Contaminant Effects on California Bay-Delta Species & Human Health

University of California, Davis (UC Davis) | December 1st, 2016

Many contaminants in the California Bay-Delta exceed regulatory standards, impact aquatic species, and potentially affect human health. Recent studies provide evidence th

Many contaminants in the California Bay-Delta exceed regulatory standards, impact aquatic species, and potentially affect human health. Recent studies provide evidence that contaminants impact species of concern in the Bay-Delta (e.g., the decline of several important fish species referred to as the “Pelagic Organism Decline”). Multiple chemicals impair processes at cellular and physiological levels (measured as growth, development, and behavior abnormalities), ultimately affecting populations. As an important example, the population decline of the endangered delta smelt (Hypomesus transpacificus) is significantly associated with multiple stressors, including insecticide use. New analyses presented in this paper show significant correlations between pyrethroid (an insecticide) use and declining abundance of POD fish species. Water sampled from the Bay-Delta causes multiple harmful effects in fish and delta smelt. Fish prey items are also impacted by contaminants; this may have an indirect effect on their populations. Co-occurrence with thermal changes or disease can worsen contaminant effects. Contaminants also pose threats to human health via consumption of fish, drinking water, and contact recreation, in particular, mercury, toxins, disinfection byproducts, pesticides, pharmaceuticals, and personal care products. The role of contaminants in the decline of Bay-Delta species is difficult to accurately assess in a complex, dynamic system. However, tools and approaches are available to evaluate contaminant impacts on Bay-Delta species, and separate the effects of multiple stressors. Integrated monitoring and focused mechanistic studies are instrumental for addressing management needs. Impact and risk assessments should be conducted for different species across multiple life stages, with emphasis on early life stages of high-priority Bay-Delta species.  

Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations 2018 Update

San Francisco Estuary Institute (SFEI) | September 3rd, 2018

The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) has been investigating contaminants of emerging concern (CECs) since 2001. CECs can be broad

The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) has been investigating contaminants of emerging concern (CECs) since 2001. CECs can be broadly defined as synthetic or naturally occurring chemicals that are not regulated or commonly monitored in the environment, and have the potential to enter the environment and cause adverse ecological or human health impacts.

Contaminants of Emerging Concern in San Francisco Bay: A Strategy for Future Investigations. 2017 Revision

San Francisco Estuary Institute (SFEI) | November 1st, 2017

More than 100,000 chemicals have been registered or approved for commercial use in the US. For many of these chemicals, major information gaps limit evaluations of their

More than 100,000 chemicals have been registered or approved for commercial use in the US. For many of these chemicals, major information gaps limit evaluations of their potential risks, and environmental monitoring of these chemicals has not been required by regulatory agencies. Nevertheless, researchers and government agencies have begun to collect occurrence, fate, and toxicity data for a number of these chemicals.  As a result, a growing number of chemicals have been classified as contaminants of emerging concern (CECs), broadly defined as synthetic or naturally occurring chemicals that are not regulated or commonly monitored in the environment, but have the potential to enter the environment and cause adverse ecological or human health impacts. The primary challenge for scientists and regulators is investigating and managing this ever-expanding number of emerging contaminants to ensure that they do not harm human and ecological health. The Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) has been investigating CECs since 2001, and established a formal workgroup to address the issue in 2006. The RMP Emerging Contaminants Workgroup (ECWG) includes representatives from RMP stakeholder groups, regional scientists, and an advisory panel of expert researchers that work together to address the Workgroup’s guiding management questions.

