Re-Oaking Silicon Valley: Building Vibrant Cities with Nature

San Francisco Estuary Institute (SFEI) | August 1st, 2017

In this report, we investigate how integrating components of oak woodlands into developed landscapes — “re-oaking” — can provide an array of valuable functions fo

In this report, we investigate how integrating components of oak woodlands into developed landscapes — “re-oaking” — can provide an array of valuable functions for both wildlife and people. Re-oaking can increase the biodiversity and ecological resilience of urban ecosystems, improve critical urban forest functions such as shade and carbon storage, and enhance the capacity of cities to adapt to a changing climate. We focus on Silicon Valley, where oak woodland replacement by agriculture and urbanization tells a story that has occurred in many other cities in California. We highlight how the history and ecology of the Silicon Valley landscape can be used as a guide to plan more ecologically resilient cities in the Bay Area, within the region and elsewhere in California. We see re-oaking as part of, and not a substitute for, the important and broader oak woodland conservation efforts taking place throughout the state.  

Recent declines in salmon body size impact ecosystems and fisheries

Nature Portfolio (Springer Nature) | August 19th, 2020

Declines in animal body sizes are widely reported and likely impact ecological interactions and ecosystem services. For harvested species subject to multiple stressors, l

Declines in animal body sizes are widely reported and likely impact ecological interactions and ecosystem services. For harvested species subject to multiple stressors, limited understanding of the causes and consequences of size declines impedes prediction, prevention, and mitigation. We highlight widespread declines in Pacific salmon size based on 60 years of measurements from 12.5 million fish across Alaska, the last largely pristine North American salmon-producing region. Declines in salmon size, primarily resulting from shifting age structure, are associated with climate and competition at sea. Compared to salmon maturing before 1990, the reduced size of adult salmon after 2010 has potentially resulted in substantial losses to ecosystems and people; for Chinook salmon we estimated average per-fish reductions in egg production (−16%), nutrient transport (−28%), fisheries value (−21%), and meals for rural people (−26%). Downsizing of organisms is a global concern, and current trends may pose substantial risks for nature and people.

Recent global decline in endorheic basin water storages

Nature Portfolio (Springer Nature) | November 30th, 2018

Endorheic (hydrologically landlocked) basins spatially concur with arid/semi-arid climates. Given limited precipitation but high potential evaporation, their water storag

Endorheic (hydrologically landlocked) basins spatially concur with arid/semi-arid climates. Given limited precipitation but high potential evaporation, their water storage is vulnerable to subtle flux perturbations, which are exacerbated by global warming and human activities. Increasing regional evidence suggests a probably recent net decline in endorheic water storage, but this remains unquantified at a global scale. By integrating satellite observations and hydrological modelling, we reveal that during 2002–2016 the global endorheic system experienced a widespread water loss of about 106.3 Gt yr−1, attributed to comparable losses in surface water, soil moisture and groundwater. This decadal decline, disparate from water storage fluctuations in exorheic basins, appears less sensitive to El Niño–Southern Oscillation-driven climate variability, which implies a possible response to longer-term climate conditions and human water management. In the mass-conserved hydrosphere, such an endorheic water loss not only exacerbates local water stress, but also imposes excess water on exorheic basins, leading to a potential sea level rise that matches the contribution of nearly half of the land glacier retreat (excluding Greenland and Antarctica). Given these dual ramifications, we suggest the necessity for long-term monitoring of water storage variation in the global endorheic system and the inclusion of its net contribution to future sea level budgeting.

Reclamation’s NEPA Handbook

U.S. Bureau of Reclamation (USBR) | January 31st, 2012

This edition of the Bureau of Reclamation’s (Reclamation) National Environmental Policy Act (NEPA) Handbook has been developed in response to the Council on Environment

