Young activists gather in Marina.

Some teens spend their free time hanging out at coffeehouses, texting friends and obsessing about their latest crush. Others, like 16-year-old Sabrina Russo (when she’s not in choir practice, or writing her novel, or volunteering at the Monterey Bay Aquarium) prefer to spend their energy on more important things. Like saving the planet.

Russo, a sophomore at Carmel High, entered the Monterey County Science Fair last month, where she presented a project she’s been working on for a good part of this academic year: the effects of global warming on blue fin tuna. She got the idea while job-shadowing biologists at Hopkins Marine Station over the summer. “One of the researchers was doing respirometry tests on tuna,” she says.

Huh?

“Essentially, they were monitoring the oxygen in the water,” she says, breaking it down for a reporter who took one science class in college—marine biology—and got extra credit for eating seaweed. “I got to feed the tuna,” Russo continues. “That was cool.” (For the record, tuna eat sardines, squid and supplemental vitamins.)

Russo is tall, with straight black hair pulled into a ponytail. She wears a black sweater over a white blouse, dark jeans and silver jewelry. She’s bright and self possessed, and speaks with the authority of someone much older, and with several more degrees.

“The blue fin tuna has a very special metabolism, mostly seen in sharks—they’re warm-blooded,” she says. “The tuna make these huge migrations; the problem being, they’re pelagic [or open sea] and prefer colder water. With global warming, it’s making the water warmer. The warm water is metabolically stressful to blue fin tuna. I said, ‘Well, if that’s true, what’s going on with global warming?’ ”

So she plotted ocean temperatures over a four-year period. “And what I ended up finding is with the increased temperatures, the tuna landings—how many the fishermen are bringing up—were getting smaller.”

On Sunday, April 29, Russo will present her findings to a group of her peers at the TeenThrive Earth Fest, a project of the Marina Technology Cluster and Family Thrive, a group with the mission of “empowering the next generation of conscious leaders.”

At the free festival, teens can win money by filming the event and posting videos on YouTube. The best one wins $100. Attendees can also build and race solar cars, listen to live music, participate in bio-diesel demos, and talk with reps from local colleges, earth-friendly companies and other local teens who will share cool stuff they are doing to make a difference. Russo will be one of these teens.