Continuous water-quality and suspended-sediment transport monitoring in San Francisco Bay, California, water years 2020–21

U.S. Geological Survey (USGS) | December 29th, 2022

Coordinated Long-Term Operation of the Central Valley Project and State Water Project, Final Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | November 30th, 2015

Costs of Ecosystem Management Actions for the Sacramento-San Joaquin Delta

Public Policy Institute of California (PPIC) | April 22nd, 2013

California is at a critical juncture on policy for the Sacramento–San Joaquin Delta. This report summarizes the results of a wide-ranging study of cost-effective wa

California is at a critical juncture on policy for the Sacramento–San Joaquin Delta. This report summarizes the results of a wide-ranging study of cost-effective ways to improve the health of the Delta ecosystem. It highlights the need for science-based, integrated management of the many sources of ecosystem stress. The report also recommends improvements to the highly fragmented system of oversight that now involves dozens of federal, state, and local agencies. Several companion reports contain related findings: Aquatic Ecosystem Stressors in the Sacramento–San Joaquin Delta (Mount et al. 2012) summarizes the science of Delta ecosystem stressors for a policymaking audience. Integrated Management of Delta Stressors: Institutional and Legal Options (Gray et al. 2013) lays out proposals for institutional reform of science, management, and regulation. Scientist and Stakeholder Views on the Delta Ecosystem (Hanak et al. 2013) presents detailed results of the two surveys conducted by the report’s authors. Stress Relief: Prescriptions for a Healthier Delta Ecosystem (Hanak et al. 2013) summarizes the overall research project and the recommendations it generated. Where the Wild Things Aren’t: Making the Delta a Better Place for Native Species (Moyle et al. 2012) outlines a realistic long-term vision for achieving a healthier ecosystem.

Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

University of California, Davis (UC Davis) | July 1st, 2005

Cruise Plan: 2016 Regional Monitoring Program (RMP) Bivalve Deployment Cruise

San Francisco Estuary Institute (SFEI) | June 2nd, 2016

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) bivalve deployment cruise. This Cr

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) bivalve deployment cruise. This Cruise Plan was developed based upon the decisions of the RMP Technical Review Committee in 2002 to reduce the number of bivalve transplant stations from twelve to nine, utilize deployment cages rather than bags at all stations, and deploy only Mytilus californianus. These changes went into effect with the 2003 program and continued through the 2012 deployments. In 2014, the RMP Technical Review Committee reduced bivalve deployment transplant stations from 9 to 7 stations, 3 of which are back-up deployment sites. In addition, as instituted initially with the 2006 deployments, there is no mid-deployment maintenance cruise, as previous analyses showed no difference in bivalve growth or survival between maintained and unmaintained deployments. 

Cruise Plan: 2016 Regional Monitoring Program (RMP) Bivalve Retrieval Cruise

San Francisco Estuary Institute (SFEI) | September 27th, 2016

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) bivalve retrieval cruise. This Cruise Plan

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) bivalve retrieval cruise. This Cruise Plan was developed based upon the decisions of the RMP Technical Review Committee in 2002 to reduce the number of bivalve transplant stations from twelve to nine, utilize deployment cages rather than bags at all stations, and deploy only Mytilus californianus. These changes went into effect with the 2003 program and continued through the 2012 deployments. In 2014, the RMP Technical Review Committee reduced bivalve deployment transplant stations from 9 to 7 stations, 3 of which are back-up deployment sites. In addition, as instituted initially with the 2006 deployments, there is no mid-deployment maintenance cruise, as previous analyses showed no difference in bivalve growth or survival between maintained and unmaintained deployments. 

Cruise Report 2016 Regional Monitoring Plan (RMP) Bivalve Deployment Cruise, June 28 – July 1, 2016

San Francisco Estuary Institute (SFEI) | July 7th, 2016

This report describes activities associated with the 2016 bivalve deployment cruise of the Regional Monitoring Program (RMP). Measurement of contaminant concentrations in

This report describes activities associated with the 2016 bivalve deployment cruise of the Regional Monitoring Program (RMP). Measurement of contaminant concentrations in transplanted bivalves accumulated during dry season deployment is designed to provide long-term data on the bioaccumulation of select trace elements and trace organic compounds in tissue throughout the Estuary.