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Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento-San Joaquin River Delta, California, USA

July 20, 2016

Survival of out-migrating juvenile Chinook salmon (Oncorhynchus tshawytscha) in the Sacramento–San Joaquin River delta, California, USA, varies by migration route. Survival of salmonids that enter the interior and southern Delta can be as low as half that of salmonids that remain in the main-stem Sacramento River. Reducing entrainment into the higher-mortality routes, such as Georgiana Slough, should increase overall survival. In spring 2014, a floating fish-guidance structure (FFGS) designed to reduce entrainment into Georgiana Slough was deployed just upstream of the Georgiana Slough divergence. We used acoustic telemetry to evaluate the effect of the FFGS on Chinook entrainment to Georgiana Slough. At intermediate discharge (200–400 m3 s–1), entrainment into Georgiana Slough was five percentage points lower when the FFGS was in the on state (19.1% on; 23.9% off). At higher discharge (>400 m3 s–1), entrainment was higher when the FFGS was in the on state (19.3% on; 9.7% off), and at lower discharge (0–200 m3 s–1) entrainment was lower when the FFGS was in the on state (43.7% on; 47.3% off). We found that discharge, cross-stream fish position, time of day, and proportion of flow remaining in the Sacramento River contributed to the probability of being entrained to Georgiana Slough.

Citation Information

Publication Year 2016
Title Evaluation of a floating fish guidance structure at a hydrodynamically complex river junction in the Sacramento-San Joaquin River Delta, California, USA
DOI 10.1071/MF15285
Authors Jason G. Romine, Russell W. Perry, Adam C. Pope, Paul Stumpner, Theresa L. Liedtke, Kevin K. Kumagai, Ryan L. Reeves
Publication Type Article
Publication Subtype Journal Article
Series Title Marine and Freshwater Research
Series Number
Index ID 70174982
Record Source USGS Publications Warehouse
USGS Organization California Water Science Center