A brief geologic and hydrologic reconnaissance of the Furnace Creek Wash area, Death Valley National Monument, California

U.S. Geological Survey (USGS) | July 1st, 1964

A conceptual model for floodplains in the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | October 3rd, 2012

Floodplains are among the most biologically productive and diverse ecosystems on Earth and they provide significant benefits to society such as attenuation of floodwaters

Floodplains are among the most biologically productive and diverse ecosystems on Earth and they provide significant benefits to society such as attenuation of floodwaters, groundwater recharge, filtration of nutrients and sediments, carbon sequestration, fisheries productivity and recreation.  However, floodplains are also among the most converted and threatened ecosystems.  Floodplain habitats in the Sacramento-San Joaquin Delta, and throughout California’s Central Valley, have been greatly reduced from their historic extent and key processes that create and maintain floodplains, such as flood flows and meander migration, have been greatly altered.  These widespread alterations to habitats and processes have lead to declines in many species’ populations in California’s Central Valley and Delta, creating challenges for both environmental and water management. To address these challenges numerous entities and programs are now focused on restoring floodplains and other Delta habitats.  This paper provides a conceptual model for floodplains that characterizes the key features and identifies the critical processes, drivers, and linkages that allow floodplains to produce a variety of functional outputs of management importance.  These outputs include: (1) the floodplain habitat mosaic, including riparian vegetation and its associated wildlife; (2) spawning and rearing habitat for native fish; and (3) food-web productivity that can support native fish on the floodplain as well as be exported to downstream ecosystems.  The model emphasizes that the production of these outputs from floodplains requires vertical and lateral hydrological connectivity across a broad range of flow conditions.  For example, long-duration flooding in the spring promotes native fish spawning and food-web productivity that benefits native species.

A Delta Renewed: A Guide to Science-Based Ecological Restoration in the Sacramento-San Joaquin Delta

San Francisco Estuary Institute (SFEI) | November 15th, 2016

This final report of the Delta Landscapes Project, A Delta Renewed, offers guidance for creating and maintaining landscapes that can provide desired ecological functi

This final report of the Delta Landscapes Project, A Delta Renewed, offers guidance for creating and maintaining landscapes that can provide desired ecological functions for decades to come. Based on extensive research into how the Sacramento-San Joaquin Delta used to function, how it has changed, and how it is likely to evolve, we make recommendations for how to re-establish the dynamic natural processes that can sustain native Delta wildlife as healthy populations into the future. The approach, building on work others have piloted and championed, is to restore or emulate natural processes where possible, establish an appropriate configuration of habitat types at the landscape scale, and use multi-benefit management strategies to create a more viable Delta ecosystem that can adapt and continue to provide valued functions as the climate changes. This approach is designed to integrate with the human landscape: ecosystem improvements as a part of a robust agricultural economy, water infrastructure and diversions, and urbanized areas. Strategic restoration which builds on the history and ecology of the region can contribute to the strong sense of place and recreational value of the Delta in the future. See more at: http://www.sfei.org/projects/delta-landscapes-project#sthash.RryQdaII.dpuf

A Delta Transformed: Ecological Functions, Spatial Metrics, and Landscape Change in the Sacramento-San Joaquin Delta

San Francisco Estuary Institute (SFEI) | October 1st, 2014

In A Delta Transformed, completed in 2014, SFEI researchers used the spatial data generated in the Delta Historical Ecology Investigation, as well as updated modern veget

In A Delta Transformed, completed in 2014, SFEI researchers used the spatial data generated in the Delta Historical Ecology Investigation, as well as updated modern vegetation and land cover datasets, to carry out detailed analyses of how the Delta landscape has been altered since the early-1800s. By quantifying changes in metrics relevant to native wildlife (such as the extent and timing of inundation, habitat patch sizes, length of channel networks), the report provides a foundation for defining, designing, and evaluating landscapes that support desirable ecological functions in the future. See more at: http://www.sfei.org/projects/delta-landscapes-project#sthash.RryQdaII.dpuf

