One by one, 40 brook trout raised by Betsy Wilson’s environmental science students at Greencastle-Antrim Middle School were taken from a water-filled cooler in a plastic cup and released into Buck Run at the Mercersburg Sportsman Association Tuesday morning.

Before putting the fish in the stream, known locally as Dickeys Run, the eighth-graders had to make sure the water was healthy for them. That included checking the water temperature — it was between 9 and 10 degrees celsius — and looking under rocks for macroinvertebrates — or water bugs — for them to eat. The students also were reminded that there’s a chance the trout may get eaten themselves.

This is the third year for the Pennsylvania Trout In the Classroom at G-AMS and the first year students got to be at the release, thanks to transportation funding from the Falling Spring Chapter of Trout Unlimited.

Trout In the Classroom is partnership between PA Fish and Boat Commission and PA Council of Trout Unlimited. It was created to introduce students to cold water resources and the importance of maintaining healthy streams. The partnership provides brook trout eggs, trout food, technical assistance, curriculum connections and teacher workshops each year.

“The trout arrive in the fall as eggs, and are usually hatching within a few days of arrival. The students care for the trout throughout the school year with the hope of releasing fingerling sized trout in the spring,” according to Ashley Martin, who started the program at G-AMS three years ago. She is now an administrative intern who accompanied Wilson and her students on Tuesday.

“Brook trout are indicator species in cold water streams, meaning that if they are present in the stream it indicates the stream is healthy,” Martin explained.

The brook trout also is the state fish of Pennsylvania, she noted.

“Brook trout are very susceptible to pollution and therefore the students were responsible for maintaining a healthy ecosystem within the classroom to sustain the trout. They routinely tested the water, performed water changes, and cleaned the tank while feeding and caring for the trout.”

Breaca Patterson said she liked the responsibility of knowing they were in charge of caring for the fish and raising them.

Learah Foreman was surprised to learn brook trout don’t have to be fed daily, unlike goldfish. She learned about keeping the water cleaning, checking levels and knowing what to add.

Mariah Bingaman’s favorite part was testing the water to make sure the trout would be safe, both in the classroom and in the stream. She explained the tests were looking for things like pH, nitrates and ammonia.

The trout were released into Buck Run because is a cold water stream accessible to the public, according Tio Paci of Greencastle, a member of Trout Unlimited, which also initially helped to pay for the classroom tank.