Local hydraulics influence habitat selection and swimming behavior in adult California Central Valley Chinook salmon at a large river confluence

Fisheries Research (Elsevier) | February 2nd, 2023

Long-term variation in concentrations and mass loads in a semi-arid watershed influenced by historic mercury mining and urban pollutant sources

Science of the Total Environment (Elsevier) | December 15th, 2017

Urban watersheds are significantly anthropogenically-altered landscapes. Most previous studies cover relatively short periods, without addressing concentrations, loads, a

Urban watersheds are significantly anthropogenically-altered landscapes. Most previous studies cover relatively short periods, without addressing concentrations, loads, and yields in relation to annual climate fluctuations, and datasets on Ag, Se, PBDEs, and PCDD/Fs are rare. Intensive storm-focused sampling and continuous turbidity monitoring were employed to quantify pollution at two locations in the Guadalupe River (California, USA). At a downstream location, we determined loads of suspended sediment (SS) for 14 yrs., mercury (HgT), PCBs, and total organic carbon (TOC) (8 yrs), total methylmercury (MeHgT) (6 yrs), nutrients, and trace elements including Ag and Se (3 yrs), DDTs, chlordanes, dieldrin, and PBDEs (2 yrs), and PCDD/Fs (1 yr). At an upstream location, we determined loads of SS for 4 yrs. and HgT, MeHgT, PCBs and PCDD/Fs for 1 yr. These data were compared to previous studies, climatically adjusted, and used to critically assess the use of small datasets for estimating annual average conditions. Concentrations and yields in the Guadalupe River appear to be atypical for total phosphorus, DDTs, dieldrin, HgT, MeHgT, Cr, Ni, and possibly Se due to local conditions. Other pollutants appear to be similar to other urban systems. On average, wet season flow varied by 6.5-fold and flow-weighted mean (FWM) concentrations varied 4.4-fold, with an average 7.1-fold difference between minimum and maximum annual loads. Loads for an average runoff year for each pollutant were usually less than the best estimate of long-term average. The arithmetic average of multiple years of load data or a FWM concentration combined with mean annual flow was also usually below the best estimate of long-term average load. Mean annual loads using sampled years were also less than the best estimate of long-term average by a mean of 2.2-fold. Climatic adjustment techniques are needed for computing estimates of long-term average annual loads.

Los Angeles Department of Water & Power response to Mono Lake Committee Request for a Drought Emergency Regulation

California State Water Resources Control Board (SWRCB) | January 11th, 2023

Los Angeles Department of Water and Power 2016 Annual Owens Valley Report

Los Angeles Department of Water & Power (LADWP) | December 1st, 2015

This report includes Los Angeles Department of Water and Power’s (LADWP) proposed Owens Valley operations plan for the first six months of the 2016-17 runoff year, an u

This report includes Los Angeles Department of Water and Power’s (LADWP) proposed Owens Valley operations plan for the first six months of the 2016-17 runoff year, an update on Owens Valley conditions, the current status of LADWP’s environmental mitigation projects, and the status of other studies, projects, and activities.

Loss and Transformation of Coastal Wetlands due to Global Change in the Conterminous United States: Past, Present, and Future

Publisher not available | June 26th, 2026

Coastal wetlands are being transformed by global change, impacting the ecological and societal benefits provided by these ecosystems. Synthesizing knowledge of historical

Coastal wetlands are being transformed by global change, impacting the ecological and societal benefits provided by these ecosystems. Synthesizing knowledge of historical and expected future transformations in coastal wetlands can help inform forward-looking planning and stewardship efforts. Here, we review anticipated future ecological transformations in coastal wetlands of the conterminous United States and contrast them with past transformations. We examine trends at the national scale but focus in detail on the following six wetland-rich regions: (1) Everglades, (2) Mississippi River delta, (3) Chesapeake Bay, (4) San Francisco Estuary, (5) Puget Sound, and (6) Great Lakes. This review is among the first to integrate and compare coastal wetland transformations in the Great Lakes with their oceanic counterparts. Between 1850 and 1970, wetland losses across the nation were high because coastal wetlands were viewed as flooded wastelands needing to be drained, filled, or excavated to make room for other land uses. Over the last 50 years, growing public and scientific appreciation of the ecological and societal benefits provided by coastal wetlands has fostered tremendous gains in wetland restoration and legal protection. Looking to the future, climate change and accelerated sea-level rise have become critical threats to coastal wetlands and are emerging as major drivers of ecological loss and transformation. This review synthesizes regional knowledge regarding past, present, and future changes to help coastal scientists, environmental managers, and the public better anticipate and prepare for future coastal wetland transformations due to climate change, accelerated sea-level rise, land-use change, and other aspects of global change.

Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | June 30th, 2008

Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of

Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha) and delta smelt (Hypomesus transpacificus) to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults) corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young). These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15%) although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%). The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

Lower Peninsula Watershed Condition Assessment 2016: Southwest San Francisco Bay, Santa Clara County, San Francisquito to Stevens Creeks. Technical memorandum prepared for the Santa Clara Valley Water District

San Francisco Estuary Institute (SFEI) | October 2nd, 2017

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the C

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the California Rapid Assessment Method (CRAM), for the Lower Peninsula watershed in Santa Clara County; consisting of Stevens-Permanente Creek, Adobe Creek, southern extent of San Francisquito Creek, and their tributaries. The Lower Peninsula watershed covers approximately 98 square-miles with creeks flowing from the Santa Cruz Mountains into southwest San Francisco Bay and its tidal wetlands.  The Santa Clara Valley Water District’s (District) Safe, Clean Water and Natural Flood Protection Program has many priorities, including Priority D for restoring and protecting vital wildlife habitat, and providing opportunities for increased access to trails and open space. The D5 Project focuses on ecological data collection and analysis at a watershed scale to support the District, other County agencies and organizations in making informed ecological asset management decisions. The key performance indicators (KPIs) for D5 are to:  1. Establish new or track existing ecological levels of service for streams in 5 watersheds.  2. Reassess streams in 5 watersheds to determine if ecological levels of service are maintained or improved. 

Lower Peninsula Watershed Condition Assessment 2016. Technical memorandum prepared for the Santa Clara Valley Water District - Priority D5 Project

San Francisco Estuary Institute (SFEI) | October 2nd, 2017

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the C

This report describes baseline information about the amount and distribution of aquatic resources, and evaluates that overall ecological conditions of streams using the California Rapid Assessment Method (CRAM), for the Lower Peninsula watershed in Santa Clara County; consisting of Stevens-Permanente Creek, Adobe Creek, southern extent of San Francisquito Creek, and their tributaries. The Lower Peninsula watershed covers approximately 98 square-miles with creeks flowing from the Santa Cruz Mountains into southwest San Francisco Bay and its tidal wetlands.

Making Nature's City: A science-based framework for building urban biodiversity

San Francisco Estuary Institute (SFEI) | July 1st, 2019

Cities will face many challenges over the coming decades, from adapting to a changing climate to accommodating rapid population growth. A related suite of challenges th

Cities will face many challenges over the coming decades, from adapting to a changing climate to accommodating rapid population growth. A related suite of challenges threatens global biodiversity, and many species face potential extinction. While urban planners and conservationists have long treated these issues as distinct, there is growing evidence that cities not only harbor a significant fraction of the world’s biodiversity, but that they can also be made more livable and resilient for people, plants, and animals through nature-friendly urban design. Urban ecological science can provide a powerful tool to guide cities towards more biodiversity-friendly design. However, current research remains scattered across thousands of journal articles and largely inaccessible to practitioners. Making Nature’s City fills this gap, synthesizing global research to develop a science-based approach for supporting nature in cities. We identify seven key elements of urban form and function that work together to maximize biodiversity, and we illustrate these elements through a case study in California’s Silicon Valley. Using the framework developed in this report, urban designers and local residents can work together to link local parks, greenways, green roofs, street trees, stormwater basins, commercial landscaping, and backyards to support biodiversity while making cities better places to live. As we envision the healthier, and more resilient cities, Making Nature’s City provides practical guidance for the many actors who together will shape the nature of cities.

Making the Delta a Better Place for Native Fishes

Orange County Coastkeeper | March 1st, 2018

The Sacramento-San Joaquin Delta is the heart of California’s water delivery system, connecting the precipitation-rich regions of the north with the dry farmlands and

The Sacramento-San Joaquin Delta is the heart of California’s water delivery system, connecting the precipitation-rich regions of the north with the dry farmlands and demanding urban areas of the south and coast, including the Bay Area. Scarce water resources create conflicts between people and fishes; as demand by people for water grows, less water is available for the environment. This white paper explores the ways to keep the native fishes, and the functional ecosystems they require, from disappearing. Our analysis is fish-oriented because salmon, smelt, and other declining fishes are major drivers of decisions on where to focus aquatic restoration efforts.  The goals of this white paper are to first provide a brief introduction to the Delta and then to describe why restoration of native fishes and natural processes is such a challenge in this system. We follow this with some general guidelines for restoration projects in the Delta and apply those guidelines with a project evaluation tool. We used this tool to evaluate 26 projects, mostly part of EcoRestore, to provide insights to help determine action items. We then present 17 action items, listed below, some of which can be accomplished fairly quickly, some that will take longer, and few that will have to be continuous. But taken together, our recommended actions could significantly improve the welfare of native fishes and help to create a novel aquatic ecosystem with many desirable features.