Seminar: Emily Eidam, UNC-CH MASC

UNC Marine Sciences’ is proud to host a seminar by Emily Eidam, Ph.D. This event is scheduled for Wednesday, October 31st, at 3:35pm in room G201 on the ground floor of Murray Hall at the University of North Carolina at Chapel Hill. This seminar will also be broadcast live to both UNC’s Institute of Marine Sciences room 222 and online via Zoom.

Presenter Affiliation: UNC-CH, Department of Marine Sciences

Title:  Sediment dynamics and societal concerns in a Northwest estuary

Abstract: Estuaries provide critical habitat for eelgrass, oysters, and other species, and also serve as natural sediment traps. The sediment regimes of many modern estuaries are evolving, however, in response to land use changes, shoreline alterations, dredging, and other human impacts. In order to assess hydrodynamics and sediment dynamics in the Coos Bay Estuary (Oregon), we used an unstructured finite-volume model (FVCOM) and multi-year measurements of water velocities, salinities, and turbidities to re-construct patterns of water and sediment flow. Despite relatively low inputs of sediment and strong tidal forcing, a ~10-km-long estuarine turbidity maximum (ETM) persists in the upper estuary, in association with a pool of bottom sediment which requires annual dredging. Rainstorms generate 10-fold increases in the strength of the ETM, but tidal currents flush this new material to the lower reaches of the estuary within 3 weeks. Ongoing efforts between researchers and stakeholder groups including federal reserve managers, tribal managers, the Port of Coos Bay, and port expansion consultants are seeking to understand the impacts of these modern sediment dynamics on water quality and habitats, in order to make informed management decisions about future channel deepening.