LISBON — Tucked away inside two Lisbon greenhouses are dense seas of floating lettuce.

Baby romaine, green leaf, and Bibb lettuce plants grow with their roots completely submerged in water, each supported by floating sheets of foam.

It may sound odd at first, even unfeasible. There is little dirt to be found in either of the greenhouses. Instead, perhaps odder still, swimming nearby in the same greenhouses are nearly 50,000 fish.

In a process called aquaponics, the two greenhouses — soon to be three — provide organic lettuce to all Hannaford stores, from New York to Maine.

Springworks is not an ordinary farm. Founded in 2014 by 19-year-old Trevor Kenkel, Springworks grows lettuce and raises fish in a complex, closed system of circulating water.

A cross between “aquaculture” and “hydroponics,” aquaponics is an alternative agricultural technique that intertwines fish farming and crop cultivation. Fish waste is converted into essential nutrients by bacteria. The plants then absorb the nutrients and filter the waste from the system, returning clear water to the fish in a continuously flowing cycle.

Springworks is the largest aquaponics grower in New England, and one of the largest in the U.S. Inside the two greenhouses, 50,000 tilapia at all stages of growth provide the nutrients necessary to grow 1 million heads of lettuce each year. The only major input to their organic-certified system is the fish food.

Ironically, aquaponics uses 90% less water than traditional farming methods. Evaporation is minimal, and unused water is recycled in the system. The technique is also space efficient, growing upward of 20 times more produce by area.

The produce is safer to eat, too, Kenkel says.

“Over the years we’ve been in business, there’s been a significant E. coli outbreak every year (somewhere in the nation’s food system),” Kenkel said. “By producing in a controlled space like this, we’re not exposing the plants to those types of risks, where runoff from a nearby farm can contaminate the lettuce.”

Particularly in Maine, where the growing season is relatively short, cultivating produce using aquaponics allows Kenkel to grow fresh local produce year-round. Lights affixed to the top of the greenhouse help supplement the sun on gray, cloudy days.

While he admits that the energy needed to run an aquaponics system is high, Kenkel explained that more energy is conserved overall by growing food locally. His retail clients — which also include Whole Foods Market — are able to reduce their reliance on products grown out West, sourcing local food and reducing carbon emissions from cross-country transports.

“We produce so much closer to where it’s consumed that we’re shaving food miles off, (and) by shaving food miles off, we’re also able to offer a product that lasts longer in your fridge and is taster, so people want to eat more salads,” said Kenkel.

Meanwhile, the tilapia raised at the operation are sold to wholesalers and distributed to local businesses.

Developing an aquaponics system may sound simple, however creating an environment where the fish and produce can thrive simultaneously is a constant balancing act. Both components must be considered when any aspect of the system is altered. A tweak that benefits one side may negatively impact the other.

“What we do, it’s challenging, it’s complicated,” Kenkel said. “Because you’re managing an ecosystem, there’s a lot of interactions there. It takes growing over years to figure those things out.”

IT STARTED WITH FIVE GOLDFISH

Kenkel grew up playing in the woods of Montana.

He became interested in sustainable farming practices after noticing the disappearance of frogs and fish from a small stream near his home. The culprit, he found, was excess nutrients leached from a canola field upstream.

“Too often, the negative impacts of the things that we buy are externalized onto those ecosystems, and often without people really even seeing the impact, you know, out of sight, out of mind,” Kenkel said. “Growing up in a place where you can see the impact, I’ve been passionate about sustainability ever since.”

After making an organic garden and raising some chickens, Kenkel wasn’t satisfied. Montana’s short growing season meant he had only a small window to grow produce each year. He began researching alternative techniques and came across aquaponics.

The summer before he started high school, Kenkel made his first aquaponics system with five goldfish, a pump, a 20-gallon tank, some fluorescent lights, and a package of lettuce seeds.

His first attempt was met with little success. The lettuce plants, which he grew in a closet, were stringy and unappealing.

Determined to make it work, he made adjustments to the system and continued to persist.

Three years later, he was successfully growing lettuce for his family and a local restaurant in his 300-square-foot greenhouse.

A serious concussion from playing football led him to take a gap year after graduating from high school in 2013. He came to the Northeast to receive treatment from Massachusetts General Hospital, and began formulating a business plan for what would soon become Springworks.

With the support of private investors, Kenkel purchased 168 acres of land in Lisbon and started building Springworks’ first greenhouse in 2014. Originally recruited to play football at Bowdoin, he still entered Bowdoin and chose Lisbon in part so he could grow the business while pursuing his undergraduate degree.

