This chemistry lesson takes a strong stomach: It starts with grinding up fish in a big blender.

At first, Sarah Lenney, 15, was nervous. Her partner, Stephen Furlong, 17, admits it is something he never thought he would do in school. But they break into grins as they explain their work.

"It was kind of gross yesterday, because we had to touch it with our hands," Furlong laughs.

Instead of working in a traditional classroom setting, high school students participating in an alternative program at the Mystic Aquarium and Institute for Exploration are getting a hands-on learning experience alongside beluga whales, seals and other marine life.

Though other alternative programs exist in Connecticut, many are aimed at students with behavioral problems.

At Mystic, the idea is a little different. The Wheeler's Aquarium Vocational Experience for Students tailors its coursework to give students a chance at success.

The participants -- eight students from the Stonington, North Stonington and Preston school districts -- do not have behavior problems, but they have not grasped reading, writing and arithmetic. Most are substantially behind in credits. Before coming to Mystic, some were at risk of dropping out.

"I call them my square pegs in a round hole," said Natalie Pukas, superintendent of the North Stonington school district, which operates the program with Mystic. "They are the kids that have the ability to succeed, they have the talent to succeed. But somewhere, they've lost the will and the motivation, or we failed to meet their needs."

The school day starts later, at 9 a.m., giving students more time to get to class. Afternoons are spent at the aquarium, where students work as interns in the departments for animal care, public education, food service, human resources and lab research. They also move through online distance learning courses at their own pace.

"We tell them they are the captains of their own ship," said teacher Cheryl Biekert, a 19-year special-education veteran who runs the program. "They really are in charge of their destiny here."

Lenney and Furlong's research in the chemistry lab is playing an important role and eventually will help the aquarium establish the proper diet for its marine life.

"They may think they're doing this just for their own benefit to learn, but I'm actually using them to get the method up and running," said Lisa Mazzaro, a researcher who oversees the lab.

Another student, Natalie Browne, 16, attended summer school several times but earned only enough credits to be a sophomore. She hopes to graduate with her class next year from Wheeler High School in North Stonington.

"I love it," she said after a half-hour session learning about beluga whale behavior. "It's so different because we work independently, and there's nobody breathing over my shoulder."

Deborah Browne said her instinct told her that her daughter just needed a different way to learn.

District officials hope to expand the program, which cost $120,000 for the first year.

Back in the lab, Lenney and Furlong carefully weigh samples of lipids and record the numbers in a log. There is a lot of work to do before tomorrow.

The next task: analyzing penguin blood.

Students Justin Risica and Natalie Browne watch trainer Lynn Marcoux work with Naku, a beluga whale.