San Francisco Estuary Institute, Regional Monitoring Program for Trace Substances

Introduction

Welcome to the second issue of the San Francisco Bay Mercury News! The purpose of this electronic newsletter is to foster communication and collaboration among researchers, regulators, and stakeholders by providing summaries of current mercury research activities in the Bay area. For the newsletter, researchers have provided summary paragraphs regarding the purpose of their research and recently accomplished milestones. Contact information follows each project summary. The newsletter is distributed by the San Francisco Estuary Institute (SFEI) as part of the Regional Monitoring Program. If you missed the first issue of the newsletter, you can download it from the SFEI web site at

http://www.sfei.org/rmp/mercury_newsletter/HgNews10_06_04.htm

NOTE: Some investigators with currently active studies were not able to submit updated entries for this newsletter. For a more complete picture of current mercury investigations in the Bay-Delta, please refer to both this issue and issue #1.

The second annual San Francisco Bay Wetland Mercury Research Coordination Meeting is rapidly approaching. The meeting will be held this year on February 23rd, 2005 at the San Leandro Marina Inn, 68 San Leandro Marina, San Leandro, California. The meeting will consist of short presentations by a variety of researchers and regulators from 10 am until approximately 4 pm (lunch will be provided). The agenda will be distributed shortly. If you would like to present at this event, please send Meg Sedlak an e-mail at meg@sfei.org. If you would like to register for this event, please send Linda Russo an e-mail at linda@sfei.org. Please RSVP by February 16th, 2005.

SFEI welcomes contributions to the newsletter and is actively seeking new contributors for our next issue that will be distributed in September 2005. If you have a summary for the newsletter or questions or comments, please e-mail or call Meg Sedlak at SFEI (meg@sfei.org or tel. (510) 746-7345). Also if you did not receive this newsletter from SFEI directly and you would like to subscribe to this newsletter, please visit the SFEI website to register for the San Francisco Bay Mercury News (http://mail.sfei.org/mailman/listinfo/mercury_newsletter). Similarly, if you received this newsletter erroneously, you may unsubscribe by going to our web site.

In this issue

On-going Projects

1. Guadalupe River Watershed Mercury TMDL Project

The Santa Clara Valley Water District (with technical services provided by TetraTech) conducted a comprehensive watershed-wide data collection effort from March 2003 through September 2004. These data include dry season and wet season sampling results and load estimates, and dry season methyl mercury production and loads in two reservoirs. Over 300 adult and year-1 fish fish samples from reservoirs, impoundments, creeks and the River provide for statistically significant comparisons between the water bodies. We successfully identified year-1 largemouth bass as a biosentinel species.

TetraTech, under contract to the Water Board, is using the Data Collection Report to finalize the Conceptual Model for Mercury in the Guadalupe River Watershed. The Water Board expects to release the Final Conceptual Model Report in March 2005.

Pond A8 - Connect to Guadalupe?

Prior to construction of the South Bay Salt Ponds, the Guadalupe River flowed through Guadalupe Slough to the Bay. The River now flows through Alviso Slough to the Bay. Alviso Slough does not have sufficient capacity for 10-year storms. A flood control project work group is evaluating whether 10-year storm overflow from Guadalupe River can be directed into Pond A8 to protect Alviso from flooding. The Santa Clara Valley Water District will be responsible for removing mercury deposited by the River in Pond A8.

Citation and link:

The Final Data Collection Report, and all other reports produced for the study, are available on the District's web site at www.valleywater.org

Contact information:

Carrie M. Austin, P.E.
Note new e-mail: caustin@waterboards.ca.gov
Coordinator - Water Quality Grants (Prop 13) / Project Manager - Hg TMDL in Guadalupe
SFB RWQCB

Dave Drury at the Santa Clara Valley Water District (ddrury@valleywater.org)

2. Mercury and Dissolved Organic Matter in Delta Wetlands

The U.S. Geological Survey in cooperation with the California Bay-Delta Authority is initiating an investigation of how dissolved organic matter (DOM) in the Delta facilitates mercury transport. Plans are centered on measuring mercury and methylmercury concentration changes during tidal cycles from a wetland slough. This research will be added to an existing study characterizing DOM in the Sacramento-San Joaquin Delta. These data will be combined with ancillary data and water flux to determine fluxes from the tidal wetland. The study focuses on evidence that DOC from tidal wetlands in the Delta convert insoluble forms of sedimentary mercury into mobile forms mercury. We plan to quantify the capacity of DOM from representative Delta wetlands to solubilize the major sedimentary forms of mercury in the Delta – cinnabar, metacinnabar, and elemental mercury – and determine the dissolved and particulate fluxes of mercury and methylmercury at representative wetland sites in the Delta.

