2016 Updated ambient concentrations of toxic chemicals in San Francisco Bay area sediments

San Francisco Estuary Institute (SFEI) | February 26th, 2016

 The purpose of this memo is to communicate the most recent results for the ambient concentrations of mercury, Total PAHs and Total PCBs in San Francisco Bay area sedime

 The purpose of this memo is to communicate the most recent results for the ambient concentrations of mercury, Total PAHs and Total PCBs in San Francisco Bay area sediments.  Regulation of dredging and dredged material disposal or reuse under the San Francisco Bay Long Term Management Strategy for Dredging (LTMS) involves, in part, evaluation of sediment chemistry characteristics. For dredged material in California, for most chemicals, there are no numeric sediment quality standards or objectives that define chemical suitability for disposal or reuse at particular placement sites.1 Consequently, Bay dredged sediments are compared to various published screening values and other guidelines, to reference site chemistry, and where available and appropriate, to ambient sediment contaminant concentrations for the Bay as a whole. Therefore, starting in 2011, the LTMS agencies have asked SFEI to calculate the ambient concentrations for a small subset of sediment contaminants that are either subject to TMDL limits for in-Bay dredged material disposal or are relevant for bioaccumulation testing for dredging (DMMO, n.d.). 

2017 Bay Margins Sediment Study Cruise Plan

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

2017 Margins Microplastics Cruise Report

San Francisco Estuary Institute (SFEI) | October 2nd, 2017

This report contains information on the summer field sampling efforts conducted by Coastal Conservation & Research (CC&R) in support of two Regional Monitoring Pr

This report contains information on the summer field sampling efforts conducted by Coastal Conservation & Research (CC&R) in support of two Regional Monitoring Program (RMP) studies: South Bay Margins and Moore Microplastics. The South Bay Margins is the second round of a larger San Francisco Bay study collecting sediment and water in shallow margin areas of the bay. The first round was conducted in Central Bay in 2015. The Moore Microplastics study is a collaborative effort with the Moore Foundation to collect sediment and fish samples in San Francisco and Tomales Bays. The work for both studies was contracted through the San Francisco Estuary Institute (SFEI) to CC&R. Since overall project management and sampling locations were coordinated between the two projects, activities from both studies will be presented as they occurred. 

2017 Regional Monitoring Program (RMP) Bay Margins Sediment Samples Quality Assurance Report

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

 In 2017, composited sediment samples were collected from 40 sites, with samples analyzed for select trace elements, ancillary sediment quality parameters, and PCBs. The

 In 2017, composited sediment samples were collected from 40 sites, with samples analyzed for select trace elements, ancillary sediment quality parameters, and PCBs. The sampling and analysis was conducted under the Regional Monitoring Program for Water Quality in San Francisco Bay, as part of a multi-year plan to characterize sediment contamination in the shallow water/intertidal “margins” of the Bay. The details of the cruise and sample collection methods are described in the RMP Quality Assurance Program Plan, cruise plans, cruise reports, and field sampling reports.

2017 Regional Monitoring Program (RMP) Water Samples Quality Assurance Report

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

 In 2017, grab water samples were collected from 22 sites, with samples analyzed for select trace elements (Cu, MeHg, Se), ancillary water quality parameters (DOC, POC,

 In 2017, grab water samples were collected from 22 sites, with samples analyzed for select trace elements (Cu, MeHg, Se), ancillary water quality parameters (DOC, POC, SSC, hardness) and weak acid dissociable cyanide. Additionally, water samples were collected for toxicity tests from 7 sites, and one site (Golden Gate) sampled for nutrients (nitrogen species, silica). The sampling and analysis was conducted by the Regional Monitoring Program for Water Quality in San Francisco Bay. The details of the cruise and sample collection methods are described in the RMP Quality Assurance Program Plan, cruise plans, cruise reports, and field sampling reports.

