Student Studies Isotopes at Carnegie Geophysical Lab
Marine biology student Alyssa Frederick never imagined that she’d spend her days grinding away at dried corals for the sake of research. Once a premed major, Frederick admits she never actually had any intentions of becoming a doctor. But now a junior, she has found her niche, quietly situated among samples of dried coral and isotope data in the Carnegie Institution of Washington Geophysical Laboratory.
When Frederick’s interest in marine biology continued to grow during her sophomore year, she asked Dr. Kiho Kim, the chair of environmental science, for a chance at research experience. After working closely with Dr. Kim, she had the opportunity to start researching nitrogen pollution of Mexican corals at the Geophysical Laboratory at the Carnegie Institution of Washington for AU alum David Baker, MS biology’04, during her junior year.
Baker, now the post doctoral associate at the Geophysical Laboratory, and Frederick are looking closely at two regions in Mexico for sources of what might be causing nitrogen pollution in the coral. In lowly populated Mahahual, Mexico, Frederick has found that the dried coral samples she tests are pure and unpolluted. However, in the highly populated tourist area near Cozumel, Fredrick has found that the coral samples are polluted by what she believes is sewage.
By using a method known as stable isotope analysis, Frederick can determine the source of the nitrogen pollution. “It’s kind of like a fingerprint that tells us what’s going on there,” says Frederick. “The mass spectrometer can tell us which nitrogen isotopes we’re looking at, and we know that the heavy isotopes come from sewage and the light ones come from fertilizer.”
For the most part, Frederick’s research concludes that the nitrogen pollution is stemming from sewage of the heavily populated area rather than fertilizer. “Hopefully this research will be able to be used by people who can influence policy to get a more effective sewage treatment plan,” she says.
If nitrogen pollution continues to contaminate the water and corals in highly populated areas like Cozumel, residents may soon experience a decrease in particular fish populations, discoloration and murky waters, and a rise in new toxic aquatic species.
While Frederick continues testing coral samples in the lab, she plans to elaborate on the research and methods she’s learned and tie them back to her studies. “I'd like to finish my honors capstone next fall working on a similar project from a different region or looking at a different aspect of environmental changes using the same technique, stable isotope analysis.”