1. Dr. Herbert Fredrickson, Dr. Victor McFarland, Dr. Elly Best, Dr. Greg Kiker, Dr.Robert Jones, Dr. Gui Lotufo, Dr.Rod Millward and Mr. Richard Price Dr. Herbert Fredrickson, Dr. Victor McFarland, Dr. Elly Best, Dr. Greg Kiker, Dr.Robert Jones, Dr. Gui Lotufo, Dr.Rod Millward and Mr. Richard Price U.S. Army Engineer R&D Center, Environmental Laboratory, Waterways Experiment Station, Environmental Laboratory,Vicksburg, MS 39180-6199 Dr. Holger Hintelmann and Dr. Brian Dimock Chemistry Dept., Trent University, Peterborough, Ontario, Canada. San Francisco Bay Wetland Reconstruction and Mercury Biogeochemistry – How to do the right thing?

2. Hamilton Army Airfield Hamilton Army Airfield and Bel Marin Keys China Camp

3. Hamilton Army Airfield HAAF will require <10 M yd 3 of dredged material

4. China Camp State Park – Reference Site Spartina foliosa Salicornia virginica

5. Mercury Levels & Relevance Relevance THg µg/g Earth’s crustal average0.08 SF Bay sed. baseline0.06 1997 SF Bay sediment < 40% fines0.25 40-100% fines0.43 SF Bay average fish0.09- 0.27 SF Bay striped bass0.42 Fish action levels USDA1.0 FL & WI0.5 MN0.16 SF Bay 0.23 Table 1. Total mercury levels reported in San Francisco Bay sediments in the 1997 Regional Monitoring Program Annual Report (SFEI 1999). Estuary Reach Location THg Concentration,  g g -1, dry weight RiversSacramento River San Joaquin River 0.04 0.53 Northern EstuaryHonker Bay Grizzly Bay Pacheco Creek Napa River Davis Point Pinole Point San Pablo Bay Petaluma River 0.26 0.29 0.05 0.39 0.04 0.23 0.36 0.48 Central BayRed Rock Point Isabel Richardson Bay Horseshoe Bay Yerba Buena Island 0.05 0.28 0.25 0.15 0.23 South BayAlameda Oyster Point San Bruno Shoal Redwood Creek Dumbarton Bridge South Bay Coyote Creek 0.27 0.23 0.24 0.32 0.33 0.51 0.78 Southern SloughsSan Jose Sunnyvale 0.18 0.16 Estuary InterfaceStandish Dam Guadalupe River 0.14 1.08

6. THg and MeHg in surface (0-4 cm) sediments from various wetlands Aquatic Systems Produce Methylmercury  Only a loose relationship between THg and MeHg levels (log – log plot).  Despite history of mining level of THg and MeHg are median among contaminated sites.  However, potential for a 10X increase/decrease in MeHg levels.

7. CALFED Stakeholders Workshop 8-9 October 2002, Moss Landing Marine Laboratory 1.What are the present levels of MeHg in SF Bay wetlands with respect to biota, sub-habitats, and location within the Bay? 2.What are the rates of MeHg production? 3.What factors control MeHg production? Can these be managed? 4.Are some wetlands larger mercury exporters than others? 5.Can we model/predict the effects of wetland restoration on MeHg production and export? Research questions to be answered

8. Hamilton Army Airfield Initial sample locations Initial conditions 2005 Ten year projection 2015 Fifty year projection 2055

9. Total mercury in sediments grouped by location. Boxes are medians and interquartile range. Whiskers are 10th and 90th percentiles. Triangles are outliers. Data shown are from the dry season. Survey of THg and MeHg in HAAF sediments  THg averages 0.3 µg/g in soils, consistent with other reports.  MeHg levels are highly variable.

10. 1. What are the present levels of MeHg in SF Bay wetlands with respect to sub-habitats ?