2018 Regional Monitoring Program (RMP) Sediment Cruise Report

San Francisco Estuary Institute (SFEI) | September 5th, 2018

This report outlines details from the annual Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) sediment cruise, conducted August 14 – 21,

This report outlines details from the annual Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) sediment cruise, conducted August 14 – 21, 2018. The Regional Monitoring Program conducts routine monitoring of water, sediment and biological tissue. The current study design calls for monitoring of water and bivalves every two years and sediment every four years. Bird egg monitoring (cormorant and terns) is conducted triennially, while sport fish are monitored on a five-year rotation. 

2018 RMP Sediment Sampling and Analysis Plan

San Francisco Estuary Institute (SFEI) | June 26th, 2018

This report details plans associated with the annual Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) sediment cruise. The Regional Monit

This report details plans associated with the annual Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) sediment cruise. The Regional Monitoring Program through the Status and Trends conducts routine monitoring of water, sediment and biological tissue. The current study design calls for monitoring of water and bivalves every two years and sediment every four years. Bird egg monitoring (cormorant and terns) is conducted triennially, while sport fish are monitored on a five-year rotation. For 2018, sampling operations will entail dry season sample collection at 27 RMP sediment sampling sites.

A 450-year record of environmental change from Castle Lake, California (USA), inferred from diatoms and organic geochemistry

Journal of Paleolimnology (Springer) | November 11th, 2020

A 39-cm sediment core from Castle Lake, California (USA) spans the last ~ 450 years and was analyzed for diatoms and organic geochemistry (δ15N, δ13C, and C:N), wi

A 39-cm sediment core from Castle Lake, California (USA) spans the last ~ 450 years and was analyzed for diatoms and organic geochemistry (δ15N, δ13C, and C:N), with the goal of determining sensitivity to natural climate variation and twentieth century anthropogenic effects. Castle Lake is a subalpine, nitrogen-limited lake with ~ 5 months of annual ice cover. Human impacts include light recreational use, past fish stocking, and experimental use by the Castle Lake Research Station. The base of the core (below 32 cm; pre mid-1700s) represents the period of maximum ice cover. In contrast, the end of the Little Ice Age (mid 1700s–early 1800s) is dominated by cyclotelloids (mostly Discostella stelligera), indicating significant open-water periods, a condition that persisted into the early 1900s. Cyclotelloids began to decline in the 1960s and were replaced by the Fragilaria tenera grp. (peak in 1970s), succeeded by Asterionella formosa (peak ~ 2010), and accompanied by a reduction in δ15N values and a decrease in C:N that may represent increased atmospheric nitrogen deposition. Another anthropogenic signal was discerned in the core and was interpreted to be the result of an ammonium nitrate fertilization experiment of the epilimnion that was conducted in 1980 and 1981. This signal was manifested in the core largely by a negative excursion in δ15N, possibly caused by fractionation during denitrification in surface sediment. A phytoplankton monitoring dataset collected by the Castle Lake Research Station from 1967 to 1984 corroborates the timing of increased araphid euplanktonic species in the 1970s, and increases in two benthic diatoms (Staurosirella pinnata and Tabellaria fenestrata), entrained in the phytoplankton tows during the experimentation years. Both ice cover and nitrogen addition appear to be strong drivers that affected the lake diatoms, although additional drivers, such as fish stocking and associated cascade effects need further exploration. These data will be helpful for interpreting longer core records from Castle Lake, should the opportunity arise, as well as cores from similar systems in the region.

A Menu of Fire Response Water Quality Monitoring Options and Recommendations for Water Year 2019 and Beyond

San Francisco Estuary Institute (SFEI) | July 2nd, 2018

In October 2017, the Tubbs Fire and the Nuns Fire burned 93,400 acres of the Mark West Creek and Santa Rosa Creek watersheds, killing 22 people, and incinerating approxim

