Two general types of data are contained within this database: 1) Modern Field Data and 2) Core data - primarily faunal assemblages
The USGS South Florida Ecosystem History Project is designed to integrate studies from a number of researchers compiling data from terrestrial, marine, and freshwater ecosystems within south Florida. The project is divided into 3 regions: Biscayne Bay and the Southeast coast, Florida Bay and the Southwest coast, and Terrestrial and Freshwater Ecosystems of Southern Florida. The purpose of the projects is to provide information about the ecosystem's recent history based on analyses of paleontology, geochemistry, hydrology, and sedimentology of cores taken from the south Florida region. Data generated from the South Florida Ecosystem History project will be integrated to provide biotic reconstructions for the area at selected time slices and will be useful in testing ecological models designed to predict floral and faunal response to changes in environmental parameters.
Biscayne Bay is of interest to scientists because of the rapid urbanization that has occurred in the Miami area and includes Biscayne National Park. Dredging, propeller scars, and changes in freshwater input have altered parts of Biscayne Bay. Currently, the main freshwater input to Biscayne Bay is through the canal system, but many scientists believe subsurface springs used to introduce fresh groundwater into the Bay ecosystem. Study of the modern environment and core sediments from Biscayne Bay will provide important information on past salinity and seagrass coverage which will be useful for predicting future change within the Bay.
Plant and animal communities in the South Florida ecosystem have undergone striking changes over the past few decades. In particular, Florida Bay has been plagued by seagrass die-offs, algal blooms, and declining sponge and shellfish populations. These alterations in the ecosystem have traditionally been attributed to human activities and development in the region. Scientists at the U.S. Geological Survey (USGS) are studying the paleoecological changes taking place in Florida Bay in hopes of understanding the physical environment to aid in the restoration process.
As in Biscayne Bay, scientists must first determine which changes are part of the natural variation in Florida Bay and which resulted from human activities. To answer this question, scientists are studying both modern samples and piston cores that reveal changes over the past 150-600 years. These two types of data complement each other by providing information about the current state of the Bay, changes that occurred over time, and patterns of change.
Terrestrial ecosystems of South Florida have undergone numerous human disturbances, ranging from alteration of the hydroperiod, fire history, and drainage patterns through implementation of the canal system to expansion of the agricultural activity to the introduction of exotic species such as Melalueca, Australian pine, and the Pepper Tree. Over historical time, dramatic changes in the ecosystem have been documented and these changes attributed to various human activities. However, cause-and-effect relationships between specific biotic and environmental changes have not been established scientifically. One part of the South Florida Ecosystem History group of project is designed to document changes in the terrestrial ecosystem quantitatively, to date any changes and determine whether they resulted from documented human activities, and to establish the baseline level of variability in the South Florida ecosystem to estimate whether the observed changes are greater than what would occur naturally.
Specific goals of this part of the project are to 1) document the patterns of floral and faunal changes at sites throughout southern Florida over the last 150 years, 2) determine whether the changes occurred throughout the region or whether they were localized, 3) examine the floral and faunal history of the region over the last few millennia, 4) determine the baseline level of variability in the communities prior to significant human activity in the region, and 5) determine whether the fire frequency, extent, and influence can be quantified, and if so, document the fire history for sites in the region.
Quinn, J. F., Jr.; Bogan, A. E.; Coan, E. V.; Hochberg, F. G.; Lyons, W. G.; Mikkelsen, P. M.; Neves, R. J.; Roper, C. F. E.; Rosenberg, G.; Roth, B.; Scheltema, A.; Thompson, F. G.; Vecchione, M.; Williams, J. D.
Maddocks, R. F.
Wantland, K. F., and Pussey, C., III, editors
Abbott, R. T.
Schwengel, J. S.
Tappan, H.
Pollen assemblages and geochronology were analyzed from samples collected at 1-2 cm intervals throughout the cores. Pollen was isolated from the samples using standard palynological techniques, including carbonate and silicate removal with HCl and HF when necessary, acetolysis to reduce the amount of phytodebris, sieving through 8 micron mesh to remove clay-size particles, heavy liquid treatment when needed, and staining with Bismarck Brown before mounting on microscope slides with glycerin jelly.