Contact Information:

Project Primary contact: Dr. Brian Bergamaschi (bbergama@usgs.gov)

Field studies: Jacob Fleck or Bryan Downing (jafleck@usgs.gov, bdowning@usgs.gov)

Laboratory studies: George Aiken (gaiken@usgs.gov)

3. Mercury Speciation in Tidal Waters, Suspended Solids and Sediments from the San Francisco Bay. Research conducted by University of Notre Dame

This project is funded by the U. S. Army Corps of Engineers (USACE) San Francisco District and the U. S. Army Research Office (Jeffrey Talley, PI; Xiangru Zhang, Co-PI). The objectives are to develop a method for the simultaneous analysis of methyl mercury and mercuric ion at sub-ppt levels, and to determine the concentrations of methyl mercury and mercuric ion in the tidal water, suspended solid and sediment samples from the San Francisco Bay. This project is in support of the USACE San Francisco District’s on-going efforts to characterize inorganic mercury and methyl mercury at the Hamilton Army Airfield Wetlands Restoration Site, and will be integrated into the current research being conducted by the Engineer Research and Development Center – Waterways Experiment Station which has the ultimate objective of providing site-specific data and modeling methods for managing mercury methylation at the Hamilton Army Airfield Wetlands Restoration Site. For the method development, we initially worked on an instrument, solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS), at the Environmental Health Laboratories (EHL) in South Bend, IN. We optimized the parameters including derivatization temperature and time, SPME sample volume, mode, fiber desorption time and temperature, and salt effect, GC columns and ramp program, MS scan mode and ionization mode, etc. The minimal reporting levels (MRLs) of methyl mercury and mercuric ion in water samples were around 10 ppt. Then, we used a purge and trap (PT) unit to substitute the SPME unit. We optimized the PT unit by changing autosampler transfer line, the trap type, purge flow rate, purge time, dry-purge time, trap desorption temperature, trap transfer line temperature, moisture control temperature, etc. Under the optimized condition of the derivatization/PT-GC-MS system, the MRLs of methyl mercury and mercuric ion were around 0.5 ppt for purging a 200-mL water sample, or 0.2 ppt for purging a 500-mL sample, or 0.05 ppt for purging a 2-L sample. In the next stage, we would apply the optimized system to determining the concentrations of methyl mercury and mercuric ion in the real samples from the San Francisco Bay.

Contact Information:

Xiangru Zhang xzhang1@nd.edu
Jeffrey Talley jtalley1@nd.edu
Bill Davis wedavis@us.ul.com
Ed George ed.george@ehl.ul.com

4. Mercury Fate and Transport Study of the San Jose / Santa Clara Water Pollution Control Plant Treatment Process

The City of San Jose is conducting a multi-year project to evaluate the fate and transport of mercury through the San Jose / Santa Clara Water Pollution Control Plant. Preliminary measurements of total mercury showed high variability in Raw Sewage, averaging roughly 300 ppb. Final effluent averages approximately 3 ppb. Not surprisingly, the largest drops in total Hg occur at process steps that remove solids; however, the chemical fate of removed mercury and the small amount not removed, remains somewhat uncertain. Therefore, the study is designed to evaluate total, dissolved and methyl mercury as it passes through the treatment plant processes, as well as various ancillary variables that may affect mercury speciation and methylation.

The initial phase of the study began in October 2004, with weekly ultra-clean collection and analysis of Raw Sewage, Settled Sewage, Primary Effluent, Secondary Effluent, Filtration Influent, Filtration Effluent and Plant Final Effluent waters. Sludge samples have been collected monthly from the Primary and Secondary (activated sludge) treatment processes, sludge digester influent and effluent, and sludge drying lagoons. After evaluation of trends and variability, sampling design will be optimized for a second phase beginning in 2005, designed to evaluate seasonal trends.

Because the treatment process involves aerobic and anaerobic biological steps, one study objective is to determine if the Plant Processes generate methyl mercury. Data to date suggest that this is not happening. At the secondary (activated sludge) process step, methylmercury is reduced by approximately 97%. Although limited data are yet available, indications are that methylmercury concentrations do not change greatly through sludge digestion.

Contact Information:

Mercury Fate and Transport Study: James Downing (City of San Jose) james.downing@sanjoseca.gov

5. The Quality Assurance Oversight Program for Mercury Studies

The Mercury Strategy authors recognized the critical need for quality assurance (QA) management of mercury research and monitoring studies. In their final report, the authors emphasized the importance of a robust QA program and identified necessary program components. As part of implementing the Mercury Strategy, the California Bay-Delta Authority contracted the California Department of Fish and Game (DFG) to execute the QA program. Through a competitive bidding process, DFG selected Van Buuren Consulting (VBC) to further refine and implement the large-scale effort. VBC is located in Seattle, Washington and is owned and managed by Beverly H. van Buuren.

With Max Puckett from DFG, Ms. van Buuren co-designed and managed the previously successful CALFED Mercury QA oversight program from 1999-2002. In addition to her duties for the Mercury Studies program, Ms. van Buuren is the QA Officer for the state of California’s Surface Waters Ambient Monitoring Program (SWAMP). After careful consideration and evaluation, VBC chose Brooks Rand Laboratory located in Seattle, Washington to act as the referee laboratory. Brooks Rand has 15 years of experience in mercury speciation analysis. Nicolas Bloom from Studio Geochimica will assist VBC in annual assessment of the referee lab and will provide blind performance samples. The QA Officer and the referee laboratory must be independent and maintain a performance-based relationship.

