projects > geochemical monitoring of restoration progress > 2001 Proposal
Project Proposal for 2001
Place Based Studies Program FY 2001
Project chief: Kimberly K. Yates
Statement of the Problem: The flow of freshwater from the Everglades to Florida Bay and the interaction of Bay water with the Gulf of Mexico and Atlantic Ocean are critical processes that have defined the Florida Bay Ecosystem. Reconstruction of historical changes in the Florida Bay Ecosystem using paleoecological and geochemical data from cores and historical databases indicates that significant changes in water quality and circulation (McIvor et al., 1994; Rudnick et al., 1999; Boyer et al., 1999; Halley and Roulier, 1999; Stumpf et al, 1999; Swart et al., 1999), and biological species composition and ecology (Brewster-Wingard and Ishman, 1999; Fourqurean and Robblee, 1999; Hall et al., 1999; Zieman et al., 1999) have been coincident with alteration of drainage patterns in the Everglades and construction of bridges linking the Keys. For example, historical salinity records and paleoecological information derived from cores suggest that salinity patterns changed in the early 1900s in response to railroad and canal system construction and again around 1940 in response to water management practices, and that average salinity and hypersalinity have increased recently (Halley et al., 1996; Robblee and Smith, 1999; Brewster-Wingard and Ishman, 1999). Paleoecological data from cores also indicates that changes in the abundance of seagrass and algae in the Bay have been coincident with salinity changes (Brewster-Wingard and Ishman, 1999), and that significant loss of seagrass on mud banks and basins has occurred over the last several years (Robblee et al., 1991; Carlson et al., 1998). Stable isotope data from sediment cores indicate decreased circulation in the Bay coincident with railroad building and early drainage in South Florida (Halley and Roulier, 1999).
Water management practices in South Florida are already being altered in an effort to restore the Everglades and Florida Bay. Resulting changes in water chemistry will first affect biogeochemical processes, and may, subsequently, result in changes in species distributions (such as seagrass, algae, etc.) in the Bay. An extensive water quality monitoring program for Florida Bay has been in operation for several years. Primary participants include ENP (fixed water quality monitoring stations), NOAA (salinity, chlorophyll, and transmittance bimonthly surveys), SFWMD (northeast Bay and north coast monitoring), and FIU (nutrient monitoring. These programs have provided detailed information on concentrations of water quality parameters in the Bay. However, in situ monitoring of key biogeochemical processes resulting directly from biological activity has not been undertaken. Monitoring changes in biogeochemical processes is critical to early identification of ecological response to restoration and predicting changes in species distribution within the Bay. Additionally, these processes may directly impact water quality. For example, production and accumulation of carbonate sediments may play a key role in the removal of phosphate from the water column due to binding of phosphate to sediments. Calcification, photosynthesis, and respiration directly affect dissolved oxygen, pH, dissolved inorganic carbon and a number of other chemical characteristics of the water column. This information will enable managers to evaluate the progress and success of South Florida restoration efforts.
Project objectives and strategy: Carbonate environments such as Florida Bay are characterized by three primary biogeochemical processes including 1) carbonate sediment production by calcifying organisms and dissolution, 2) photosynthesis and 3) respiration (referred to collectively as productivity). These processes are sensitive to changes in water quality including salinity and nutrients, and show distinct rate changes before visual evidence of environmental disturbances such as seagrass die-off, algal blooms, and shifts in ecosystem success indicator species. Therefore, measuring changes in these processes relative to changes in water quality (such as salinity and nutrients) provides a mechanism for monitoring restoration progress. This project employs geochemical analytical techniques and salinity, pH, dissolved oxygen, and turbidity surveys to measure current rates of productivity in Florida Bay, and to monitor changes in productivity during implementation of restoration plans to assess progress and effects of restoration in South Florida on environmental health.
FY2000 efforts (to be completed by Sept. 30, 2000) focused on measuring current seasonal rates of productivity (including carbonate sediment production, photosynthesis and respiration) in Florida Bay to establish baselines for these parameters from which to monitor restoration progress. Additional project objectives to be addressed in FY2001 and subsequent years include 1) monitoring productivity over the next 3-4 years to assess restoration progress and its effect on critical environmental processes in the Bay, 2) performing Bay-wide, bimonthly salinity, pH, dissolved oxygen, turbidity, dissolved inorganic carbon (DIC), dissolved organic carbon (DOC), total organic carbon (TOC), and particulate organic carbon (POC) surveys to measure changes in these parameters during implementation of restoration, and to identify additional monitoring locations where sustained water quality changes may result in ecosystem stress, and 3) comparison of results from productivity monitoring efforts to historical cycles of salinity change, carbonate sediment accumulation, and distribution patterns of subaquatic vegetation and indicator species to help identify when restoration has been accomplished. Each of these objectives will be addressed as tasks described below.
