The Delta is a critical area for sustainable water management, facing significant challenges due to climate change. One of these challenges is in understanding and mitigating maladaptation – climate-aligned actions that may increase vulnerabilities or reduce adaptive capacity. Given the uncertainties surrounding climate change, management actions that seek to achieve high-level goals of climate change adaptation while accounting for maladaptation must be robust, ensuring adequate, multicriteria performance across all climate futures. This work responds to two gaps: (1) the absence of tools for assessing the performance of management actions in the Delta under hydroclimatic uncertainty and (2) a lack of research that explores how stakeholders can account for maladaptation in water governance. Among Delta stakeholders and researchers alike, the discourse and science surrounding ecological flow guidelines, the social complexities of water governance, and the use of integrated climate models to inform robust and adaptive decisions is active and rapidly advancing. This positions the Delta not only as an ideal case study for the academic study of maladaptation, but also as one that is of immediate relevance to stakeholders, responding to several Delta Management Needs (Science Actions 3B, 6E, and 1A) as they concern open science and the exploration of the Delta as a socioecological system and the facilitation of decision-making under climate change and its associated uncertainties.
Bridging Science and Community: Engaging Youth in Delta Conservation through the Spinning Salmon Program is designed to enhance scientific understanding and engagement among underrepresented youth in the Sacramento-San Joaquin Delta. Leveraging the Youth-Focused Community and Citizen Science (YCCS) framework, the program connects youth to local ecosystems while addressing ecological challenges such as the Thiamine Deficiency Complex affecting Central Valley Chinook Salmon. The objectives focus on enhancing students' understanding of scientific concepts and processes, fostering science identity, self-efficacy, and environmental science agency, and cultivating a sense of environmental stewardship. Additionally, the program emphasizes the active involvement of community members in co-creating and refining educational strategies, ensuring these approaches are tailored to the diverse cultural and educational needs of the Delta community. This aligns with Science Action C under Management Need 4 in the 2022-2026 Science Action Agenda (SAA), contributing to a broader understanding of community-engaged research methodologies.
The proposed project is driven by the need to understand how land use has changed historically in California's Central Valley due to various drivers including environmental changes and socio-economic developments. Given the region's dependency on agriculture and its vulnerability to climate change—marked by shifts in precipitation patterns and water availability—it's crucial to model these dynamics accurately to forecast future conditions and plan effectively. Using Agent-Based Modeling (ABM) provides a sophisticated means to dissect past interactions between land use and environmental factors at a granular level. This historical understanding is pivotal as it sets the stage for projecting future scenarios. Additionally, the integration of future hydrology data generated from the CalSim3 model and socio-economic scenarios allows for a comprehensive analysis of potential future states. This analysis aims to explore strategic land use modifications that can meet future socio-economic goals under varying water availability scenarios.
This research supports several key science actions, making it highly relevant to current policy discussions. It provides actionable insights into large-scale experiments (Science Action 1C), assesses the impact of climate on ecosystems (Science Action 6A), and explores water allocation strategies (Science Action 6E), thereby equipping policymakers and stakeholders with the necessary tools for informed decision-making. These decisions are crucial for maintaining ecological flows and ensuring the longterm viability of both the agricultural sector and the natural ecosystems upon which they depend.
Due to pervasive anthropogenic influences (e.g., habitat alteration, climate change), current rates of biodiversity loss in the Sacramento-San Joaquin Delta are unprecedented. Application of appropriate management regimes and mitigation measures thus require effective biological monitoring to adaptively manage systems. Non-invasive environmental DNA (eDNA)-based tools for endangered species monitoring have gained attention as a complementary approach to traditional sampling because of their increased sensitivity and accurate quantification. However, the unique characteristics of environmental RNA (eRNA) make it a novel tool, allowing us to gain additional information that is not possible to obtain with eDNA. Using novel eRNA tools to improve detection and quantify health status of Smelt has only been theorized and remains to be empirically tested. Both Delta and Longfin Smelt species were historically ubiquitous in the Sacramento-San Joaquin Delta, but have declined precipitously over the past several decades. One source of mortality is entrainment into the south Delta water export pumps. Although the entrainment of juvenile and adult smelt has been regularly monitored at fish salvage facilities, entrainment of larval smelt (< 20 mm) is not quantified, thus remains largely unknown. Moreover, given the current climate change effect (e.g., increased heat stress), an understanding of how these endangered species will respond to acute stress response in the wild is lacking.
The Sacramento-San Joaquin Delta is a highly altered and impaired ecosystem that is critical to the freshwater infrastructure of the State of California. Salt intrusion from San Francisco Bay into the Delta, however, threatens freshwater delivery to the southern portions of the state and so management and restoration actions within the Bay-Delta must continuously balance both ecosystem and operational needs. While previous numerical modeling studies have sought to examine changes in the estuarine physics of the system, these tools are costly to develop and run. Thus there is a need to develop alternate methods for monitoring the movement of water through the Bay-Delta, as proposed here. The proposed research project approaches tracking the mixing between the Bay and Delta waters through the novel use of daily satellite color imagery. These findings will be linked to in situ measurements throughout the system and used to inform relevant agencies of flow characteristics within the waterways. This work is motivated by a need for high frequency monitoring of finescale features within the dynamic Bay-Delta ecosystem and to take advantage of new advanced remote sensing technology to inform on long-term trends within the Delta.
The primary objectives of this research are to: 1. Enhance monitoring programs to inform management in the presence of climate change and additional stressors, 2. Inform on ecosystem resilience to interannual hydrologic variations and climate change impacts, and 3. Evaluate how climate change and flow regime changes will impact water quality in the Delta.
The San Francisco Estuary (SFE) supports the southernmost reproductive population of longfin smelt (LFS) along the Pacific Coast. Long term monitoring studies have observed a precipitous decline of LFS in the SFE over the past several decades, and the San Francisco Bay-Delta Distinct Population Segment was listed as endangered under the Endangered Species Act in July of 2024. There are important gaps in our understanding of LFS ecology and movement within the highly urbanized SFE, posing challenges to the development of effective recovery strategies. More complete information about the movement and migration of LFS in the wild can lead to improved life-cycle modeling and provide insight into the species’ relationship with temperature, salinity and other habitat features of the SFE. An effective tool to learn about fish migration and movement is through a tracking method known as acoustic telemetry. Until recently this practice has been impossible on small fish such as LFS due to their body size relative to existing acoustic transmitters, or ‘tags’. With recent advances in telemetry technology, we now have an opportunity to implant newly miniaturized acoustic transmitters into adult LFS. However, before the results of telemetry studies utilizing these newly developed transmitters can be used to make inferences about wild populations, it is imperative to determine whether the tagged individuals are surviving and behaving in the same way as their un-tagged counterparts. The study aims to establish post-tagging survival and transmitter retention rates of wild and captive-reared LFS surgically implanted with newly miniaturizes acoustic transmitters, as well as the sublethal effects of transmitter implantation on LFS swimming performance. The results of this study will directly inform the implementation of acoustic telemetry on LFS, aiding in the conservation and recovery of an imperiled native species.
