The CDFW Fish Restoration Program will collect fish and invertebrate data near existing and planned tidal wetlands. These data will provide information on how fish and invertebrate communities change pre-/post-restoration. While collecting these data, the variability of invertebrate catches will be assessed for each gear type to determine the optimal number of samples per sampling site.
Under the 2008, 2019, 2024 State Water Project/Central Valley Project Joint Operations Biological Opinion from United States Fish and Wildlife Service, 2009, 2019, 2024 National Marine Fisheries Service, and 2009, 2020, and 2024 State Water Project Incidental Take Permit, Department of Water Resources (DWR) is required to restore >8,000 acres of tidal wetlands in the Sacramento-San Joaquin Delta (Delta) and Suisun Marsh to improve habitat and food web resources for threatened fishes. The Fish Restoration Program is responsible for biological monitoring in these restored tidal habitats to assess their success for providing habitat and food web benefits for at-risk native fishes.
Assess the food web resources (nutrients, phytoplankton, zooplankton, and macroinvertebrates) associated with pre- and post-restoration tidal wetlands, as well as with existing reference wetlands
Assess the fish community of restoring wetlands including use by rearing salmonids and characterization of the predator and competitor communities
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.
Invasive aquatic vegetation (IAV) is a threat to aquatic ecosystems worldwide, leading to a major loss of biodiversity and extensive damages and costs to human uses of those ecosystems. The Sacramento-San Joaquin River Delta (the “Delta”) is the hub of California’s water system, supporting over 35 million water users and a $54 billion agricultural industry. The Delta reform act mandates management decisions meet both water supply needs while maintaining the ecological function of the system. The Delta is a global biodiversity hotspot, and the focal point of $750-$950 million in restoration. It has also been called one of the most invaded estuaries in the world. Over the past 15 years, submerged and floating IAV have more than doubled in extent, threatening water supply and ecosystem health of the Delta. There is mounting evidence that herbicide treatments are not effective, and that water management actions, and wetland restoration may be having huge impacts on IAV. This presents both a risk to increasing IAV, but also an opportunity to prevent and even effectively combat IAV through considered water management actions and better restoration planning, meeting the state’s co-equal goals of water security and Delta ecosystem conservation.
This project will meet the needs of multiple state agencies by advancing operational Earth observation-based monitoring program for community-level submerged aquatic vegetation (SAV) and genus-level floating aquatic vegetation (FAV) and modeling tools to enable the Delta management community to assess the effect of previous management actions on IAV and forecast the effects of future actions to inform multi-agency decision making. Specifically, this work will 1) Operationalize IAV class mapping using Sentinel-2 satellite imagery, 2) Finalize and validate species distribution Models (SDM) for SAV community and FAV at genus-level to assess the impacts of previous water actions on IAV and predict IAV distribution in future scenarios, 3) Co-design IAV-based performance metrics to inform future actions.
The proposed project fills a critical data gap in monitoring for state and federal agencies and stakeholders by implementing the first sustainable mapping effort for IAV. Monthly and seasonal estimates of SAV and FAV coverage will enable the Delta Stewardship Council to improve their performance metrics for evaluation of the Delta Plan and will help the Interagency Ecological Program assess whether management is meeting the co-equal goals for the Delta. Species distribution models will enable Department of Water Resources to evaluate how previous restoration flow actions have affected the spread and persistence of IAV and incorporate what they learn into future Structured Decision Making to better account for negative consequences of IAV when setting future restoration targets and implementing actions.
Water primrose (Ludwigia spp.) is a highly invasive, non-native floating macrophyte in the Delta. In recent years, water primrose has extended its niche into marsh habitat, causing extensive mortality of marsh macrophytes including tules and cattails. The goal of this project is to determine whether the growth strategy of water primrose, its allelopathic properties, or factors related to plant community structure are the cause of marsh loss following water primrose invasion in the Delta. Part of this study will identify and map the marshes most vulnerable to loss and quantify the spatial trajectory of marsh loss during the past 15 years. The ultimate benefit will be an improved understanding of the water primrose invasion processes in the Delta, which can be used to prioritize herbicide treatment of this highly invasive plant in marshes most vulnerable to invasion and with the highest habitat value.
Objectives:
Since 2015, the DIISC Team has organized a biennial Delta Invasive Species Symposium. The symposium is a forum for Delta managers, researchers, and decision-makers to meet, share and synthesize information, and communicate best practices and lessons learned. https://deltaconservancy.ca.gov/diisc-team-activities/
Invasive submerged aquatic species (SAV) greatly impact habitat for endangered species in the Delta. In the past decade, we have seen a huge increase in SAV cover and an influx of new invasive species like ribbonweed. This study will build species distribution models (SDM) for SAV using predictors such as water speed, depth, salinity from the UnTRIM hydrodynamic model, turbidity derived from Sentinel-2 and temperature derived from ECOSTRESS satellite imagery. The SDMs will be used to study the effect of flow management actions and restoration activities on SAV distribution. SAV community data collected in the field (available on EDI) will be analyzed to study if the SAV community composition has changed from 2007-08 to present time. The same dataset will be used to explore if the SAV SDM can be refined based on species presence data to see if there are significant differences in SDMs of individual SAV species.
Invasive aquatic vegetation has been identified as a major concern in the IEP Science Strategy document and a topic meriting more study. Assessing the effects of flow alteration management actions on the Delta is also a recommended key topic of research. This study furthers both these objectives. It complements ongoing projects such as the water primrose ecoengineering project (PEN #348), which is similarly building an SDM for Ludwigia spp., determining plant characteristics that enable Ludwigia invasion and mapping invasion risk for the remnant Delta marshes. The work also builds off the conclusions of the Sentinel project which mapped the temporal phenological signal of SAV in the Delta. The results of this study will help design restorations to be more resistant to invasion, plan for climate change impacts, and predict invasion risk in Delta regions that are being reconnected tidally to the Delta waterways network through current and future restoration projects.