Task 1: Seasonal Productivity Monitoring
Task 2: Bimonthly Geochemical Surveys
Task 3: Historical Comparisons
Potential impacts and major products: Productivity monitoring efforts will allow resource managers to evaluate progress and success of restoration efforts. Geochemical productivity monitoring provides a mechanism for measuring early response of the Florida Bay ecosystem to environmental perturbations. This will enable resource managers to identify ecological responses to restoration and to evaluate the need for alteration of restoration procedures prior to the onset of visual shifts in sub-aquatic plant and animal populations. Geochemical survey data will provide information on the extent and magnitude of salinity shifts in the Bay due to freshwater inflow from the Everglades and the effects of freshwater inflow on other parameters critical to environmental health in the bay including dissolved oxygen, pH, turbidity, DIC, TOC, DOC, and POC. Presenting resource managers and decision makers with a comparison of monitoring data to historical cycles in sediment accumulation rates, shifts in indicator species, and salinity changes will assist them in defining restoration criteria and identifying when restoration has been accomplished. This geochemical monitoring program will serve as a model for developing similar programs for monitoring other coastal and lacustrine environments targeted in future projects.
WORK PLAN (Time line FY 2000 to project end):
FY 2001 activities: Fiscal year 2001 activities will focus on monitoring rates of production in the Bay (task 1) and bimonthly geochemical surveys (task 2). Productivity rates will be established by measuring rates of calcification, photosynthesis, and respiration (using geochemical techniques described in task 1) associated with mud bank and basin benthic habitats. Monitoring sites will include those sites established during FY2000 (Russell Bank, Manatee Key Basin, Buchanon Bank); additional sites in the eastern section of the Bay near Pass Key, Barnes Key (an area of seagrass die-off currently monitored by FMRI), and benthic algal mat locations (coordinated with FMRI and USF nutrient study sites) to be established during summer 2000, and sites of potential water quality stress determined from geochemical monitoring in Task 2. Biological characterization of geochemical monitoring sites by FMRI and USGS will provide critical information used for hind-casting production rates based on historical information from cores. Rates of productivity at each site will be measured for 24 hour periods during seasonal (2-4 time/year), two week field excursions to establish daily, seasonal, and annual rates of production in the Bay. These data will be compared to baselines productivity data established in FY2000 to identify changes in ecosystem health. Water samples from the S.H.A.R.Q. will be collected from each monitoring and experimental site for radon-222 and radium isotope analyses. These analyses will indicate rates of groundwater seepage into incubation chambers and determine whether geochemical data will need to be corrected for groundwater mixing.
Bay-wide geochemical surveys will be conducted bimonthly throughout the year. Salinity, conductivity, dissolved oxygen, pH, and turbidity will be measured using a YSI 6820 Sonde multi-parameter water quality system, with a sampling frequency of approximately 10-30 seconds, towed behind a small research vessel. Survey tracts will target the perimeter of each of the smaller basins in the Bay, transect larger basins, and include sampling sites near canal and slough discharge areas. Water samples for DIC, DOC, and TOC analyses will be collected from each of 24 sites distributed throughout the Bay. Analyses will be performed using a carbon coulometer. The cost of a carbon coulometer has been distributed between this work plan and a workplan submitted to the Coastal and Marine Geology Program for Coral Reef investigations. These data will establish the effects of alteration of freshwater flow to Florida Bay on critical geochemical parameters and assist in establishing links between changes in water quality, biogeochemical processes, and ecosystem health.
FY 2001 deliverables/products:
FY 2001 outreach:
Boyer, J.N., Fourqurean, J.W., and Jones, R.D. 1999. Seasonal and long-term trends in the water quality of Florida Bay. Estuaries 22(2).
Brewster-Wingard, G.L. and Ishman, S.E. 1999. Historical trends in salinity and substrate in Florida Bay: a paleoecological reconstruction using modern analogue data. Estuaries 22(2).
