Mercury in the Everglades
Rebecca Barefoot
EnvE 524
The Everglades
The Everglades•Once covered 11,000 miles of South Florida
•“The River of Grass” – 60 miles wide in some places. Only 6 inches deep in others.
•Marshy mix of salt and freshwater.
•Only place where Alligators and Crocodiles live side-by-side
•Altered and reduced flows have reduced diversity and native plant and animal life.
Florida Department of Environmental Protection
Actions• Pushed for reductions
from mercury emitting sources.
• Monitoring of water and fish in everglades
• 30 year Restoration Plan begun in 2000.
• Political issue Presidential Election in 2004
Anthropogenic Mercury Sources
• Combustion Processes (90%)– Coal-fired power generation– Medical waste incinerators– Municipal waste combustors
• Manufacture of metals, alkali, and cement• Incinerators• Landfills• Dental Preparations and Laboratory
Procedures• Pigment Manufacture• Geothermal Power Generation
Natural Mercury Sources
• Volcanoes• Forest Fires
Mount St. Helens
Forest Fire in Yellowstone Park
Mercury Data
• USGS Toxic Substances Hydrology ProgramNational Assessment of Mercury in Aquatic Ecosystems
• 1995 to 1999• Three types of Mercury
– Particulate Methyl Mercury– Filtered Methyl Mercury– Filtered Total Mercury
Mercury in the environment is complex!!
From Florida Department of Environmental Management Website
Analysis
• Temporal in nature• GIS is limiting• For each location:
– Averaged multiple data for same days – Then averaged data for entire year
• Saved data as comma separated value (csv)• Added csv to ArcGIS • Added x and y data from csv• Used symbology tab to indicate the year or field
to graph
Particulate Methyl Mercury (ng/L)
Filtered Methyl Mercury (ng/L)
19951999 Minus 1995
19991998
1997
1996
Filtered Methyl Mercury Percent Change
F1
3a-15
2bs
U3
Filtered Total Mercury (ng/L)
Filtered Total Mercury Percent Change
F1
U3
Mercury Trends 1995-1999 for Selected Everglades Locations
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
95 96 97 98 99
Year
Mer
cury
Co
nce
ntr
atio
n
(ng
/L)
3a-15 FMM
3a-15 FTM
3a-33 FMM
3a-33 FTM
F1 FMM
F1 FTM
L67@S151 FMM
L67@S151 FTM
U3 FMM
U3 FTM
FMM: Filtered Methyl Mercury
FTM: Filtered Total Mercury
Did not use Particulate Methyl Mercury Data since it had few locations with multiple years of data.
F1
U3
3a-33
L67@S151
3a-15
Results and Future Recommended Analysis
• Mercury either stayed the same or increased from 1995 to 1999.
• Methyl Mercury did not change much.
• Total Mercury tended to stay the same or increase.
• Look at more recent data.
• Use data from Storet source.