Sacramento River Temperature Task Group Annual Report of Activities October 1, 2013 through September 30, 2014

Delta Stewardship Council (Delta Council) | October 6th, 2014

Sacramento River Temperature Task Group Annual Report of Activities October 1, 2017 through September 30, 2018

Delta Stewardship Council (Delta Council) | November 21st, 2018

Sacramento River Temperature Task Group Annual Report of Activities, October 1, 2015 through September 30, 2016

Delta Stewardship Council (Delta Council) | October 31st, 2016

Salinity Changes the Dynamics of Pyrethroid Toxicity in Terms of Behavioral Effects on Newly Hatched Delta Smelt Larvae

Toxics (MDPI) | February 20th, 2021

Salinity can interact with organic compounds and modulate their toxicity. Studies have shown that the fraction of pyrethroid insecticides in the aqueous phase increases w

Salinity can interact with organic compounds and modulate their toxicity. Studies have shown that the fraction of pyrethroid insecticides in the aqueous phase increases with increasing salinity, potentially increasing the risk of exposure for aquatic organisms at higher salinities. In the San Francisco Bay Delta (SFBD) estuary, pyrethroid concentrations increase during the rainy season, coinciding with the spawning season of Delta Smelt (Hypomesus transpacificus), an endangered, endemic fish. Furthermore, salinity intrusion in the SFBD is exacerbated by global climate change, which may change the dynamics of pyrethroid toxicity on aquatic animals. Therefore, examining the effect of salinity on the sublethal toxicity of pyrethroids is essential for risk assessments, especially during the early life stages of estuarine fishes. To address this, we investigated behavioral effects of permethrin and bifenthrin at three environmentally relevant concentrations across a salinity gradient (0.5, 2 and 6 PSU) on Delta Smelt yolk-sac larvae. Our results suggest that environmentally relevant concentrations of pyrethroids can perturb Delta Smelt larvae behavior even at the lowest concentrations (<1 ng/L) and that salinity can change the dynamic of pyrethroid toxicity in terms of behavioral effects, especially for bifenthrin, where salinity was positively correlated with anti-thigmotaxis at each concentration.

San Joaquin River Restoration Program

San Joaquin River Restoration Program | December 13th, 2007

San Luis Obispo Coastkeeper v. Santa Maria Valley Water Conservation District

United States District Court, Central District of California | September 23rd, 2022

Sediment Mobility and River Corridor Assessment for a 140-Kilometer Segment of the Main-Stem Klamath River Below Iron Gate Dam, California

U.S. Geological Survey (USGS) | January 26th, 2021

This river corridor assessment documents sediment mobility and river response to flood disturbance along a 140-kilometer segment of the main-stem Klamath River below Iron

This river corridor assessment documents sediment mobility and river response to flood disturbance along a 140-kilometer segment of the main-stem Klamath River below Iron Gate Dam, California. Field and remote sensing methods were used to assess fundamental indicators of active sediment transport and river response to a combination of natural runoff events and reservoir releases during the study period from 2005 to 2019. Discharge measurements at two gaged sites and bed-material samples at two ungaged sites provided direct and indirect evidence of mobile bed conditions, scour and fill, and surface flushing of fine sediment. Available remote-sensing datasets collected in 2005, 2009, 2010, and 2016 were used to determine sediment storage, flood inundation boundaries, and provide indirect evidence of flood-induced scour. These datasets validate channel-maintenance flows defined by Shea and others (2016). During the study period, flows greater than or equal to 6,030 cubic feet per second mobilized the substrate, caused localized scour, and flushed fine sediment from bar surfaces. Flows greater than or equal to 10,400 cubic feet per second stripped vegetation from bars and floodplains and produced deeper scour. Flood disturbance within the study reach is produced by the combined effect of natural flows and reservoir releases, which resulted in mobile bed conditions during the study period. Periodic scour and substrate disturbance are considered by the U.S. Fish and Wildlife Service to be integral for managing disease-induced mortality of juvenile and adult salmonids. Substrate conditions conducive to parasites that host infectious diseases, particularly Ceratonova shasta, occur periodically. Additional studies are required to determine whether disease prevalence can be mitigated by well-timed reservoir releases. Study results are useful for interpreting linkages among physical and biological processes and for evaluating the effectiveness of flow management targeted to improve river bed conditions for endangered salmonid populations.