The QA Oversight Program will commence in February 2005 and will combine the following elements: a comprehensive and updated QA project plan, on-site systems assessments of laboratories (audits), inter-laboratory comparison exercises, split sample analysis by a referee laboratory, evaluations of laboratory methods for sample analysis, evaluations of laboratory method detection limit studies, third-party data set verification and validation, regular QA meetings, and a QA website and toolbox (www.vanbuurenconsulting.com). The first laboratory audit is scheduled for February 17th when the QA team will visit Mark Stephenson’s group at the Moss Landing Marine Laboratories in Monterey, California. The QA kick-off meeting will be scheduled for March 2005 and held in the Sacramento area.

Contact Information:

Beverly H. van Buuren (beverly@vanbuurenconsulting.com or www.vanbuurenconsulting.com) or Amara Vandervort (amara@vanbuurenconsulting.com)

6. Mercury Projects funded by the California Bay-Delta Authority: Implementation of the Mercury Strategy

The mercury strategy “Mercury Strategy for the Bay-Delta Ecosystem: A Unifying Framework for Science, Adaptive Management, and Ecological Restoration” (Wiener et al, 2003) was finalized in 2004 and to date, CBDA has provided more than $30 million in funds to implement the strategy. The goal of the strategy is to provide a framework for investigations needed to build a scientific foundation for assessment and eventual reduction of mercury risks, ecosystem restoration and environmental planning. Although there are many activities currently underway which implement the recommendations of the strategy, over the next year, CBDA and its implementing agencies will be developing an implementation workplan that more formally documents current activities and priority next steps in the implementation of the strategy. In the past year, a number of new projects have been funded and we have made progress on the development of a mercury QA program, data integration for fish tissue data, and planning of the annual mercury review workshop. Below is a list of mercury –related projects that have been approved for funding by CBDA.

The mercury strategy document is available on the website:

http://www.science.calwater.ca.gov/pdf/MercuryStrategyFinalReport.pdf

Wiener, J.G.; Gilmour, C.C.; Krabbenhoft, D.P.; Mercury Strategy for the Bay-Delta Ecosystem: A Unifying Framework for Science, Adaptive Management, and Ecological Restoration; Final Report to CBDA; December 31, 2003.

Components of the Mercury Strategy

Core Component	Management Goal(s) Addressed
1. Quantification and evaluation of mercury and methylmercury sources	To identify mercury sources that contribute most strongly to the production and bioaccumulation of methylmercury
2. Remediation of mercury source areas	To identify remedial actions that can reduce loadings of mercury from sources to surface waters and decrease the exposure of aquatic biota to methylmercury
3 Quantification of effects of ecosystem restoration on methylmercury exposure	To document and understand the effects of ecosystem restoration in wetland and floodplain habitats on the production and bioaccumulation of methylmercury in the Bay-Delta ecosystem
4. Monitoring of mercury in fish, health-risk assessment, and risk communication	To provide a “performance measure” to gage methylmercury contamination of the Bay-Delta ecosystem during restoration
5. Assessment of ecological risk	To protect fish and wildlife from adverse effects of methylmercury exposure
6. Identification and testing of potential management approaches for reducing methylmercury contamination	To identify and evaluate potential landscape management approaches for reducing the production and abundance of methylmercury in the ecosystem, as well as the associated exposure of resident biota