11. San Rafael Average Temperature and Rainfall JanFebMarAprMayJunJulAugSepOctNovDec Rainfall, Inches 0 2 4 6 8 10 Temperature, o F 0 10 20 30 40 50 60 70 80 90 Precipitation Minimum Temp Maximum Temp D w The Effects of Wet and Dry Seasons An important driver for most Bay functions.  Relative MeHg levels are 3X greater on average in the wet season.

12. High Primary Production – Hallmark of Intertidal Wetlands Spartina foliosa Salicornia virginica epipelon Vascular Plants Annual Rates of Biomass Production 0.5-1 kg/m 2 above ground 0.5-1 kg /m 2 below ground Epipelon – high production/quality 1. What are the present levels of MeHg in SF Bay wetlands with respect to biota ?

13.  Relative to ~ 2% Std. Analytical Error, THg & MeHg levels are variable.  Levels of MeHg in plant roots are higher than surrounding sediment. Entry into food web? THgMeHgTHgMeHg ng/g dw (SD) Bare Mud378 (89)1.78 (1.80)327 (17)1.56 (1.12) Epipelon296 (51)1.27 (0.25) 288 (12) 7.42 (3.72) Spartina foliosa Mud 407 (30)1.35 (1.42)371 (59)2.22 (1.29) Roots 260 (62)4.24 (0.54)175 (32)5.59 (3.75) Stems 28 (-)2.65 (-) 18 (-)1.08 (-) Leaves 17 (10)0.68 (0.36) 39 (25)0.90 (0.35) Salicornia virginica Mud 314 (42)1.11 (0.79) 304 (36) 2.39 (1.68) Roots 330 (170)3.03 (1.22) 123 (-) 2.28 (-) Stems 114 (-)1.28 (-) 203 (-)1.29 (-) Leaves 24 (12)1.01 (0.58) 18 (5) 0.95 (0.24) HAAFChina Camp Marsh compartment 1. What are the present levels of MeHg in SF Bay wetlands with respect to biota ?

14. Decomposing macrophyte litter generates MeHg

15. Geukensia demissa Hemigrapsus oregonensis Nassarius obsoletus 1. What are the present levels of MeHg in SF Bay wetlands with respect to biota ? Mercury Bioaccumulation Factors (BAF) MeHg THg

16. 1. What are the present levels of MeHg in SF Bay wetlands with respect to biota ? Dr. Joy Zedler’s Study (1997) of Tijuana Estuary d 34 S can differentiate seawater from rainwater

17. Mollusc Fish Crabs, Arthropods, Insects Salt Pond Algae Salicornia Spartina 1. What are the present levels of MeHg in SF Bay wetlands with respect to biota ?

18. CALFED Stakeholders Workshop 8-9 October 2002, Moss Landing Marine Laboratory 1.What are the present levels of MeHg in SF Bay wetlands with respect to biota, sub-habitats, and location within the Bay? 2.What are the rates of MeHg production? 3.What factors control MeHg production? Can these be managed? 4.Are some wetlands larger mercury exporters than others? 5.Can we model/predict the effects of wetland restoration on MeHg production and export? Research questions to be answered

19. Hg 2+ bioavailable MeHg Biomass O 2 + Eh SRB - Eh Hg 2+ not bioavailable ?? Food Web Microbial Production of Methylmercury 2. What are the rates of MeHg production? 200 Hg 2+ 200 Hg 2+ Me 200 Hg Me 200 Hg 199 Hg 2+ 199 Hg 2+ Me 199 Hg 5-72 hr. Add Measure

20. 4. Are some wetlands larger mercury exporters than others? Hamilton Army Airfield China Camp Petaluma River Sonoma Baylands Gilmour and Henry 1991 200 – 500 μM SO 4 -2

21. SUMMARY Quantitatively most important pools: Sediment THg Sediment MeHg Tidal water Plant biomass Quantitatively most important processes: 1.Methylation rate 2.Demethylation rate 3.Sedimentation rate 4.MeHg entry into and magnification up marsh/Bay food webs 5.THg & MeHg flushing – marsh/Bay 6.Atmospheric flux

22. Thanks Eric Poulsen, Brian Dimock, Olivier Clarisse John Brezina, Jim Cole