Temporary Urgency Change Petition for February 1, 2023, through March 31, 2023

California State Water Resources Control Board (SWRCB) | February 13th, 2023

The Collapse of Pelagic Fishes in the Upper San Francisco Estuary: El Colapso de los Peces Pelagicos en La Cabecera Del Estuario San Francisco

American Fisheries Society (AFS) | January 9th, 2007

Although the pelagic fish community of the upper San Francisco Estuary historically has shown substantial variability, a recent collapse has captured the attention of res

Although the pelagic fish community of the upper San Francisco Estuary historically has shown substantial variability, a recent collapse has captured the attention of resource managers, scientists, legislators, and the general public. The ecological and management consequences of the decline are most serious for delta smelt (Hypomesus transpacificus), a threatened species whose narrow range overlaps with large water diversions that supply water to over 25 million people. The decline occurred despite recent moderate hydrology, which typically results in at least modest recruitment, and investments of hundreds of millions of dollars in habitat restoration and environmental water allocations to support native fishes. In response to the pelagic fish collapse, an ambitious multi-agency research team has been working since 2005 to evaluate the causes of the decline, which likely include a combination of factors: stock-recruitment effects, a decline in habitat quality, increased mortality rates, and reduced food availability due to invasive species.

The Decline of Striped Bass in the Sacramento-San Joaquin Estuary, California

American Fisheries Society (AFS) | July 1st, 1985

The abundance of young striped bass Morone saxatilis in the Sacramento-San Joaquin Estuary has suffered an unsteady but persistent decline from population levels that wer

The abundance of young striped bass Morone saxatilis in the Sacramento-San Joaquin Estuary has suffered an unsteady but persistent decline from population levels that were high in the middle 1960s. The decline was particularly severe in 1977 and abundance of young striped bass has been low every subsequent year. The adult striped bass population also has fallen during the past 20 years, but the exact period over which the decline occurred and the rate of decline are not clear. The adult population is now about one-quarter of its former size and there is little sign of recovery. We believe the Sacramento-San Joaquin striped bass population and the fishery that it supports are in serious danger. The cause is most likely one or more of four factors. (1) The adult population is now so low that egg production may be inadequate. (2) The plankton food supply of young striped bass in the western Sacramento-San Joaquin Delta and Suisun Bay has been greatly reduced each spring. Diversion of water from the delta for agricultural purposes is a prime suspect for the decrease in food production. (3) Large numbers of young fish are lost by entrainment in water diversions. (4) The population is stressed by toxic substances such as petrochemicals and pesticides. Additional studies are underway to help determine the principal cause(s) of the striped bass decline.

The Delta Plan: Ensuring a reliable water supply for California, a healthy Delta ecosystem, and a place of enduring value

Delta Stewardship Council (Delta Council) | May 16th, 2013

The Sacramento-San Joaquin River Delta is the grand confluence of California’s waters, the place where the state’s largest rivers merge in a web of channels—and in

The Sacramento-San Joaquin River Delta is the grand confluence of California’s waters, the place where the state’s largest rivers merge in a web of channels—and in a maze of controversy. The Delta is a zone where the wants of a modern society come into collision with each other and with the stubborn limitations of a natural system. In 2009, seeking an end to decades of conflict over water, the Legislature established the Delta Stewardship Council with a mandate to resolve long-standing issues. The first step toward that resolution is the document you have before you, the Delta Plan.

The effects of kaolin clay on the amphipod Eohaustorius estuarius: Part Two

San Francisco Estuary Institute (SFEI) | April 3rd, 2017

A number of lines-of-evidence suggest that the amphipod Eohaustorius estuarius has variable tolerance to clay in sediments. In Phase 1 of the current RMP special study, l