CBDA-Funded Mercury Projects

Title	Description	Organization	Status	Core comp.
A Science Strategy for Mercury Investigation in the Bay-Delta Ecosystem: Development of a Unifying Framework linked to Ecological Restoration”	With input from researchers, stakeholders, and agency staff, develop a framework to guide future scientific studies	Wiener, Krabbenhoft, & Gilmour	Completed
Effects of Wetland Restoration on Methyl Mercury Levels	Evaluate relationship of physical, chemical, and biological gradients on methyl mercury production and bioaccumulation.	UC Davis	Completed	3
Assessment of Ecological and Human Health Impacts of Mercury in the Bay-Delta Watershed	This project will determine the major sources of mercury in the watershed, which forms are most bioavailable, where methylation is most active, fish tissue concentrations, and mercury effects on avian populations. Two major study areas are Cache Creek and the Delta.	SJSUF – Moss Landing Marine Lab	Completed	1,2,3,4,5
Investigation of Abandoned Mines Sites – Yuba River Watershed	Preliminary site assessments of 100 abandoned mine sites in the Yuba River Watershed & development of abandoned mine database.	Dept. of Conservation	Completed	1,2
Evaluation of Mercury Transformations and Trophic Transfer in the San Francisco Bay/Delta: Identifying Critical Processes for ERP	This project will examine processes that affect the biogeochemical transformations and transfers of mercury among physical (sediment and water) and biotic (food web) compartments at Franks Tract and the Cosumnes River.	USGS	In progress	1,3
Abandoned Mine Lands Inventory & Assessment	Field evaluations of mine sites in several watersheds, including report development. Facilitate several groups related to abandoned mine issues, including statewide forum and legal workgroup.	Dept of Conservation	In progress	1,2
Phase 1 – Fish consumption study, outreach and education for the Sacramento-San Joaquin Delta and its tributaries	Scoping study to gather information, establish priorities, and design further phases of fish consumption studies, and outreach and education activities. Cost share with RWQCB and DTMC.	Department of Health Services	Completed	4
Transport, Cycling and Fate of Mercury and Monomethyl Mercury in the San Francisco Delta and Tributaries, An Integrated Mass Balance Assessment Approach	This project will evaluate the transport, cycling and fate of mercury and methylmercury on a temporal and spatial basis using a biogeochemical mass balance framework to assess sources, sinks and biogeochemical processes.	SJSUF – Moss Landing Marine Labs	In progress	1,3
Cache Creek Settling Basin Feasibility Study	Feasibility study to evaluate if the Cache Creek Settling Basin flood control project could be modified to trap additional mercury-laden sediment from Cache Creek watershed before it enters the Delta.	Camp, Dresser, McKee	In progress	2
Programmatic quality Assurance and Quality Control for CBDA Mercury research and monitoring projects	Implement and oversee a mercury QA program to ensure comparability and reliability of mercury data from multiple projects. Includes methods evaluation and interlab comparisons.	DFG	In progress	Oversight
Regulatory Activities of Inactive Mercury Mine Sites Affecting Delta Water Quality	The Central Valley Regional Water Quality Control Board staff person will prepare regulatory permits and enforcement orders to control discharges from inactive mercury mines that are affecting Bay-Delta water quality.	Central Valley Regional Water Quality Control Board	In progress	2
Development of fish tissue database and integration of existing fish tissue data	The goal of this project is to provide an integrated data management system that allows data aggregation and comparability for mercury data from researchers, agencies and other ongoing data collection programs.	DWR	In progress	4
Mercury in San Francisco Bay/Delta Birds: Trophic Pathways, Bioaccumulation, and Ecotoxicological Risk to Avian Reproduction	This project will evaluate the risks of mercury (Hg) exposure to avian reproduction. This project will integrate a field assessment of exposure and effects with a laboratory assessment of the variation in sensitivity of avian embryos to methylmercury.	USFWS	In progress	5
Mercury and Methylmercury Processes in North San Francisco Bay Tidal Wetland Ecosystems	This study investigates mercury cycling in tidal wetlands of the Petaluma river, with emphasis on quantifying and understanding processes that influence the abundance of methylmercury.	SFEI	In progress	1,3,5
Research, Outreach, and Education on Fish Contamination in the Sacramento-San Joaquin Delta Watershed, Phase 2	Funding for Phase 2 covers pilot fish consumption studies for certain populations, formation of stakeholder and technical advisory groups, and outreach and education activities.	Department of Health Services	In progress	4
Merced River Corridor Restoration Plan Phase IV: Dredger Tailings Reach (Task 5)	Task 6 evaluates mercury concentrations in dredge tailings and in biota in the Merced River	Stillwater Science	Completed	3
Implement Upper Yuba Studies Program Water Quality and Sediment Studies - USGS	The overall objective is to improve understanding of sediment supply, transport, and storage of sediment in the Yuba River watershed, and to improve understanding of the current level of mercury contamination of Engelbright Lake sediments and biota.	US Geological Survey	3
Measurement of Mercury Release from Delta Wetlands: Amounts, Alterations, and Implications; an amendment to existing CALFED project 00-G01	This amendment to a project on organic carbon loads from wetlands, will add mercury measurements. This project will evaluate mercury fluxes from tidal wetlands on Brown’s Island and interactions between mercury and organic carbon.	US Geological Survey	In progress	1,3
A Pilot Program for Monitoring, Stakeholder Involvement, and Risk Communication Relating to Mercury in Fish in the Bay-Delta Watershed	This project is a collaborative pilot program to address mercury contamination in fish in the watershed with a 3-pronged approach: monitoring of mercury in fish, stakeholder involvement, and risk communication.	SFEI	Waiting for contract	4

Contact information:

If you would like additional information on the projects or status, please contact Donna Podger at CBDA for more information: dpodger@calwater.ca.gov.

