State of the Salton Sea: A Science and Monitoring Meeting of Scientists for the Salton Sea

U.S. Geological Survey (USGS) | January 19th, 2017

The Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have

The Salton Sea (Sea) is an ecosystem facing large systemic changes in the near future. Managers and stakeholders are seeking solutions to the decline of the Sea and have turned to the scientific community for answers. In response, scientists gathered in Irvine, California, to review existing science and propose scientific studies and monitoring needs required for understanding how to retain the Sea as a functional ecosystem. This document summarizes the proceedings of this gathering of approximately 50 scientists at a September 8–10, 2014, workshop on the State of the Salton Sea (SoSS).  In 1997, a similar gathering of nearly 100 scientists and others in Palm Springs, Calif., yielded a number of scientific proposals establishing a foundation for a program of integrated science investigations. The 1997 workshop results were combined with recommendations from a U.S. Geological Survey (USGS) Tiger Team (Shipley and others, 1999), resulting in the eventual creation of a Strategic Science Plan (SSP) for the Salton Sea (Salton Sea Science Subcommittee, 2000). The vision from the 1997 workshop of an integrated and coordinated program of scientific investigations, embraced by the SSP, was implemented through the SSC and the USGS Salton Sea Science Office (Science Office). The integrated science program, mandated by the Salton Sea Reclamation Act of 1998 (Public Law 105–372) and spelled out in the SSP, directly led to an increased scientific understanding of the Salton Sea ecosystem. The workshop concluded that “rehabilitation of the Sea is essential and requires that current ills be rectified in a manner that allows the Sea to sustain social values of importance to the human populations of the Imperial and Coachella Valleys, as well as society in general” (U.S. Fish and Wildlife Service, 1997). The 2014 SoSS workshop built upon the foundations of the 1997 workshop, with particular emphasis on changes in the condition of the Sea and its environment in the intervening years. Over the past five decades, investigations of the Salton Sea have addressed water quality, biological, recreation, and (or) economic issues at the Salton Sea (California Resources Agency, 2006, chap. 8). Many stakeholders believe that the Salton Sea has been “studied to death” (Claiborne, 1996). Although it is true that a great deal of research has been completed at the Salton Sea, much of it has been short term and focused on specific topics with little or no integration across science disciplines, time, and space. Additionally, there have been numerous attempts at resource management of the Salton Sea (previously referred to as restoration planning).  Study objectives have differed, but the main focus has generally been on methods to control the salinity and elevation of the Salton Sea (California Resources Agency, 2006, chaps. 1 and 4). Most investigations resulted in proposed plans to preserve the Salton Sea as a thriving fishery and recreational destination, and most of these plans addressed methods to preserve the “whole Sea.” More recently, however, studies have recognized that maintaining a smaller Salton Sea should be considered, owing to declining inflows to the Salton Sea (California Resources Agency, 2006).  Prior investigations considered hundreds of alternatives for managing Salton Sea salinity, nutrients, and water elevation. Some alternatives generated revenue to help pay for rehabilitating the Sea. These alternatives have been addressed in multiple studies, as summarized in chapters 1 and 4 of the “Salton Sea Ecosystem Restoration Program Draft Programmatic Environmental Impact Report” (California Resources Agency, 2006).  Although there have been multiple efforts to characterize the Salton Sea ecosystem and develop management plans, it was not until 1996 that a comprehensive and integrated research needs assessment was developed (U.S. Fish and Wildlife Service, 1997). The 1997 report captured the combined thinking of scientists and managers and identified several areas of scientific research that would be required for a fuller, more complete understanding of the Salton Sea necessary to undertake any management project. The report defined these broad categories of science as physical environment, biological environment, cultural resources, pathogens and diseases, and contaminants. These categories form the basic framework for all scientific investigations at the Salton Sea. Some science categories continue to receive greater emphasis because limited funding has required the prioritization of projects.  A Salton Sea Science Subcommittee (SSC) authorized by Public Law 105–372, representing a broad range of Federal, State, local, and other stakeholder interests, endorsed a long-range Strategic Science Plan for the Salton Sea (Salton Sea Science Subcommittee, 2000). Whereas the U.S. Fish and Wildlife Service 1997 report established the types of science needed, the SSP further established the governing processes and expectations of how this science program should be conducted. The SSP provided the framework for scientific investigations and remains the source for identifying how scientific studies should be undertaken to better understand the Salton Sea ecosystem. Based substantially on the U.S. Fish and Wildlife Service (1997) analysis of science needs, and in consultation with many stakeholders, the SSC authorized and funded a number of initial reconnaissance-level projects. The structure of this SoSS document follows the basic framework of the U.S. Fish and Wildlife Service 1997 report, placing emphasis on physical environment (air and water quality), biological environment (birds, fish, invertebrates, carbon, and algae), contaminants, and socioeconomics.  The SoSS meeting in 2014 was convened to build upon previous scientific efforts and to provide guidance to managers on what experts believe are the most critical science needs going forward. Experts were invited to participate in the SoSS meeting based on a review by the organizing committee of individuals with subject area expertise and experience working at the Salton Sea or in similar environments. The SoSS organizing committee presented a synopsis of known science to the gathered scientists, who were then tasked to evaluate the completeness of that science and make recommendations for science needs to fill information gaps. Participants were challenged to think and act independently of their organizational affiliation in order to generate conceptual proposals designed to address scientific and monitoring concerns identified by the managerial meeting participants.

