WIESBADEN, Germany- Earth Day, or "Green Day," as Wiesbaden Middle School student Jona Cardenas calls it, is a day to celebrate and honor the environment. On April 22, U.S. Army Corps of Engineers Europe District Environmental Branch colleagues Vanessa Pepi, Erika McCormick and Nicole Silva presented Earth Day topics to more than 200 students here.

The three female environmentalists - a biologist, chemist and project manager - spoke to students in grades six through eight about natural resources, green energy, deforestation, the Endangered Species Act and environmental careers.

In Chris Thomas' science class, Pepi focused on the Endangered Species Act of 1973, a result of the first Earth Day, and her biology work in support of natural resources. To demonstrate the importance of population monitoring, Pepi walked students through a bean counting exercise, simultaneously testing their math and critical-thinking skills. Each bean type -- great northern, kidney and black -- represented a different animal species. During the exercise, the students identified their species, counted the total number of species, or beans, and calculated the proportion of each species to the whole population to determine the most abundant.

"I didn't put a lot of restraints on the exercise I had them do, so they made up fake animals," Pepi said. "They used Godzilla, Pegasus and unicorns. When Godzilla turned out most abundant, I said, 'Does that make sense?' You can't really have a bunch of huge predators running around eating everything. I wanted to get them thinking critically."

In the real world, where Godzilla doesn't rule, bacteria are actually the most numerous organisms on Earth. The abundance of bacteria surprised the students, and the level of student engagement surprised Pepi.

"The kids definitely did get involved," she said. "Even the ones that weren't looking interested in the beginning participated by the end."

That's because the students here are interested in science, technology, engineering and mathematics, or STEM, Thomas said.

"In our schools, I don't see a disinterest in STEM. [The students] are 'geeked' about it -- specifically girls," he said. "We see lots of girls moving toward these fields; they have been encouraged to pursue them and are good at them."

Pepi's Earth Day presentation connected real-world applications with classroom lessons. The presentation went hand-in-hand with teacher standards, Thomas said.

"It's not what I was doing yesterday, it's not what I'll be doing tomorrow, but populations are part of my standards, proportions are part of a math standard," Thomas said. "Anytime the kids have an opportunity to connect with real-world, local experts, it is good for all of us."

Students here are dreaming about their futures - especially sixth-graders. They are excited about the world around them and want to know more, Thomas said.

"We had a girl stick around to talk to Vanessa because she wants to be a marine biologist. Here is someone who can answer the questions she's had in the back of her head," Thomas said.

Pepi was pleased by the student interest in her educational background and career. She highlighted experiences such as working with protected sea turtles on a remote Hawaiian Island and for the U.S. Navy at Pearl Harbor.

"I don't think [the students] knew that the Department of Defense has biologists on staff and that we manage natural resources," Pepi said.

In fact, DoD manages nearly 30 million acres of land, air and water resources and USACE manages an additional 12 million acres. One of Thomas' students could wind up protecting these areas and the species that depend upon them in the future.

Meanwhile, in a classroom down the hall, Pepi's co-worker, McCormick, talked to students about environmental cleanup and green energy.

McCormick provided a brief history of Earth Day and creation of the Environmental Protection Agency's Superfund. The Superfund is a federal government program to clean up the nation's uncontrolled hazardous waste sites, according to the agency's website.

"These sites really exist and we need to take care of them for the future," McCormick stressed.

After listening to the presentation, Brandon Parrella, a sixth-grade student, said he plans to pick up more trash and recycle what he can.

"People don't really know how bad the landfills are," he said. "People don't know what's going on."

The students were engaged and asked many questions of McCormick.

"I was impressed with their questions. They asked questions that I couldn't answer, that I will look up later," McCormick said.

McCormick's presentation culminated with two volunteers trying on personal protective equipment, used by environmentalists in the field. The PPE protects McCormick during sampling of hazardous sites.

Roberto Eiseman, a sixth-grade volunteer, reluctantly dressed in the suit, booties, gloves, protective eyewear and helmet. Each piece of gear is critical to avoiding dangerous contamination. Consequently, PPE is designed for safety rather than comfort.

"If you are in there for a long time it would be kind of warm," Eiseman observed. "I think you would be sweaty."

Fully dressed in PPE, Eiseman elicited a few chuckles from his classmates and even his teacher. The students had fun celebrating Earth Day and hopefully, according to McCormick, gained awareness.

"Even at their age, they are responsible to contribute and realize some of our natural resources are diminishing," she said. "They have to think about alternative energy for their future. In 2030, we don't know what we will use, we don't know what we will have, and we don't know who we will be depending upon.

"I think with Earth Day everybody is responsible, they're responsible."