7. UC-Davis Study of Bioavailability of Mercury and Production of Methyl Mercury in Stege Marsh and Walker Creek Estuary

The original goal of our PEEIR-supported study was to determine whether there were site-to site differences at Walker Creek Estuary (Tomales Bay, CA) in bioavailability of inorganic mercury or in production of methylmercury by sediment bacteria. At this site, which experiences Hg-contamination from the Gambonini Mine, sediment Hg levels were found to be extremely heterogeneous even on a small scale, and this made identification of high and low-Hg sites problematic. Thus, we switched to a focus on the [Hg] in leg muscle of the “lined shore crab” as our survey tool and also included: (1) Tom’s Point Estuary as a putative non-impacted control site, 1.5 km removed from Walker Creek, and (2) Stege Marsh, which is impacted by diverse heavy metal and xenobiotic contaminants and also by the normal Hg-load from San Francisco Bay. The concentration of Hg in crab muscle emerged as an intriguing indicator/ integrator of Hg-bioavailability within a given estuary. We found very different tendencies for trophic magnification (within individual lined shore crabs of different sizes) depending on the estuary selected. Stege Marsh crabs showed moderate Hg levels (200 ppb; wet weight) and no tendency toward biomagnification in larger individuals, while large crabs from Walker Creek contained in excess of 1000 ppb Hg, roughly five times the concentration found in small individuals there. Elevated concentrations were also detected in Tom’s Point crabs, which suggests that the impact of the mine extends beyond Walker Creek Estuary. Low-Hg crabs collected at Bodega Marine Lab Reserve, “outplanted” to these diverse estuarine sites, and fed local food sources showed similar tendencies to bioaccumulate Hg regardless of the site to which they were transferred. Because this finding is at odds with our survey data, we are investigating trophic levels of the various crabs via 15N analyses. We are also investigating how far up and down Tomales Bay the impact of the Gambonini Mine can be detected using indicator crabs.

Contact Information:

Doug Nelson at UC-Davis (dcnelson@ucdavis.edu)

8. The CBDA Fish Mercury Project (aka A Pilot Program for Monitoring, Stakeholder Involvement, and Risk Communication Relating to Mercury in Fish in the Bay-Delta Watershed)

In August 2004, the Board of Directors for the California Bay-Delta Authority approved funding of a $4.5 million proposal to monitor mercury in fish in the Bay-Delta watershed, establish an organizational structure to allow stakeholder input on the monitoring, and conduct risk assessment and risk communication activities to raise public awareness about fish contamination issues with the goal of reducing human exposure to methylmercury in the watershed. Partners in this project include SFEI, UC Davis, Moss Landing Marine Lab, the California Department of Health Services, and the California Office of Environmental Health Hazard Assessment. This project will include monitoring of 1) sport fish to characterize human exposure and spatial patterns and 2) small fish as an indicator of temporal and spatial patterns and exposure of piscivorous wildlife. The sampling will include trend monitoring sites, screening of areas in the watershed that have not recently been sampled, and monitoring of restoration projects. A Steering Committee is being formed to guide the design of the monitoring program. The first meeting of the Steering Committee is scheduled for March 9. Sampling will begin in summer of 2005.

Contact Information:

Stakeholders interested in participating in this study should contact:

Rainer Hoenicke at SFEI (rainer@sfei.org).

Other contacts:

Sport fish sampling: Jay Davis, SFEI (jay@sfei.org)

Small fish sampling: Darell Slotton, UC Davis (dgslotton@ucdavis.edu)

Public involvement and communication: Alyce Ujihara, DHS (aujihara@dhs.ca.gov)

Advisory development: Bob Brodberg, OEHHA (rbrodber@oehha.ca.gov)

9. Transport, Cycling, and Fate of Mercury and Monomethyl Mercury in the San Francisco Delta and Tributaries: An Integrated Mass Balance Assessment ApproachPrevious Mercury Research in the Delta

A team of 19 mercury researchers were funded in 1999 by CALFED to investigate mercury sources, cycling, and wildlife and human health effects in the Delta and Cache Creek watershed. The investigators and results of these studies can be found at

http://loer.tamug.tamu.edu/calfed/

A summary of the results is as follows:

Concentrations of mercury in sport fish from the Delta region represent a potential human health concern. Most large sport fish have concentrations near or exceeding the EPA tissue criteria.
Mercury tissue concentrations in striped bass have not changed in the last 30 years suggesting natural processes are not cleaning up mercury contamination.
Consistent multi-species methyl mercury tissue concentrations exist in the Bay-Delta Estuary. The highest tissue concentrations were consistently measured in individuals and species collected in mercury-contaminated tributaries in the Central Valley and immediately downstream in the Delta. Lower values were observed in the central Delta and near the State and Federal export pumps to southern California. Significant mercury accumulation occurs in food webs on both sides of the Valley and in both the Sacramento and San Joaquin watersheds, despite of the different forms of mercury present (e.g., cinnabar vs elemental mercury).
Mercury concentrations in eggs of some bird species in the Bay/Delta ecosystem were above embryotoxic thresholds suggesting mercury could cause reproductive and development problems in fish-eating birds.
The major source of mercury to the Delta is the Sacramento River.
Monomethyl mercury is removed from the water column along the transport pathway across the Delta as water flows from the Sacramento River to the export pumps in the southern Delta and to San Francisco Bay during the summer months (low flow).
Monomethyl mercury is produced Delta sediments and its exchange flux into the water column from the sediments is the major source of methyl mercury to the Delta only during low river flow conditions.
Within the Delta, methyl mercury in sediments varies with season (summer is highest at most stations), geography and habitat. Wetland and marsh regions appear to be major sites of methyl mercury production.
The amount of methyl mercury transported out of wetlands to the Delta has not been quantified sufficiently to evaluate the impact of wetlands on mercury bioaccumulation in the Delta as a whole.
During high water flow events mine sites and geothermal springs are major sources of mercury and methyl mercury to the Delta.
Effective mine site remediation should be based on general site erosion control measures. Measures to reduce the amount of sulfate entering waterways from thermal springs should also be considered because sulfate has been known to stimulate methyl mercury production.
Sediments of Cache Creek below the mine sites and geothermal sources are also a source of mercury and methyl mercury to the aquatic ecosystem because of a greater than 100 year history of erosion from mine sites and because of continuous discharge from geothermal springs.