Status of Clear Lake Hitch in Lower Blue Lake, Lake County, California, 2024

California Fish and Wildlife Scientific Journal | December 29th, 2025

Clear Lake Hitch (Lavinia exilicauda chi) is a native minnow found primarily in Clear Lake, Lake County, California that is listed as threatened under the California Enda

Clear Lake Hitch (Lavinia exilicauda chi) is a native minnow found primarily in Clear Lake, Lake County, California that is listed as threatened under the California Endangered Species Act and has been petitioned for listing under the United States Endangered Species Act. Management interest in Clear Lake Hitch originates, in part, from historical accounts which indicate it was formerly highly abundant and an important resource for Native American Tribes (Moyle 2002; CDFW 2014). A variety of factors are thought to have contributed to a substantial decline in Clear Lake Hitch abundance. These factors include the loss and degradation of stream habitat used for spawning and rearing caused by changes in land and water use in the watershed, and the loss and degradation of lacustrine habitat caused by shoreline development, reclamation of wetlands, and broad-scale changes to biological and physio-chemical components of Clear Lake (Moyle 2002; CDFW 2014).

Still Imperilled, Still Important: The Little Hoover Commission’s Review of the CALFED Program

Little Hoover Commission | November 17th, 2005

The Sacramento-San Joaquin River Delta is a treasured and imperiled resource. And CALFED has been the best hope to restore it. The ambitious state-federal partnership is

The Sacramento-San Joaquin River Delta is a treasured and imperiled resource. And CALFED has been the best hope to restore it. The ambitious state-federal partnership is proof that political will and leadership can resolve seemingly intractable conflicts. And yet in recent years, the program also has demonstrated the propensity for rudderless bureaucracies to get caught in inescapable eddies. It is not too late for the Delta, or for CALFED. But restoring the estuary and managing the resource in a sustainable manner will require continuous political support, expert leadership, and smart management.

Storing Water for the Environment: Operating Reservoirs to Improve California’s Freshwater Ecosystems

Public Policy Institute of California (PPIC) | August 23rd, 2022

Large reservoirs like those that rim the Central Valley are essential for managing water in California’s highly variable climate. They provide multiple benefits includi

Large reservoirs like those that rim the Central Valley are essential for managing water in California’s highly variable climate. They provide multiple benefits including water supply, hydropower, flood management, and recreation. However, construction and operation of these reservoirs have also imposed significant environmental costs, including native fishes’ loss of access to high-quality habitat above dams and degradation of freshwater ecosystems below them. Moreover, regulatory uncertainty for water users is rising as these ecosystems decline. California needs a new approach for managing environmental water in its large reservoirs, particularly as the climate warms and droughts become more intense.

Strategic Forest Reserves can protect biodiversity in the western United States and mitigate climate change

Nature Portfolio (Springer Nature) | December 14th, 2021

Forest preservation is crucial for protecting biodiversity and mitigating climate change. Here we assess current forest preservation in the western United States using sp

Forest preservation is crucial for protecting biodiversity and mitigating climate change. Here we assess current forest preservation in the western United States using spatial data and find that beyond the 18.9% (17.5 Mha) currently protected, an additional 11.1% (10.3 Mha) is needed to achieve 30% preservation by 2030 (30 × 30). To help meet this regional preservation target, we developed a framework that prioritizes forestlands for preservation using spatial metrics of biodiversity and/or carbon within each ecoregion. We show that meeting this preservation target would lead to greater protection of animal and tree species habitat, current carbon stocks, future carbon accumulation, and forests that are important for surface drinking water. The highest priority forestlands are primarily owned by the federal government, though substantial areas are also owned by private entities and state and tribal governments. Establishing Strategic Forest Reserves would help protect biodiversity and carbon for climate adaptation and mitigation.

