9.1.7.3.3. Terrestrial and freshwater ecosystem history 
Although considerable effort is going into understanding the nature of the observed stress on 
the Everglades ecosystem, there is little knowledge of what conditions were like prior to 
anthropogenic influences and particularly what, if any, natural ecosystem cycles existed in the 
past. This project compared modern, historic, and prehistoric biotic assemblages in sediments 
from a wide variety of settings. Data on naturally occurring ecosystem variability, including 
dires and biodiversity, helped established a baseline for restoration of the ecosystem. 
9.1.7.4. Florida Bay Water quality 
9.1.7.4.1. Geophysical mapping of fresh ground water 
The groundwater component of freshwater flow into Florida Bay is not quantified. This project 
used airborne geophysical techniques to map the freshwater/salt-water interface beneath the 
Everglades immediately north of the Bay. Repeated surveys related the interface position to 
hydrologic conditions and provided the basis for supplying groundwater discharge values to 
future salinity models. 
9.1.7.4.2. Marine groundwater seepage 
The effect of groundwater inflow on the quality of water in Florida Bay is largely ignored in 
assessments and models. Seepage meters were installed in Florida Bay as well as the coastal 
reef tract to measure pressure and collect samples of fluid seeping through the rock-water 
interface. Ground water was analyzed for nutrients, salinity, dissolved oxygen and fecal 
coliform bacteria. These data furthered the understanding of the water and chemical budget for 
the Bay. 
9.1.7.4.3. Groundwater flow from the Florida Keys 
The fresh and saline ground water beneath the Florida Keys is known to be contaminated by 
effluent from domestic sewage-disposal systems but the flow mechanism and pathways that 
enable this water to reach Florida Bay and coastal waters is poorly understood. This project 
quantified groundwater flow by means of observation wells and tracer studies. This project 
was the onshore complement to a planned study of seepage rates and quality in the Bay. 
9.1.7.4.4. Florida Bay sedimentation 
The bathymetry of Florida Bay has not been systematically mapped in 30 yrs and new 
bathymetric data helped assess sedimentation rates and provided a foundation for a sediment 
budget. This project employed new techniques allowing for the collection of highly accurate data 
in shallow water and provided bank-top and tidal flat elevation data previously unavailable. 
These data are critical to the development of circulation and sediment budget models. 
9.1.7.4.5. Remote sensing of turbidity and sedimentation 
Although current monitoring programs provide data on water quality at periodic intervals, they 
do not address the questions of the frequency and magnitude of turbidity events or the quantity 
and fate of the sediment being transported. This project used highly processed satellite 
imagery, coupled with field measurements, to produce time-series data on water reflectance, 
sediment load, light attenuation and water temperature. 
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