1) Water samples were collected from Webster Duck Pond in Syracuse, NY along an anthropogenic gradient from a disturbed area near visitor facilities to a more natural, spring-fed area. 2) Phosphorus and iron and manganese concentrations were higher in samples taken near the disturbed area, likely due to duck waste, while other trace elements did not vary. 3) This provides a real-world example of how human activities can increase phosphorus levels and change pond water chemistry from oxic to more anoxic conditions near the disturbed shoreline.

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TotalP(mg/L)
Site (from one side to other)
[Total P] Across
Sites
Trace Element and Phosphorus Concentrations Across An
Anthropogenic Gradient in Webster Duck Pond, NY
Adrian E. Alvarez, Syracuse University
Introduction
Webster Duck Pond is a popular yet
somewhat hidden tourist attraction in the city
of Syracuse, NY. For a considerable portion
of the year, ducks and other waterfowl flock
to the area and are fed corn by visitors,
provided by the Anglers Association of
Onondaga who run the pond. Management
issues have been raised as the ducks
contribute a great deal of waste material to
the pond.
It is noteworthy to mention that this feeding,
along with other anthropogenic influences, is
mainly present toward one side of the lake,
near the Angler’s Association building. The
other side is less disturbed and naturally
spring-fed, creating an anthropogenic
gradient of sorts.
Question and Hypothesis
• Question: Do trace element and phosphorus
concentrations vary across this anthropogenic
gradient?
• Hypothesis: Trace element concentrations
should be relatively constant throughout the
pond, but phosphorus concentrations should
be higher near the more disturbed end.
Collection Sites
Procedure
1. Upon collection, water samples were filtered at
the limnology laboratory (Illick 251) into glass
containers; a new filter was used for each bottle
2. Three drops of concentrated HNO3 were added
to each glass container
3. Raw samples and filtered ones were kept in
freezer on 4th floor of Illick until 12/1/2014
4. Filtered containers were sent to ATS for
concentrations of Ba, Ca, Fe, Mg, Mn and Sr
using ICP-OES
5. Raw samples and more filtered samples were
measured for total P and total dissolved P by
the soils lab using spectroscopy methods
Results
Conclusion/Discussion
• With the exception of Fe and Mn, all other trace elements
did not vary across the anthropogenic gradient; Fe and Mn
were higher among sites near the disturbed end (Angler’s
Association and road)
• Phosphorus concentrations were higher at the disturbed
end; possible real-life example of the iron trap
• possible explanation: duck waste matter contributed to this
increase
• Conditions near the more disturbed end may be anoxic as
represented by high P, high Fe, high Mn (low redox potential)
• Useful to anglers as (artificially stocked) fish may be near
spring-fed end
• Many thanks to Ben Amos for helping with sample collection, filtering and
storage; Professor Schulz for good feedback and referring me to the right people
for sample analyzing; Deborah Driscoll for running trace element measurements;
Charles Schirmer for running phosphorus measurements.
• Water samples were collected on 11/21/2014
at Webster Pond, Syracuse NY
• The weather was overcast with recent snowfall
and the surface of the pond was partly frozen
• Four collection sites were chosen along the
shore of the pond; 2 acid-washed bottles were
filled at each site at surface water level
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1. Side near Angler’s Association (AA)
2. Side near road
3. Far side near stream
4. Stream
Acknowledgments
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[Fe](ug/L)
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[Fe] Across Sites
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[Mn](ug/L)
Site (from one side to other)
[Mn] Across Sites
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TotalDissolvedP(mg/L)
Site (from one side to other)
[Total Dissolved P]
Across Sites
• One-way ANOVA tests were performed for each element vs
site (only Fe, Mn, TP, and TDP yielded p-values below < 0.01)
• Tukey HSD revealed two distinct groupings in Fe, Mn, and TDP
(AA and road vs. stream and far end) Red font = similar groups
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Purpose: To study the effects of human urbanization on a pond in terms of phosphorus and trace elements