Strategic Plan to Protect California Coast and Ocean 2020-2025

California Ocean Protection Council (COPC) | February 26th, 2020

Strontium isotopes reveal ephemeral streams used for spawning and rearing by an imperiled potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi

Marine and Freshwater Research (CSIRO Publishing) | April 18th, 2019

Identification of habitats responsible for the successful production and recruitment of rare migratory species is a challenge in conservation biology. Here, a tool was d

Identification of habitats responsible for the successful production and recruitment of rare migratory species is a challenge in conservation biology. Here, a tool was developed to assess life stage linkages for the threatened potamodromous cyprinid Clear Lake hitch Lavinia exilicauda chi. Clear Lake hitch undertake migrations from Clear Lake (Lake County, CA, USA) into ephemeral tributary streams for spawning. An aqueous isoscape of strontium isotopic ratios (87Sr/86Sr) was constructed for Clear Lake and its watershed to trace natal origins and migration histories of adult recruits. Aqueous 87Sr/86Sr differentiated Clear Lake from 8 of 10 key tributaries and clustered into 5 strontium isotope groups (SIGs) with 100% classification success. Otolith 87Sr/86Sr showed all five groups contributed variably to the population. The age at which juveniles migrated from natal streams to Clear Lake ranged from 11 to 152 days (means.d.,4334 days) and was positively associated with the permanency of natal habitat. This information can be used by resource managers to develop conservation actions for Clear Lake hitch. This study demonstrates the utility of strontium isotopes in otoliths as a tool to identify important freshwater habitats occupied over the lifespan of an individual that would otherwise be challenging or impossible to trace with other methods.

Suisun Marsh Monitoring Program Annual Data Summary Water Year 1999

California Department of Water Resources (DWR) | July 31st, 2001

This report summarizes data collected in the Suisun Marsh during Water Year 1999 (October 1, 1998 through September 30, 1999) pursuant to the following agreements, perm

This report summarizes data collected in the Suisun Marsh during Water Year 1999 (October 1, 1998 through September 30, 1999) pursuant to the following agreements, permits, and water rights decisions: • State Water Resources Control Board Decision 1485, August 1978 (SWRCB 1978); • State Water Resources Control Board Order WR 95-6, 1995 (SWRCB 1995a); • Suisun Marsh Preservation Agreement, 1987 (USBR and others 1987); • Suisun Marsh Monitoring Agreement, 1987 (DWR and others 1987); • San Francisco Bay Conservation and Development Commission Permit No. 35-78 (M) Amendment 7, 1997 (for construction of the initial facilities, namely the Roaring River Distribution System, Morrow Island Distribution System, and Goodyear Slough Outfall) (BCDC 1997); • San Francisco Bay Conservation and Development Commission Permit No. 4-84 (M) Amendment 4, 1991 (for construction of the Suisun Marsh Salinity Control Gates) (1991); and, • U.S. Army Corps of Engineers Permit No. 16223E58 (for construction of the Suisun Marsh Salinity Control Gates), Special Condition 1, 1986 (USACE 1986). This report fulfills a portion of the annual reporting requirements of the above-listed, agreements, permits, and water rights decisions as detailed in Table 1. Remaining reporting requirements will be fulfilled in other Department of Water Resources (DWR) and/or University of California Davis reports. DWR and the California Department of Fish and Game (DFG) primarily collected data summarized in this report. The data include • general hydrologic data; • continuous channel water specific conductance and tidal height measurements; • marsh-wide vegetation survey update; • waterfowl abundance; and • salt marsh harvest mouse occurrence.

Summary Matrix of the NMFS and Service Coordinated Long-term Operation BiOps RPA actions

Delta Stewardship Council (Delta Council) | July 1st, 2019

Summary Report on the Transactions of the Smelt Working Group in Water Year 2014

Delta Stewardship Council (Delta Council) | August 29th, 2014

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opi

The Bay‐Delta Fish and Wildlife Office (BDFWO) has prepared this report to summarize the implementation the U.S. Fish and Wildlife Service’s (Service) biological opinion on the Central Valley Project (CVP) and State Water Project (SWP) Long‐term Operations (BiOp) in Water Year (WY) 2014. In addition to background information pertinent to implementation of the BiOp , this report provides a summary of the transactions of the Smelt Working Group (SWG), as well as water operations and during WY 2014. The SWG is a technical team that evaluates biological and technical issues regarding Delta Smelt (Hypomesus transpacificus) and develops recommendations for consideration by the Service during implementation of the BiOp’s Reasonable and Prudent Alternative (RPA) actions. During WY 2014 the SWG made no recommendations for more restrictive water operations and the Service issued no determinations to reduce water exports.