With a global population of 8 billion people (updated, July 2023), there is enormous pressure on our planet to produce adequate food. Each day, more than 2.6 billion people depend on the oceans for protein. Sadly, humans take far more from the oceans than is naturally replenished and studies show that big-fish stocks have fallen 90 percent since 1950. As the population increases, the demand for seafood will soar while the wild-caught supply will not.

Some experts believe that if we don’t change our global food production systems, there could be catastrophic results within a few decades. Wild-caught seafood catches have likely stagnated and cannot handle increased demand from a growing population. In addition to overfishing, the oceans face the threat of rising temperatures, destruction of coral reefs and ocean acidification.

Can land-based aquaculture help meet the growing demand for seafood?

One promising approach is land-based fish farming with recirculating aquaculture systems. Decades of research has led to advancements in aquaculture, making certain systems far more sustainable than wild-caught seafood.

”If we need to produce two times the amount of seafood in the next three or four decades, everyone in the industry needs to innovate,” says Erik Heim, CEO of Nordic Aquafarms, a company planning the world’s largest land-based salmon farm in Midcoast Maine. “How can we produce more with less?”

Fish require much less feed than livestock for the same food output because fish are cold-blooded and live in a buoyant environment. In addition, fish feed has a low environmental footprint when it contains sustainable ingredients, such as microbes, microalgae, seaweed and insects.

Isn’t aquaculture bad for the environment?

Aquaculture is currently responsible for about 20 percent of world’s fish supply, with China leading the way. It has gotten a bad name due to overuse of chemicals and antibiotics, disease transfer to wild populations, and escaped fish breeding with wild populations.

Aquaculture has significant growth potential as wild fisheries stagnate. Contrary to logic, fish require relatively little water and even feed per volume when raised in recirculating aquaculture systems. In fact, this system produces the most resource-efficient animal protein besides insects.

Can land-based fish farms increase regional production of fish?

In the United States, 90 percent of seafood is imported. In addition, it is difficult to trace the origins of much of this wild-caught seafood and therefore to determine its exposure to pollutants. Land-based aquaculture in a traceable food source because fish are raised in one location throughout their lives. This approach has the potential to dramatically reduce the seafood deficit in the United States.

Development is underway for two large-scale salmon plants in the U.S. Atlantic Sapphire is constructing a site west of Miami with an initial estimated production of 800 metric tons of salmon by 2020. Nordic Aquafarms is planning a large salmon farm in Maine with a production capacity of 33,000 metric tons annually.

Because of their proximities to major markets, trucks would transport the yields regionally, reducing fossil fuel use for transportation. Nordic Aquafarms is also investigating the use of electric trucks, further reducing the use of fossil fuels.

“If you want to produce fish in this [Northeast and Mid-Atlantic] market, there isn’t a cleaner way to do it,” Heim says.

Do land-based fish farms pollute waterways?

Biofilters eliminate the need for antibiotics and medications, and Nordic Aquafarms claims it removes more than 90 percent of the nutrients from the water before discharging it. Heim views this high-energy sludge as a resource with soil enrichment potential. If it moves forward with plans to construct the fish farm in Maine, the company says there will be little impact on the water quality of the bay where the water is discharged.

Is land-based fish farming too good to be true?

Certainly, advances have made it far more sustainable than the aquaculture practices of yesteryear. Although Nordic Aquafarms believes the proposed site in Midcoast Maine is very promising, it still needs to determine if there is adequate access to water for salmon production on this scale.

Nordic Aquafarms plans to use brackish water at this plant. This will reduce the strain on freshwater resources and help to naturally reduce fungal issues in the fish due to higher levels of salinity, yet a large volume of water is needed to produce 8 percent of the U.S. salmon market.

The 40-acre site is located on the Penobscot Bay and has access to relatively clean seawater. The company is currently conducting studies of the wells on-site to determine if there are adequate water resources available to sustainably run the facility. With access to both salt and freshwater, this site is relatively unique and highly promising.

As concern about food quality and sustainable fisheries increases, consumer demand for sustainably produced fish has soared. Land-based fish farms have the potential to meet this demand with regionally produced fish. The next few years will be important for this promising approach.

By Sarah Lozanova

Sarah Lozanova is an environmental journalist and copywriter and has worked as a consultant to help large corporations become more sustainable. She is the author of Humane Home: Easy Steps for Sustainable & Green Living, and her renewable energy experience includes residential and commercial solar energy installations. She teaches green business classes to graduate students at Unity College and holds an MBA in sustainable management from the Presidio Graduate School.