Originally, Virginia Pan wanted to see if horseshoe crabs would be bothered by having a bit of their blue blood drawn in a high school classroom.

The 18-year-old at Thomas Jefferson High School for Science and Technology in Alexandria, VA, had a soft spot for the shelled creatures and wanted to see if the extraction of blood — which is then commonly used for medical purposes — might make it harder for them to survive when returned to the wild.

But Pan decided that bleeding the crabs would be a bit messy.

So she chose an experiment with equal ambition but a lighter touch: “My project is on the effect of light-dark cycles on the locomotion of Limulus polyphemus,” Pan said after completing most of the project in May. Then, she paused for a moment to add, for the reporter in the room, the species’ common name, “or Atlantic horseshoe crabs.”

That’s not the type of scientific jargon expected at most high schools. Yet each of the more than 400 students who will graduate this June from the elite Northern Virginia magnet school has undertaken a thesis-like project with similarly high aim. Some of their research will be diffused throughout the broader scientific community as the students compete in local and national competitions or reference them on college applications.

The 2014 Chesapeake Bay Watershed Agreement calls for all high school students to have a “meaningful watershed education experience,” but few have experiences like those of students at TJ, as the school is also known.

Granted, this is not the average public high school. Fairfax County students have to apply for acceptance to TJ, which offers classes in neuroscience and artificial intelligence. Just 17 percent of the 2,841 applicants for the school’s class of 2019 were admitted.

During a visit to TJ a few weeks before graduation, students seemed like most other teenagers as they clustered in the entryway to watch one student invite another to the senior prom. (The elaborate ask involved king-and-queen crowns and a crowd.) But, inside the classrooms, the experience skews collegiate.

The Oceanography and Geophysical Systems Lab led by Lisa Wu is one of 14 labs at the school offering equipment more common to prestigious universities than to public high school classrooms.

“I’ve had students come back as alumni and look at our oceanography lab and say, ‘This is better than what we have at MIT,’” Wu said with a grin before adding, “I can’t say that I can verify that.”

Some of the equipment comes to this classroom by way of Wu’s former students, too. One went to work in a lab that produces a piece of equipment called the FlowCam, which can analyze, photograph and, with some models, count and sort microscopic particles. The machine would cost tens of thousands of dollars if Wu’s former student hadn’t asked her to try it out on the lab students for free. (If they are able to use it, the company, Fluid Imagine Technologies, Inc. might consider selling a version of the equipment geared toward high schools, Wu said.)

Emily Sun, 16 and also a senior in Wu’s lab class (she skipped a grade), used the FlowCam to create images of the tiny Cyclotella and Thalassiosira plankton she chose to study for her senior project.

“I’m looking at how different species of phytoplankton found in the Chesapeake Bay respond when they’re given different levels of nitrogen in an algal growth medium,” she said matter-of-factly.

Sun hypothesized that both species would benefit from the addition of nitrogen, as they are thought to in the Bay, but she thought one genus might do better than the other. She wanted to determine which of the two types of diatoms — a type of plankton — would outcompete the other, because that one would likely pose more of a risk to a Baylike ecosystem, or at least the one represented by the brackish water in her flasks.

“I’ve added sodium nitrate to the flasks, which is the form of nitrogen found in a lot of fertilizers,” Sun said. “So it’s possible that that’s the nitrogen actually going into the Bay.”

When algal blooms decay in the Bay, they deplete the ecosystem of the oxygen needed to support other species, resulting in so-called “dead zones” that can kill fish and other aquatic life. In the Bay, excessive nutrient pollution from cities and agricultural lands in the watershed is thought to fuel algal blooms, which are composed of tiny plankton like the ones Sun studied.

Sun came across a study while researching this topic that questioned the link between human-produced nutrients and algal blooms because there are so many other factors that can contribute. So she decided it merited further research.

Also, she said, “I think these diatoms are particularly interesting, because they play such a big role in the environment.

“Is it 30 percent, Virginia? Is that the amount of oxygen that diatoms create?” she asked her classmate before turning to Google on the laptop open in front of her. “Yeah, this website says diatoms alone produce 20 to 40 percent of our oxygen. We don’t think about them a lot but they’re really important to the ecosystem.”

Sun plans to continue studying diatoms and their comrades as a biology or environmental science major at Williams College in Williamstown, MA. But, before attending the No. 1-ranked liberal arts college in the country, according to U.S. News & World Report, she’ll take a gap year to participate in a youth exchange program in Chile.

Sun and Pan said the criteria for what their senior projects could study in the Oceanography and Geophysical Systems Lab were pretty open-ended.

“Anything related to the environment, really,” they said in near unison.

Two students in their class of a dozen people had teamed up to build an autonomous underwater vehicle (AUV) out of thin air with the classroom’s 3D printer. The AUVs are used like robots to conduct underwater research and can be shaped into tiny versions of marine mammals like whales.

The computers used for modeling and 3D printing are lined up against a back wall of the classroom. Behind that wall is the lab, with a half-dozen rows of aquarium tanks and an area for assembling AUVs or other projects against one wall.

In a back corner, oyster spat was growing in 5-gallon buckets as water pumped over them in a continuous cycle. A student from another class was studying how the introduction of copper into the water might affect the oysters’ growth, Wu said.

“We don’t have a connection to the Bay physically, but we can grow spat in these little microcosms,” she said, clearly excited that the student had successfully grown baby oysters in the classroom lab.

Pan was equally thrilled that she had kept her juvenile horseshoe crabs alive and used them to produce decent data about their day-and-night movements. She had spent the summer before her senior year studying horseshoe crabs’ behavior during an internship at the Chincoteague Bay Field Station at Wallops Island. Their research found more active horseshoe crabs on the shore of Chincoteague Bay’s calmer waters but more empty shells on the seaside, where crabs molt and spend the majority of their lives.

But when and why they become more active was an area of research Pan found lacking. So, for her school project, she set up motion-detecting, infrared cameras over the tanks that would send her an email each time a crab moved, which she then filtered, counted and graphed. She spent much of the year hypothesizing and preparing to conduct her actual study. Finally, she simulated day-and-night cycles for four days with automatic lights and then a totally dark cycle for four days by placing cardboard around the tank.

As Pan expected, though contrary to some of the research she had read, the crabs moved more during the day than at night, even at a young age. Though they moved far less the first day she turned the lights off, they eventually caught back on to a similar pattern, moving more during daylight hours even during the period when all the lights remained off. This indicated to Pan that there were other factors in play — and more reasons to research whether tides, age or mating habits might play a role in behavior.

“Using adult horseshoe crabs would be better, because they would mate,” which would make their movements more authentic, Pan said. “I could also watch them for a longer period of time.”

Pan will attend Duke University next year and is already planning her next experiment.