As the water in the 1,200-gallon blue tank bubbles and tilapia swim up from the depths to gulp down pellets, farmer and full-time Bowdoin student Trevor Kenkel ’18 peers at the darting fish to gauge their health. The fish are the foundation to Kenkel’s aquaponic farming system, so he keeps a close eye on how they’re doing.
At the moment, he has 300 fish fertilizing watery beds that are filled with rows of plants. Springworks Farm, Kenkel’s aquaponics farm in Lisbon, Maine, works as a closed loop. The fish swimming about in the five big tanks eat and produce waste, specifically ammonia that is converted by bacteria into nitrate, which plants love. The fertilized water from the fishtanks, after being filtered to remove solids, is pumped into long troughs in Kenkel’s greenhouse. There, the plants are held in punctured styrofoam rafts that float on six inches of water. Their roots dangle directly into the nutritious water.
This summer is the first operating season for Springworks Farm. Last winter, in addition to taking four courses and studying, Kenkel oversaw the construction of a 6,000-square-foot greenhouse and a state-of-the-art water heating and pumping system. A few weeks ago, Kenkel and his crew of three employees and four interns began harvesting their first greens — four types of lettuce, plus cilantro, mizuna, basil, bokchoi and tatsoi.
Kenkel has already established several customers, including Wild Oats Bakery and Cafe, Solo Bistro restaurant, Henry and Marty’s restaurant, Gelato Fiasco (they use his basil in their sorbettos) — and Bowdoin. The College plans to buy Springworks greens for its September “Maine Theme Dinner” for first-year students and for President Clayton Rose’s inaugural dinner in mid-October.
Kenkel is not a newbie to aquaponics technology. He built his first aquaponics system when he was a high school student in Kalispell, Montana. Using proceeds from summer jobs, he developed a system that grew enough vegetables to supply his family and neighbors, with plenty of leftovers. He has faith in aquaponics as a cleaner, more sustainable alternative to industrial agriculture. He remembers as a child seeing all the fish disappear from a favorite creek after it became contaminated with agricultural runoff. Later, he became convinced farming needn’t be environmentally damaging.
With his earlier aquaponics system, Kenkel experimented by growing tomatoes, honeydew melons, cucumbers and other vegetables. Now, in Maine, he is focusing on leafy green vegetables that he says are in the highest demand and are the easiest to grow in his system. Back in Montana, he used catfish as his fertilizer source. He’s using tilapia here because it is what the state of Maine allows, he says, but he adds that many different types of fish can work. He controls the quality and density of the fertilizer by controlling the amount of food he gives them.
At Springworks, everything is organic — even the fish food. Kenkel said, however, that this particular product is tough to find. “We bought half of the organic fish food on the market last year,” he noted with a grin. Springworks, after being assessed by Organic Certifiers Inc., is the first aquaponics farm in New England to be certified organic.
There are other environmental and commercial advantages to aquaponics, Kenkel said. His farm does not waste water; indeed, theoretically he never needs to refresh the supply. The 26,000 gallons of water that is used in the fish tanks and greenhouse is continuously circulating. The plants, by sucking up the nutrients in the water, clean it so that it can be safely returned to the fish tanks. Because of this, Kenkel says, Springworks uses 90 percent less water than a comparable “soil” farm. Also, plants can grow more densely in a smaller footprint, increasing the annual yield. The other advantage to an aquaponics system is that it operates year-round. “Maine is at the end of the distribution chain,” Kenkel said, “and it is challenging to source good quality ingredients throughout the year.”
Mainebiz, citing a report from from Industry ARC, a consulting company, reports that an aquaponics operation can potentially generate three to four times more food than a soil farm, even while using less land and water. Industry ARC estimates that global sales for aquaponics could hit $1 billion by 2020, and that the return on investment ranges from one to two years, depending on the farm’s size and the farmer’s experience.
Kenkel says he attracted investors to support his start-up. He plans to continue to scale up to get a return on investment. Part of his plan is to add a second greenhouse and develop some of the 168 acres of his farm into a “forest garden,” with orchards, shrubs, herbs and vegetables. In the meantime, he anticipates that just with lettuce alone, he will produce between 200,000 and 250,000 heads this year.
The rising sophomore has absolutely no plans to put his Bowdoin education on the back burner while he builds his business, he says. “I’m not going to be a drop-out!” he said with a laugh, “or go Mark Zuckerberg.” He will major in biology and minor in economics when he declares them next year.
In the fall, he has signed up for courses in plant ecophysiology, organic chemistry, calculus and English. He will live on campus and travel to his farm two days a week, which will be managed by one of his employees. “I want to expand my knowledge,” he said. “That will help us continue to make breakthroughs. The more science I know, the more I can apply it to make the business more efficient and sustainable.”
Some of the fish at Springworks Farm