Viability assessment for Pacific salmon and steelhead listed under the Endangered Species Act

National Marine Fisheries Service (NMFS) | July 25th, 2016

The Endangered Species Act (ESA) requires that the National Marine Fisheries Service (NMFS) review the status of listed species under its authority at least every five ye

The Endangered Species Act (ESA) requires that the National Marine Fisheries Service (NMFS) review the status of listed species under its authority at least every five years and determine whether any species should be removed from the list or have its listing status changed. Assessments of the viability of ESA-listed Pacific salmonids were conducted by the Southwest Fisheries Science Center and the Northwest Fisheries Science Center. The information from these assessments is incorporated into the West Coast Region’s status review, and the NMFS West Coast Region will make final determinations about any proposed changes in listing status, taking into account not only biological information (viability assessments) but also threats to the species and ongoing or planned protective efforts. This report from the Southwest Fisheries Science Center covers 10 ESA-listed Evolutionarily Significant Units (ESUs) and Distinct Population Segments (DPSs) that lie wholly or partially in California. In this review, we consider 1) new information relevant to the delineation of ESU/DPS boundaries, and 2) new information on status and trends in abundance, productivity, spatial structure and diversity specifically addressed by viability criteria previously developed by Technical Recovery Teams (TRTs). These viability assessments summarize current information (through the 2014–2015 spawning year where available) with respect to the viability criteria developed by the TRTs.  Consequently, the current assessments consider not only changes in populations that have occurred since the 2010 assessments but also the status of populations and ESUs/DPSs in relation to the viability criteria developed by the TRTs. For eight of the ESUs/DPSs (Southern Oregon/Northern California Coho Salmon, Central California Coast Coho Salmon, California Coastal Chinook Salmon, Northern California Steelhead, Central California Coast Steelhead, South-central California Steelhead, Southern California Steelhead, and California Central Valley Steelhead) the new information suggests that there has been no change in extinction risk since 2010 viability assessments. For two ESUs (Central Valley Spring-run Chinook Salmon, and Sacramento River Winter-run Chinook Salmon) the new information suggests a change in extinction risk. The viability of Central Valley Spring-run Chinook salmon appears to have improved since the 2010 assessment, but this ESU is far from being viable and is still facing relatively high extinction risk. The viability of Sacramento River Winter-run Chinook Salmon has been reduced and the ESU faces greater extinction risk since the 2010 assessment.

Visual, spectral, and microchemical quantification of crystalline anomalies in otoliths of wild and cultured delta smelt

Nature Portfolio (Springer Nature) | December 1st, 2022

Developmental abnormalities in otoliths can impact growth and survival in teleost fishes. Here, we quantified the frequency and severity of developmental anomalies in oto

Developmental abnormalities in otoliths can impact growth and survival in teleost fishes. Here, we quantified the frequency and severity of developmental anomalies in otoliths of delta smelt (Hypomesus transpacificus), a critically endangered estuarine fish that is endemic to the San Francisco Estuary. Left–right asymmetry and anomalous crystalline polymorphs (i.e., vaterite) were quantified and compared between wild and cultured populations using digital image analysis. Visual estimates of vaterite were validated using X-ray diffraction, Raman spectroscopy, laser ablation ICPMS, and electron probe microanalysis. Results indicated that cultured delta smelt were 80 times more likely to contain a vateritic otolith and 18 times more likely to contain relatively large (≥ 15%) amounts of vaterite. Similarly, cultured fish exhibited 30% greater asymmetry than wild fish. These results indicate that cultured delta smelt exhibit a significantly higher frequency of vestibular abnormalities which are known to reduce fitness and survival. Such hatchery effects on otolith development could have important implications for captive culture practices and the supplementation of wild fish populations with cultured individuals.

