Tracking migration, movement patterns, and survival of juvenile salmonids in the Central Valley has been a difficult task, producing fragmentary and often confusing results. Recent advances in acoustic tagging and tracking technology, most notably the reduction in tag size and increase in battery life of the tags, provide an opportunity to gather accurate, high-resolution, information on the movement patterns and survival of juvenile salmonids. This information is critical to determining the timing and duration of migration through the Central Valley and San Francisco Estuary, which sections of the migration corridor appear to be used for holding and rearing, and most importantly, which sections produce significant mortality.
Starting in 2007, a project funded by the CALFED Science Program and in collaboration with Peter Klimley of the University of California, Davis will acquire movement and survival data of salmonids through the Central Valley and San Francisco Estuary. Chinook salmon and steelhead, two salmonid species with different life history strategies will be followed. We will place acoustic receivers in the Sacramento River and San Francisco Estuary to monitor passage of acoustically tagged fish past key reference points related to human activities and watershed morphology. Within the estuary, several agencies, including the U.S. Army Corps of Engineers, the Port of Oakland, and the Bay Planning Coalition will collaborate with this project by placing additional receivers in areas of interest to their organizations’ missions. Juvenile steelhead and late-fall run Chinook salmon from Coleman National Fish Hatchery will be implanted with acoustic tags yearly during the winters of 2007, 2008, and 2009 and released over a month’s time in Battle Creek and the upper Sacramento River. Time of passage data retrieved from the receivers will be used to reconstruct and model rates of movement and survival through system segments. The results will be correlated with water projects, hydrologic data (e.g., temperature, flow), and land use patterns to determine their relationships to survival and movement patterns.
Contact: SWFSC Fisheries Ecology Division, Salmon Ocean Ecology Team