Rainbow trout project provides science application opportunity

When Rocky Mountain Middle/High School science teacher Jessee Wilson saw an opportunity to apply the lessons taught in class to something real his students could relate to, he jumped at the chance.

The opportunity? Why, raising rainbow trout, of course.

Around the beginning of the school year, Wilson, himself a 2011 graduate of Rocky Mountain High School, heard about a program through the Wyoming Game and Fish Department where teachers and their students would hatch and raise rainbow trout in a classroom aquarium.

“I got an email and thought, ‘That sounds cool,’” Wilson said. “I applied and was accepted into the program.”

The school district stepped up to supply materials and equipment, and Wilson said he appreciates the support of the district in general and principal Betsy Sammons. With the funding in place, it was a matter of “getting stuff in and constructing everything.” 

And so into one side of his classroom was moved a 55-gallon tank and a tank chiller that circulates water and keeps the water at about 55 degrees.

“Trout are so finicky about the temperature of the water, so that’s a crucial piece,” he said.

Another part of the setup is a filtration system that cycles water through and “sucks up the gross stuff,” he said, adding, “It does a great job keeping the tank clean.”

The water in the tank must be tested every other day to make sure the pH (acidity) is balanced and that ammonia and nitrite levels are kept low. One of the biggest steps in providing an environment for the trout to thrive was establishing a biofiller, essentially a mini ecosystem in which bacteria “eat up” ammonia and nitrites and convert them in to nitrates, which trout tolerate better than nitrites, Wilson said.

“It’s a pretty delicate balance, which is cool,” he said. “We have our own little ecosystem in the tank.”

The application

“My goal with this project is to show the kids that science is everywhere and get out of the textbook and think of some real-world application,” Wilson said. “It’s just exciting – an attention grabber for kids. The kids come into check on the fish and see how they’re doing, which is fun.

“The cool thing is that we can take any of the components in the project and connect them to what we’ve been learning in class: biology, chemistry and physics.

Sixth grade classes apply thermal energy transfer, climate and water temperature impacts, Wilson said. Seventh graders study chemical reactions based on water quality, he said, noting that it’s fun to connect the science to the tank and testing, and they also study populations within ecosystems, the cycle of energy and nitrates and energy transfer.

Eighth-grade students study adaptation and niche environments, and the high school biology class studies life cycles, cell development and ecology.

The tank perfectly applies the science the students are studying.

The program

With the tank set up, the trout eggs – already fertilized and with visible eyes -- were delivered right after the Christmas break and placed in a floating basket. The fish started to hatch in about two weeks, around January 19.

Wilson said he received 150 eggs, and he said about 90 percent of them hatched – about 15 not hatching, a hatch rate Wilson said was “really good.” About two more perished after hatching, he said.

For about 2½ weeks the fry lived in the basket, at first in an alevin state with a yolk sac attached to nourish the fry, then moving into the swim-up stage where the fish started to swim up to the top of the basket, an indication to start feeding them. The fish feed on a special food supplied by Wilson and the students, almost like coffee grounds.

When about 60 percent of the fish reached the swim-up stage, it was time to open and drop the basket to the bottom of the tank. That key event took place Thursday, and students entering the classroom excitedly pointed to the fish swimming free in the tank, some gathering near the surface, some down in a corner and others still in the basket.

“The cool thing for me is that I knew nothing about aquariums,” Wilson said. “It’s a huge learning experience and makes it fun.”

Wilson said the 55-gallon tank is large enough that there shouldn’t be any issues with crowding as the fish grow, and he will have the fish for three more months, whereupon they will be released into Pond 5 in the Yellowtail Wildlife Habitat Unit.

One of the things that has made the project fun, even though it takes some weekend time testing water and checking on the fish, is that Wilson’s 3½-year-old son Mack gets to come with him to see the fish.

“It’s a good excuse to get out of the house and come check on the fish,” he said.