Above: Lynd School students Dulanki Alahakoon and Angie Villeda took a closer look at a minnow caught in the Redwood River in Camden State Park on Wednesday morning. Students in seventh and eighth grade searched for invertebrates like crayfish and insect larvae, to learn whether the river was a healthy environment for trout.

CAMDEN STATE PARK — Learning about science doesn’t always happen in a classroom. Sometimes, you need to put on hip waders and step into a river.

On Wednesday morning, groups of seventh and eighth-grade students from Lynd Public School were spread out around a stretch of the Redwood River in Camden State Park, carrying different types of nets. They checked the bottom of the riverbed, and around the rocks, until they found invertebrates like water bugs.

“We found like, a giant crayfish!” called one student, while classmates gathered around to help catch it.

The survey of animals in the Redwood River was part of a new educational project for Lynd students, said teacher Martin Boucek. Students will be raising trout over the winter, with the goal of releasing them in the spring, Boucek said. But first, they were learning more about the kind of environment trout needed to live in.

Over the past couple of years, Lynd School students have gotten plenty of hands-on learning opportunities at Camden Park’s trout stream. Students have helped Minnesota DNR staff stock the Redwood River with trout in the spring, and have also taken class trips to go fishing in the park.

“We have some good sponsors,” who have helped provide fishing gear for students, Boucek said.

This year, Boucek reached out to Minnesota Trout Unlimited, for an additional educational opportunity. Trout Unlimited’s Trout in the Classroom program allows students to raise their own trout from eggs in a special cold-water aquarium.

Boucek said that stage of the class project will happen over the winter. On Wednesday, students learned more about river life with the help of Trout Unlimited educator Jim Emery.

Students waded into the Redwood River and caught insect larvae, crayfish and even minnows. They put their catches in plastic bins before carrying them to shore for identification.

“You guys did great work down there,” Emery said. The invertebrates students caught were good signs for the health of the river in the park, he said.

Among the creatures students brought back were stonefly larvae. Emery said stonefly larvae were very sensitive to pollution. Being able to find them in the river, he said, “is a super good sign for our water quality.”

Going out into the river water was a chilly experience, students said. “You feel it,” even with waders on, said student Sergio Solis. But that didn’t stop students from walking in almost up to their waists in search of critters. Finding and catching river animals was the fun part of the trip, kids said.

“I liked catching crayfish,” Scarlett Leos said.

“You see how big they are,” Solis added.