OCN 780 Seminar | Biogeochemical Variability and Ecosystem Response in the Columbia River Estuary: Sustained Observations for Tribal Stewardship | Gradoville

Presenter: Dr. Mary R. (Rosie) Gradoville

Title: Biogeochemical Variability and Ecosystem Response in the Columbia River Estuary: Sustained Observations for Tribal Stewardship

Abstract: The Columbia River estuary is a fast-flowing, river-dominated, mesotidal system where water column biogeochemistry is strongly influenced by river flows and tidal exchange from a wind-driven coastal upwelling system. The Columbia River Inter-Tribal Fish Commission (CRITFC)’s Coastal Margin Observation and Prediction (CMOP) program maintains a long-running physical and biogeochemical observation network and numerical modeling capabilities spanning the river–estuary–ocean continuum. Since 2020, CMOP has operated within CRITFC, a tribal organization serving the Yakama, Umatilla, Warm Springs, and Nez Perce Tribes, and its observatory and modeling efforts are being reshaped to better support tribal stewardship of the Columbia and its coastal margin. Historical observatory data are being analyzed in relation to ecologically relevant thresholds for threatened salmon populations; for example, dissolved oxygen in the lower estuary drops below salmon physiological stress thresholds summer due to the tidal delivery of upwelled waters. The observatory is also being expanded to include additional biological indicators, including a pilot environmental DNA (eDNA) project using time-series samples and multi-marker metabarcoding to examine seasonal and episodic shifts in food web structure. This seminar will present an overview of the CMOP program, analysis of patterns and drivers of estuarine hypoxia, and preliminary results from this eDNA pilot study, highlighting CMOP as a rare example of an ocean and estuary research program under tribal leadership.

Location: (Hybrid) MSB 100 & Zoom (No password needed)

Time: 3:00 pm to 4:15 pm