Eighty rainbow trout go into a frenzy as Rene LaMarche sprinkles food pellets into their 300-gallon tank. The surface of the water erupts in turbulence as the fish feed with noisy gulps.
The trout have a symbiotic relationship with garden vegetables floating on rafts in LaMarche’s backyard. The process, called aquaponics, marries aquaculture (fish-rearing) with hydroponics (growing plants without soil).
Fish waste, converted to non-toxic fertilizer, feeds the plants. The plants clear the water of fertilizer and it is returned clean to the tank.
LaMarche and his wife Linda of Sunnyslope are excited about the technology, which they learned about on vacation in Hawaii. Aquaponics has great potential as a sustainable food source, say LaMarche and his mentor Clyde Tamaru of the University of Hawaii. But for both, it’s been a rapid learning curve.
An Inquisitive Mind
The LaMarches earlier this year traveled to Oahu, where Linda grew up. By chance, they chatted with a resident Hawaiian about aquaponics. Intrigued, Rene LaMarche got on the Internet, searched the term, and he was hooked.
He found the technique was being heavily explored in the Virgin Islands and Hawaii, both island cultures seeking to reduce their dependence on imported food. He saw potential for adapting the technology to the Northwest.
LaMarche is naturally inquisitive and has a bent for science. Formerly in construction, he became a consultant in “construction forensics,” testifying at trials about building damage. His background in research served him well as he dove into aquaponics.
“We had to learn a lot about chemistry when we got into this,” he said. “Chemistry, hydrology, plumbing and electricity.”
Besides information he gleaned online, LaMarche connected with Tamaru and others at the U of H, who gladly provided guidance.
Tamaru was interested to see how the technique played out in a colder climate, and LaMarche has been sending him data to add to the university’s body of knowledge on aquaponics.
Tamaru and his colleagues have been an invaluable source of information and support to the couple.
“I think we would have gotten discouraged when we started losing fish the first time,” LaMarche said. “Their advice and information has gotten me encouraged and kept me going.”
Getting Set Up
Aquaponics technology has multiple models, but all work on the same principals. LaMarche settled on the “raft” model, advanced in research conducted at the University of the Virgin Islands.
LaMarche’s system includes the fish tank, a filtration chamber, piping and four 4-by-8-foot raft boxes. The foam raft has holes for the vegetables, whose roots dangle in nutrient-rich water. LaMarche spent $2,000 on materials, although a system half the size and cost could easily provide fresh produce for a family of four year round, he said.
Tilapia or koi are typically the fish of choice in tropical areas. LaMarche chose trout because he figured they would thrive better in the Northwest, and because he enjoys eating them.
LaMarche had the system up and running by early summer. Once he got the water chemically in balance, tending the system became less labor-intensive.
The system uses little electricity (LaMarche’s monthly bill went up about $3 a month) and very little water. About 25 gallons evaporate each week from the circulating 1,000 gallons. Figures from the U.S. Geological Survey show that’s equal to about eight toilet flushes. The technique could been a boon to drought-plagued countries, LaMarche said.
A Bumper Crop
In aquaponics, the cyclical process begins when fish excrete liquid and solid waste. Ammonia produced by the fish activates a chemical process in the waste, creating nitrites. The waste sediment is collected in a basketlike chamber open to the air. On exposure to oxygen, the nitrites are converted to nitrates, which plants use as fertilizer. Water containing the nitrates flows by gravity from the filter to the first box, then the second, the third and the last.
Since roots are continuously bathed in nutrients and don’t have to fight their way through soil, the plants grow significantly bigger. Linda LaMarche held up a lettuce plant plucked from the raft and one from the couple’s regular garden. The raft-grown specimen was more than twice as large as its traditionally grown neighbor.
Any leafy vegetable thrives in the raft, the LaMarches found. Root crops like potatoes did poorly, they have grown tomatoes, squash, beans, bell peppers, eggplant and a host of herbs. The success of each crop was limited only by this summer’s wet weather. The couple have locally marketed a small amount of produce under their company label, Thelma Leong Pedersen Aquaponic Farms, named in honor of Linda’s elderly mother, who lives next door.
Spreading the Word
With success in their first growing season, the LaMarches are set to expand their commercial venture. Rene LaMarche plans an indoor system to produce vegetables and fish year round. He’s confident the business will be not only viable but lucrative.
Beyond that, he’d like to share his expertise with others, including students and food banks. South Kitsap Helpline this year purchased a nursery property LaMarche sees as ideal for aquaponics.
Like the Johnny Appleseed of aquaponic gardening, LaMarche envisions systems installed far and wide in garages and commercial buildings left empty by the recession.
“We have aspirations of getting Kitsap County back on the map as an agricultural center,” LaMarche said. “We’ve got a lot of expectations, not only for growing vegetables for a living, but also teaching people so they can eat healthier and live healthier.”
LaMarche’s work dovetails with a project just getting off the ground at South Kitsap High School. Denise Watson, head of the school’s agriculture department, has had a small demo aquaculture tank in her classroom. This year, students in the program will build a three-tank raft system, using tilapia. Unlike LaMarche’s system, the fish and the plants will be in the same container.
Watson and Thomas Mosby, director of vocational and technical education, look forward to tapping LaMarche’s knowledge.
“That fits right in with some of the things our students are starting to explore in the natural resources area,” said Mosby.
The Hawaiian Connection
In Hawaii, the use of fish to fertilize plants has a long history, beginning 400 or 500 years ago, when islanders irrigated crops with water from fish ponds. At some point, they had noticed plants watered from the fish ponds grew better than with plain water.
Aquaponics as a technology has been around for several decades, but it’s only become widespread in Hawaii within the past three or four years.
“Commercial folks are starting to look at it seriously, but it’s the private homeowner that’s really taken an interest,” Tamaru said.
Tamaru is an aquaculture extension specialist with the College of Tropical Agriculture and Human Resources. The college is funded by the U.S. Department of Agriculture and, like all land grant colleges, dedicated to advancing scientific knowledge of agriculture wherever and however possible. Part of Tamaru’s research is a project to create energy from plant waste as a by-product of aquaponics. Success in this area would make the process fully self-sustaining.
Tamaru and his colleagues were overwhelmed by the response they got to an aquaponics workshop in 2009. More than 200 people attended and they’ve been hungry for information ever since.
LaMarche presented a unique challenge to Tamaru, who was unfamiliar with trout and who had little data on aquaponics in cooler climates.
“It was a learning experience on both sides,” Tamaru said.
Tamaru is bullish on LaMarche’s chances for commercial success. He credits LaMarche’s pioneering spirit.
“You have to admire the guy, any farmer actually for the risks they take,” Tamaru said. “When we see someone like that, we go all out for them. This guy is out there on a limb. He deserves a pat on the back.”