Water Ages Explain Tradeoffs Between Long-Term Evapotranspiration and Ecosystem Drought Resilience

American Geophysical Union (AGU) | May 23rd, 2023

Water and Suspended-Sediment Flux Measurements at the Golden Gate, 2016-2017

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

Sediment is an important resource for San Francisco Bay (SFB), in the context of restoration projects, dredging operations, ecosystem health, and contaminant transport an

Sediment is an important resource for San Francisco Bay (SFB), in the context of restoration projects, dredging operations, ecosystem health, and contaminant transport and fate. Understanding the transport and fate of sediment in SFB is important to ecosystem researchers and managers. Previous studies have shown that sediment exchange at the estuary-ocean boundary of SFB (Golden Gate inlet) is the most poorly understood element of the SFB sediment budget, owing to logistical challenges that inhibit routine field observations, and the fact that net flux is a small fraction of the instantaneous peak values experienced on a daily basis. Improved understanding of sediment exchange at the estuary-ocean boundary of SFB is essential to updating SFB-wide sediment budgets, which account for sources, sinks, and storage of sediment (and sediment-associated contaminants). In this study, field observations of water and suspended-sediment fluxes at the Golden Gate were made over one ebb tide and one flood tide on three occasions: 1) 21-22 March 2016, following a large storm event that triggered the first flow into Yolo Bypass flood control structure since 2011 2) 23 June of 2016, during a period of low freshwater inflow; 3) 27-28 February 2017, following several large storms of the wettest winter in northern California in recorded history.

Water for a Growing Bay Area: How the region can grow without increasing water demand

Pacific Institute | October 21st, 2021

The San Francisco Bay Area is at a crossroads. The region, blessed with a beautiful natural setting, multiple shipping ports and world-class universities, is a driver of

The San Francisco Bay Area is at a crossroads. The region, blessed with a beautiful natural setting, multiple shipping ports and world-class universities, is a driver of global economic growth. But the region’s housing supply has not kept up with population growth. Many low-income households, disproportionately made up of people of color, have been forced into overcrowded and substandard housing or displaced from the urban center to new neighborhoods far from their jobs, friends and families. The most vulnerable have lost their homes entirely and are among the region’s 35,000 unhoused people. Over the next half-century, the Bay Area’s need to add housing will only grow more intense. The region is projected to add 2 million new jobs by 2070, which would attract as many as 6.8 million people, and needs to build at least 2.2 million new housing units just to prevent housing affordability from worsening. This represents 83% more people, 74% more housing units and 38% more jobs over the next 50 years.

Water is a master variable: Solving for resilience in the modern era

Water Security, Elsevier | November 21st, 2019

Resilience is increasingly recognized as an imperative for any prospect of sustainable development, as it relates to our ability to sustain human well-being and progress

Resilience is increasingly recognized as an imperative for any prospect of sustainable development, as it relates to our ability to sustain human well-being and progress under the planetary and societal changes that we face now and into the future. Yet, we are ill-prepared to meet this challenge. We neither fully understand nor manage consistently for resilience of the human and natural systems that we must steward through extraordinary change. A unifying approach and common currency would help us to understand and manage for resilience under uncertain futures. Water is an essential, defining element in human and natural systems. Human civilization and water systems have co-evolved as a coupled system, with the majority of natural freshwater systems transformed to meet our demands. Shifting patters of water availability in space and time will define key pathways and tipping points for our resilience, and thus requirements for water system resilience must guide the trajectories and boundaries of human development. Here, we consider the thesis that water offers a key to unlocking the complex challenge of designing and managing for the resilience of coupled human-natural systems. We examine what constitutes a resilient system, what drives freshwater resilience, and how pathways to human resilience may be charted and navigated through the medium of water. Our theoretical treatise frames a portfolio of research that tests this thesis, including modeling and applications to water and water-dependent systems.

Water Management Companion Plan (to the Statewide Wildlife Action Plan)

California Department of Fish and Wildlife (CDFW) | December 21st, 2016

The California State Wildlife Action Plan 2015 Update provides a vision and a framework for conserving California’s diverse natural heritage. SWAP 2015 also calls for t

The California State Wildlife Action Plan 2015 Update provides a vision and a framework for conserving California’s diverse natural heritage. SWAP 2015 also calls for the development of a collaborative framework to sustainably manage ecosystems across the state in balance with human uses of natural resources. To address the need for a collaborative framework, California Department of Fish and Wildlife (CDFW), Blue Earth Consultants, LLC (Blue Earth), and partner agencies and organizations undertook the preparation of companion plans for SWAP 2015. While this document reports on the progress made thus far on collaboration, the intent is to set a stage for achieving the state’s conservation priorities through continued partnerships and by mutually managing and conserving natural and cultural resources.

