Research Report to Edna Bailey Sussman Foundation
December 11, 2009
Madeline Turnquist
SUNY – College of Environmental Science and Forestry
Syracuse, NY
Creating a Predictive Spatial Model to Determine the Locations of High
Aquatic Mercury Levels in New York:
An Internship with the New York State Department of Environmental Conservation
Proposed Work and Objectives
The purpose of my internship with the New York State Department of Environmental
Conservation (NYS DEC) was to conduct field research on different aquatic species susceptible to
mercury contamination and collect data to determine correlations with mercury levels. The
primary objective of my research was to use the fish mercury levels collected along with various
lake chemistry parameters tested to create a predictive spatial model to determine where high
mercury levels are likely to be found in New York. Secondly, I would validate these predictors by
collecting independent mercury and water samples on various fish species and snapping turtles
(Chelydra serpentine). Further, a map of lakes with high predicted fish mercury levels would be
constructed. Additionally, this internship would serve to introduce me to a network of people
working within the NYS DEC and gain experience working with a state agency.
Work Completed and Samples Collected
I worked directly with Eric Paul from the NYS DEC out of Rome, NY to conduct surveys
for fish and collect water samples for chemical analysis. At the beginning of the summer, I assisted
in collecting fish from Lewey Lake, Hamilton County, NY and Delta Lake, Oneida County, NY.
The fish were collected either through gill nets or angling. I would aid in removing fish from the
gill nets, and I would also help record the data about each fish that was collected. The fish were
then put on ice and transported to the lab were they were analyzed for mercury levels. While fish
from other lakes were collected, I was not involved in sampling these lakes for fish.
In July, I again worked with Eric Paul and his field technician, Ben Durie, to collect water
samples from various lakes across the state. I assisted in collecting water samples from at least 10
lakes with Eric and Ben. For each lake, a secchi disk depth was recorded and a temperature and
dissolved oxygen profile were created. Water samples were taken to measure total phosphorus,
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chlorophyll-α, pH, nitrates, sulfur, acid neutralizing capacity, dissolved organic carbon, and
various other water chemistry variables.
Through working with Eric and Ben, I was able to meet other state employees at the Rome,
NY fish hatchery and interact with them. I was also able to see first hand the workings of a
department within a state agency and observe how different procedures are handled and how
different research activities are carried out. It was a good experience to see if working for a
government organization is something I would like to pursue for a career path.
Besides working directly with the NYS DEC to collect fish and water samples, I collected
snapping turtles to analyze for mercury levels. I developed a non-lethal sampling method to obtain
a shell and muscle sample from the turtles. This involved baiting hoop nets to collect the turtles
(Figure 1). Once the turtles were collected, I removed a small section of the top layer of their shell
and used a tissue biopsy punch to collect the muscle sample from their hind legs and tail (Figure
2). Precautions were taken to clean and sterilize the turtle’s skin before the samples were taken as
well as to minimize infection. The turtles were also measured and weighed before being release
back into the environment (Figure 3).
Figure 1. Setting a hoop net at Montezuma National Wildlife Refuge, NY to trap snapping turtles.
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Figure 2. The location of the tissue biopsy
samples on a snapping turtle. The sample sites are
circled in red and were already coated with
antibacterial ointment and closed shut before the
picture was taken.
Figure 3. A picture of myself holding a
29lb snapping turtle at Francis Lake, NY
prior to release after the shell and tissue
samples were taken.
I surveyed 13 different lakes across NY for snapping turtles, and I successfully caught
turtles at nine of these 13 sample lakes. The sample lakes were spread across NY to obtain a
variety of lake types and various water parameters in each lake. The lakes were chosen based on
lakes the NYS DEC had or was going to survey for fish mercury levels. Lakes were surveyed
across the Adirondack region, in the southern portion of NY by Binghamton, NY, and near the
Syracuse area. I also trapped for turtles at Montezuma National Wildlife Refuge, Seneca Falls, NY
to obtain turtles from a vast wetland complex system to examine the amount of mercury turtles
obtain from living directly in wetlands were mercury methylation occurs versus living in a lake
with adjacent wetlands.
At the lakes were I obtained snapping turtle samples, if water samples were not collected
by the NYS DEC, I collected water samples to examine correlations with the turtle mercury levels.
