Jilian Xiong (Coastal PO Faculty Search Candidate) - SMSP Spring Seminar Series 2026

Jilian Xiong

Abstract: Estuaries are increasingly affected by environmental stressors such as hypoxia and harmful algal blooms. Effective coastal management depends on our ability to predict these events accurately, which in turn requires a mechanistic understanding of how circulation and mixing regulate transport pathways and timescales, and how those physical controls interact with tracer-specific biological and chemical processes. In this talk, I use two case studies from contrasting large estuarine systems - the Salish Sea on the U.S. and Canada West Coast and Chesapeake Bay on the U.S. East Coast - to examine how circulation and mixing connect estuaries to the continental shelf and broader coastal ocean, and how those connections shape the transport of ecologically important tracers. The first case focuses on seasonal deep-water renewal and hypoxia relief in Hood Canal, a fjord-type estuary within the Salish Sea. The second examines a rare coastward expansion of a harmful algal bloom in Chesapeake Bay and highlights event-driven export and retention at the estuary-shelf boundary. Using regional ocean models, observations, circulation analysis, and tracer diagnostics, I show how exchange pathways, mixing hotspots, and regional forcing shape tracer distributions across both systems. A consistent picture emerges: physics sets the dominant pathways and timescales of transport, while tracer-specific biological and chemical processes determine the ecological outcomes. I conclude by discussing how I would extend this framework to Delaware Bay and the adjacent Mid-Atlantic Bight, where estuary-shelf-open-ocean connectivity and mixing play centrals in tracer fate, regional water quality, and ecosystem variability.