STUDY SITES

1
Figure 1. Chemical structure for atrazine, a
triazine.
STUDY SITES Wetlands are lowlands where the
water table is usually at or near the surface or
the land is covered by shallow water (Mitsch and
Gosselink, 1993). Wetlands are referred to by
such names as bogs, marshes, fens, swamps,
sloughs, wet meadows, and potholes, just to name
a few. A couple of common wetland types found in
southern Indiana include bottomland hardwoods
(BLH) and marshes. We sampled both of these
wetland types located in the Highland-Pigeon
Creek watershed. This watershed is influenced
mostly by mining activities, agriculture (a
source of atrazine), and urban areas (Jung,
2002). Howell wetlands (Figure 2a) are a
group of restored wetlands located near the
intersection of Broadway Avenue and Tekoppel Road
in Evansville. This wetland complex was once used
as an unofficial dump site by nearby residents.
These dumping habits along with agricultural
runoff severely degraded these wetlands. The
restoration project, finished in 1998, intends to
educate the community on the importance of
wetlands and to help return this area to its
natural state (Environmental Management
Consultants, 1997). The Howell wetlands now
consists of a slough surrounded by BLH habitat
and two marshes. The marsh vegetation is
dominated by emergent vegetation such as grasses,
sedges and cattails, while the forested wetlands
are dominated by hardwood tree species typical
for BLH wetlands (Jung, 2002). The Heim Road
area (Figure 2b) is another wetland complex
containing BLH and marsh habitat and is located
north of Heim Road and just west of Pigeon Creek
in Warrick county. It is a 5.4 acre area created
to comply with Section 404, of the Clean Water
Act, to replace wetlands destroyed in the
building of the Heim road bridge. The new
wetland area was designed to mimic the existing
wetlands and was structured into varying
elevation zones. Thirty-four plant species
typical of the native wetlands were introduced to
this site (Bernardin and Lochmueller, 1996). The
final wetland sampled for this project was the
Diamond Avenue wetland (Figure 2c). This wetland
is another created wetland located north of
Diamond Avenue between the Pigeon Creek Greenway
and Pigeon Creek in Evansville. It is a
freshwater marsh that was constructed by the
Indiana Department of Natural Resources to
increase wetland habitat along the greenway.
(a)
(b)
(c)
(d)
(e)
Figure 3. The five major steps in sample
preparation for GC/MS analysis (a) conditioning
SPE cartridge, (b) sample extraction, (c)
removing interstitial water, (d) sample elution,
and (e) sample concentration.
Table 1. Atrazine concentration (ppb) for marsh
and bottomland hardwood wetland types in three
southern Indiana wetland areas using ELISA.
(c)
(b)
(a)
Figure 2. The three wetland areas sampled for
this project (a) Howell, (b) Heim Road, and (c)
Diamond Avenue.
ORGANIC CHEMISTRY LAB A The atrazine project was
conducted as a special project in the freshman
organic chemistry lab under the direction of Dr.
D.L. Batema. Members of Lab A involved with the
atrazine project were Monica Qualkenbush Anna
Krodel Leah Madding Rachel Wassmer Megan
Miller Lauren Williams Justin Carter Jared
Eaton Devin Spencer Nicole Uhrin Ben
Wallace Diana Hadel Dan Dollison