From Sustainability Demo to Fish Taco: Aquaponics at Michigan Tech

The water flowing into the clay pebbles.
The water flowing into the clay pebbles.

Rob Handler is about to harvest his research. Typically, that means the gigantic kale and nice-sized onions and basil he’s growing nine stories up in the Dow Environmental Science and Engineering greenhouse. Today, though, it means the key ingredient for fish tacos, to be served at a residence hall.

“We have been growing tilapia,” he says. “They are a hardy fish that grows well in a controlled environment.”

They are also the key ingredient in his aquaponics project, where fish waste fertilizes the plants and plants keep fish healthy by cleaning the water.

“It’s the same interaction that happens in the natural world,” says Handler, operations manager of the Sustainable Futures Institute at Michigan Technological University. “We are just managing things with tanks and pipes.”

Handler's interest in sustainable agriculture took an unexpected turn after moving to Houghton, where he learned about indoor aquaponic gardening as a way to combat the region's short growing seasons. He realized that aquaponics could also be a captivating education and outreach tool. Drawing on advice from Professor Nancy Auer, a fish biologist, he designed and built the system last year. Since then, more than 1,500 people of all ages have toured the facility, and several departments have incorporated it into course work. Supporters can now donate to the project on Michigan Tech's Superior Ideas fundraising site. “It's been a great success," says Handler. "We're really pleased with the awareness that has grown on and off campus."

His work is a combination of biology, chemistry and engineering. Pipes galore run between fish tanks, storage tanks and the plant beds, which are made up of small clay pebbles; more efficient for growing, Handler says. Roots don’t have to branch out as far because all the nutrients are brought to them.

Sometimes that efficiency can cause problems.

“We’ve grown cherry tomatoes that grew so tall I need to harvest them with a ladder,” Handler says.

Aquaponics is an old concept, he says. People in Southeast Asia discovered hundreds of years ago that when they added tilapia to the rice fields, they got better yields.

Recently, Michigan Tech Entrepreneurship Club students—Jacob Bray '13, Joshua Davis and Josh Krugh, with Handler as mentor—won $10,000 in a venture competition and are in the process of forming a company to explore commercial possibilities involving aquaponics.

Aquaponics ties into the locavore movement, which includes people who prefer eating food that is locally produced.

“It’s the kind of set-up you could do in your garage or basement,” he says. “And it’s got commercial capabilities; it can be done on a large scale on independent farms.”

Aquaponics systems do need to be monitored closely, though. The recirculating system has to be working, especially when the fish will end up in Wadsworth Residence Hall’s dining room.

“They’ve hit the one pound mark, good for harvesting,” he said.

He’s already done a taste test.

“One jumped out of the tank, so I had to try it.”

And the verdict?

“It was good.”

There are other benefits from the research, beyond salads and fish fillets. Handler has had many students from a variety of majors come through—biology, humanities, engineering—to look at his operation.

“We are even going to get a computer model created by students,” he says. “They’ll be modeling how the water flows through the system, how the nutrients and oxygen flow through the system.”

And after this batch of fish has been harvested?

“I’d like to try it with yellow perch,” he says. “It’s a local favorite that does well in cooler weather. I’d like to develop some more research questions, too."

Meanwhile, getting your protein and your produce all from one, clean source? It’s a natural.

And the fish tacos? They were a resounding success, according to Judy Klutts of Wadsworth Hall Dining Services.

“They went fast. The kids loved them,” she said. “And we combined it with a coleslaw that used carrots and cabbage from our garden, so it really was a sustainable meal.”

Michigan Technological University is a public research university founded in 1885 in Houghton, Michigan, and is home to more than 7,000 students from 55 countries around the world. Consistently ranked among the best universities in the country for return on investment, Michigan’s flagship technological university offers more than 120 undergraduate and graduate degree programs in science and technology, engineering, computing, forestry, business and economics, health professions, humanities, mathematics, social sciences, and the arts. The rural campus is situated just miles from Lake Superior in Michigan's Upper Peninsula, offering year-round opportunities for outdoor adventure.