Data collected by G. Lynn Wingard, Scott Ishman, Thomas Cronin, Jessica Albietz, James Murary, Joseph Murray, Joel Hudley, Rob Stamm, Bane Schill, Carleigh Trappe, Guy Means, Marci Marot, Casey Saenger, James Gillespie, Chuck Holmes, Eugene Shinn, Margot Corum, Sara Schwede, Jacqueline Huvane, Gary Dwyer, Kristi Alger, Jeffery Stone, Lauren Hewitt, Tom Scott, Carlos Budet, Laura Pyle, Jill D'Ambrosio, Stephen Wandrei, Casey Lowe, and Christopher Williams
Graham, Ian; D'Ambrosio, Jill
Cronin, Thomas M.; Brewster-Wingard, G. Lynn; Ishman, Scott E.; Wardlaw, Bruce R.; Holmes, Charles W.
Cronin, T. M.; Dwyer, G. S.; Ishman, S. E.; Willard, D. A.; Holmes, C. W.; Bernhardt, C. E.; Williams, C. P.; Marot, M. E.; Murray, J. B.; Stamm, R. G.; Murray, J. H.; Budet, C.
Cronin, Thomas M.; Holmes, Charles W.; Willard, Debra A.; Dwyer, Gary; Ishman, Scott E.; Orem, William; Williams, Christopher P.; Albietz, Jessica; Bernhardt, Christopher E.; Budet, Carlos A.; Landacre, Bryan; Lerch, Terry; Marot, Marci; Ortiz, Ruth E.
Brewster-Wingard, G. Lynn
Cooper, Sherri R.; Huvane Jacqueline K.
Ishman, Scott E.,; Willard, Debra A.; Edwards, Lucy E.; Holmes, Charles W.
Means, Guy H.; Brewster-Wingard, G. Lynn
Brewster-Wingard, G. Lynn; Fellman, Claire; Ishman, Scott E.
Ishman, Scott; Cronin, Thomas; Edwards, Lucy E.; Willard, Debra A.; Halley, Robert B.
Stone, Jeffery R.; Holmes, Charles W.
Ishman, S. E.; Edwards, L. E.; Willard, D. A.
Brewster-Wingard, G. L.; Willard, D. A.; Cronin, T. M.; Edwards, L. E.; Holmes, C. W.
Cronin, Thomas M.; Holmes, Charles W.; Willard, Debra A.; Budet, Carlos A.; Ortiz, Ruth E.
Cottrell, D. J.; Tagett, M. G.; Tedesco, L. P.; Warzeski, E. R., Jr.
Monty, C. V., Boscence, D. W. J., Bridges, P. H., and Pratt, B. R., editors
Core collection sites are determined on the basis of examination of digital orthophotoquadrangles, aerial photos, maps, reconnaissance, and discussion with land managers. Collecting cores is essential to the purpose of this project - to reconstruct the history of the ecosystem over biologically significant periods of time (decades to centuries) and to determine what the system looked like prior to significant human alteration. The sediments, faunal and floral remains in the cores retain this record.
