Assessing Regional Strategies to Cope with Drought, Climate, and Environmental Flow Policy Impacts for a Sustainable Water Supply: A Case Study of the Bay Area

American Chemical Society (ACS) | December 27th, 2024

Assessing the Impact of Periodic Dredging on Macroinvertebrate Prey Availability for Benthic Foraging Fishes

U.S. Geological Survey (USGS) | July 1st, 2017

Due to its importance for special status fish, the San Francisco Bay (SFB) estuary has been designated as Essential Fish Habitat (EFH) under the Magnuson-Stevens Fishery

Due to its importance for special status fish, the San Francisco Bay (SFB) estuary has been designated as Essential Fish Habitat (EFH) under the Magnuson-Stevens Fishery Conservation and Management Act ([MSA; 16 U.S.C. 18559b)]. Within this estuary, benthic macroinvertebrate communities provide important prey resources for many economically significant fish species that rely on EFH. Periodic maintenance dredging can impact these infaunal communities; however, there is a lack of scientific information specific to SFB on the degree of benthic community disruption caused by dredging. In addition, rates of benthic community recolonization and recovery following dredging and subsequent effects on foraging fish are unknown. For this reason, it is difficult for regulatory and resource agencies to determine the impacts of maintenance dredging. Thus, the National Marine Fisheries Service (NMFS) and the consortium of agencies (US Environmental Protection Agency (EPA), US Army Corp of Engineers (USACE), San Francisco Regional Water Quality Control Board (SFRWQCB), and San Francisco Bay Conservation and Development Commission (BCDC)) comprising the San Francisco Bay Long Term Management Strategy for Dredging (LTMS) effort identified a study of dredging impacts on SFB fish foraging habitat as one of their highest priorities in their 2011 Programmatic EFH Agreement. 

Assessing the presence of current-use pesticides in mid-elevation Sierra Nevada streams using passive samplers, California, 2018–19

U.S. Geological Survey (USGS) | February 9th, 2023

Passive sampler devices were deployed in six northern California streams five times between November 2018 and December 2019 to measure the presence or absence of current-

Passive sampler devices were deployed in six northern California streams five times between November 2018 and December 2019 to measure the presence or absence of current-use pesticides in surface water. In the targeted areas, there are reported pesticide uses for agriculture, commercial forestry, and rights of way maintenance along with unreported pesticide use at private residences and cannabis grow sites. The sites sampled in this study were not previously monitored for current-use pesticides. Streams in the Sierra Nevada foothills of northern California are important habitats for many sensitive species including salmonids, but the logistics of sampling these areas can be difficult using traditional water-quality sampling techniques, especially when sampling watersheds where contaminant transport is episodic. Chemcatcher passive sampling devices and silicone bands were deployed in these areas to concentrate pesticides for days to weeks at a time. The U.S. Geological Survey, in cooperation with the Central Valley Regional Water Quality Control Board, was responsible for developing passive sampler field deployment and laboratory analytical methods for current-use pesticides, providing pesticide measurements from streams in the study region, and determining how well passive samplers detect pesticides in these environments. Six sites were monitored during the study, and passive sampler extracts were analyzed for a total 155 current-use pesticides in this study. A total of 19 out of the 155 pesticides including 9 insecticides, 5 fungicides, and 5 herbicides were detected in extracts from passive samplers. The most frequently detected pesticides were the herbicides hexazinone and dithiopyr, the insecticides bifenthrin and methoxyfenozide, and the fungicide azoxystrobin.

Assessment of Nutrient Status and Trends in the Delta in 2001–2016: Effects of drought on ambient concentrations and trends

San Francisco Estuary Institute (SFEI) | March 1st, 2018

Nutrients and the effects of nutrients on water quality in the Sacramento-San Joaquin Delta is a priority focus area for the Delta Regional Monitoring Program (Delta RMP)

Nutrients and the effects of nutrients on water quality in the Sacramento-San Joaquin Delta is a priority focus area for the Delta Regional Monitoring Program (Delta RMP). The Program’s first assessment question regarding nutrients is: “How do concentrations of nutrients (and nutrient-associated parameters) vary spatially and temporally?” In this analysis, we confirmed previously reported declining trends in the San Joaquin River for nutrient concentrations at Vernalis and chlorophyll-a concentrations at Buckley Cove and Disappointment Slough. A slight increasing trend for dissolved oxygen at Buckley Cove was also detected which could be confirmation that management actions for the San Joaquin River Dissolved Control Program are having the desired effect. Finally, at stations in Suisun Bay, the Confluence region, and Franks Tract, chlorophyll-a showed modest increasing trends, which were not evident in previous analyses. The new analyses presented in this report and the findings from earlier reports constitute encouraging early progress toward answering the Delta RMP’s assessment questions. Specifically, due to the existence of long-term data sets and synthesis efforts, spatial and temporal trends in the concentrations of nutrients and nutrient-related parameters are reasonably well understood and so are the magnitudes of the most important sources of nutrients from outside the Delta. However, additional synthesis work could be done to understand the factors behind these trends. Large knowledge gaps remain about nutrient sinks, sources, and processes within the Delta. The mechanistic, water quality-hydrodynamic models being developed for the Delta may be able to address these questions in the future.

