IDENTIFYING INFORMATION
Project title: Geochronology in South Florida Ecosystem, Chesapeake Bay and Salton Sea.
Geographic area: South Florida, Maryland and Virginia, and Southern California
Project start date: October 1996
Project end date: September 1999
Project chief: Charles W. Holmes
Region/Division/Team/Section: Eastern/WRD-GD/Atlantic Coastal and Marine Geology/St. Petersburg
Email: cholmes@usgs.gov
Phone: 813 893-3 100 (ext 3056)
Fax: 813-893-3333
Mailing Address: 600 4th Street South, St. Petersburg, FL, 33701
 
Program(s) Integrated Natural Resource Science Program

Program element(s)/task(s) SOUTH FLORIDA STUDY AREA/ ELEMENT 2.Task 2.10 Terrestrial and fresh water ecosystem history. ELEMENT 6. Task 6.2 Isotopic dating: ELEMENT 7. Task 7.1 Florida Bay Turbidity, Bathymetry and Sedimentation .Task 7.2 Hydrogeology of Florida Bay and Florida Keys. Task 7.3 Nutrients and diagenesis of sediments in Florida Bay and Biscayne Bay Task . (70%) CHESAPEAKE BAY STUDY AREA Element 5. Study the history and evolution of the Chesapeake Bay ecosystems and their response to changes in sedimentation, salinity, and nutrient load during historic time scales. Task 5.4 (15%) USGS SALTON SEA STUDY AREA ELEMENT 4. Environmental Baselines and ELEMENT 6. Geologic Characterization. (15%)
 
BACKGROUND NARRATIVES

Project summary: Many ecological questions require temporal information before a management decision can be reached. This project supplies important time series information for process-based studies (both in the terrestrial and coastal environment), time information for the ecological history research, the timing of sealevel rises and storm events, the rate of sediment transport and deposition and the rate of flux of ground water.

Project objectives and strategy: Resource managers, in order to provide adequate leadership in balancing natural and anthropogenic needs, must understand how the system works. In the document South Florida Ecosystem Restoration: Scientific Needs, there is a list of questions that require temporal data for the answer; the timing of chemical loading in the terrestrial formation for the ecological and fire history research, the timing of sealevel rises and storm events, the rate of sediment transport and deposition and the flux of ground water all require a method of ascertaining a time function. These needs transcend all regions.
    Over the past three decades there has been a dramatic increase in the volume and range of research on the determination of the timing of environmental changes that have occurred over the past 100 years. Much of this research effort has been aimed at understanding short-lived processes (decadal time scales) and the result of anthropogenic manipulation of natural processes. The lack of historical records documenting changes in most regions dictates that other methods be used to measure ìrates of change.î A common method is to use the decay of naturally occurring radioactive nuclides. The usefulness of any radioactive nuclide requires certain conditions be met. These conditions are 1. the chemistry of the nuclide (element) is known; 2. The nuclide once incorporated into the substrate changes only by decay, and 3. in order to be useful, it is relatively easy to measure. The objective of the project is to measure the distribution of short lived radionuclides to provide a temporal component to the processes at work within the Ecosystem. It is the strategy of this program to provide the best time related data by examining the distribution of all the suitable isotopes in sediment samples and ascertaining the best temporal model.

Potential impacts and major products: The product of this program is data relating the changing of conditions or the timing of events from one region to another. This information has the impact of relating to the managers the excepted outcome and ìhow long in will taken for that outcome to occurî. The information developed from this program is necessary for the development of models that are being developed to predict changes. The major product is the data which are used by other investigators. In addition there are reports on the temporal dynamics of some systems, for example the development of the Pass Key Ban or the relative development of the banks within Florida Bay. There is also a report looking into the relationship between phosphorous concentration and the rates of accumulation in the Water Conservation Areas. Another report will be created relating the increase of mangrove development along the northern fringe of Florida Bay.

Collaborators, clients Florida Bay - Robert B. Halley, and Bruce Wardlaw will use the data in the developing the synthesis of sediment dynamics and paleoecosystems. South Florida Terrestrial Bill Orem uses the information in developing nutrient flux models for both the terrestrial and marine environment in south Florida (this aspect also bears on the mercury studies) Deb Willard used the data to develop eco and fire histories. SFWMD ( Fred Skalar and others) used this information in developing the ìlandscapeî models for the ìTree Islandî program. SFWMD (Susan Newman with John Robbins (GLERL)and R. Reddy ( University of Florida) The cooperative effort into ascertaining the ìcorrectî rates of accumulation in the WCA 2A impacted by a major flux of phosphorous. The results of these collaborations will be used by the Corp of Engineers and the agencies of the Department of Interior ( DIA, NPS, F &W.L) and the state of Florida under the Everglades Forever Act in the development of management strategies. Chesapeake Bay Tom Cronin and Steve Colman are using this data in the environmental studies in the bay as is related to the Pfisteira sp. problem. Salton Sea This newly generated data will be used to defining the timing of changes within this ecosystem.