This edition of the Bureau of Reclamation’s (Reclamation) National Environmental Policy Act (NEPA) Handbook has been developed in response to the Council on Environmental Quality’s (CEQ) and the U.S. Department of the Interior’s (Interior) implementing regulations on NEPA. These regulations state that each agency will interpret the provisions of NEPA as a supplement to its existing authority and as a mandate to view its policies and missions in the light of its national environmental objectives. This handbook has been designed as a guidance tool for use by all Reclamation staff. It should also be useful to applicants, contractors, tribal representatives, the general public, and others who may be involved in Reclamation’s NEPA process, or those who develop environmental reports for Reclamation’s use in preparing NEPA documents. This handbook describes Reclamation guidance for implementing the National Environmental Policy Act of 1969 (42 United States Code [U.S.C.] 4321, et seq.), CEQ’s Regulations for Implementing the Procedural Provisions (40 Code of Federal Regulations [CFR] Parts 1500–1508), Interior’s NEPA Regulations (43 CFR Part 46), and the Departmental Manual (DM) Chapter 516. This handbook draws these requirements together and provides guidance on how to apply them to Reclamation programs and activities. The Reclamation Manual NEPA Policy (ENV P03) refers to this handbook as the source of additional information on NEPA compliance for Reclamation. The handbook also presents and summarizes other related environmental laws and Executive orders (EO) which should be addressed during NEPA compliance. This handbook provides an overview of NEPA in chapter 2. Chapter 3 contains a general description of the requirements and procedures of NEPA. Chapter 4 provides information on integrating NEPA with other Reclamation activities. Specific information on categorical exclusion checklists (CEC), environmental assessments (EA), and environmental impact statements (EIS) can be found in chapters 5, 6, and 7, respectively. This organizational structure has been selected to allow the user to quickly locate specific, step-by-step information on the different levels of NEPA compliance. Chapter 8 addresses EIS content, and chapter 9 discusses the requirements of a record of decision (ROD). Chapters 10 and 11 present other information that can be useful in the various situations that arise in applying NEPA to Reclamation’s Federal actions. Chapter 12 concludes the handbook with information on gaining additional assistance on NEPA issues. In addition, various issues and special problems are discussed throughout the handbook. Where possible, solutions that have worked historically, or approaches that seem most reasonable, are recommended.

Reconciling fish and farms: Methods for managing California rice fields as salmon habitat

PLOS | February 24th, 2021

Rearing habitat for juvenile Chinook Salmon (Oncorhynchus tshawytscha) in California, the southernmost portion of their range, has drastically declined throughout the pa

Rearing habitat for juvenile Chinook Salmon (Oncorhynchus tshawytscha) in California, the southernmost portion of their range, has drastically declined throughout the past century. Recently, through cooperative agreements with diverse stakeholders, winter-flooded agricultural rice fields in California’s Central Valley have emerged as ecologically functioning floodplain rearing habitat for juvenile Chinook Salmon. From 2013 to 2016, we conducted a series of experiments examining methods to enhance habitat benefits for fall-run Chinook Salmon reared on winter-flooded rice fields in the Yolo Bypass, a modified floodplain managed for flood control, agriculture, and wildlife habitat in the Sacramento River Valley of California. Investigations included studying the effect of 1) post-harvest field substrate; 2) depth refugia; 3) duration of field drainage; and 4) duration of rearing occupancy on in-situ diet, growth and survival of juvenile salmon. Post-harvest substrate treatment had only a small effect on the lower trophic food web and an insignificant effect on growth rates or survival of rearing hatchery-origin, fall-run Chinook Salmon. Similarly, depth refugia, created by trenches dug to various depths, also had an insignificant effect on survival. Rapid field drainage yielded significantly higher survival compared to drainage methods drawn out over longer periods. A mortality of approximately one third was observed in the first week after fish were released in the floodplain. This initial mortality event was followed by high, stable survival rates for the remainder of the 6-week duration of floodplain rearing study. Across years, in-field survival ranged 7.4–61.6% and increased over the course of the experiments. Despite coinciding with the most extreme drought in California’s recorded history, which elevated water temperatures and reduced the regional extent of adjacent flooded habitats which concentrated avian predators, the adaptive research framework enabled incremental improvements in design to increase survival. Zooplankton (fish food) in the winter-flooded rice fields were 53-150x more abundant than those sampled concurrently in the adjacent Sacramento River channel. Correspondingly, observed somatic growth rates of juvenile hatchery-sourced fall-run Chinook Salmon stocked in rice fields were two to five times greater than concurrently and previously observed growth rates in the adjacent Sacramento River. The abundance of food resources and exceptionally high growth rates observed.