A freshwater conservation blueprint for California: prioritizing watersheds for freshwater biodiversity

Society for Freshwater Science | April 18th, 2018

Conservation scientists have adapted conservation planning principles designed for protection of habi- tats ranging from terrestrial to freshwater ecosystems. We

Conservation scientists have adapted conservation planning principles designed for protection of habi- tats ranging from terrestrial to freshwater ecosystems. We applied current approaches in conservation planning to prioritize California watersheds for management of biodiversity. For all watersheds, we compiled data on the pre- sence/absence of herpetofauna and fishes; observations of freshwater-dependent mammals, selected invertebrates, and plants; maps of freshwater habitat types; measures of habitat condition and vulnerability; and current manage- ment status. We analyzed species-distribution data to identify areas of high freshwater conservation value that op- timized representation of target taxa on the landscape and leveraged existing protected areas. The resulting priority network encompasses 34% of the area of California and includes ≥10% of the geographic range for all target taxa. High-value watersheds supported nontarget freshwater taxa and habitats, and focusing on target taxa may provide broad conservation value. Most of the priority conservation network occurs on public lands (69% by area), and 46% overlaps with protected areas already managed for biodiversity. A significant proportion of the network area is on private land and underscores the value of programs that incentivize landowners to manage freshwater species and habitats. The priority conservation areas encompass more freshwater habitats/ha than existing protected areas. Land use (agriculture and urbanization), altered fire regimes, nonnative fish communities, and flow impairment are the most important threats to freshwater habitat in the priority network, whereas factors associated with changing climate are the key drivers of habitat vulnerability. Our study is a guide to a comprehensive approach to freshwater conservation currently lacking in California. Conservation resources are often limited, so prioritiza- tion tools are valuable assets to land and water managers.

A functional flows approach to selecting ecologically relevant flow metrics for environmental flow applications

River Research and Applications (Wiley) | January 8th, 2020

A General Framework for Analyzing Sustainability of Social-Ecological Systems

American Association for the Advancement of Science (AAAS) | July 24th, 2009

A major problem worldwide is the potential loss of fisheries, forests, and water resources. Understanding of the processes that lead to improvements in or deterioration o

A major problem worldwide is the potential loss of fisheries, forests, and water resources. Understanding of the processes that lead to improvements in or deterioration of natural resources is limited, because scientific disciplines use different concepts and languages to describe and explain complex social-ecological systems (SESs). Without a common framework to organize findings, isolated knowledge does not cumulate. Until recently, accepted theory has assumed that resource users will never self-organize to maintain their resources and that governments must impose solutions. Research in multiple disciplines, however, has found that some government policies accelerate resource destruction, whereas some resource users have invested their time and energy to achieve sustainability. A general framework is used to identify 10 subsystem variables that affect the likelihood of self-organization in efforts to achieve a sustainable SES.

A global spatial analysis reveals where marine aquaculture can benefit nature and people

PLOS | October 9th, 2019

Aquaculture of bivalve shellfish and seaweed represents a global opportunity to simultaneously advance coastal ecosystem recovery and provide substantive benefits to hum

Aquaculture of bivalve shellfish and seaweed represents a global opportunity to simultaneously advance coastal ecosystem recovery and provide substantive benefits to humanity. To identify marine ecoregions with the greatest potential for development of shellfish and seaweed aquaculture to meet this opportunity, we conducted a global spatial analysis using key environmental (e.g., nutrient pollution status), socioeconomic (e.g., governance quality), and human health factors (e.g., wastewater treatment prevalence). We identify a substantial opportunity for strategic sector development, with the highest opportunity marine ecoregions for shellfish aquaculture centered on Oceania, North America, and portions of Asia, and the highest opportunity for seaweed aquaculture distributed throughout Europe, Asia, Oceania, and North and South America. This study provides insights into specific areas where governments, international development organizations, and investors should prioritize new efforts to drive changes in public policy, capacity-building, and business planning to realize the ecosystem and societal benefits of shellfish and seaweed aquaculture.

