Project Title: Sedimentation, Sea-Level Rise, and Circulation in Florida Bay
Location of Field Area: Florida Bay, Florida
Project Start Date: FY1995
End Date: FY1999

Project Chief: Robert B. Halley
Region/Division/Team/Section: Eastern Region/Geologic Division/M&CG Team/ St. Pete
E-mail: rhalley@usgs.gov
Phone: (813) 803 8747
Fax: (813) 893 3333
Mail Address: USGS Coastal Center, 600 4th St. South, St. Petersburg, FL 33701

Program(s): Integrated Natural Resource Science Program

Program Element(s)/Tasks: South Florida Study Area, Element 7 (Florida Bay, Florida Keys, and the Coral Reefs), Task 7.1 (Florida Bay Turbidity, Bathymetry and Sedimentation)

Collaborators/Clients (names, affiliation, roles):
Tom Armentano, Robert Brock (Everglades National Park, Florida Bay Program Coordinators)
Ron Hilton, Mike Choate (ACOE, Jacksonville FL, South FL Restudy)
Susan Olson (South Florida Water Management Distict, Florida Bay Program Supervisor)
Bill Krisincky (EPA, Florida Keys Water Quality Program Manager)
John Hunt (FL Department of Environmental Regulation, Florida Keys Program Manager)
Billy Causey (NOAA, Florida Keys National Marine Sanctuaiy Coordinator)
David Rudnick (South Florida Water Management District)
Bill Lyons (Florida Department of Environmental Protection)

BACKGROUND NARRATIVES

Project Summary: The goal of this USGS project is to document decade- to century- scale processes associated with sediment production and transport in Florida Bay. The results will be compared to short-term production rates measured during FY 1999.

Project Objectives: Five interrelated activities are completed or almost completed for this project: 1) core analyses; 2) local sediment elevation surveys; 3) mudbank profiling and surveys; 4) integration of sedimentary analyses with circulation patterns and sea-level history; and 5) salinity surveys to document effects of mudbanks on circulation. A sixth activity, the measurement of short-term productivity and carbonate precipitation, will be completed during the summer of 1999. These data will provide the measurements necessary for a comparison of current sedimentation rates with long-term sediment accumulation measures by lead-210 dating and elevation surveys from previous year of the project.

Overall Strategy: Coring and lead-210 dating for this project have been completed. Four activities will continue and be completed during FY 1999. They are:

1) Sediment elevation stations will be surveyed for the last time in FY 1999.
2) Two more bank profiles will be added in the Fall of 1998
3) Bimonthly salinity surveys will continue through life of project.
4) Productivity measurement, described in detail below, will conclude data collection activities for this project.

Timeline: Regular (semimonthly) meetings are planned with clients through committee and group activities and as required by our cooperative agreement. Field work is planned for two weeks during the winter or 1998/1999 and two weeks during the summer of 1999 to complete data collection. Field work is subject to delay or extension pending weather, availability of boats and vehicles, etc.

FY 1999 activities: All activities except productivity and calcification measurements have been described in previous workplans. Productivity measurements in Florida Bay, including calcification and net photosynthesis, will be performed using geochemical techniques that have proven successful for measuring production in carbonate reef and seagrass bed ecosystems (Smith 1973, Barnes 1983, Barnes and Devereux 1984, Frankignoulle and Disteche 1984, Gattuso et al. 1993). These measurements will be used to provide insight into the discrepancy between long term sediment accumulation rates (Stockman et. al,. 1967) and short term production measurements (Bosence, 1989).
    Total alkalinity, pH, calcium concentrations, salinity, irradiance, temperature, wind and current speed, and air-sea CO₂ and O₂ fluxes will be measured along transects across carbonate mud banks in Florida Bay. Transects will be located parallel to unidirectional current flow across a given bank. Sample stations along each transect will be positioned at the upstream, middle, and downstream ends of each transect. Geochemical and physical parameters will be measured at each station along a transect at different times (and irradiances) during the day.
    Total alkalinity and pH will be used to calculate calcification and net photosynthesis using the alkalinity anomaly technique of Smith and Key (1975) such that calcification (C) = half the change in total alkalinity, and net photosynthesis (P) = total carbon -calcification. Total carbon will be calculated using carbonate system equations from Millero (1979). Calcium measurements will provide an independent measure of calcification for comparison. Air-sea CO₂ fluxes will be measured directly at each station inside of a floating bell (Sugiura et al. 1963, Frankignoulle and Disteche 1984, Frankignoulle 1988, Gattuso et al. 1993, Kayanne et al. 1995) using the procedure and calculations of Frankignoulle (1988). Air-sea O₂ fluxes will be determined by measuring atmospheric and water pO₂ and calculating fluxes as described in Wanninkhof (1992). Differences in oxygen and carbon metabolism between upstream and downstream stations will be corrected for O₂ and CO₂ exchange with the atmosphere as described in (Gattuso et al., 1993).
    Productivity and metabolic rates per unit area will be calculated using the difference in concentration between upstream and downstream stations, the volume of water transported along a transect, and the transect area such that the change in concentration of a parameter (dC/m²/s) = C/m³ x m³/hr)/m² (Barnes and Devereux, 1984). Productivity data from multiple transects in Florida Bay will be used to estimate daily production rates for Florida Bay. Comparison of these data with previous productivity estimates and sediment accumulation rates will indicate whether discrepancies between production and accumulation rates are due to measurement and calculation techniques or to some real change in the productivity of the Bay.

Barnes, D.J. and Devereux, M.J. 1984. Productivity and calcification on a coral reef: a survey using pH and oxygen electrode techniques. Journal of Experimental Marine Biology and Ecology 79:213-231.

