Climatic regulation of the neurotoxin domoic acid

National Academy of Sciences (NAS) | January 9th, 2017

Domoic acid is a potent neurotoxin produced by certain marine microalgae that can accumulate in the foodweb, posing a health threat to human seafood consumers a

Domoic acid is a potent neurotoxin produced by certain marine microalgae that can accumulate in the foodweb, posing a health threat to human seafood consumers and wildlife in coastal regions worldwide. Evidence of climatic regulation of domoic acid in shellfish over the past 20 y in the Northern California Current regime is shown. The timing of elevated domoic acid is strongly related to warm phases of the Pacific Decadal Oscillation and the Oceanic Niño Index, an indicator of El Niño events. Ocean conditions in the northeast Pacific that are associated with warm phases of these indices, including changes in prevailing currents and advection of anomalously warm water masses onto the continental shelf, are hypothesized to contribute to increases in this toxin. We present an applied domoic acid risk assessment model for the US West Coast based on combined climatic and local variables. Evidence of regional- to basin-scale controls on domoic acid has not previously been presented. Our findings have implications in coastal zones worldwide that are affected by this toxin and are particularly relevant given the increased frequency of anomalously warm ocean conditions.

Colorado River Basin Environmental Transfers Scorecard

Stanford University | March 16th, 2017

The Colorado River and its tributaries support more than 35 million people and irrigate more than four million acres of farmland. At the same time, the river supports 30

The Colorado River and its tributaries support more than 35 million people and irrigate more than four million acres of farmland. At the same time, the river supports 30 fish species found nowhere else on earth and inspires millions of visitors and residents alike with its sheer beauty. However, growing water scarcity caused by increased water use, hydrologic variability and climate change loom over all the Colorado River provides. Click here for follow-up report.

Comments of San Francisco Baykeeper et al re: Draft Staff Report on Sacramento/Delta Updates

San Francisco Baykeeper | January 19th, 2024

In the face of a growing and severe ecological crisis, the Board has spent the better part of two decades crafting updates to the Bay-Delta Plan to reasonably protect fi

In the face of a growing and severe ecological crisis, the Board has spent the better part of two decades crafting updates to the Bay-Delta Plan to reasonably protect fish and wildlife beneficial uses. These delayed and too often meager efforts have so far done nothing to reverse the catastrophic path we are on, despite the potential permanent loss of these beneficial uses. The Draft Staff Report’s proposed project and the Voluntary Agreement alternatives will not change our course.

Comments on the Scientific Basis for Implementation of Voluntary Agreements for the Sacramento River, Delta, and Tributaries

Delta Stewardship Council (Delta Council) | March 8th, 2023

Comparing and integrating fish surveys in the San Francisco Estuary: Why diverse long-term surveys are important

UnIversity of California, Davis (UC Davis) | June 30th, 2020

Compliance with D-1641 San Joaquin River October Flow Requirements

California State Water Resources Control Board (SWRCB) | October 9th, 2023

Conceptual Model to Support PCB Management and Monitoring in the San Leandro Bay Priority Margin Unit Final Report

San Francisco Estuary Institute (SFEI) | November 2nd, 2019

The goal of this report is to answer three questions related to management and monitoring of PCBs in priority margin units. To this end, a conceptual model was develope

The goal of this report is to answer three questions related to management and monitoring of PCBs in priority margin units. To this end, a conceptual model was developed that includes four major elements: 1. loading from the watersheds; 2. initial deposition and retention; 3. processes determining the long-term fate of PCBs in sediment and water; and 4. bioaccumulation in the food web

Conserving California’s Coastal Habitats: A Legacy and a Future with Sea Level Rise

Nature Conservancy | May 15th, 2018

The California coast that we know today will not be the coast of the future. Sea level rise and other climate change impacts will have profound effects on o

The California coast that we know today will not be the coast of the future. Sea level rise and other climate change impacts will have profound effects on our coastline and its natural resources. California harbors high numbers of native, rare, and imperiled species in an array of unique coastal habitats. A majority of California’s coastline exists as natural habitat, over one-third of which has been preserved by a legacy of conservation efforts. Yet, this conservation legacy is at risk and we must act now to conserve the unique values of California’s coast—for both people and nature—into the future. To inform current and future adaptation decisions and conservation actions we conducted the first statewide, comprehensive assessment of the vulnerability of California’s coastal habitats, imperiled species, and conservation lands to sea level rise. Coastal habitats exist in narrow bands at the land-sea interface and are therefore extremely susceptible to inundation by sea level rise. However, some habitats may be able to adapt vertically and possibly move inland, assuming local topography and the built environment do not constrain this movement. We assessed the vulnerability of 40 habitats to sea level rise by quantifying the sensitivity and spatial extent of projected exposure of each habitat patch to intertidal and subtidal waters, relative to its ability to move inland in response to rising sea levels.