WORK PLAN
Time line (FY 1999 to project end): The tasks to be complete in FY 1999 are:
1. Complete the analysis of the cores collected in FY98. There were 37 sites occupied in the summer of 1998 and these cores are being prepared for analysis- Holmes / Margot/Remick
2. Analyze the cores collected from Chesapeake Bay- Holmes / Margot/Remick
3. Analyzed the cores collected during the initial phases of the Salton sea study- Holmes / MargotlRemick.
4. Complete report on the Cesium/ ²¹⁰Pb investigation and comparison in WCA2A C.Holmes ( With Robbins, Reddy and Newman)
5.Collect winter data for the Pass key sediment transport study and compare this information with the summer data collected in 1998--.Holmes / Margot/Remick
6. Test the geochronological model developed to determine the rate of sediment accumulation in the Terrestrial environments

FY 1999 activities: This is the completion year for the South Florida Study and the start up year for the Salton year
Sea Program. In accordance with this and the tasks listed above, the project will complete reports on the south Florida work. These will be submitted to the appropriate individuals who are responsible for the syntheses products. The only field work request this year is a winter sampling on the Pass Key back so the ⁷Be data may be compared with the summer data. Field work is also requested for the Salton Sea and Chesapeake Bay Studies.

FY 1999 deliverables/products: The products for this program in FY1999 are:
1. "Sedimentary dynamics of Florida Bay Muds on a decadal timescale"
2. "Geochronology and the accumulation rates of organic sediments in the South Florida Terrestrial Ecosystem"
3. "The dynamics of sediment transport in the formation of the Pass Key Bank"
4. The development of selected ìtree Islandsî in Taylor Slough. In addition data will be provided the collaborators for their studies.

FY 1999 outreach: The information derived from this project will be presented at the annual meeting of the Ecosystem program, the Ecological history workshop, and at the information Environmental Geochemical meeting. In addition, the Paleocological investigators will be present data from this project a the AGU on other conferences. Fact sheets will developed summarizing the more technical reports listed as products

New directions or major changes for FY 1999: The anticipated changes for the coining year is the start up of the Salton Sea Program.

ACCOMPLISHMENTS, OUTCOMES, PRODUCTS, OUTREACH
FY 1998: This past year a study was undertaken to resolve the conflict in dating procedures in the terrestrial environment particularly Water Conservation Area 2A. The preliminary results of this study demonstrated that Cesium does migrate within the sediment and that any chronology based on this isotope is suspect. ²¹⁰Pb, however. apparently remains strongly attached and offers the highest potential for obtaining accurate dates within this critical system. Models have been developed to use this isotope as a chronological tool presently being tested.

