Dr. Mary Lang
Edwards
Erskine
Biology Professor Awarded SCICU Research Grant
Erskine biology professor Dr. Mary Lang Edwards,
known for her work with tracking turtles using
radiotelemetry, has revealed an interest in
amphibians, garnering a South Carolina Independent
Colleges and Universities (SCICU) grant of $2,200 for
a research project on the decline in amphibian
populations and its possible connection with PCB
contamination.
Edwards will work with rising Erskine College
junior Emily Rogers, daughter of Mr. and Mrs. Richard
Rogers, Clinton, who is a biology major. The project
is a continuation of one begun in 1998 by Edwards
with Rogers and Jonathan Roling, a 2000 Erskine
graduate.
“PCBs are well-known industrial pollutants
that are released into rivers and lakes. It has been
known for some time that these toxicants create all
kinds of problems for organisms,” Edwards
explained. “One ongoing area of research among
scientists targets amphibians. Are pollutants one
cause of the worldwide decline in amphibiam
populations?”
Edwards's project description notes that since
amphibians spend a major part of their lives in
water, “it is likely that they are particularly
vulnerable to toxicants that readily pass through
their skin.” She cites recent research showing
that amphibians can accumulate toxicants through the
uptake of chemicals directly from the water during
feeding and submersion.
Edwards's current project aims to explore the
effect of PCBs on amphibians, looking especially at
the effect of these pollutants on metamorphosis from
the tadpole to the adult frog.
“If PCBs do interfere with this transition to
the adult stage in the life of frogs, then we need to
document that,” says Edwards. “We already
have some evidence that PCBs do affect metamorphosis
in one species of frog. We would also like to figure
out exactly how this toxin affects the process of
metamorphosis.”
The project, which will be conducted during this
summer and fall, will include examining several ponds
or lakes in the upstate, Edwards said, looking for
PCB contamination in several local bodies of water
using gas chromatography, a method of separating a
sample mixture into its component compounds.
Edwards and Rogers will also measure the effects
of the PCB Aroclor 1260 on metamorphosis and growth
in a particular tadpole species (Xenopus laevis).
They will attempt to determine the effects of PCB
Aroclor 1260 on dopamine activity in the brain, the
mechanism by which growth and metamorphosis are
regulated.