A number of lines-of-evidence suggest that the amphipod Eohaustorius estuarius has variable tolerance to clay in sediments. In Phase 1 of the current RMP special study, laboratory dose-response experiments were conducted in 2014 with kaolin clay to evaluate whether clay effects varied with amphipod size. The results indicated that smaller amphipods were more tolerant of clay than larger individuals. Average survival was 81%, 79%, and 65% for small, medium and large amphipods, respectively, in concentrations > 50% clay. As part of Phase 2 confirmation studies conducted in 2015-2016, the original kaolin dose-response experiments were repeated. Results of this experiment showed that average amphipod survival was 88%, 63%, and 41% for small, medium and large amphipods, respectively, in concentrations > 50% clay. Standard 96-hour reference toxicant tests with cadmium chloride (CdCl2) were conducted to determine whether there were size-specific differences in response to this metal reference toxicant. The CdCl2 median lethal concentrations (LC50s) for small, medium and large amphipods were 6.78, 5.13, and 4.63 mg/L, respectively. Responses of all three size classes to cadmium were within historic confidence intervals for this reference metal, and were not significantly different from one another based on overlapping confidence intervals. Additional experiments with high clay reference site sediments from San Francisco Bay were conducted to confirm the size related response with field sediments. The results confirm that use of smaller amphipods in routine monitoring of high clay sediments will reduce the influence of this factor on test results. 

The Effects of Salmon Fisheries on Southern Resident Killer Whales

National Marine Fisheries Service (NMFS) | November 30th, 2012

The National Significance of California’s Ocean Economy

National Oceanic and Atmospheric Administration (NOAA) | December 17th, 2015

The purpose of this report is to present empirical evidence that illustrates the inland significance of California’s marine transportation and ocean tourism sec

The purpose of this report is to present empirical evidence that illustrates the inland significance of California’s marine transportation and ocean tourism sectors. This report begins with a discussion of California’s economy and then takes a closer look at six economic sectors that depend on ocean resources. Finally, we take an even closer look at two of these sectors—marine transportation and coastal tourism and recreation—and the way these ocean-based activities support local economies across the country.

The NOAA NCEI marine microplastics database

Nature Portfolio (Springer Nature) | October 20th, 2023

Microplastics (<5 mm) pollution is a growing problem affecting coastal communities, marine ecosystems, aquatic life, and human health. The widespread occurrence of m

Microplastics (<5 mm) pollution is a growing problem affecting coastal communities, marine ecosystems, aquatic life, and human health. The widespread occurrence of marine microplastics, and the need to curb its threats, require expansive, and continuous monitoring. While microplastic research has increased in recent years and generated significant volumes of data, there is a lack of a robust, open access, and long-term aggregation of this data. The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) now provides a global open access to marine microplastics data on an easily discoverable and accessible GIS web map and data portal. The objective of this data portal is to develop a repository where microplastics data are aggregated, archived, and served in a user friendly, consistent, and reliable manner. This work contributes to NCEI’s efforts towards data standardization, integration, harmonization, and interoperability among national and international collaborators for monitoring global marine microplastics. This paper describes the NOAA NCEI global marine microplastics database, its creation, quality control procedures, and future directions.

The Pacific Decadal Oscillation modulated marine heatwaves in the Northeast Pacific during past decades

Nature Portfolio (Springer Nature) | June 19th, 2023

The Rebirth of California Fish & Game Code Section 5937: Water for Fish

University of California, Davis (UC Davis) | July 1st, 2012

Swarms of living creatures will live wherever the river flows. There will be large numbers of fish, because this water flows there and makes the salt water fresh; so wh

Swarms of living creatures will live wherever the river flows. There will be large numbers of fish, because this water flows there and makes the salt water fresh; so where the river flows everything will live. Fishermen will stand along the shore; from En Gedi to En Eglaim there will be places for spreading nets. In an average year, California receives inflows and imports of water totaling around 200 million acre-feet,2 enough water to cover the entire state twenty-three inches deep. But California is a state of spatial and temporal water extremes. Spatially, precipitation varies wildly: Death Valley in the Southeast averages less than three inches per year, yet the northwestern corner of the state averages over 140 inches per year. More than 70% of California’s stream flow originates north of Sacramento, but more than 80% of the water is used south of Sacramento. Temporally, precipitation varies both seasonally and annually. California’s wet season typically runs from October or November to April or May, with little or no precipitation during the growing season, from May to September.7 Annual rainfalls of 40% or more below average and 36% or more above average each typically occur once every six to seven years.  To balance these extremes, over 1,300 dams store water across the state, supplying water for urban, industrial, and agricultural uses. While these uses sustain a tremendous part of California’s economy, they also come at high, often unappreciated costs. Fish also need water, so dams that alter water flows for human benefits may also have marked negative impacts on fish.