Coastal wetlands and estuaries in Mediterranean and semi-arid climates are impacted by both oceanic and watershed processes. From the ocean, these systems are vulnerable to sea-level rise and coastal erosion, while climate and land-use changes alter freshwater and sediment delivery. Wetlands in Mediterranean climates (e.g., California, Chile, Australia, South Africa) have soils with low organic content, relying on watershed-sourced sediments to cope with sea-level rise. However, limited understanding of both hydrodynamic and sediment transport processes in small bar-built estuaries typical of these regions makes predicting the future of coastal wetlands challenging. Here, we present field measurements from the central Chilean Maipo estuary aimed at quantifying dominant processes in the exchange of suspended sediments between the estuary and the marsh. Measurements on an intertidal flat show that low-frequency waves, modulated by tides and salinity stratification, dominate sediment movement across the flat. These mechanisms will be presented, and implications for management discussed, highlighting estuaries in both Chile and California.

The event will take place in person in the Mitchell 350/372 room on Main Campus, and it will also be broadcasted in the Isabella Abbott Lecture Hall, located in the Boat Works building at Hopkins Marine Station.