The symbiotic, closed-loop system, wherein a stored tank of fish produce wastewater that's used as fertilizer to feed beds of vegetation, has taken off in Hawaii
Sustainably-sourced agriculture is a perennial crowd-pleaser on dining menus, but within a widening swath of the world, it’s more about necessity than it is bending to the whim of culinary catchphrases. When preparing food on an island in the middle of the Pacific Ocean, for example, the quality of the final product is wholly dependent upon building a harmony with the surrounding land. In Hawaii, this requires ingenuity. A surprising lack of arable acreage has forced growers to forge creative workarounds for harvesting meaningful yields. Chief among them: aquaponic farming. More than mere trend, it might just be the future of food.
Along the verdant, western shore of Oahu, Martin Knaubert oversees food and beverage for the Four Seasons Resort at Ko Olina. He works with nearby producers to provide virtually all of the fruits and vegetables working their way on to the property. “One of the first steps in setting up our restaurants two years ago was to find farms that would align with our approach to use as many local products as possible,” he explains. It was during this discovery process that the chef stumbled upon the value of aquaponic agriculture and its particular value to this isolated island chain.
Aquaponics consist of a symbiotic, closed-loop system, wherein a stored tank of fish produce wastewater that's used as fertilizer to feed beds of vegetation. The plant life, in turn, filters the liquid through its roots, returning cleaned water back into the aquarium. “I never knew how self-sufficient this system is, once set up properly,” Knaubert says. “I am amazed at how low-impact it is on soil and natural resources, but yet delivers a great yield of superior quality products.”
Today, Knaubert and his team work closely with Kahumana Organic Farm, where two hot-tub sized vats, teeming with Tilapia, are enough to fuel a commercial output of nutrient-rich greenery. “It’s really just a mini-ecosystem where you’re having the fish living in harmony with the plants,” explains Kristin Jamieson, who works on the property. “Soil can have nematodes, bugs, pests, diseases. We’re able to control this environment by lifting it off the ground, and placing it on cinders.” The pristine land here is blessed with healthy dirt, and so aquaponics—though environmentally worthwhile—isn’t as nutritionally vital as it is in more developed parts of the island.
“Where aquaponics really makes sense is in urban landscapes where there isn’t great soil,” says Jamieson. “There are places with lead leftover in the ground — from when we used to put it in our fuel — that will work its way into the food supply.” Beyond the farmland applications, she’d love to see the process migrate to the city. “It doesn’t have to be this big,” she points to the outsized yard holding the vegetable beds. “It could be something small in your apartment, the size of your fish tank.”
Even more surprising than the sight of fish tubs abutting a raised garden, is the diversity of the plant life that thrives in this setup: green onions, watercress, spinach — there’s even coconut trees taking root in the cinders. It’s a vibrant cornucopia of flavor, which helps inform Knaubert’s decisions in the kitchen. “The products drive the menu and the creative process,” he concedes. “The simple fact is that most of the time, locally sourced, sustainable products taste way better than imported foods and make simple local dishes outstanding.”
It requires a good deal of maneuverability when you consider the Four Seasons holds cuisine varying from traditional Polynesian at The Fish House to the spruced up modern Italian at Noe. “It has to start with the products and their relevance to the concept of the restaurants,” says Knaubert, adding that the process is generally more intuitive than it seems. “[The ingredients] are often so good they stand up for themselves. We often pair them with locally caught fish, or Kurobuta pork from the Big Island. Pairing local with local. True and honest food needs no pretension. The same principles apply to food as apply to terroir and wine.”
For now, aquaponics exists as a novel technique for most food producers. But forward-thinking chefs like Martin Knaubert recognize it as more than mere trend. “Most certainly, this is the way to go in the future to help solve issues with clean food production,” he contends. “It is a give and take: what you take out of nature you give back.” And when you give yourself to responsible sourcing, what you take away isn’t just a healthier meal, but a healthier planet.