In October 2017, the Tubbs Fire and the Nuns Fire burned 93,400 acres of the Mark West Creek and Santa Rosa Creek watersheds, killing 22 people, and incinerating approximately 7,000 structures. After the fires, many agencies worked together to deploy water and sediment related best management practices (BMPs) in the burn area (e.g., waddles, emergency hydroseeding, and filter systems on storm drains) and worked on removing contaminated debris and soil from burned properties. The City of Santa Rosa conducted water quality sampling to verify that the BMPs were working. Water quality samples were collected at selected sites before and after flow interacted with the BMP; the City was generally pleased with the results. Subsequently, the North Coast Regional Water Quality Control Board (Water Board) developed a preliminary monitoring design for WY 2018 to measure potential water quality impacts of the fires in relation to beneficial uses. Selected streams were sampled for parameters that could be compared to regulatory water quality criteria. The attachment contains a summary of the results for WY 2018. Based on this initial dataset, the apparent early success of the BMP program, and the soil clean-ups that have occurred, the focus going forward should be on monitoring larger-scale and longer-term impacts. This document outlines monitoring options for consideration for WY 2019 and beyond for four categories: Water Chemistry, Hydromodification, Geomorphic Response, and Ecology. 

A Summary of Water-Quality and Salt Marsh Monitoring, Humboldt Bay, California

U.S. Geological Survey (USGS) | September 16th, 2022

This report summarizes data-collection activities associated with the U.S. Geological Survey Humboldt Bay Water-Quality and Salt Marsh Monitoring Project. This work was u

This report summarizes data-collection activities associated with the U.S. Geological Survey Humboldt Bay Water-Quality and Salt Marsh Monitoring Project. This work was undertaken to gain a comprehensive understanding of water-quality conditions, salt marsh accretion processes, marsh-edge erosion, and soil-carbon storage in Humboldt Bay, California. Multiparameter sondes recorded water temperature, specific conductance, and turbidity at a 15-minute timestep at two U.S. Geological Survey water-quality stations: (1) Mad River Slough near Arcata, California (U.S. Geological Survey station 405219124085601) and (2) Hookton Slough near Loleta, California (U.S. Geological Survey station 404038124131801). At each station, discrete water samples were collected to develop surrogate regression models that were used to compute a continuous time series of suspended-sediment concentration from continuously measured turbidity. Data loggers recorded water depth at a 6-minute timestep in the primary tidal channels (Mad River Slough and Hookton Slough) in two adjacent marshes (Mad River marsh and Hookton marsh). The marsh monitoring network included five study marshes. Three marshes (Mad River, Manila, and Jacoby) are in the northern embayment of Humboldt Bay and two marshes (White and Hookton) are in the southern embayment. Surface deposition and elevation change were measured using deep rod surface elevation tables and feldspar marker horizons. Sediment characteristics and soil-carbon storage were measured using a total of 10 shallow cores, distributed across 5 study marshes, collected using an Eijkelkamp peat sampler. Rates of marsh edge erosion (2010–19) were quantified in four marshes (Mad River, Manila, Jacoby, and White) by estimating changes in the areal extent of the vegetated marsh plain using repeat aerial imagery and light detection and ranging (LiDAR)-derived elevation data. During the monitoring period (2016–19), the mean suspended-sediment concentration computed for Hookton Slough (50±20 milligrams per liter [mg/L]) was higher than Mad River Slough (18±7 mg/L). Uncertainty in mean suspended-sediment concentration values is reported using a 90-percent confidence interval. Across the five study marshes, elevation change (+1.8±0.6 millimeters per year [mm/yr]) and surface deposition (+2.5±0.5 mm/yr) were lower than published values of local sea-level rise (4.9±0.8 mm/yr), and mean carbon density was 0.029±0.005 grams of carbon per cubic centimeter. From 2010 to 2019, marsh edge erosion and soil carbon loss were greatest in low-elevation marshes with the marsh edge characterized by a gentle transition from mudflat to vegetated marsh (herein, ramped edge morphology) and larger wind-wave exposure. Jacoby Creek marsh experienced the greatest edge erosion. In total, marsh edge erosion was responsible for 62.3 metric tons of estuarine soil carbon storage loss across four study marshes. Salt marshes are an important component of coastal carbon, which is frequently referred to as “blue carbon.” The monitoring data presented in this report provide fundamental information needed to manage blue carbon stocks, assess marsh vulnerability, inform sea-level rise adaptation planning, and build coastal resiliency to climate change.