Minnesota is known to many people by its state slogan, Land of 10,000 Lakes. Determined to maintain its reputation as a recreational haven and an unspoiled home for wildlife, the state pays due diligence in keeping its waters pure. Gallaudet biology majors Carolina Kohn and Scott Symes recently contributed to the effort through an internship where they monitored water quality in five major lakes.
All around the world, pristine lakes that once teemed with fish have slowly choked and died after becoming polluted by industrial chemicals, fertilizers, even unwanted prescriptions that people thoughtlessly flush down their toilets and eventually find their way into bodies of water. Not only can swimming in a contaminated lake make people sick, pollution leads to massive fish kills, infects aquatic life with toxins that makes it dangerous for people or animals to eat them, and causes bizarre genetic mutations, such as fish being born with two heads or sharing male and female reproductive organs.
Understanding that the best way to keep lakes healthy is by prevention rather than treatment, Minnesota has an aggressive plan to monitor the quality of its lakes. Maintaining a lake's water quality can be challenging, however, because once a pollutant enters, it can quickly disperse through the water.
"Rain runoff can carry chemicals into the lake, causing algal blooms, like when fertilizers seep into the lake," said Scott, a junior from St. Paul, Minn. He explained that too many nutrients create algal blooms that are harmful to aquatic life, pets, and people. Swimmers and boaters who are exposed to these toxins can get skin rashes, digestive problems-or worse.
Compounding the health of a lake are boat landings, which allow boats to be transported from one lake to another, and therefore introduce pollutants from a contaminated lake to a clean one.
Carolina and Scott were joined in their lake studies by Gallaudet chemistry professor Daniel Lundberg. They collected chemical and biological data from the lakes and sent water samples to a lab for analysis. "We also measured dissolved oxygen and water temperature," said Carolina, a senior from Turin, Italy, and determined water clarity. The results of these factors combined indicate a lake's Trophic Status Index (TSI): the lower the index, the more clear the lake is.
The interns also devised a net to capture zooplankton, one of the smallest microorganisms that live in water, and viewed them under a microscope. Zooplankton are a crucial food source for fish, and they are sensitive to changes in lake health, such as pH levels, pollution, and algae. Zooplankton also eat algae, so they are beneficial to the lake by keeping the algal population at bay.
Collecting water samples is a painstaking task, and since the lakes are so large, a time-consuming one. The issue was solved by A.W. Research Laboratories(AWRL), which has a plane with cameras that measure TSI values for an entire lake. The interns and Lundberg were grateful for the opportunity to work on their project with AWRL.
Carolina and Scott shared their findings with adjoining lake property owners, and, thankfully, all of the lakes sampled had the desired TSI.
Both internships were supported by the Gordon Brown fund, managed by Gallaudet's Career Center. Juniors or seniors who are chemistry and biology majors are preferred for an internship, but anyone who has an interest in the environmental sciences is eligible.
Scott said his goal is to work a year in the ecology field before entering graduate school, and Carolina plans to specialize in education and environmental science.
To view the students' PowerPoint presentation to the Agate Lake Association on their research work (one of the lakes they worked on during the summer), please click here.
Megan Clancy contributed to the article.