This study focuses on understanding how restored tidal wetlands with different physical configurations function as refuge and rearing habitat for fishes, including native and imperiled species such as delta smelt and juvenile Chinook salmon. This research will assess the spatial distribution of predation risk as it varies within and across tidal wetlands. The proposed research will generate a statistical model that helps predict predation outcomes from various restored tidal wetland designs and channel configurations. This will be a powerful tool for managers to forecast how proposed habitat restoration or water management actions may impact native fish populations.
The goal of this research is to better understand how climate change will affect fishes with different life histories and habitat associations across the San Francisco Estuary. Existing datasets will be incorporated in synthetic analyses and cutting-edge statistical models to identify fish community responses to climate, flows, and habitats along the estuarine salinity gradient. This synthesis-science project will use rich long-term datasets that have been collected by Bay-Delta researchers for decades that will then be analyzed in a reproducible and open science framework. It will also support efforts by the Interagency Ecological Program’s Climate Change Project Work Team.
The Environmental Monitoring Program (EMP) began in 1975 to conduct baseline and compliance monitoring of water quality, phytoplankton, zooplankton, and benthic invertebrates in the San Francisco Bay-Delta estuary. This monitoring program was designed to track the impact of water diversions to the State Water Project (SWP) and Central Valley Project (CVP) on the Bay-Delta. In the decades since, EMP scientists have monitored these constituents at fixed and floating stations throughout the estuary and ensured compliance with state and federal mandates such as Water Right Decision 1641 (D-1641). In the years and decades since its inception, EMP has become one of the cornerstones for scientists' and managers' understanding of the pace and pattern of change in this critical ecosystem. By sampling water quality and biological communities concurrently, EMP has created a dataset that is uniquely useful in better understanding causal connections between physical, biological, and biogeochemical processes.
Invasive aquatic vegetation (IAV) is widespread in the Sacramento-San Joaquin Delta (Delta) and its change in coverage has been mapped at the species level using spectroscopy data collected once a year, from 2004 to 2008 and from 2014 to 2019. There was no funding to conduct a similar mapping campaign in 2020. This work aims to collect and analyze imagery in summer of 2020 to fulfill two main objectives. First is to inform the monitoring framework for aquatic vegetation put forth for the Interagency Ecological Program (IEP). Comparing spring and fall imagery of 2019 and the summer imagery of 2020, the project will evaluate which time period is ideal for optimal mapping of aquatic vegetation considering the logistical challenges of airborne imagery acquisition and the phenology of the species being mapped. The project will also contrast the pros and cons of the 3 proposed scenarios in the IEP monitoring framework: 1) two hyperspectral acquisitions a year (2019; “best case” scenario), 2) one acquisition a year (2020, “moderate” scenario) and 3) satellite data based monitoring (the Sentinel-2 study, “bare bones” scenario). The second objective of the project is to determine if the new treatment framework (new herbicide formulations and application schedules) is effective in controlling the old (Brazilian waterweed, water hyacinth) and newly added target weed species (water primrose, alligator weed) in the Delta ecosystem.