Boscence, D. 1989a. Biogenic carbonate production in Florida Bay. Bull. Mar. Sci. 44(1): 419-433

Frankignoulle, M. 1988. Field measurements of air-sea CO₂ exchange. Limnology and Oceanography 33(3):313-322.

Frankignoulle, M. and Disteche, A. 1984. CO₂ chemistry in the water column above a Posidonia seagrass bed and related air-sea exchanges. Oceonol. Acta 7(2):209-
219.

Gattuso, J.P., Pichon, M., Delesalle, B., and Frankignoulle, M. 1993. Community metabolism and air-sea CO₂ fluxes in a coral reef ecosystem (Moorea, French Polynesia. Marine Ecology Progress Series 96:259-267.

Kayanne, H., Suzuki, A., and Saito, H. 1995. Diurnal changes in the partial pressure of carbon dioxide in coral reef water. Science 269:214-216.

Millero, F.J. The thermodynamics of the carbonate system in seawater. Geochimica et Cosmochimica Acta 43:1651-1661.

Smith, S.V. 1973. Carbon dioxide dynamics: a record of organic carbon production, respiration, and calcification in the Eniwetok reef flat community. Limnology and Oceanography 18(1): 106-120.

Smith, S. V., and Key, G. 5., 1975. 1975 Carbon dioxide and metabolism in marine environments. Limnology and Oceanography 20:493-495

Stockman, K.W., R.N. Ginsburg, and E.A. Shinn. 1967. The production of lime mud by algae in South Florida. J. Sediment Petrol. 37(2): 633-648.

Sugiura, Y., Ibert, E.R., and Hood, D.W. 1963. Mass transfer of carbon dioxide across sea surfaces. Journal of Marine Research 2 1(1): 11-24.

Wanninkhof, R. 1992. Relationship between wind speed and gas exchange over the ocean. Journal of Geophysical Research 97:7373-73 82.

FY 1999 Deliverables/Products: We plan presentation at the USGS South Florida Ecosystem Meeting, the annual Florida Bay Science Conference, and one national meeting. Abstracts will be written, reviewed and approved for all meetings that require formal presentations. One journal manuscript will be prepared. Semimonthly salinity maps of Florida Bay will continue to be produced. All results are posted on the internet or presented at science meetings. Results are conveyed to management at managers meetings, through workplans, proposals, and reports.

FY1999 Outreach Activities:
During FY 1999 client requirements will continue to be met through continued regular client meetings, through direction from the Florida Bay Interagency Science Program Management Council, and through continued interaction with collaborators and clients listed above in the first section.

New Directions, Expansion of Continuing Project
This project does not anticipate new directions or expansions. It does however support the principle investigatorís time and travel on long range planning for the Florida Bay PMC and the USGS South Florida Program. Productivity measurements are new this year, but have been planned for as an essential part of the sediment budget. They do not require the multi-year data collection necessary for the longer-term sedimentation analyses (lead-210 or sediment elevation measurements).

ACCOMPLISHMENTS, OUTCOMES, PRODUCTS, OUTREACH

FY 1998 Accomplishments, Outcomes, Including Outreach
A) Successful completion of our contract work on Ecosystem History with the South Florida
Water Management District during FY 1998. B) Continued to serve as GD representative to
Program and Florida Bay Coordinator and C) represent the USGS on the Interagency Florida Bay
Program Management Council. D) Seven maps made available on the web. E. Two presentations to
the South Florida Water Management District.

FY 1997 Deliverables, Products completed
1. Halley, R. B., Smith, D., and Hansen, M., 1998, Florida Bay Surface Salinities Jan, April, June, Aug, Oct, Dec, 1997 and Feb, Open File Report 98-142.

2. Halley, R. B., Vacher, L. H., Shinn, E. A. 1997 Geology and hydrogeolgy of the Florida Keys, in Vacher, H. L. and Quinn, T. E., editors, The Geology and Hydrogeology of Carbonate Islands, Elsevier, New York, pp. 2 17-248.

3. Halley, R. B., Holmes, C. W., Prager, E. J., 1997, Florida Bay Mud Banks: Relatively New Piles of Mostly Old Sediments, US Geological Survey Open File Report 97-385, p. 26-27.

4. 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.

5. 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.

6. Prager, E. J., and Halley, R. B., 1997, Bottom types of Florida Bay, USGS Open-File Report
97-526.

7. Halley, R. B., Cronin, T. M., Wingard, G. L. and Ishman, S. E., 1998, Increased salinity of Florida Bay and saltwater Intrusion of the Biscayne Aquifer during the early 20th Century: Simultaneous consequences of falling water tables along the margins of the Everglades, in Proceeding of the 1998 Florida Bay Science Conference, Sea Grant, University of Florida, p 22-23.

8. Halley, R. B., 1998, West Everglades winter freshets during the current wet period and seasonal phase shifts in salinity cycles across Florida Bay, in Proceeding of the 1998 Florida Bay Science Conference, Sea Grant, University of Florida, p 24.

PROJECT SUPPORT REQUIREMENTS

Names and expertise (e.g. carbonate petrology) of key project staff (list by fiscal year for duration of project):

Halley (carbonate sedimentation, overall coordination, FY 1999,)
Prager (oceanographer, sediment transport, FY 1999)
Yates (geologist, budgets and modeling, FY 1999)
Tao (computer scientist, data processing, FY 1999)

Other required expertise for which no individual has been identified: none

Major equipment/facility needs (list by fiscal year for duration of project): FY1999 - An alkalinity titrator is required for the productivity measurments

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