“Having a severe concussion really puts things like career plans and life into context,” he said. “Certainly, growing up I didn’t necessarily think I was going to start something like Springworks at that age, but as I got better and returned back to normal life, the idea of biding my time and going a more traditional career route . . . it didn’t seem as important.”

Modern aquaponic systems date back to the 1920s. While the technique’s popularity for recreational and commercial production continues to grow, aquaponics remains a relatively niche method for growing crops.

Building the infrastructure necessary for an aquaponics system takes significant time, experience, and capital. Creating a small system can be challenging; a commercially productive system is even more so. Many aspects of Springworks’ system were designed by Kenkel himself.

“There’s fundamentally a lot of engineering associated with all of this, (for example) the fluid dynamics of managing water flow through systems,” said Kenkel, who graduated from Bowdoin in 2018 with a degree in biology.

Starting small and growing at a slow pace has been beneficial for his business, Kenkel explained. The experience has helped him successfully build bigger and more effective systems.

“Mistakes made at the infrastructure level can be either impossible or very difficult to correct, or expensive, I guess I should say. A more gradual growth plan has been more conducive to troubleshooting those things as we grow each facility,” he said.

Springworks has grown significantly in its six years of operations, especially during the pandemic. Labor shortages in the West forced retailers like Hannaford and Whole Foods to rely more on local producers, like Springworks.

A third greenhouse is scheduled to be completed this month and four more much larger greenhouses are planned in the next five years. An announcement of the expansion last month stated the new greenhouses will increase Springworks’ current operation space nearly 20 times.

“There’s so much opportunity,” Kenkel said. “The way we grow plants through this system, we are constantly able to trial and learn. We’ve got multiple harvests coming through every week, so we can always tweak things, get better. I think it keeps it very exciting and dynamic, because we have an opportunity to fundamentally change the way produce is grown (and) distributed.”

Local is not only important to Kenkel for efficiency and environment, it’s also important from the community perspective. Last spring, at the start of the pandemic, Springworks donated $20,000 worth of lettuce to local residents in a drive-by giveaway. Kenkel said they wanted to help people access fresh produce during the difficult time.

THE FUTURE OF FOOD PRODUCTION?

Aquaponics is rapidly emerging as a sustainable farming technique in the U.S. and around the world.

As the world population increases, there is growing concern about whether food production will be able to keep up.

By 2050, the global population is expected to rise to 9.7 billion people, a 32% increase from 2015, according to the United Nations. With 70% of available freshwater currently used for agricultural purposes, rising demand for water also poses a significant challenge.

Some think commercial aquaponics systems like Springworks may be a part of the solution. 

Paul Brown is a professor at Purdue University, where he studies aquaponics. He is the lead researcher for the Aquaponics Association and on its board of directors.

He believes aquaponics has the ability to revolutionize urban food systems and improve agricultural production in arid regions. Efficiency is key when water and space are in short supply; Brown said aquaponic systems excel at maximizing productivity and outputting fresh, local produce year-round.

“There’s huge savings if you can put these food production systems in urban areas,” Brown said, referring to the reductions in carbon emissions from cross-country transport. 

“I’m not suggesting we replace our current food production systems at all,” he added. “But, we have to have some new ones introduced, if we’re going to continue eating the good healthy foods at reasonable prices that we have.”

Aquaponics can be used to raise more than just lettuce and tilapia. One of Brown’s graduate students is currently researching marine aquaponics, pairing shrimp with saltwater-tolerant plants. Using shrimp in aquaponics can be beneficial because growers can potentially make more money than with other fish, Brown explained.

“It changes the economics dramatically, because you can produce three crops of shrimp per year, whereas the fish (like tilapia) are taking at least a good nine to 12 months to get to the market,” he said. 

Previously it was thought that tubers, such as potatoes and beets, couldn’t be grown with aquaponics. Brown said this has since proven to be untrue and that even root vegetables can be grown. 

Aquaponics is an emerging field with many potential applications and unanswered questions. Brown explained that one of the most challenging aspects for him has been choosing which parts of the system to research.   

He is currently investigating the nutrient content of produce grown with aquaponics. Although he admits he is still in the early states of the project, his data suggests that the quality of aquaponics-grown produce is higher than field-grown crops.

Both Brown and Kenkel believe that growing foods in controlled systems will become more common as consumer demand for fresh produce rises. 

“We have control systems which manage the environment, keep it very stable for our plants,” Kenkel said. “It leads to a product which is very consistent and very high quality. And also, it’s produced out of a protected space, so we can improve the food safety associated with it,” he said.

“More produce is going to be growing in a controlled facility, I think, in the future,” he added.

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