Carlson, P., Landsberg, J., and Blakesley, B. 1998. Seagrass mortality and recovery on Florida Bay mudbanks: year 1 progress report covering the period August 1, 1997 July 31, 1998. Prepared for Everglades National Park.
Hall, M.O., Durako, M.D., Fourqurean, J.W., and Zieman, J.C. 1999. Variations in water clarity in Florida Bay from 1985 to 1997. Estuaries 22(2).
Halley, R.B. and Roulier, L.M. 1999. Reconstructing the history of eastern and central Florida Bay using mollusk-shell isotope records. Estuaries 22(2).
Halley, R.B., and Yates, K.K. 1999. Sediment production is critical to reef restoration. International Conference on Scientific Aspects of Coral Reef Assessment, Monitoring, and Restoration, Program and Abstracts, Ft. Lauderdale, FL, April 14-16, 1999.
Halley, R.B., Smith, D., and Hansen, M. 1996. Florida Bay salinity maps, surface and bottom salinity, 11/94; 1, 4, 6, 8, 10, 12/1995; 2,4,6/1996: USGS Open-File Report 95-634.
Fourqurean, J.W. and Robblee, M.B. 1999. Florida Bay: a history of recent ecological changes. Estuaries 22(2).
Frankignoulle, M. and Distéche, A. 1984. CO2 chemistry in the water column above a Posidonia seagrass bed and related air-sea exchanges. Oceologica 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.
McIvor, C.C., Ley, J.A., and Bjork, R.D. 1994. Changes in freshwater inflow from the Everglades to Florida Bay including effects on biota and biotic processes: a review. In: Everglades the Ecosystem and it Restoration, S.M. Davis and J.C. Ogden (Eds.), St. Lucie Press, Delray Beach, FL, chap. 6.
Millero, F.J. 1979. The thermodynamics of the carbonate system in seawater. Geochimica et Cosmochimica Acta 43:1651-1661.
Millero, F.J., Zhang, J., Lee, K., and Campbell, D.M. 1993. Titration alkalinity of seawater. Marine Chemistry 44:153-165.
Prager, E. and Halley, R.B. 1997. Florida Bay Bottom Types. U.S.G.S. Open File Report #97- 526.
Rama and Moore, W.S., 1996. Using the radium quartet for evaluating ground water input and water exchange in salt marshes. Geochim. Cosmochim. Acta 60: 4645-4652.
Robbins, J.A., Holmes, C.W., Halley,R.B., Bothner, M., Shinn, E., Graney, J., Keeler, G., tenBrink, M., Orlandini, K.A., and Rudnick, D. in press. First-order time average fluxes of 137Cs, Pb and 239+240Pu to 210Pb dated sediments in Florida Bay. Journal of Coastal Research.
Robblee, M.B., Barber, T.R., Carlson, P.R., Durako, M.J., Fourqurean, J.W., Muehlstein, L.K., Porter, D., Yarboro, L.A., Zieman, R.T., and Zieman, J.C. 1991. Mass mortality of the tropical seagrasses Thalassia testudinum in Florida Bay (USA). Marine Ecology Progress Series 71:297-299.
Robblee, M.B. and Smith, D.T. 1999. Salinity pattern in Florida Bay: a synthesis. U.S. Geological Survey Program on the South Florida Ecosystem. Proceedings of South Florida Restoration Science Forum, May 17-19, Boca Raton, Florida.
Rudnick, D.T., Chen, Z., Childers, D.L., Boyer, J.N., and Fontaine, T.D. 1999. Phosphorous and nitrogen inputs to Florida Bay: the importance of the Everglades watershed. Estuaries 22(2).
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.S. 1975. Carbon dioxide and metabolism in marine environments. Limnology and Oceanography 20:493-495.
Swart, P.K., Healy, G., Greer, L., Lutz, M., Saied, A., Anderegg, D., Dodge, R.E., and Rudnick, D. 1999. The use of proxy chemical records in coral skeletons to ascertain past environmental conditions in Florida Bay. Estuaries 22(2).
Swarzenski, P.W. 1999. Examining freshwater-saltwater interface processes with four radium isotopes. USGS Fact Sheet #FS-065-99.
Zieman, J.C., Fourqurean, J.W., and Frankovich, T.A. 1999. Seagrass dieoff in Florida Bay (USA): long-term trends in abundance and growth of Thalassia testudinum. Estuaries 22(2).