Students at Eagle Cap innovative high school learn to raise fish and grow plants in the same operation
By Lisa Britton
For the Baker City Herald
The fish dart from side to side, trying to escape the eyes on the other side of the glass.
But the students are tasked with observing the behavior of these fish, so the swimmers better get used to being watched.
These fish are the control group, whose size will be measured against the fingerlings across the room that are part of an aquaponics project at Eagle Cap innovative high school in Baker City.
Science teacher Burke Smejkal introduced the concept to his Engineering Systems class, which includes youth from both Eagle Cap and Baker High School.
Aquaponics is a combination of hydroponics (growing plants in water) and aquaculture (growing fish).
Their choices for the system are tilapia fish and basil plants.
Although the system looks complicated at first glance — six blue tanks connected by lengths of PVC pipe — the basic concept is taking the fish waste (ammonia) and turning it into nitrogen to feed the plants, which in turn oxygenate the water that returns to the fish.
(Each piece was numbered to help students construct the system. However, the initial sanitizing “removed all the stickers that told us the sequence,” Smejkal said. It took some experimenting to figure out which piece went where.)
The system was developed by Nelson and Pade, based in Wisconsin.
There are six stages to the process:
1. The fish swim around a tank and produce ammonia through respiration, food and waste.
2. Water from the fish tank flows into the clarifier where bacteria break down the ammonia.
3-4: The next two tanks create nitrites and nitrates.
5-6: Then the water, now full of nitrogen and minerals naturally found in Baker City’s water, flow into the shallow tubs where basil plants grow in a platform that floats on the water.
“The plants gobble up the nitrogen and send the oxygenated water back to the fish,” Smejkal said. “It’s a living and working biochemical system.”
Smejkal has never tried aquaponics before, and says he is learning right along with the students.
“Quite honestly, we’re all in this together,” he said to his students in class on Friday.
That day, the teenagers were divided into groups to study different aspects of the aquaponics project — fish behavior, pH, nitrogen, food and oxygen saturation.
They transferred stations through the class, learning the concepts from each other in an “each-one-teach-one” model.
Smejkal hopes to “raise the level of relevance and understanding” about food scarcity and food systems because, essentially, they are learning how to grow their own food in a way that doesn’t depend on the weather.
Plus, they must be actively involved to make the system work.
“In my experience as a student, it was all hands-on learning,” Smejkal said.