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UNTREATED URBAN EFFLUENT EFFECTS ON
PHYTOPLANKTON COMMUNITY STRUCTURE AND FUNCTION IN LAKE
PONTCHARTRAIN, LA
Research by Dr. James L. Pinckney
Department of Marine Science Program and Department of
Biological Sciences
 The
floodwaters pumped back into Lake Pontchartrain
contained toxic chemicals, carcinogens, pathogens, and
human waste. University of South Carolina researchers
recognized that the rate of loading of these
contaminants was unprecedented and presented a unique
opportunity to describe ecosystem responses to this
catastrophic event. Documentation of changes in
phytoplankton community composition provides a sensitive
bioindicator for quantifying changes in ecosystem
processes following Hurricane Katrina.
USC researchers’ overall objective was to quantify the
response of the phytoplankton community composition and
biomass to massive inputs of untreated urban wastewater
into Lake Pontchartrain. This rare event will provide
observations of how ecological processes in Lake
Pontchartrain were altered after the catastrophic
addition of millions of gallons of untreated effluent.
Spatio-temporal contour maps of phytoplankton community
composition distributions were constructed to determine
the locations of large or unusual blooms in Lake
Pontchartrain. The system responses to this large-scale
perturbation were minimal and conditions in the lake
rapidly returned to pre-hurricane conditions. The
collective results were used to assess how the ecosystem
responds and determine if and when the system returns to
pre-hurricane conditions. Their research findings are
invaluable for developing models of how coastal
ecosystems respond to catastrophic inputs of untreated
urban wastewater.
USC researchers developed a working relationship with
colleagues at Louisiana State University and Loyola
University. They are seeking funding to continue their
sampling program to look for longer-term effects on Lake
Pontchartrain. The proposal requests support to analyze
phytoplankton samples collected by a Research Team at
LSU.
Three undergraduate students were trained to use high
performance liquid chromatography for the analysis of
photopigments in phytoplankton samples and performed all
of the analyses in this project. The results of this
study were presented in a special symposium at the
Southeastern Estuarine Research Society meeting in St.
Augustine, Florida.Biography
Dr. Jay Pinckney is an associate professor in the
Department of Biological Sciences at the University of
South Carolina. From 1992 to 1998 he was a research
assistant professor at the University of North Carolina
at Chapel Hill, Institute of Marine Sciences in Morehead
City, North Carolina. He accepted a faculty position in
the Department of Oceanography at Texas A&M University
in College Station in 1998. Estuarine and coastal
studies form the core of his research activities. Most
of Dr. Pinckney’s work over the past 20 years has
emphasized investigations of the ecophysiology of
benthic and phytoplanktonic communities and their
contribution to ecosystem function.
Research Team/Collaborators:
The Research Team at Louisiana State University
conducted weekly sampling trips in Lake Pontchartrain.
Dr. James Wee, Loyola University, documented the
floristic composition of the samples, as resources
allowed, using light microscopy, electron microscopy,
and culture isolations. USC undergraduate students
Meghan Jelloe, Michael Coggins, and Danielle Johnson
conducted all of the sample analyses as part of a
training program in the laboratory. |