Water management in mediterranean river basins: a comparison of management frameworks, physical impacts, and ecological responses

Hydrobiologia (Springer) | September 11th, 2012

Rivers in mediterranean climates have been extensively modified by water management infrastructure and practices, yet patterns of development and consequent effec

Rivers in mediterranean climates have been extensively modified by water management infrastructure and practices, yet patterns of development and consequent effects on freshwater ecosystems have not been compared across multiple regions. To evaluate the influence of water management on mediterranean-climate rivers, we compare the historic progression of management policies, institutions, and ecosystem impacts in the Sacramento River (California, USA), Ebro River (Spain), and Biobío River (Chile) basins. There are broad similarities in patterns of ecosystem alterations related to the extensive development of dams and water management infrastructure in the three study basins. Flow regimes have been altered by the reduction of winter peak flows and increased summer baseflows. There are also common patterns of disturbance from sediment transport alteration, water quality degradation, and declines in freshwater biodiversity. Current approaches are inadequate for addressing the formidable water management challenges in California, Spain, and Chile, yet the dramatic evolution of water policies and institutions over the past 150 years suggests that further adaptation is possible. Advances toward integrated and sustainable water management models are likely to occur through incremental change, driven by growing awareness of climate change effects and public demands for water-use efficiency and improved environmental quality.  

Water Quality Challenges in the San Francisco Bay/ Sacramento-San Joaquin Delta Estuary: EPA’s Action Plan

U.S. Environmental Protection Agency (EPA) | August 22nd, 2012

The U.S. Environmental Protection Agency (EPA) developed this Action Plan after assessing the effectiveness of current regulatory mechanisms designed to protect water qua

The U.S. Environmental Protection Agency (EPA) developed this Action Plan after assessing the effectiveness of current regulatory mechanisms designed to protect water quality in the San Francisco Bay Sacramento-San Joaquin Delta Estuary (Bay Delta Estuary) and its tributaries. EPA’s assessment concludes that Clean Water Act (CWA) programs currently are not adequately protecting aquatic resources of the Bay Delta Estuary. In this document, EPA recommends actions to restore water quality for aquatic species protection using existing EPA authorities and resources, as well as actions EPA believes are important and appropriate for the State Water Resources Control Board (State Water Board). EPA is one of more than 25 state and federal governmental agencies with responsibilities in the Bay Delta Estuary. EPA’s major statutory mission in the Estuary is to implement the CWA. EPA has delegated many CWA program authorities to the State Water Board while providing financial support,1 technical assistance, and oversight (including, in some cases, review and approval of State actions). Much of EPA's work in this Action Plan (as well as elsewhere in California) is done in support of and in partnership with the State. For example, water quality standards, which define water quality goals for our waterbodies, are typically developed and adopted by the State with EPA assistance, review, and ultimately, approval or disapproval. In the Bay Delta Estuary, EPA focuses on assuring that the many designated uses of the Estuary’s aquatic resources are protected. EPA emphasizes the CWA goals of maintaining and improving water quality – the chemical, physical, and biological integrity of the water – to ensure the Bay Delta Estuary can function as a vibrant, healthy estuary. About 90 species of fish are found in the Delta. The Delta’s channels serve as a migratory route and nursery area for Chinook salmon, striped bass, white and green sturgeon, American shad, and steelhead trout. These anadromous fish spend most of their adult lives either in the lower bays of the Estuary or in the ocean. Resident fish in the Estuary include delta smelt, longfin smelt, Sacramento splittail, catfish, largemouth bass, black bass, crappie, and bluegill. All Bay Delta Estuary waters are impaired by one or more contaminants. In addition, the reduction in the quantity and quality of estuarine habitat limits the Estuary’s ability to support aquatic species. EPA’s Action Plan describes a suite of activities to: 1. Strengthen water quality standards to protect estuarine habitat 2. Advance regional water quality monitoring and assessment 3. Accelerate water quality restoration through Total Maximum Daily Loads 4. Strengthen selenium water quality criteria 5. Prevent pesticide pollution 6. Restore aquatic habitats while managing methylmercury 7. Support the Bay Delta Conservation Plan Collectively, these activities will contribute to the restoration of the Bay Delta Estuary. Even if they are all successfully implemented, however, they are not sufficient to resolve the complex problems that have stressed the ecosystem to the point of collapse. Any solution to the ecological problems of the Bay Delta Estuary must be multi-faceted, including providing sufficient flows, physical habitat which is sufficiently large, connected, diverse, and self-sustaining, as well as a reduction of many types of stressors, such as contaminants, invasive species, and predation.

Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969–2015

Nature Portfolio (Springer Nature) | August 8th, 2017

The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest reco

The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.