North American Green Sturgeon Impact Mitigation Measures in the Upper Sacramento River, California

Between 2008 and 2011 a multi-entity collaborative research effort documented life history characteristics of the Federally listed as Threatened Southern Distinct Population Segment of the North American green sturgeon in the spawning reach of the Sacramento River, California.  Through tagging and tracking of adults, egg sampling, and juvenile migration data collection, impacts of water resource management activities to green sturgeon could be evaluated.  Due in part to the data collected, the Red Bluff Diversion Dam and its operations were determined to result in a jeopardy decision of the Central Valley Project water resource operations in this area.   Augmentation of operations and ultimately, replacement of the diversion dam with a high capacity water pumping plant were considered to be sufficient to reduce the impacts of these water diversions to acceptable levels.  Additional mitigation measures in the highly regulated Sacramento River should be evaluated by water resource managers, in terms of temperature and discharge levels and timing, to take into consideration two sturgeon species in addition to the current operations focusing on threatened and endangered salmonids.