MEXICO — Four years ago, Woodstock Elementary School teacher Tonya Prentice and her fifth-grade class began raising endangered Atlantic salmon from eggs.

In the spring, they took a field trip to the Mexico Recreation Park and released the fry into the Swift River, hoping the fish would survive and make the short swim to the Androscoggin River and, a few years later, as adults into the Atlantic Ocean.

Those that survive should, theoretically, return to their release spot to spawn, student Brianna Benson said.

Early afternoon on Thursday, Prentice and her 15 fifth-grade students arrived with more fish hatched from 200 eggs delivered the first week of February from Boothbay Hatchery. After the students added small cups of river water to the cooler of fish to acclimate them to the sun-warmed water, the children eagerly stood in line to get a cup of fish to release in the river near stones and boulders.

“They’ll go right to a dark spot when you first release them,” Sheryl Morgan, a School Administrative District 44 director from Woodstock, said. “They huddle in the dark and they’ll look for rocks and get right in there.”

Morgan has participated with each class and photographed the event. She and Prentice said each group of children named several of the fish, which all look the same to adults.

However, the students can identify characteristics, like a “poofed out” fish Benson calls Poofy, and a fish with a big belly they call Bubbles. And then there’s Nemo, who is more orange than the others, and Goofy, and two curled-up fish Benson dubbed The Curly Twins.

Prentice said she asks her students every day how they know which fish are the named ones. “They seem to have their little techniques or whatever they remember.”

Prentice works with The Atlantic Salmon Federation, which is dedicated to the conservation, protection and restoration of wild Atlantic salmon and the ecosystems on which their life and survival depend.

“Our first year, those fish should be going out to the Atlantic Ocean, because they stay in fresh water for two to three years, and we’re hoping that they’ll be able to tag some and get some results back from that,” Prentice said as students clambered atop rock ledge along the shore for a group photo.

She said the school gets 200 eggs each year. “We’ve had pretty good results, so far. We usually release around 180. Those are very good percentages, so we’re pretty happy with that.”

Thursday they released 151.

Prentice said she’s educated her students about the effects of predation, pollution and river dams on Atlantic salmon. She chose the Swift River as a release point, because it’s easier for the students to reach. Additionally, it’s a short swim downriver to the Androscoggin River, “so it works out well for us,” she said.

Prentice said students don’t have to feed the young salmon after they hatch.

“They have their own food source — their egg sacs attached to their belly — so we kind of monitor and watch them, and when that egg sac is gone, they become fry and we know it’s time to release them,” she said.

Atlantic salmon grow fast. Within a couple of years, they can weigh up to 40 pounds and be 2 to 3 feet long, Prentice said.

Learning about and monitoring Atlantic salmon in their classroom, and then getting to release them in the spring, has been a big hit with the students.

“The kids did great on the way here,” she said. “They were awesome! A little excited, a little wound up today, you know, but we’re trying to get some energy out here.”

tkarkos@sunmediagroup.net