A Historical Perspective of the Interagency Ecological Program: Bridging Multi-Agency Studies into Ecological Understanding of the Sacramento-San Joaquin Delta and Estuary for 40 Years

Interagency Ecological Program (IEP) | February 8th, 2013

The Interagency Ecological Program (IEP) has been in existence in some form for almost 50 years. As the San Francisco Estuary evolved due to natural and man-caused pertur

The Interagency Ecological Program (IEP) has been in existence in some form for almost 50 years. As the San Francisco Estuary evolved due to natural and man-caused perturbations, the IEP has responded by creating and re-creating itself to ensure the best understanding of the Estuary as it was influenced by water project implementation. The goal of the IEP has always been to provide this understanding to managers responsible for water project implementation in the most protective and efficient manner given social, political, and environmental constraints. On the whole, IEP has done an outstanding job of providing consistently useful data and information in a highly complex environment. As new programs and constraints are developed to cope with the ever changing natural environment and demands of society, an understanding of the history of IEP is valuable, and to learn from past experience is wise. This descriptive history is meant to document in some detail the development, strengths, and weaknesses of this one-of-a-kind multi-agency consortium that has attempted to bridge the gap between water management and estuarine science in the most significant Estuary on the west coast of North America. Sources of information for this account are personal interviews with program participants, annual reports, IEP Newsletters, coordinator meeting summaries, director meeting summaries, management team meeting notes, and personal experiences of the author. This history may err on the side of excessive detail, but that has been intentional; the author believes it is important to have detailed information available in a single reference so that interested parties can readily obtain knowledge about IEP. Some individuals may not want to read the entire report, but can easily be guided to topics of interest by consulting Appendix A, which lists significant events that influenced the IEP by page number in the report.

A Literature Review and Hypsometric Analysis to Support Decisions on Trout Management Flows on the Colorado River Downstream from Glen Canyon Dam

U.S. Geological Survey (USGS) | August 7th, 2024

Fish stranding has been studied in select rivers worldwide, often with the purpose of determining how to mitigate adverse effects of dam operations on highly valued salmo

Fish stranding has been studied in select rivers worldwide, often with the purpose of determining how to mitigate adverse effects of dam operations on highly valued salmon and trout populations. However, where a reduction in trout population size is desired by resource managers, as is the case downstream of the Glen Canyon Dam on the Colorado River, flow manipulations termed trout management flows (TMFs) may be used to optimize fish stranding and mortality. To inform the design and implementation of potential future TMFs, we reviewed relevant literature to identify key factors that influence fish stranding. We found that key factors were highly interdependent and site-specific, but general trends suggest that down-ramping (decreasing flow) at rapid rates in daytime during the late spring to summer emergence period would lead to stranding of age-0 rainbow trout in shallow shoreline habitat. A hypsometric analysis was then used to predict stranding risk for age-0 rainbow trout in Glen Canyon for a range of TMFs, which incorporated existing bathymetric data and flow and habitat suitability models. Our results indicate that a TMF with a steady high flow ranging from 12,000 to 16,000 cubic feet per second (ft3/s) combined with a minimum flow ranging from 3,000 to 5,000 ft3/s may effectively strand age-0 fish while also minimizing risk to water storage in Lake Powell and other resources. This strategy implemented under normal hydropeaking operations was predicted to lead to a substantive stranding risk when paired with low flows of 5,000 ft3/s, and especially 3,000 ft3/s. However, there remains uncertainty associated with elements of implementing an effective TMF downstream from Glen Canyon Dam. The main uncertainties include (1) the down-ramp rate that maximizes stranding of age-0 trout, (2) the duration of drawdown to maximize stranding mortality while minimizing impact to downstream resources, (3) duration of high flows required for age-0 fish to colonize newly created shoreline habitat (this is only for certain TMF hydrographs), (4) number of repetitions of TMF cycles to minimize compensatory survival response, and (5) recruitment threshold of both rainbow and brown trout populations to trigger TMF implementation.