In January, Hannah Hastings ’08 and Andrea Pain
‘08 collected seagrass from the ocean floor to study nutrient content in a
dinoflagellate-rich ecosystem off the southwest coast of Puerto Rico.
The seniors returned to Wesleyan and analyzed their samples for carbon,
nitrogen and phosphorus levels. They discovered a high ratio of nitrogen to
phosphorus compared to the normal ratio in the ocean.
“We discovered that high dinoflagellate concentrations are directly
associated with elevated nitrogen to phosphorus ratios,” Pain said during
Part I of the Earth and Environmental Science Department’s Senior Seminar
Research Project colloquium March 6. Part II of the colloquium is scheduled
for March 25.
Hastings and Pain were among 15 students and two faculty members who
traveled to Puerto Rico Jan. 7 to 13 to carry out multiple research projects
on the island. These students are enrolled in the E&ES 398 course, Senior
Seminar, the capstone course for the E&ES major. Tim Ku and Dana Royer, both
assistant professors of earth and environmental sciences, teach the class.
“This year, we chose to take the class to Puerto Rico because the island has
a wide variety of terrain and different environments to study,” Ku said.
“The students come up with an original research question and the procedures
necessary to answer that question.”
Ku and Royer suggest general research topics to their classes; however the
students are encouraged to come up with their own ideas, too. The students
break into groups of two and three, and direct their own study and analysis.
Michelle
Chen '08 and Rebecca Sorell '08 studied the depositional history of a salt
flat near the shoreline city of Cabo Rojo, Puerto Rico. The duo, along with
their classmates, waded through worm-infested, mushy terrain collecting 10
sediment core samples in a lagoon. Afterwards, they dissected the core,
photographed the contents and described the sediments’ substance.They discovered layers of clay, shell hash,
silt, salt and organic layer, within their samples, and even traces of
mangrove roots, and halite, or rock salt. Halite forms in evaporated water
basins.
“We think this area was once completely wet and underwater, but then
completely dried out where we found the salt layers,” Sorrell explained.
“Future projects could involve comparing this lagoon to others on the
island.”
Marie Brophy '08, Sophia Kim '08 and Miles Turner '08 studied the geology of
the Bermeja Complex, the oldest rock formation on the island of Puerto Rico.
The Bermeja terrain, which is estimated to be 200 million years old, is made
of serpentinite, a green rock comprised of minerals from Earth’s
seafloor.
“Our question was, ‘how did these rocks get to where they are today,’”
explained Brophy. “They could have been pushed onto land directly from the
seafloor or plunged first into the mantle and then emplaced on the Earth’s
surface through volcanic activity.”
The group studied the Bermeja’s serpentinite and diorite rocks through
optical microscopy and a scanning electron microscope at Wesleyan and
developed emplacement theories based on their studies.
 The group concluded the rocks were pushed, or obducted, directly onto land
from the seafloor.
All students traveled the island together, and helped one another with their
particular projects.
“Every student gets to be a leader at some point,” Royer explained. “For
example, when Hannah and Andrea conducted their seagrass study, they acted
as the leaders and directed the other students to areas to collect
samples.”
The students pay for their own airfare, but an endowment pays for all
housing, island travel, meals and research expenses.
The remaining students involved in the Senior Seminar studies in Puerto Rico
will speak at noon March 25 in Exley Science Center Room 405. These groups
will present their research on rainforest plants (Gabriela Doria '08, Margo
Fernandez-Burgos '08, Dana Powell '08, Jordan Schmidt '08), bat droppings
(Jessica Fischer '08, Sharon Newman '08, Ulyana Sorokopoud '08, and mogote
topography (Julius Pasay '08).
For more information on the capstone course, contact Dana Royer at
860-685-2873 or Tim Ku at 860-685-2265.
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