This was funded by CALFED grant ERP -02-C06-A&B

Current Mercury Research

Sediment Studies

We have completed 19 months of seasonal sampling at Brown’s Island, Sycamore Slough, Franks Tract, and Snodgrass Slough. Samples are currently being collected monthly. In addition, we have completed three collections of 28 sites from throughout the Delta. Analysis of samples is still in progress.

Wetland Studies

Twitchell Island was studied for the 17th month. Imports and exports of methyl mercury were determined on two ponds, one 100% vegetated and the other half vegetated. The 100% vegetated pond produces up to 70 times more methyl mercury than the half vegetated pond. On-going studies will try to determine the cause of the difference in methyl mercury production in the two ponds.

In order to determine the mass loading of methyl mercury from wetlands, we studied 7 sites in Suisun Marsh. Results from the Suisun Marsh July sampling event were presented as a poster at the 2004 CALFED Science Conference. DWR (Chris Enright) and USGS (Jon Burau) collected data to quantify the mass transport of water on and off the wetland and agreed to share this data to quantify the mass of methyl mercury moving on and off the wetland. Preliminary data indicates methyl mercury concentrations at the mouth of Suisun Slough are around .04 ng/l, and in the marsh up to 2-4 ng/l . The latter values (2-4 ng/l ) are higher than any measured before in the Delta (to our knowledge). In addition, Suisun Marsh imported methyl mercury during this sampling event. This is contrary to what we expected. We have started similar studies in Mandeville Cut, and will soon start studies in Browns I. and Big Break.

Atmospheric Deposition Studies

Atmospheric deposition samples are currently being collected at three sites; Pt. Reyes, Twichell I, and Woodland. Sediment cores have been collected at four lakes and are currently being analyzed for mercury and lead 210 (study funded by Central Valley Regional Water Quality Control Board). Analysis is still in progress.

Photodemethylation Studies

Photodemethylation studies were conducted during July and December 2004. Data from July indicate photodemethylation can be up to 22% per day in surface samples. Several more photodemethylation studies are planned to determine seasonal differences in photodemethylation rates. In addition, studies of air-water exchange of dissolved gaseous mercury, total gaseous mercury and reactive gaseous mercury are in progress.

Mass Loading Studies

Monthly mass loading studies have been conducted on all major water inputs and exports sites from the Delta since July 2004. In addition, monthly mass loading studies have been conducted in the Sacramento River Basin since March 2003 (using RWQCB funds and CALFED funds). Mass loading studies have also been conducted in sub watershed studies in Cache Creek, the San Joaquin River, and the Yolo Bypass. The studies continue to confirm that the Sacramento River is the main source of methyl mercury to the estuary when the Yolo Bypass is dry. The data also continues to show a loss in methyl mercury concentrations downstream of Rio Vista. A midterm report will be available in early summer.

Contact Information:

Investigators: Mark Stephenson (DFG), Kenneth Coale (SJSUF), Gary Gill (TAMUG), and Chris Foe (CRWQCB). Dr Stephenson can be reached via e-mail at mstephenson@mlml.calstate.edu.

10. Mercury and Methylmercury Processes in North San Francisco Bay Tidal Wetland Ecosystems

In December 2003 the California Bay-Delta Authority Board of Directors approved funding of a $1.6 million proposal to study mercury and methymercury processes in wetlands of the Petaluma River and San Pablo Bay. Partners in this project include SFEI, USGS Menlo Park, USGS Biological Resources Division, USGS Wisconsin, and Avocet Associates. A primary interest of this project is to examine processes that lead to mercury exposure and accumulation by several species of threatened or endangered wetland birds, including the California clapper rail. This project will examine Hg and MeHg concentrations in the sediments, water and biota of tidal marshes along a salinity gradient up Petaluma River. Influences of seasonal and interannual variation in environmental parameters on Hg geochemistry and bioaccumulation will also be examined. Physiographic differences among marshes of different ages to be studied are also expected to impact Hg geochemistry. Relationships found previously in other estuarine ecosystems will be sought, and changes with marsh progression will be examined to project likely long-term outcomes of restoration projects. This knowledge is needed for deciding where and how to restore selected wetlands and to anticipate possible impacts of projects. For restoration projects that proceed, additional studies can then be conducted to confirm projected changes and further refine understanding of Hg transformation and bioaccumulation processes in an adaptive management process. The project is currently still in contracting with CBDA, but the co-PIs have begun some preliminary site reconnoissance and project planning. Field work is expected to begin in February-March 2005.