Considerations for Management of the Mouth State of California’s Bar-built Estuaries

Southern California Wetlands Recovery Project | January 10th, 2019

Bar-built estuaries are the dominant estuary type in California, and many of these small estuaries are subject to closure with a sand barrier separating a lagoon

Bar-built estuaries are the dominant estuary type in California, and many of these small estuaries are subject to closure with a sand barrier separating a lagoon estuary from the ocean for days, months or even years. In the lagoon impounded behind the sand barrier, water levels may rise or fall depending on net water budget and water quality extremes may develop. These conditions and the obstruction of fish passage motivate managed breaching of the sand barrier in many systems statewide – an intervention that alleviates or preempts environmental problems, but which also can result in undesirable secondary impacts due to the acute effect of a single breach or the chronic effect of repeated breaching over years. Management decisions are based on an implicit trade-off between anticipated benefits and costs that depend on the values and priorities of stakeholders. This report was written to provide an overview of considerations for managed breaching in California. It presents a synthesis of processes and phenomena related to mouth closure and breaching in general and uses this to identify potential impacts of breaching, without intending any judgment of which impacts are more or less desirable. Three specific systems are reviewed in detail: Los Peñasquitos Lagoon in San Diego County, Scott Creek Estuary in San Mateo County and Russian River Estuary in Sonoma County. While there are fundamental similarities in the closure and breaching cycle across all bar-built estuaries statewide, there is also an immense diversity between these systems due to differences in size, in hydrology (wet north to dry south), and in development (rural, urban, agricultural, road/rail). The local community is likely to develop the best management strategy where there is significant effort and experience in local monitoring, science, and stakeholder consultation. However, where there is limited monitoring, science or consultation, the considerations outlined in this report provide preliminary guidance – and comparison with one of the study systems can provide more specific insight to the potential impacts of breaching management decisions. We synthesize current understanding related to how mouth state influences estuary functions and conditions, which in turn affect ecological services. While both natural and managed breaching affect many processes and phenomena in the estuary, breaching events and managed breaching regimes do not occur in isolation and many other factors affect the estuary functions and conditions, including freshwater inputs, the adjacent landscape, and stressors in the watershed. However, managed breaching is one of very few short-term management options and therefore a valuable adaptive management tool, specifically in systems that are already perturbed or impacted by human encroachment. Although emergency breaches may be required in rare occasions, our recommendation is to develop a breaching strategy for specific systems in which breaching has been used or in which it is likely to be used as a management tool. In this context, we recommend ways in which science can provide improved support for management decisions and identify a few systems in California in which there is already a well-developed, science-based management plan. Associated document: "Wetlands on the Edge: The Future of Southern California's Wetlands - Regional Strategy 2018"

Considering Water Use Efficiency for the Environmental Sector

California Department of Water Resources (DWR) | April 29th, 2010

The goal of this report is to provide a starting point from which the water planning community can move toward improving the allocation of water within the environmental

The goal of this report is to provide a starting point from which the water planning community can move toward improving the allocation of water within the environmental sector. To facilitate that process, this report presents: 1.  A discussion that highlights the water community’s points of agreement on the concept of analyzing the application of water to the environment 2.  A term, Managed Environmental Water Use Efficiency (MEWUE), to reflect that concept, and a definition of that term 3.  A survey of existing methods that could be used to develop MEWUE 4.  Suggestions about how to proceed with implementing MEWUE Based on our analysis, we found that there was genuine interest in understanding and improving how water is allocated to the environment. The idea of maximizing environmental benefits for a given amount of allocated water is a unifying thread among stakeholder interests. We focus on this idea throughout the report as the central concept that MEWUE is intended to achieve. We propose a new term to reflect the stated concerns of stakeholders that other terms, Environmental Water Use Efficiency and Ecosystem Restoration Water Use Efficiency, did not fully address. We propose Managed to indicate that MEWUE does not evaluate the environment’s use of water per se but rather the effectiveness of water in controlled systems. We propose Environmental to reflect the range of “uses” of water in the ecosystem, including ecosystem maintenance, restoration, and water quality. Lastly, we support the use of the word Efficiency because efficiency communicates the intent of maximizing benefit for a given amount of water, providing a basis for comparison of the benefits obtainable from different uses of that water. MEWUE: a mechanism to analyze alternative uses of managed environmental water to determine which allocation of a given amount of water will maximize environmental benefits, and a means to improve decision-making over time. We address the issue of why having an explicit decision-making mechanism is essential. It is hard to allay the fears that some have of incorrectly measuring environmental benefits. However, it is even more difficult to claim that decisions based on implicit measures and beliefs are better for the environment than those based on some imperfect but explicit consideration of environmental benefits.