Shasta Dam Fish Passage Evaluation – Pilot Implementation Plan – U.S. Bureau of Reclamation

U.S. Bureau of Reclamation (USBR) | September 1st, 2015

State of the Salmonids: Status of California’s Emblematic Fishes 2017

University of California, Davis (UC Davis) | August 1st, 2017

California has, or had, 32 distinct kinds of salmonid fishes. They are either endemic to California or at the southern end of their ranges. Most are in serious decline:

California has, or had, 32 distinct kinds of salmonid fishes. They are either endemic to California or at the southern end of their ranges. Most are in serious decline: 45% and 74% of all salmonids will likely become extirpated from California in the next 50 and 100 years, respectively, if present trends continue. Our results suggest that California will lose more than half (52%) of its native anadromous salmonids and nearly a third (30%) of its inland taxa in just 50 years under current conditions. Climate change is a major overarching threat driving population declines throughout California and strongly affects the status of 84% of all salmonids reviewed. In addition, dams, agricultural operations, estuary alteration, non-native species, production hatcheries, and myriad other human-induced threats have contributed to declines. 81% of salmonids in California are now worse off than they were in 2007, when the previous version of this report was prepared. The changes in species status are the result of the 2012-2016 historic drought, improved data collection and review, and an improved understanding of climate change impacts. Returning these iconic species to sustainable levels requires access to productive and diverse habitats which promote the full range of life history diversity necessary to weather change. We recommend (i) protecting and investing in fully functioning watersheds such as the Smith River and Blue Creek, (ii) protecting and restoring source waters such as Sierra meadow systems, groundwater, and springs so that the impacts of climate change are reduced, (iii) restoring function and access to once productive and diverse habitats such as Central Valley floodplains, coastal lagoons, and estuaries, (iv) adopting reconciliation ecology as a basis for management in human dominated landscapes, (v) improving habitat connectivity and passage to historical spawning and rearing habitat, and (vi) improving salmonid genetic management throughout California.

Status Review of California coho salmon north of San Francisco

California Department of Fish and Wildlife (CDFW) | May 9th, 2002

On July 28, 2000, the Fish and Game Commission (Commission) received a petition to list coho salmon north of San Francisco as an endangered species under provisions of th

On July 28, 2000, the Fish and Game Commission (Commission) received a petition to list coho salmon north of San Francisco as an endangered species under provisions of the California Endangered Species Act (CESA). The Commission referred the petition to the Department of Fish and Game (Department) on August 7, 2000, for evaluation. The Department found that the information in the petition was sufficient to indicate the action may be warranted and recommended the Commission accept the petition. The petition was accepted by the Commission on April 5, 2001. On April 27, 2001 the Commission published a Notice of Findings in the California Regulatory Notice Register declaring coho salmon a candidate species, thereby starting the candidacy period. The Department solicited information and undertook a status review of the species using the best scientific information available. This report contains the results of the Department’s status review and recommendations to the Commission. The Department evaluated the status separately for the two coho salmon Evolutionarily Significant Units (ESU) that occur in California: Southern Oregon/Northern California Coast Coho ESU (SONCC Coho ESU - those populations from Punta Gorda north to the Oregon border) and the Central California Coast Coho ESU (CCC Coho ESU - those populations from San Francisco Bay north to Punta Gorda). This approach is consistent with previous listings, the federal approach to species’ evaluation, and the generally accepted biological criterion that a species is “a group of interbreeding organisms that is reproductively isolated from other such groups.”