five stations are, central Florida; Lake Barco 13 pg Hg nr 2 yr 1 , South Florida; Ft. 
Myers 19 pg Hg nrv 2 yr 1 , Fakahatchee Strand 20 pg Hg nrr 2 yr 1 , Tamiami Trail 21 pg 
Hg m* 2 yr 1 , and Everglades Research Station 25 pg Hg nr 2 yr -1 . 
1994 0 
Hanisak, M. D., and S. L. Miller (1994) Spatial and temporal variability in the elemental 
composition of benthic macroalgae in the Florida Keys. Abs., ASLO/PSA Joint Mtg., Miami, 
FL. a-33. 
[ABSTRACT ONLY. DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] Macroalgae are 
sensitive integrators of nutrients in coastal ecosystems. The nutrient status of 
representative field-collected macroalgae is being assessed at a series of stations in 
the Florida Keys. Preliminary analyses indicate considerable differences among the 
nitrogen contents of the dominant algal taxa. Nitrogen levels are higher for algae 
growing in sediment [e.g., Penicillus (mean = 2.8% N) and Avrainvillea (mean = 3.5% 
N)] than algae that do not [e.g., Laurencia (mean = 1.2% N) and Dictyota (mean = I .4% 
N)]. We hypothesize that, just as seagrasses do, these macroalgae are deriving 
nutrients from sediments rather than from, or in addition to, the water column. 
Temporal (i.e., seasonal) and spatial variability (nearshore vs. offshore, upper vs. 
middle Keys) in the N and P tissue contents also occur. This study will document 
ecosystem-level inputs of nutrients throughout the Keys, will determine if 
anthropogenic sources of nutrients cause pollution 'hot spots*, and will help support or 
refute recent claims that nutrient eutrophication significantly impacts the Florida Reef 
T ract. 
1994 0 
Kotra, R. K., L. P. Gough, W. H. Orem, and E. C. Spiker (1994) Geochemical studies of South 
Florida wetlands. Abs., ASLO/PSA Joint Mtg., Miami, FL. a-41. 
[ABSTRACT ONLY. DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] South Florida is 
an environmentally sensitive region of rapid population growth. Agricultural activities, 
residential development, and historical water management practices all affect drainage 
patterns and are potential sources and agents of stress on wetland ecosystems. Our 
geochemical studies are in support of south Florida earth science projects, including: 
geologic mapping, water quality assessments, and environmental investigations. In 
cooperation with the National Park Service, samples of water, sediment, soil, peat, and 
biota are being characterized to understand the biogeochemical cycling and flux of 
several important elements (e.g. C, N, S, P, Hg, and As) which may be impacting south 
Florida wetland ecosystems. We are focusing our efforts on organic rich materials, 
particularly peat. Preliminary results show related levels of Hg (up to 240 ng g* 1 ) in 
peat cores from a variety of wetland ecosystems and from recent sediment samples 
from several locations in south Florida. Sawgrass from wetlands and bromeliads from 
cypress swamps did not contain unusually high levels of mercury. Biogeochemical 
factors (such as peat biodegradation and oxidation) which may be influencing the 
distribution and cycling of Hg and other elements are being investigated. 
1994 0 
Rood, B. E., J. F. Gottgens, and J. J. Delfino (1994) Spatial and temporal distribution of 
mercury and other trace metals in Florida Everglades flooded soils. Abs., ASLO/PSA Joint 
Mtg., Miami, FL. a-63. 
[ABSTRACT ONLY. DATE OF SAMPLING UNKNOWN OR NOT APPLICABLE.] Elevated Hg 
concentrations were identified previously in freshwater fish in the Florida Everglades. 
The goals of this research were to determine the spatial distribution of mercury in 
Everglades soils and to identify temporal changes of Hg accumulation since the turn of 
the century. Soil cores or grab samples were retrieved from sixty locations in the 
Everglades. Seventeen cores were dated after radionuclide assay for 210 Pb and 137 Cs. 
377 
