Science Synthesis

The Delta Science Program performs analysis and synthesis of scientific information to report on the status and trends of key scientific issues within the Sacramento-San Joaquin Delta. It also coordinates workshops and symposia that result in synthesis reports that update the scientific state of knowledge, guide adaptive management, and identify science needs and data gaps.

For ease of access to synthesis data among scientists, managers, and the public, the Delta Science Program uses Shiny - a digital interface for creating interactive point-and-click applications with the statistical programming language R. Those developing Shiny applications with a connection to the Sacramento-San Joaquin Delta are encouraged to submit an application to be featured on the Delta Science Program’s Shiny account. For more information, please email shiny@deltacouncil.ca.gov.

Ongoing Syntheses

Using Acoustic Data to Describe Diversity in Juvenile Chinook Salmon

While metrics such as growth, condition, and survival are commonly used to measure fish performance, life history diversity has emerged as an equally important factor to population resilience and conservation. However, juvenile salmon life history is difficult to quantify, and resource managers have traditionally relied upon an oversimplified approach. To address this issue, this study uses acoustic telemetry data to better assess diversity in migration timing with data collected for survival studies. This is a logical next step for acoustic data; towards understanding how juvenile salmon use these river reaches of interest to navigate the risks and rewards of freshwater residency. Visit the Delta Science Program’s Shiny account to view data from this study in an interactive map app.

Zooplankton Synthesis

Zooplankton - small floating animals too small and weak to swim against currents - are important food sources for many fishes in the Delta such as salmon, sturgeon, and Delta smelt. Since 1972, zooplankton have been continuously monitored in the region by the Interagency Ecological Program. Conducted collaboratively among the Delta Science Program, the California Department of Water Resources, and the California Department of Fish and Wildlife, this zooplankton synthesis project integrated zooplankton data from five major surveys into a comprehensive dataset comprised of over two million data points from over eighty thousand zooplankton samples. The integrated dataset can be accessed via the Delta Science Program’s Shiny account or R package. Current efforts are focused on publishing a report on zooplankton methods in the Delta, hosting workshops on zooplankton ecology and taxonomy, and analyzing the integrated dataset for relationships among habitat characteristics and zooplankton abundance, at both the species and community levels.

Mercury: Sources, Biogeochemistry, and Biotic Effects 2003 - 2018

Mercury is a legacy contaminant that has haunted natural resource managers in the Bay-Delta region for decades. Methylmercury, the most toxic form of mercury, is associated with adverse effects to fish, wildlife, and humans. The Delta Science Program, in collaboration with the U.S. Geological Survey, Delta Conservancy, and California Department of Fish and Wildlife, coordinated a series of workshops in January and June 2016. This mercury synthesis effort will be the first in over a decade and present the most up-to-date scientific information, while also identifying crucial gaps in knowledge.

State of Bay-Delta Science (SBDS)

A collection of peer-reviewed syntheses intended to inform science and policy audiences about the “state of the science” for topics of high management concern in the Bay-Delta system. The 2008 edition of SBDS is available via requests to archives@deltacouncil.ca.gov, while the 2016 edition can be accessed via an interactive webpage. The next edition is anticipated to be released in 2021, with future updates following every two years.

Past Syntheses:

Please contact archives@deltacouncil.ca.gov with questions about access to or the status of a particular synthesis.

2012-2016 Drought Management and Science Synthesis

The purpose of this effort is to develop a concise synthesis report based on the management decisions made during the 2012-2016 drought and the scientific information utilized to inform those decisions. Lessons learned from these actions are discussed and intended to inform future drought-related management decisions.

False River (Emergency Drought) Barrier

During spring 2015, a rock barrier was constructed in False River to limit salinity penetration into the central Delta and to the water intakes in the south Delta. This Barrier allowed reduce Delta outflow while maintaining salinity below criteria at selected control points, thereby saving water in the reservoirs while preventing water quality problems. This synthesis will result in a manuscript that summarizes the different studies that investigated the ecological responses to the Barrier. A False River Barrier synthesis report was produced.

Ecological and Physiological Impacts of Salinization of Aquatic Systems from Human Activities

September 26, 2018 - A symposium held with the UC Davis Coastal Marine Sciences Institute to discuss how changing salinity regimes affect the Bay-Delta and other estuarine ecosystems. A synthesis report is in progress.

Salmon Disease Ecology

March 14, 2018 - A symposium and workshop held with the UC Davis Coastal Marine Sciences Institute to discuss what is known about pathogens and diseases in wild salmon populations in the Central Valley, what monitoring and research gaps exist, and how other systems manage to control or reduce impacts of pathogens/disease. A synthesis report is in progress.

