENING NEARSHORE SEDIMENT LIFELINE FOR U.S. COASTAL WETLANDS UNDER RISING SEAS
The nearshore ocean is increasingly recognized as a critical source of sediments to coastal shorelines and embayments that support wetland ecosystems, including blue carbon systems and critical intertidal habitats. Along many coastlines, sediments are resuspended from the seafloor by wind-driven waves and transported to adjacent wetlands, where they promote vertical accretion and enhance resilience to sea-level rise. Over decadal timescales, suspended sediment supply is therefore a key determinant of whether wetlands persist or collapse under relative sea-level rise and other external forcings. Here, combining various in situ observations with optical remote sensing data, we show that the U.S. East and Gulf Coasts have experienced a pronounced, coastwide decline in suspended sediment concentration (SSC) over recent decades. Attribution analyses indicates that relative sea-level rise, by increasing water depth and reducing wave-driven bottom shear stress, provides a physically consistent explanation for this decline, particularly in nearshore environments where sediment dynamics are dominated by resuspension. Comparisons between offshore coastal waters and adjacent embayments further reveal contrasting trends that expose previously unrecognized instability in some bay systems. By linking SSC trends to observed wetland trajectories, we provide a framework for identifying coastal systems that are most vulnerable to ongoing sea-level rise. These results highlight the value of long-term optical remote sensing observations for diagnosing sediment dynamics and assessing coastal resilience at regional scales.
Cédric Fichot, Boston University, [email protected], https://orcid.org/0000-0002-1099-5764
Hangjie Lin, Boston University, [email protected], https://orcid.org/0009-0006-7982-1830
Sergio Fagherazzi, Boston University, [email protected], https://orcid.org/0000-0002-4048-5968
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
