Science activities

Tradeoffs among objectives in natural resource management can be exacerbated in altered ecosystems and when there is uncertainty in predicted management outcomes. Multicriteria decision analysis (MCDA) and value of information (VOI) are underutilized decision tools that can assist fisheries managers in handling tradeoffs and evaluating the importance of uncertainty. We demonstrate the use of these tools using a case study in the Sacramento River, California, U.S.A., where two imperiled species with different temperature requirements, winter-run Chinook Salmon (Oncorhynchus tshawytscha) and Green Sturgeon (Acipenser medirostris), spawn and rear in the artificially cold Shasta Dam tailwater. A temperature-control device installed on Shasta Dam maintains cool water for Chinook Salmon; however, uncertainties exist related to the effects of temperatures on the spawning and rearing of both species. We consider four alternative hypotheses in models of early life-stage dynamics to evaluate the effects of alternative temperature-management strategies on Chinook Salmon and Green Sturgeon management objectives. We used VOI to quantify the increase in management performance that can be expected by resolving hypothesis-based uncertainties as a function of the weight assigned to species-specific objectives. We found the decision was hindered by uncertainty; the best performing alternative depends on which hypothesis is true, with warmer or cooler alternative management strategies recommended when weights favor Green Sturgeon or Chinook Salmon objectives, respectively. The value of reducing uncertainty was highest when Green Sturgeon was slightly favored, highlighting the interaction between scientific uncertainty and decision makers’ values. Our demonstration features MCDA and VOI as transparent, deliberative tools that can assist fisheries managers in confronting value conflicts, prioritizing resolution of uncertainty, and optimally managing aquatic ecosystems.

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.

SacPAS serves to provide information integration services to the Central Valley Project Improvement Act and practitioners working on matters related to ESA-listed fishes. The web-based services relate fish passage to environmental conditions and provide resources for evaluating the effects of river management and environmental conditions on salmon passage and survival.

The work performed as part of this agreement includes developing, maintaining, and making accessible query tools and decision support tools to access: historical, real-time and forecasted data; data summaries and visualizations; and hindcasts, forecasts, and scenario-derived predictions from statistical and mechanistic models. More specifically, the objectives are to: 

1)    Maintain and extend a secondary data repository of historical, real-time, and forecasted fish, environmental, and operational data from the Sacramento River and other river systems in the Central Valley, integrated from primary, public databases. 

2)    Maintain and improve the data query and visualization tools and services provided through the SacPAS website (https://www.cbr.washington.edu/sacramento/) for historical, real-time, and forecasted environmental and fish data.

3)    Conduct research and provide access to modeling tools for fish survival and migration, through the SacPAS website, in support of Reclamation-funded and ESA-mandated activities, especially in efforts to predict, track, and evaluate the efficacy of proposed or actual actions.
 

The Wetland Regional Monitoring Program (WRMP) Fish and Fish Habitat Monitoring project is a collaborative effort to track biological responses to tidal wetland restoration in the San Francisco Estuary. Monthly sampling is conducted across a network of benchmark, reference, and project restoration sites in the South Bay and North Bay, with the goal of evaluating how wetland restoration influences fish assemblages, habitat use, and ecological condition.

The study uses primarily otter trawls to monitor fish and macroinvertebrate communities. Standardized field methods align with those used in long-term monitoring programs to ensure comparability and data integration across regions. Environmental data, including water temperature, salinity, and dissolved oxygen, are collected in tandem with biological sampling to assess habitat quality and seasonal dynamics.

The program addresses WRMP Guiding Question #4: How do policies, programs, and projects to protect and restore tidal marshes affect the distribution, abundance, and health of fish and wildlife? The data support adaptive management, regulatory compliance, and science-based restoration planning by identifying key habitats, tracking restoration performance, and detecting regional patterns in species composition and abundance over time.