CHICAGO (WLS) — There is a free attraction at Navy Pier just for this week.

The U.S. Environmental Protection Agency is offering insight into their work on the Great Lakes on board Lake Guardian.

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This is specialized work. The rosette takes water samples at great depths in the Great Lakes with 12 bottles taking in 8 liters each.

“Our equipment allows us to assess water quality even at the lake’s greatest depths, utilizing many oceanographic tools,” stated Elizabeth Hinchey Malloy from the EPA Great Lakes National Program Office.

Lake Guardian is a floating laboratory for the US Environmental Protection Agency.

“We gather water samples to analyze for nutrients, water chemistry, and a variety of other factors that reflect the state of the lakes,” Malloy explained. “Monitoring the water quality of the Great Lakes is crucial to ensure it remains safe for swimming, drinking, and recreation.”

Lake Guardian has a box corer that can take samples from the bottom of the lake, and in recent years, there has been evidence of invasive species.

One rock, they said, was covered with mussels.

Malloy is a scientist and supervisor at the Great Lakes National Program Office for the EPA based in Chicago.

“What you see here is a peak in chlorophyll biological activity in the surface waters of the lake,” Malloy said.

Malloy says they are carefully watching the impact of invasive species.

“In certain areas, we’re beginning to have concerns about food availability. Before the quagga mussels arrived, there was typically a larger production of algae in the spring,” remarked Malloy.

This week, Chicagoans have a chance to see how the scientists work and how changes to the Great Lakes can impact animals and humans.

“These lakes provide drinking water to 20 million Americans. Nothing gets more important than that,” Malloy said.

You can see the Guardian and talk with the scientists. Especially if you know someone interesting in science or the environment, there are free tours on the hours through Friday from 1 p.m. to 4 p.m., except on Thursday.

Lake Guardian is docked just south of the entrance to Navy Pier.