Products completed:
    T. Cronin, C. W. Holmes, H. Dowsett, D. Keyser, G. Dwsyer, N. Waibel, 1998, Salinity and Seagrass History from Florida Bay Sediment Cores: 1870-1995, Paleocological Workshop, January, Key Largo.
    T. Cronin, R. Halley, L. Brewster- Wingard. C. W. Holmes, G. Dwyer, S. Ishman. 1998, Climatic and Anthropogenic influence on Florida Bay Salinity over the past century, May 98 Florida Bay Conference
    Orem W.H., Gough L.P., Holmes C.W., Kotra, R.K., Lerch, H.E., SpikerE.C., and Weintraub V.C. (1996) The impact of geochemical processes on water quality and wetland management in south Florida [abs.]. Watershed ë96 Meeting, Baltimore, MD, June 1996
    Willard D., Orem W., Weimer L. and Holmes C. W. (1996) South Florida ecosystems: vegetational and geochemical history [abs.]. 1996 Florida Bay Science Conference, Key Largo, FL, December 1996.
    Halley R.B., Prager E.J., Stumpf R.F., Holmes C. W., Bothner M.H., Wingard G.L., Ishman S.E., Shinn E.A., TenBrink M.B., Willard D.A., Hansen M.E. and Orem W.H. (1997) Sedimentology and Florida Bay Ecology: Past, Present, and Future [abs.]. USGS Sediment Workshop, Harpers Ferry, Wva, January 1997.
    Bates A.L., Spiker E.C., and Holmes C.W. (1998) Speciation and isotopic composition of sedimentary sulfur in the Everglades Water Conservation Area 2A, Florida, USA. Chemical Geology, in press.
    Orem W.H., Holmes C. W., Kendall C., Lerch, H.E., Bates, A.L., Silva S.R., Boylan, A., Corum, M, Marot, M, and Hedgman, C. (1998) Geochemistry of Florida Bay sediments: I. Nutrient history at five sites in eastern and central Florida Bay. J. Coastal Res., in review.
    Orem W.H., Lerch H.E., Holmes C.W., Corum M, Boylan A., Bates A., and Hedgman C. (1998) Geochemistry of sediments from USGS cores in Taylor Slough, 1996. USGS Open-File Report, in review.
    Bates A.L., Orem W.H. and Harvey J.W. (1998) Sulfate in the northern Everglades: Concentrations and sulfur isotopic composition [abs.]. AGU Spring Meeting, Boston, MA, May 1998, in review.
    Orem W.H., Lerch H.E., Corum M, Boylan A., Hedgman C., and Zielinski R. (1998) Phosphorus geochemistry of the south Florida wetlands ecosystem: Sources and biogeochemical cycling [abs.]. AGU Spring Meeting, Boston, MA, May 1998, in review.
    Orem, W.H., Holmes, C. W., Kendall, C., Lerch, H.E., Bates, A.L., Boylan, A., and Corum, M. (1998) Geochemistry of Florida Bay sediments: Investigation of nutrient and seagrass history. Annual Florida Bay Science Conference, Miami, May 1998.
    Halley, R.B., Holmes, C.W., ëPrager, E.J., 1997, Florida Bay Mud Banks Relatively New Piles of Mostly Old Sediments, US Geological Survey OpenFIle Report 97-385, p. 26-27.
    Halley, R.B., Holmes, C.W., Prager, E. J., 1997, The Dual Roles of Florida Bay Mudbanks in Restoration, Program and Abstracts, Society for Ecological Restoration, 9th International Conference, Fort Lauderdale FL, USA Nov. 12-15, 1997, p.70.
    Halley, R.B., Holmes, C.W., Prager, E.J., 1997, Seagrass Facies and Phases Recorded in the Sediments of Florida Bay, Conference Program with Abstracts, Walt Dineen Society Annual Meeting, North Miami Beach, FL, 1997, p. 44.
    Ishman, S.F., Brewster- Wingard G.L., Willard, D.A., Gronin, T.M., Edwards. L.E., and Holmes, C.W. 1996, Preliminary paleontologic report on Core T-24, Little Madeira Bay, Florida: U.S. Geological Survey Open-File Report 96-543, 27 pp.
    Brewster- Wingard, C.L.. Ishman, S.E., Willard, D.A., Halley, R.B., and Holmes, C.W., 1996. The biotic record of change in Florida Bay and the south Florida Ecosystem: Program and Abstracts 1996 Florida Bay Science Conference, Key Largo, FL (Dec. 10-12. 1996). p. 25-26.
    Brewster-Wingard, C.L., Ishman, S.E., Willard, DA.. Edwards, L.E.. and Holmes, C.W., 1997, Preliminary paleontologic report on cores 19A and 19B, from Russell Bank, Everglades National Park, Florida Bay: U.S. Geological Survey Open-file Report 97-460, 29 p.
    Brewster-Wingard, C.L., Ishman, S.E., Holmes, C.W, Willard, D.A.. and Edwards, L.E., 1997, Environmental change in the Florida Bay Ecosystem: Patterns over the last 150 years: U.S. Geological Survey Program on the South Florida Ecosystem - Proceedings of the Technical Symposium in Ft. Lauderdale, Florida, August 25-27. 1997, U.S. Geological Survey Open-File Report 97-3 85, p. 8-9.
    Brewster- Wingard, C.L., Ishman, S.E., Waibel, N.J., Willard, D.A., Edwards, L.E., and Holmes, C.W., 1998, Preliminary paleontologic report on Core 37, from Pass Key, Everglades National Park, Florida Bay: U.S. Geological Survey Open-file Report 98-122, 22 p.
    Willard, D.A., Holmes, C.W., Murray, J.B., Orem, W.H., Weimer, L.M.,1998, Biotic and geochemical changes in the south Florida ecosystem over the last two millennia. Science,
Directorís Approval, 4/29/98.
    Robbins, J.A., Holmes, C.W., Halley, R.B., Bothner, M., Shinn, E., Graney, J., Keeler, G., ten Brink, M., Orlandini, K.A., and Rudnick, D., 1998, First order time-averaging of Cs-137 and Pb fluxes to Pb-210-dated sediment in Florida Bay, in reveiw.( To be submitted to Geochmica et Cosmochemica Acta)
    Holmes, C. W, Robbins, J.A., Halley, R.B., Bothner, M, Ten Brink, M., and Marot, M, 1998, Sedimentary dynamics of Florida Bay Mud Banks on a decadal time scale, in review.( To be submitted to Journal of Coastal Research)
 
PROJECT SUPPORT REQUIREMENTS
Names and expertise:
Charles W. Holmes /Geochemist
Marci Marot/Geochemist
Bowdewjn Remick/ Lab Technician

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