About two hours north of their Brooklyn school, a class of fourth graders and two buckets full of tiny trout stood beside the Cross River. 

They were there to say goodbye — to the fish they'd first met as trout eggs in October, and had raised in their classroom at Arts & Letters 305 United, with their teacher Katie Giordano.

“We watched them grow from eggs to fry to alevin and finally fingerling, which is the stage they're at now. And so it's May. We've had them in our classroom all year,” Giordano said.

It’s a program called "Trout in the Classroom," a partnership between the city Department of Environmental Protection and the nonprofit Trout Unlimited that helps students learn more about the watershed that provides their drinking water.

“This is a really important way that students are able to connect in their classrooms to their drinking water, because they have their trout in their classroom all year. And then they come out and release them into their drinking water. So it's a really beautiful full-circle program that we offer,” Nicki Alexander, the "Trout in the Classroom" program coordinator at the DEP, said.

“It’s very cool and exciting to see where they live,” Chloe Dailly, 9, said.

It can be a little bittersweet. Students wrote letters and poems to the trout.

“I know you have to go, but I will miss you so. When you feel the flow in the water where you throw, please remember me,” one student read aloud.

Then, they checked the temperature of the river, to make sure it was within three degrees of the temperature of water in the buckets they’d used to transport the trout.

“Our trout are ready to be released!” Alexander told them.

But not without a little goodbye song, in honor of the first trout to swim off, named Little Squishy. 

“We watch the trout get raised and now watching them go by is, like, sad and also fun to, like, see them go by and, like, be, go to, like, where they’re meant to be,” Noah Shapiro, 10, said.

“It's been fun. It's like a good journey and it's like, I guess kind of being a parent — you’re just raising them,” Andrew Desriviere, 10, said.

Students carefully scooped the fish — called fingerlings at this stage of development — into cups that they dipped into the flowing water.

“It was cool to see them swim away. So I couldn't see mine because I lost it, in the water, I didn't see it. It was really fun to see them like, go, like, swim, swim, swim away,”  Lucy Auer, 10, said.