At all the lakes where I sampled for turtles, I collected a water sample at the deepest portion of the
lake one meter below the surface to have analyzed for total phosphorus. Lakes where additional
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water samples occurred were Chenango Lake State Park, Hunt’s Pond State Park, and Bowman
Lake State Park.
Additional to my field work, I gathered different map layers to incorporate into my
geographic information system (GIS) map. These layers included elevation, wetland area and
types, land use and land cover type, and area hydrography (lake) layer. These different layers were
organized and complied together to cover the whole state. These map layers are an integral part of
improving my model to predict for mercury levels in aquatic organisms.
Results and Accomplishments
Information about my field samples collected and analyzes is as follows. Currently, I am
waiting to obtain mercury results for the fish sampled and analyzed this summer from the NYS
DEC. My water sampled for total phosphorus have been run and obtained. I caught over 50
snapping turtles this summer, but only took samples from 48 turtles which were large enough to
have tissues removed safely. I have cleaned all my turtle shell samples, which I focused on
removing all organic and biological matter from the shell sample. These samples are in the process
of being crushed before analysis. All muscle samples are ready for analysis.
Beyond my field samples, I constructed databases containing both fish mercury levels as
well as water chemistry parameters for four species of fish, yellow perch (Perca flavescens),
smallmouth bass (Micropterus dolomieui), largemouth bass (Micropterus salmoides), and walleye
(Sander vitreus). These datasets will be useful in building the regression models to predict fish
mercury levels. I have calculated preliminary regression models for yellow perch using pH of the
lake and fish length as the main predictors of the fish’s mercury level.
The primary GIS layers to be incorporated into the database were obtained this summer.
Lakes in the hydrography layer corresponding to the lakes in the database have been identified and
isolated. All 131 lakes in the database have been group together for easier use. A flow direction
model/layer was also built from the elevation layer to use in calculating the watershed for each
lake.
Future Work
I have still working with the data I collected this summer and incorporating it into the
database to improve the parameters for future use in constructing various regression models. When
I obtain the additional mercury measurements from the fish that the NYS DEC colleted, this
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information will be incorporated into the databases to improve the regression models on predicting
mercury levels in each species of fish. Information about each lake that will be obtained from GIS
procedures will be added to the database as well. From the flow direction layer, I will delineate the
watershed for each lake in the database. With the watersheds obtain, I will be able to calculate lake
to watershed ratio, percent forest cover, amount of wetlands present, and amount of mercury
deposition for each watershed. These new parameters will also be incorporated into the database.
With additional parameters in the database to improve the accuracy of the regression
models, I will determine the best regression model for yellow perch, smallmouth bass, largemouth
bass, and walleye. To predict fish mercury levels in additional lakes across New York, I will use
information about lakes not sampled for fish mercury levels to enter into the regression models for
each fish species. I should be able to predict fish mercury levels for approximately 2000 lake
across New York. I will use GIS to isolate these lakes to obtain landscape feature information that
may need to be incorporated into the parameters of the mercury prediction models. Once a
prediction value is obtained for these lakes, I will use GIS to create a map of the lakes with high
predicted fish mercury levels.
Additionally, I will be analyzing my turtle shell and tissue sample in January for total
mercury levels. These samples will be analyzed in the lab of Dr. Charles Driscoll at Syracuse
University. I will then use water chemistry information and landscape information from GIS for
the lakes were turtles were obtained to create a predictive model about the levels of mercury found
in snapping turtles. I will also use the water chemistry measurements to determine which variables
are highly correlated with high levels of mercury in snapping turtles.
Any publication or presentation that results from this research, I will acknowledge the exceptional
contribution the Edna Bailey Sussman Foundation made to my research. This past month, I was
able to present to a group of SUNY-ESF students some of the work I conducted this summer, and
the Sussman Foundation was acknowledge for their contribution to my work over the summer.
Thank you for giving me this opportunity to conduct my research this past summer and
work with the NYS DEC. It was a great learning experience and an outstanding opportunity
to help me further my research and determine my career goals. It wouldn’t have been
possible without the support the Edna Dailey Sussman Foundation. Thank You!
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