Taking the Lay of the Land in Green Lake

Christopher Rider ’12, Whitney Bachow ’13 and Fallon Chipidza ’10.
Christopher Rider ’12, Whitney Bachow ’13 and Fallon Chipidza ’10.
Located only an hour away from Hamilton’s campus, Green Lakes State Park can provide a relaxing day of sun and swimming for the casual tourist. But for many scientists who visit Green Lake, the trip is full of investigation and sampling; the lake is meromictic, meaning that the layers in the lake do not mix with one another.

One of only a few meromictic lakes in the country, Green Lake is host to a variety of organisms that only exist at certain depths (that then correlate to temperatures and pressures) in the lake. Working under Professor of Biology Jinnie Garrett, Fallon Chipidza ’10, Kira DesJardins ’10, Whitney Bachow ’13 and Christopher Rider ’12 are working to plot and categorize the diverse organisms present in Green Lake.

Like a layer cake, a meromictic lake is divided into strata that do not mix with one another. First discovered to be meromictic in 1938, Green Lake is quite deep (51 meters), which inhibits the mixture of the bottom layer, called the monimolimnion, even within itself. No oxygen exists in this bottom layer; rather, sulfur dominates the chemical composition, making the existence of fish impossible in this layer.

owever, microorganisms thrive at all depths in Green Lake, but different microorgamisms prefer different niches within the lake environment. For her thesis in biochemistry this past year, Chipidza attempted to categorize these microorganisms and determine why they lived in their particular niches.
At the start of her thesis project, Chipidza was planning to categorize and explain the presence of different fungi at each depth of Green Lake. But she found a lot more than fungi; she discovered that protists exist at all levels, whereas fungi live in more isolated depths and populations. Most of all, she found huge populations of phytoplankton; “They’re primary producers for a host of organisms, so it makes sense that they’re really abundant,” Chipidza said, adding that this theory is not yet fully proven.

After preparing and sequencing samples from each depth in the lake, Chipidza performed bioinformatics to see which classes were present at which depths. Some classes of organisms existed at several different depths, but these were often different species (one preferred a more sulfuric environment, another more oxygen, for example). But after sending so many samples to be sequenced at an outside laboratory, Chipidza found that she had only six usable samples at one particular depth—not nearly enough to form a definite conclusion about the diversity at that level.

Other research students collected hundreds of samples from the lake in years past, so DesJardins, Bachow and Rider are working to increase the sample size in order to build upon Chipidza’s senior thesis. The team performs polymerase chain reactions (PCRs) in order to amplify the DNA from different organisms, such as fungi, archaea and bacteria, making the DNA easier to analyze. After the PCR has amplified the DNA, the team then runs the sample through gel electrophoresis to purify the DNA.

They then send the purified samples to an outside lab for more precise DNA analysis and, upon the sample’s return, use bioinformatics to determine the specific species of the sample. Bachow and Rider are also busy making “frozen permanents,” which require them to isolate the specific DNA fragment and freeze it for future use.

This process of species identification is a long one, but it will have important results regarding the department’s research on the lake. In the process of teaching the underclassmen how to prepare samples, Chipidza is passing the torch of interest in the Green Lakes project from one graduating class to a younger group of students. “In the future we’ll be able to really analyze what these found organisms are contributing to the ecosystem of Green Lake,” Bachow said.

A rising sophomore, Bachow enjoys working out, watching TV and playing videogames when she is not in the lab. Rider enjoys outdoor activities such as soccer, tennis and skiing. He is also a member of Hamilton’s GNAR club, a club “where you just go out and try new things, do something ridiculous and fun,” Rider explained. After graduating last month with a degree in biochemistry and economics, Chipidza will be moving to New York City at the end of the summer to pursue a job in finance. Also a recent graduate with a degree in biology, DesJardins will be attending the Ontario Veterinary College in Guelph, Ontario, Canada.

DesJardins is a graduate of Orchard Park High School in Buffalo, N.Y., Bachow graduated from Pine Crest School, Boca Raton, Fla; Rider is a graduate of Cook County High School (Minn.); and Chipidza graduated from Regina Mundi International School in Gweru, Zimbabwe.

Back to Top