Eful to managers considering understanding and managing routing of migrating salmon via complicated estuarine ecosystems. 2. Supplies and Procedures two.1. Web site Description The Sacramento-San Joaquin Delta (Delta) extends from exactly where the confluence of the Sacramento River and the San Joaquin River meet Suisun Bay towards the City of Sacramento around the Sacramento River and several kilometers south of Lathrop around the San Joaquin River (Figure 1). The study web page is in the junction of the San Joaquin River and also the head of Old River (HOR) positioned at the southern landward intense in the Delta (Figure 1). Within this tidally influenced freshwater region of your Delta, reversing tidal flows are muted for the duration of higher flow periods. The climate is Mediterranean together with the majority of rainfall occurring from November by way of April with large year-to-year variability in timing, magnitude and duration of precipitation. Flows are largely regulated by reservoirs within the San Joaquin Valley watershed. For the duration of standard flow situations, most water entering Old River in the San Joaquin River is removed at main diversions–the C.W. Bill Jones Pumping Plant of your Central Valley Project (CVP), operated by the U.S. Bureau of Reclamation, and the Harvey O. Banks Pumping Plant on the State Water Project (SWP), operated by the California Division of Water Resources. Correspondingly, fish routing via Old River are at high threat of entrainment in the water export facilities, or predation close to the facilities. A portion on the surviving smolts which arrive in the BI-0115 Inhibitor facilities are salvaged and trucked towards the western boundary on the Delta exactly where they may be released back into the Estuary [2]. Except in years in which high flow prevents installation, a short-term rock barrier has been installed in the head of Old River for the duration of the spring period of emigrating Chinook salmon as a way to cut down the passage of salmonids into Old River. In 2018 the structure was only partially installed, Safranin In Vitro extending in the southern shoreline into but not across the channel (Figure 1). The study period was March pril 2018, timed to capture the emigration of Chinook smolts. River discharge, reported at Mossdale upstream of the junction and Dos Reis andWater 2021, 13, FOR PEER REVIEW4 ofWater 2021, 13,4 of 16 installed, extending in the southern shoreline into but not across the channel (Figu 1). The study period was March pril 2018, timed to capture the emigration of Chino smolts. River discharge, reported at Mossdale upstream in the junction and Dos Reis an Head of Old River downstream ofdownstream ofwas junction, was important and variable for the duration of t Head of Old River the junction, the considerable and variable for the duration of the study period (Figure two). For the duration of the study period, study period, awas clear atwasstations,all station study period (Figure two). In the course of the a tidal signal tidal signal all clear at although the flow path reversed only at reversed only at Dosduring theonly during the reduce flow p even though the flow direction Dos Reis, and only Reis, and decrease flow period prior to 24 March.riod just before 24 March.Figure two. Chronology of (a) tagged fish release and cumulative arrival in (b) study location, and Figure two. Chronology of (a) tagged fish release and cumulative arrival within the study location, andthe measured flow upstream (b) measured flow upstream with the diffluence at Mossdale the San downstream from the diffluence on of your diffluence at Mossdale (MSD), downstream of the diffluence on (MSD), Joaquin River at Dos Reis (SJD.