At the Great Salt Lake, record salinity and low water imperils millions of birds

American Association for the Advancement of Science (AAAS) | September 9th, 2022

Utah’s Great Salt Lake is smaller and saltier than at any time in recorded history. In July, the U.S. Geological Survey (USGS) reported that the world’s third-largest

Utah’s Great Salt Lake is smaller and saltier than at any time in recorded history. In July, the U.S. Geological Survey (USGS) reported that the world’s third-largest saline lake had dropped to the lowest level ever documented. And last week researchers measured the highest salt concentrations ever seen in the lake’s southern arm, a key bird habitat. Salinity has climbed to 18%, exceeding a threshold at which essential microorganisms begin to die. The trends, driven by drought and water diversion, have scientists warning that a critical feeding ground for millions of migrating birds is at risk of collapse. “We’re into uncharted waters,” says biochemist Bonnie Baxter of Westminster College, who has been documenting the lake’s alarming changes. “One week the birds are gone from a spot we usually see them. The next week we see dead flies along the shore. And each week we have to walk further to reach the water.” After years of inaction, the prospect of a dying lake, plus the risk of harmful dust blowing from the dry lakebed, is galvanizing policymakers to find ways to restore water to the shrinking lake.

Averting disaster: Action now for the Salton Sea

Little Hoover Commission | September 1st, 2015

The Salton Sea is shrinking. Currently the state’s largest inland body of water, as it dries up, the Sea poses a substantial threat to public health and the environment

The Salton Sea is shrinking. Currently the state’s largest inland body of water, as it dries up, the Sea poses a substantial threat to public health and the environment. Left unaddressed, desert winds will lift dust from thousands of acres of newly-revealed lakebed and blow it into population centers, agricultural areas and world-class resort economies. This impending crisis is long in the making, a policy paralysis driven by years of government process without implementing a fix. There are clear, understandable and specific mitigation steps that should be taken immediately. The decisions California leaders make in the near future about this remote desert lake will determine whether this dismal scenario will be averted. The Commission urges the Natural Resources Agency to begin implementing shovel-ready projects and the Governor and Legislature to immediately begin planning and funding the next phase of Salton Sea projects while developing a long-term restoration plan. ... When California signed the QSA, it agreed to mitigate the impacts on the Salton Sea caused by the water transfers. The state clarified its intent to restore the sea through the QSA’s implementing legislation. Experts testified it would be tens of billions of dollars cheaper to mitigate the impacts of a shrinking sea up front than to deal with the adverse impacts of inaction. Fulfilling California’s commitment to the Salton Sea is an element of maintaining the terms of the QSA, which provides water security to many Californians. Continued inaction, and the consequent public health and environmental impacts, could undermine political support for the QSA. Further, in the larger picture, California’s fulfillment of its commitments is critical to its ability to negotiate future difficult agreements. ...    

Basis of Design Report - Species Conservation Habitat

California Department of Water Resources (DWR) | April 14th, 2014

The Species Conservation Habitat (SCH) project provides shallow water habitat to support fish and wildlife dependent upon the Salton Sea that is being lost due to

The Species Conservation Habitat (SCH) project provides shallow water habitat to support fish and wildlife dependent upon the Salton Sea that is being lost due to salinity increases and the declining water surface elevation. The Project is located at the southern end of the Salton Sea (Sea) in Imperial County, California. Through the environmental review process, a Preferred Alternative was selected that encompasses 3,770 acres on both sides of the New River. The Project would include water supplies, berms to contain the water, and various other support facilities. The early start construction of the project is to develop habitat consistent with the EIS/EIR preferred alternative that is scaled down to fit the level of implementation funding currently available. The design described in this report is for early start project (Project) of the SCH and is limited to the 640 acres located within the bay on the east side of the New River. This report provides a summary of the primary design features and considerations associated with the habitat development. A more detailed discussion of the background, purpose, goals, design elements, Preferred Alternative, and Project impacts can be found in the 2011 draft EIS/EIR.  

Bay Area Green Infrastructure Water Quality Synthesis

San Francisco Estuary Institute (SFEI) | June 1st, 2018

San Francisco Bay is impacted by the numerous urban pollutants that flow from the surrounding landscape during storm events. In San Francisco Bay, total maximum daily lo

San Francisco Bay is impacted by the numerous urban pollutants that flow from the surrounding landscape during storm events. In San Francisco Bay, total maximum daily load (TMDL) clean-up plans are in place for polychlorinated biphenyls (PCBs) and mercury (Hg) (Davis et al., 2007; Davis et al., 2012). As municipalities strive to reach regulatory targets, green infrastructure (GI) presents a promising solution for managing stormwater pollutants while achieving additional environmental and social benefits. However, remaining data gaps including the best design layout, media composition, and vegetation and submerged zone effects on performance can prevent local managers from accurately assessing water quality benefits provided by green infrastructure as well as the maintenance needs to sustain adequate performance.

Beaches

Scientific American | August 1st, 1960

Beaches are natural playgrounds partly under the sun and partly under the sea where people can swim and surfboard, sun themselves and study other people. This human a

Beaches are natural playgrounds partly under the sun and partly under the sea where people can swim and surfboard, sun themselves and study other people. This human activity tends to obscure the fact that the beach itself is constantly in motion, quietly changing its configuration and restlessly shifting its position, grain by grain, until huge masses of sand have been moved. On a small scale and in a matter of hours the sand castles disappear and the footprints are erased; on a large scale, after days and months, the height of the sand around the rocks changes, the waves break in new places and the beach becomes broader or narrower. Indeed, over a period of years large quantities of sand may arrive or depart, posing complex problems of conservation for the people who want to enjoy the beach. This dynamic quality was incorporated by the late Columbia University physiographer Douglas W. Johnson into a definition: "A beach is a deposit of material which is in transit either alongshore or off-and-on shore." Thus three elements make a beach: a quantity of rocky material, a shore-line area in which it moves and a supply of energy to move it.

Bending the Curve of Global Freshwater Biodiversity Loss: An Emergency Recovery Plan

Oxford University Press (OUP) | February 19th, 2020