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.