Managed Relocation Under a Changing Climate

December 4, 2017 - A symposium held with the UC Davis Coastal Marine Sciences Institute with the goal to inform scientists and managers on decision-making processes for translocations. A synthesis report is in progress.

Informing Delta Management Using Biotelemetry

November 9, 2017 - A symposium held with Cramer Fish Sciences and the Biotelemetry Laboratory at UC Davis to discuss challenges and management insights related to telemetric technology. A synthesis report is in progress.

Delta Invasive Species

August 29, 2017 - A symposium held with the Delta Interagency Invasive Species Coordination Team and UC Davis to explore tools and actions being developed to meet today’s invasive species management needs.

Contaminants in the San Francisco Bay-Delta: Novel Tools and Approaches to Evaluate Effects of Multiple Stressors

January 31, 2017 - A symposium held with the UC Davis Coastal Marine Sciences Institute and the State Water Resources Control Board discussing the impacts of multiple stressors on aquatic ecosystems. A Contaminants in the San Francisco Bay-Delta synthesis report was produced.

Science Enterprise Workshop

November 1-2, 2016 - A workshop help with the U.S. Geological Survey bringing together scientists, science-policy experts, and stakeholders to discuss how collaborative science is being managed, funded, and communicated in several high-profile ecosystems around the country. A proceedings report and executive summary were produced.

Delta and Longfin Smelt: Is Extinction Inevitable?

March 29, 2016 - A symposium held with the UC Davis Coastal Marine Sciences Institute discussing the status and decision-making efforts related to Delta and longfin smelt. A Delta and Longfin Smelt synthesis report was produced.

Primary Production

October, 2015 - A workshop held by the Delta Science Program and San Francisco Estuary Institute that resulted in a final report and research article.

Invasive Aquatic Vegetation

September 15, 2015 - A symposium held with Delta Interagency Invasive Species Coordination Team and UC Davis to explore new developments in surveillance and monitoring of aquatic vegetation. An Invasive Aquatic Vegetation synthesis report was produced.

California Salmon and Climate Variability

September 10, 2015 - A symposium held with the UC Davis Coastal Marine Sciences Institute how changing ocean and hydrologic conditions affect Central Valley salmon and their management. A synthesis report was produced.

Sturgeon in the Sacramento-San Joaquin Watershed - New Insights to Support Conservation and Management

March 3, 2015 - A symposium held with the Center for Aquatic Biology and Aquaculture about the physiology, behavior, and ecology of sturgeon to help guide management and conservation efforts. A Sturgeon in the Sacramento-San Joaquin Watershed synthesis report was produced.

Enhancing the Vision for Managing California’s Environmental Information

June 5-6, 2014 - The Environmental Data Summit brought together scientists, resource managers, decision-makers, academia, stakeholders, and others to discuss a new era in information management and discovery. The resulting white paper “Enhancing the Vision for Managing California’s Environmental Information” was used in the development of Assembly Bill AB1755, signed by the Governor in November 2016.

Interior Delta Flows and Related Stressors

April 16-17, 2014 - A workshop identifying the best available science to inform the State Water Resources Control Board’s decisions pertaining to interior Delta flows, resulting in a final panel report.

Delta Outflows and Related Stressors

February 10, 2014 - A workshop held to inform the State Water Resources Control Board’s decisions regarding Delta outflow objectives, resulting in a final panel report.

Fish Predation on Central Valley Salmonids in the Bay-Delta Watershed

July 22-23, 2013 - A workshop held by the Delta Stewardship Council, California Department of Fish and Wildlife, and National Marine Fisheries Service that resulted in a synthesis report was produced.

Tidal Marshes and Native Fishes in the Delta: Will Restoration Make a Difference?

June 10, 2013 - A symposium and workshop held with the Center for Aquatic Biology and Aquaculture and American Fisheries Society on the science of ecological linkages between tidal marshes and fish in the Delta. A Tidal Marshes and Native Fishes in the Delta synthesis report was produced.

The Science of Natural Functional Flows to the Delta

January 18, 2013 - A symposium and workshop held with the Center for Aquatic Biology and Aquaculture discussing aspects on functional flow regimes in the Delta. A Science of Natural Functional Flows to the Delta synthesis report was produced.

Salmonid Lifecycle Models

April 13, 2011 - A workshop to inform the implementing agencies of the 2009 Biological Opinions on how salmonid life cycle models could be used in a decision-making framework. A final report was produced.