Contact Information:

Stakeholders interested in this study should contact Donald Yee at SFEI (donald@sfei.org).

11. Annual monitoring for Hg and other contaminant concentrations and loads in the Guadalupe River watershed, San Jose, CA.

Guadalupe River is contaminated with mercury mostly as a result of mining in between 1845 and 1975 but there have been additional minor inputs from increased urbanization since WWII. The New Almaden District produced about 30% of the total North American mercury needs to-date and about 6% of the worlds needs since 1850. In 1975 Santa Clara County opened the New Almaden Quicksilver County Park to provide a public recreation amenity and celebrate the colorful mining history of the area. A series of remediation activities occurred in the late 80s and early 90s to make the park safe for designated human uses. Despite these efforts and huge sums of money, there remains a legacy of on- and off-site contamination that is part of the active hydrological cycle. Onsite contaminated areas include calcines piles, roads segments that were paved with cemented calcines, furnace and processing areas, landslide debris, and bed, bank and terrace deposits of intermittent and perennial first order creeks or “gulch’s”. Off-site, most of the contamination is stored in bed, bank, and terrace deposits in Guadalupe Creek, Alamitos Creek, Alamitos Lake and Guadalupe River. Most off-site contamination was deposited during extreme storms over the past 150 years. There is mounting evidence that much of this on- and off-site material is still actively part of the hydrological cycle – most especially during intense rainstorms.

The Guadalupe River TMDL, led by a partnership between the San Francisco Bay Regional Water Quality Control Board and the Santa Clara Valley Water District and other local stakeholders, seeks to collate scientific information and make defensible decisions on how reduce the impacts of mercury within the watershed and the transport and impact of mercury on San Francisco Bay. In a parallel effort, the San Francisco Estuary Institute (SFEI), with funding from Clean Estuary Partnership (CEP), the Regional Monitoring Program for Trace Substances (RMP), the U.S. Army Corps of Engineers (USACE), and the Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP), has been conducting a study on Guadalupe River to determine the concentrations and loads of suspended sediments, mercury, trace metals, polychlorinated biphenyls (PCBs), and organochlorine pesticides (DDT, chlordane and dieldrin). In water year (WY) 2003, concentrations of total mercury ranged from 0.2-18.7 µg/L and 116 kg of total mercury was transported past the measuring point at Hwy 101 and into San Francisco Bay. In the second year of study, rainfall and runoff was much less. Total mercury concentrations ranged from the detection limit (DL) - 1.4 µg/L and only 15 kg of mercury was transported past Hwy 101. Higher rainfall intensity in the first year relative to the second is thought to have mobilized mercury from some of the more hydrologically isolated areas in or adjacent to the New Almaden Quicksilver County Park but this remains an area of debate. This year (WY 2005) represents the 3rd year of study. Increased interest and funding has provided for an analysis of dissolved and methyl mercury species and the implementation of a long-discussed bed load mercury component in the study. Rainfall intensity during the third year has been intermediate and might provide for an opportunity to prove or refine our current theories of mercury source initiation and transport. We are presently awaiting laboratory results with a sense of excitement.

A report on the second year of study will be available for review in late February 2005 and the preliminary results of the 3rd year will likely be presented at the RMP annual meeting in May.

Contact Information:

Guadalupe River study: Lester McKee (SFEI) lester@sfei.org
Guadalupe River Hg impairment: Carrie Austin (SFRWQCB) CAustin@waterboards.ca.gov

**Please note ALL RB2 staff have changed their email addresses.

Recently Completed Projects

1. USGS Reports Direct Measurements of Benthic Fluxes of Mercury

Field and laboratory studies were conducted in April and November 2003 to provide the first direct measurements of the benthic flux of dissolved mercury species (total and methylated forms) between the bottom sediment and water column at two South Bay stations. During two sampling events, three replicate sediment cores from each of the two South Bay locations were used in incubations which provided "snapshots" of solute flux across the sediment-water interface. For total dissolved mercury, all individual cores at both sites and both dates exhibited positive benthic flux (i.e., transport from the sediment into the water-column). When extrapolated over the greater South Bay (south of the Bay Bridge), the average for all sites and dates is 135 ± 94 g/day of total dissolved mercury. This magnitude of this value is consistently comparable to or greater in magnitude than estimates of major riverine sources. Notably, benthic flux of dissolved mercury is of the same magnitude as particulate mercury inputs from the Guadalupe River watershed (318 ± 88 g/day in 2003; McKee 2004).

Because the benthic flux of mercury appears to represent a dominant transport process for dissolved, more bioavailable forms, an important management implication is suggested. Remediation efforts and Total Maximum Daily Load (TMDL) allocations along the Guadalupe River have dual objectives of decreasing concentrations and loads to down-gradient systems in an effort to reduce bioaccumulation of mercury in fish consumed by humans and wildlife. Using preliminary mercury-flux estimates into the estuary, our results indicate that a significant (and possibly predominant) percentage of dissolved mercury in the water column presently comes from the bay sediment. If upstream sources are controlled, which is desirable even apart from estuary effects, the change in inflow loads is likely to be compensated in part by increases in benthic flux.