Recovery plan for Central Valley winter-run chinook salmon, spring-run chinook salmon, and steelhead

National Marine Fisheries Service (NMFS) | July 7th, 2014

Recovery is the process by which listed species and their ecosystems are restored and their future is safeguarded to the point that protections under the Endangered Speci

Recovery is the process by which listed species and their ecosystems are restored and their future is safeguarded to the point that protections under the Endangered Species Act (ESA) are no longer needed. The goal of this Recovery Plan is to recover the endangered Sacramento River winter-run Chinook salmon Evolutionarily Significant Unit (ESU), the threatened Central Valley spring-run Chinook salmon ESU, and the threatened California Central Valley steelhead Distinct Population Segment (DPS). Recovering these species and the Central Valley, San Francisco Bay-Delta Estuary, and Pacific Ocean ecosystems that support them will be challenging and will require shifts in societal values. Californians must work together towards a conservation ethic and practice that ensures wild salmon and steelhead are an important part of coastal California and Central Valley culture for many generations to come.

Recovery Plan for Sacramento-San Joaquin Delta native fishes

U.S. Fish and Wildlife Service (FWS) | November 26th, 1996

Eight fish species are included in the Sacramento-San Joaquin Delta Native Fishes Recovery Plan. The delta smelt is listed as a threatened species. The Sacramento splitta

Eight fish species are included in the Sacramento-San Joaquin Delta Native Fishes Recovery Plan. The delta smelt is listed as a threatened species. The Sacramento splittail (splittail) was proposed as a threatened species on January 6, 1994. This recovery plan will recommend restoration criteria for the splittail that would be appropriate recovery criteria should the species be listed. Longfin smelt, green sturgeon, spring-run, late fall-run, and San Joaquin fall-run chinook salmon are species of concern for which restoration criteria are recommended. Information is also included on Sacramento perch, a species believed to be extirpated from the Delta at this time. Habitat Requirements and Limiting Factors: The eight species included in this recovery plan depend on the Sacramento-San Joaquin Delta for a significant segment of their life history. Threats to the Delta ecosystem and these species include loss of habitat due to increased freshwater exports resulting in increased salinity, loss of shallow-water habitat due to dredging, diking and filling, introduced aquatic species that have disrupted the food chain, and entrainment (movement offish by currents produced by diversions) in State, Federal and private water diversion. State and Federal water projects have also changed the pattern and timing of flows through the Delta. The salmon races are affected by sport and commercial harvest as well as by interactions with hatchery stocks. Recovery and Restoration Objective: Delisting of delta smelt. Restoration of splittail, longfin smelt, green sturgeon, spring-run, late fall-run, San Joaquin fall-run chinook salmon, and Sacramento perch. Recovery and Restoration Criteria: Recovery criteria are quantifiable and species specific and can be used to (1) monitor effectiveness of recovery actions, (2) determine when a species has recovered to a secure level (stabilized), and (3) determine when a species qualifies for delisting. In many cases, criteria are based on two independent measures: population abundance and geographic distribution. For each species a historic base period was established using available data to characterize abundance and distribution during a pre-decline period. The time period over which abundance and distribution criteria must be met was set at five generations. For five of the eight species there is an additional requirement of meeting the criteria through a minimum number of years of stressful environmental conditions. Action Needed: 1. Enhance and restore aquatic and wetland habitat in the Sacramento-San Joaquin River estuary. 2. Reduce effects of commercial and recreational harvest. 3. Reduce effects of introduced aquatic species on Delta native fishes. 4. Change and improve enforcement ofregulatory mechanisms. 5. Conduct monitoring and research on fish biology and management requirements. 6. Assess recovery management actions and re-assess prioritization of actions. 7. Increase public awareness of importance of Delta native fishes.

Reducing Methylmercury Accumulation in the Food Webs of San Francisco Bay and Its Local Watersheds

San Francisco Estuary Institute (SFEI) | April 8th, 2014

San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most pr

San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts.

Regional Monitoring Program (RMP) for Water Quality in San Francisco Bay, 2020 Detailed Workplan and Budget

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

Regional Monitoring Program for Water Quality in San Francisco Bay 2016 Detailed Workplan and Budget

San Francisco Estuary Institute (SFEI) | November 10th, 2015

In 2016 the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) is entering its 24th year of collecting data and communicating information to suppor

In 2016 the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) is entering its 24th year of collecting data and communicating information to support water quality management decisions. This Detailed Workplan and Budget describes the activities that will be completed in 2016 and their proposed funding levels.