All cores are collected via the "piston" coring method. This provides a minimum of disruption to the sediments. The technique of obtaining the piston core varies somewhat from site to site depending on water depth and accessibility. Following are the general procedures:
1. Marking the site: Specific core site is selected in advance by snorkeling before the boat or equipment is brought up to the site. The chosen site is marked with a float. 2. Set up: If the water depth allows, the boat is floated up to the site, anchored on at least two sides, and coring conducted through a "moon pool" (hatched hole in the bottom or back of the boat). If water depth does not allow us to float the boat over the site, we place the coring equipment on a raft or rubber dinghy, snorkel and float to the site, and proceed with coring. A tripod may be set up and utilized to assist in extracting the core. This is especially useful if the cores are long (>1.5 m) and/or if the substrate is very firm. If used, the tripod is set up prior to starting the actual coring. The purpose of the tripod is to keep tension on the piston while the core is being pushed down into the substrate. 3. Inserting the core barrels: 1. The piston (a hard rubber plug with 2 O-rings) is inserted into the bottom of a 4" outside-diameter clear acrylic tube, and a rope attached to an eye-ring in the top of the piston is threaded back through the core barrel. 2. The core barrel is lowered to just above the substrate and any air trapped in the space between the piston and the bottom of the barrel is removed and filled with water. Tension is then placed on the line attached to the piston, so when the core barrel penetrates the sediment the piston remains in a fixed position a few cm above the sediment surface; this produces a vacuum that retards compaction. 3. When the barrel is set in position it is forced down into the sediments (via muscle power) until we hit bedrock or until we cannot push the core any further. If a replicate core is being taken (side by side cores), the second core is pushed in place at this time, before the first core is extracted so that no disruption of the sediments for the second core will occur due to sediment movement during the extraction process. An aluminum clamp device with handles is usually placed around the barrel to provide a good grip for pushing. 4. Extracting the core barrels: 1. If a tripod was not set up, the aluminum clamp handles are used to extract the cores via muscle power. If a tripod is used, a cable and pulley system can be used to lift the core via a hand winch. With either method, it is critical to keep tension on the piston, because the piston provides the vacuum to retain the sediments in the core barrel as it is lifted. A benefit of the clear core barrel is that it allows us to determine if the piston is moving or if any leakage around the piston's O-ring seal occurs during the extraction process. 2. As soon as the core barrel clears the sediment surface, a person standing in the water quickly places a plastic cap over the bottom of the barrel. The barrel is hoisted vertically onto the boat and the bottom cap secured via waterproof tape. 3. Excess tubing is cut off just above the sediment surface using a large pipe cutter, and any space between the sediment surface and the top of the barrel is filled with water to prevent sloshing and disruption of the surface during transport. A top cap is placed on the barrel and sealed with waterproof tape. 4. If a replicate core is taken, the replicate also is extracted following the same procedures in a-c above.
During the coring process we are very careful to not stand on or damage any organisms (coral, sponges, etc.) or to damage the substrate other than the actual hole from the coring. In many areas, the mud is so soft that the hole caves in/collapses immediately after extraction, and no visible sign of the core is left.
Data recorded at the time of coring include: 1) GPS location (recorded on at least two instruments); 2) water depth to the substrate; 3) water depth to the sediment in the barrel (items 2 & 3 allow calculation of compaction during the coring process); 4) water properties including salinity, temperature, dissolved oxygen, and pH.
Cores are transported vertically and most are x-rayed as soon as possible (sometimes in the field at local hospitals). Cores are extruded vertically using the piston in reverse to push the sediment out of the barrel into one or two centimeter slices (resembling hockey pucks). The slices are trimmed around the edges to remove any contaminants due to contact with the barrel, bagged and weighed. Wet and dry weights are obtained for each sample.
Processing procedures may vary slightly for each core, depending on the different analyses being conducted and these procedures are reported with results for individual cores. In general, all material is retained. Small (1 cm3) plugs of sediment are removed for palynological analyses and for archival purposes. The remainder of the sample is washed with distilled and deionized water through 63 and 850 micron nylon mesh sieves and all material passing through the sieves is trapped in buckets and allowed to settle out for a period of days or weeks. The water is then siphoned off and the fine (<63 micron) fraction is air dried on filter paper under a hood, then distributed for geochemical and geochronological analyses. The 63 and 850 micron fractions are dried in a 50 degree C oven and distributed for faunal analyses.
Modern Samples:
Actual sampling methods and frequencies vary from site to site, depending on the substrate, water depth, and conditions, and the specific purpose of the sampling. In some cases we have collected small push core samples (10 cm deep by 2"diameter); in others, small samples of vegetation, scoops of sediment, or petite ponar grab samples. At every site we record information on water properties including salinity, temperature, dissolved oxygen, and pH, and where ever possible, we conduct a snorkel survey of the site listing presence/absence of various indicator macrofauna and flora.
Processing of modern samples follows procedures similar to the core samples, except the <63 micron fraction is rarely retained.
The possible attributes for the Core Locations are: General Location, Core ID #, Core Name, Related Modern Site, Public Information, Date Collected, Collectors, Longitude, Latitude, State, County, 7.5 minute quad, Total Core Length, H20 Depth, General Area Description, Substrate Description, and Additional Information. These attributes are populated as appropriate for each core.
U.S. Department of the Interior, U.S. Geological Survey
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