Reference:

McKee, L., Leatherbarrow, J., and Eads, R., 2004. Concentrations and loads of mercury, PCBs, and OC pesticides associated with suspended sediments in the lower Guadalupe River, San Jose, California. A Technical Report of the Regional Watershed Program: SFEI Contribution #86. San Francisco Estuary Institute, Oakland, CA. pp79

Citation and link:

Topping, B.R., Kuwabara, J.S., Marvin-DiPasquale, M.C., Agee, J.L, Kieu, L.H., Flanders, J.R., Parchaso, F., Hager, S.W., Lopez, C.B. and Krabbenhoft, D.P., 2004, Sediment Remobilization of Mercury in South San Francisco Bay, California: U.S. Geological Survey Scientific Investigations Report 2004-5196, 59p. Internet access at:

http://pubs.water.usgs.gov/sir2004-5196/

Contact information:

Brent Topping (btopping@usgs.gov) and James Kuwabara (kuwabara@usgs.gov)

Upcoming Hg Conferences/Workshops

1. San Francisco Bay Wetland Mercury Research Coordination Meeting, February 23, 2005.

This annual workshop brings together researchers, regulators, and stakeholders to discuss recent developments in the area of wetland mercury research. The purpose of the meetings is to facilitate the exchange of mercury information among these groups to foster collaboration. Last year’s meeting was quite well attended and productive. This year’s meeting will consist of short presentations by a variety of researchers from 10 am until approximately 3 pm (lunch will be provided). The agenda will be distributed shortly. If you would like to register for this event, please send Linda Russo an e-mail at Linda@sfei.org. Please RSVP by February 16th, 2005.

2. Eighth International Conference on Mercury as a Global Pollutant

The International Conference on Mercury as a Global Pollutant has become the preeminent international forum for formal presentation and discussion of scientific advances concerning environmental mercury pollution. The depth, breadth, and pace of scientific discovery on the sources, environmental transport and fate, biogeochemical cycling, and adverse effects of mercury have increased enormously since the inaugural conference was convened in Sweden in 1990. In view of proposed U.S. and international actions on mercury emissions, the 2006 conference will present a timely opportunity to assimilate, synthesize, and disseminate scientific knowledge and technical information in a form useful to policy discussions involving mercury in the environment.

The 8th International Conference on Mercury as a Global Pollutant will be convened in Madison, Wisconsin (USA), at the Monona Terrace Community and Convention Center, an extraordinary conference facility designed by the famed architect Frank Lloyd Wright. You are invited to participate in this global mercury conference, which will again feature scientific advances in mercury research, with an expanded scope to include socioeconomic issues and public policy. For more information regarding this conference, please see the web site.

Titles from September’s 2004 San Francisco Bay Mercury News at www.mercury2006.org.

Our first issue of the newsletter contained summaries on the following topics. To read the complete summary and obtain contact information, please go to our web site at: http://www.sfei.org/rmp/mercury_newsletter/HgNews10_06_04.htm

Current Research

Evaluation of Hg Transformations and Trophic Transfer in the SF Bay/Delta: Identifying Critical Processes for the Ecosystem Restoration Program. An investigation by USGS, University of Maryland and SUNY-Stony Brook.
A Pilot Program for Monitoring, Stakeholder Involvement, and Risk Communication Relating to Hg in Fish in the Bay-Delta Watershed (CBDA Fish Hg Pilot Program). Project led by SFEI, UC Davis, Moss Landing Marine Lab, Cal DHS, and Cal OEHHA.
Concentration and Production of Methylmercury in Wetlands in the Bay. Research project by US Army Corps of Engineers.
Description of UCSC’s Hg Studies in the San Francisco Bay Area and Recent Publications.
Wetland Design and Management Options for Control of Hg in SF Bay. LFR Levine-Fricke and WIGS Laboratory at UCSC.
Mercury and Methylmercury Processes in North San Francisco Bay Tidal Wetland Ecosystems. Project led by SFEI.
Status Report on Guadalupe River Watershed Mercury TMDL.
UCDavis Study of Bioavailability of Mercury and Production of Methyl Mercury in Stege Marsh and Walker Creek Estuary.
Annual Monitoring for Hg and Other Contaminant Concentrations and Loads in the Guadalupe River Watershed, San Jose, CA. A study by SFEI.
Montezuma Wetlands Project. Comprehensive Monitoring Program (including mercury in water, sediment, and tissues) at the Site and at Suisun Marsh Reference Sites

New Reports/Recent Academic Theses

Legacy Contaminants in the Bay. Forthcoming report from BCDC.
The San Francisco Bay Regional Water Quality Control Board to release New Fish Contaminant Study in October 2004
Mercury Research of Potential Relevance to San Francisco Bay. UC-Berkeley