A food bank in the sea 

With the global population expected to swell to 10 billion by 2050, the demand for food, especially protein, will rapidly rise with it. More than 3 billion people already rely on seafood as their main source of protein. With climate change and overfishing leading to teetering wild fish populations, aquaculture — farming seafood — can provide much needed food security. 

Aquaculture is the fastest-growing food production system in the world, but it has yet to take off in the United States. While consumers relish oysters farmed in coastal waters, and seaweed farming is surging in both popularity and profitability, larger-scale finfish farming continues to carry a bad reputation.

“The main thing that has been limiting the growth of aquaculture in the United States is the perception,” says Gavin Key, COO of Ocean Era, a Kona-based aquaculture research company. “There is a lot of misunderstanding about the potential impacts and, frankly, some justified concern about the way things used to be. When these industries first started operating, they didn't know everything we know now.”

Public skepticism stems from historical issues with pollution from fish farms, escaped farmed fish interacting with wild fish, and the depletion of wild fish used as feed for farmed fish.

These are legitimate concerns, but not insurmountable, say advocates, including the global nonprofit Environmental Defense Fund. “We have an opportunity to follow the science and understand what responsible aquaculture can deliver for our food security and climate resilience — and to grow seafood here in a way that’s environmentally sound and built to last,” says EDF’s Maddie Voorhees, who directs the organization’s U.S. aquaculture campaign. 

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Traditional knowledge can inform modern aquaculture 

In Hawaii, that science includes traditional knowledge. Aquaculture here dates back more than 800 years, with the construction of traditional fishponds, called loko iʻa.

Built out of lava rock and placed at the nutrient-rich confluence of seawater and fresh water, the ponds allow juvenile fish to enter via a small opening in the pond wall covered by a wooden grate. 

Once in the pond, small fish feed on the rich vegetation and other nutrients in the brackish pond water. Indigenous Hawaiians created what some would call today a “managed estuary” — a valuable natural ecosystem re-created to support many species of fish, wildlife and plants and create a sustainable source of food.

“When they couldn't go out and harvest wild fish, fishponds were like a food bank reserve that fed a lot of the community,” says Clay Tam of the Pacific Islands Fisheries Group, an organization that preserves traditional knowledge to support responsible fisheries management. 

With new technology, better science and lessons from ancient tradition, some aquaculture farms are charting a new course toward sustainability. Key explains, "We know a lot better now how to operate farms in a way that can work with the environment rather than against it.” 

Modern aquaculture research 

Twenty miles down the black lava rock coast from Hawaii Calls restaurant lies Ocean Era’s facility. Among the rows of bubbling tanks, Key and his team grow a variety of seaweeds and research the feasibility of raising different fish species in open ocean environments.  

A critical part of Key’s research is developing alternative fish feed that doesn’t rely on wild caught fish for protein. “We've successfully used things like poultry byproduct meal, soy, algae. We have proven that carnivorous fish can grow on a zero marine ingredient diet,” he says. 

While today’s most popular farmed fish, such as tilapia or salmon, are carnivorous, Ocean Era hopes that more sustainable feed will expand the variety of farmed fish available to consumers. “Our drummer (or rudderfish) that we're working with now is an herbivorous fish in the wild that produces sashimi quality filets and can be raised on a very sustainable diet, not requiring fish meal or fish oil,” explains Key.

But to produce food for a growing population, aquaculture can’t be confined to tanks. It needs to be scaled up and yet remain low-impact. In the U.S., what’s needed are farms in the water to demonstrate what’s possible and measure the impact on the surrounding environment.

Blue Ocean Mariculture, the only open ocean finfish farm operating in the U.S., is one such demonstration farm.

Here, Hawaiian Kanpachi are raised from eggs in a hatchery located next door to Ocean Era and are transferred to open ocean sea pens as they mature to adults.

Tyler Korte, VP for Marine Operations, lets out line over the starboard side of a dive boat, a long yellow cable attached to an underwater ROV. On the computer monitor on deck, the ROV’s camera zooms towards a massive, diamond-shaped net pen where Kanpachi are schooling.

Situated a quarter-mile offshore, the farm takes advantage of Hawaii’s deep water, which allows them to fully submerge the pens 200 feet deep, mimicking the natural habitat of Kanpachi found further offshore. The strong currents allow for fish waste to quickly disperse rather than harm the water quality. The netting material minimizes the build-up of biofoul, the anchoring system of the cages is engineered to minimize impact on other marine life in the area, and the number of Kanpachi stocked in each pen is limited to how the species would naturally school in the wild. 

“The technology and innovation that's coming to aquaculture is starting to solve some of the problems that we have seen in the past,” explains Korte. The pens, he says, are specially designed so that “the ocean does almost all the work for us.”

In addition to ensuring a clean, healthy environment for raising fish, the company regularly monitors the surrounding environment and seafloor for any ecological impact. 

“What we have found is we're having a negligible influence,” says Korte. “The water quality that you find right off one of the net pens is about the same as you'll find six miles up the coast.” And as far as the larger community of marine life, Korte goes on, “we're seeing the exact same populations of the same species in the same abundances.” 

Indeed, off the deck of the Blue Ocean Mariculture barge, dolphins and sharks glide around, attracted to the commotion of the feeding fish. Nearby, dive boats are lined up where Kona’s rocky reefs drop off in a sloping wall filled with sea life. “You can see how healthy the corals are, and the manta rays that swim around with the local fish,” says Korte. 

There’s no need to take Korte’s word for it. Blue Ocean Mariculture is forthright with sharing its data, helping scientists and federal agencies like NOAA study ocean farms and determine the standards needed to help aquaculture grow in other parts of the country.

The movement is already underway. Last fall, Congress introduced the Marine Aquaculture Research for America Act. The bipartisan bill would invest in the research and development of more open ocean demonstration farms, prioritizing community and environmental safeguards and producing data that would help lay the groundwork for national aquaculture standards. A domestic aquaculture sector also has the potential to create jobs and boost local economies in coastal communities. 

“With federal policy, we can research and sustainably develop a new food system in the U.S. — supporting ocean health, working waterfronts and American families,” says EDF's Voorhees. 

Back at Hawaii Calls, Ocean Kanekoa’s menu features Hawaiian Kanpachi four ways, showcasing the fish from head to tail. One course is a nod to an American favorite: the boneless chicken wing. Deboned, breaded and crisped to perfection, the fish eats like delectable finger food, a familiar bite from a not-yet-familiar fish. 

“The biggest part for me is actually educating the community on the fish,” says Kanekoa. “A different fish that people aren't used to eating, and how delicious it actually is.”

Could new varieties of farmed fish be coming to a menu near you? The future is tantalizingly within reach. 

Muses Gavin Key, “What makes me excited about aquaculture and its future? I mean, the potential. The doors are wide open for us right now.”