Food growers throughout the centuries have managed to cultivate plants in some of the most unlikely places on the planet, and even in space. One area we haven’t tapped for crop production is the ocean, which at approximately 71% of Earth’s surface far exceeds our land area. Beyond fish and seaweed, scientists and entrepreneurs are trying to figure how we can utilize this vast resource for other human food.
According to the United Nations, the world could easily be fed if we used just 2% of the oceans for sustainable farming. What’s more, it could eliminate the need for pesticides, greatly reduce water use, and possibly reduce carbon emissions.
So called “ocean farms” do exist but they typically produce seafood and/or seaweed. A company called GreenWave has a system for “vertical ocean farming” that grows seaweed, scallops, and mussels on floating ropes. They can grow 10 to 30 tons of sea vegetables and 250,000 shellfish on each acre per year. According to the company, the kelp produced absorbs five times more carbon than land-based plants, and the crops do not require any fertilizers, freshwater, antibiotics, or pesticides.
Taking underwater farming to the next level requires a lot more than ropes, though. The world’s first underwater farm to grow more traditional crops started back in 2012 by the Ocean Reef Group. The farm, dubbed “Nemo’s Garden,” consists of six underwater greenhouses off the coast of Noli, Italy. The project has produced several different crops including tomatoes, zucchini, beans, mushrooms, lettuce, orchids, and aloe vera plants using hydroponic techniques.
Nemo’s Garden is the brainchild of Sergio Gamberini, a professional scuba diver and amateur gardener from Liguria, a coastal region in north-west Italy. Gamerini says he started the project out of personal curiosity, just to see if it was a realistic alternative. He also hopes that if underwater farming takes off, he’ll be the one holding the patented technology.
The biospheres, which sit approximately 20 feet under the surface, use solar energy for their minimal electrical needs. Taking advantage of the unsealed, open greenhouse bottoms, a diver swims under and up into the air pocket of the pod to harvest what’s ready to eat. Just like a bottle submerged underwater, the unsealed biospheres do not fill with ocean water thanks to air trapped within the structure, leaving the upper part that houses the plants dry. The open design also allows for self-watering. When the seawater comes into contact with the warm air of the greenhouse, it condenses on the glass of the ceiling, in turn providing naturally desalinated water for the plants.
The project website says that increased pressure like that found under the ocean is actually beneficial to the speed at which plants can germinate, though they admit very little research has been published on the topic. The produce also allegedly has more intense flavor. Nemo’s Garden Project Manager Gianni Fontanesi explains that the plants face double the amount of atmospheric pressure compared to plants on land, which leads to chemical elements being distributed differently.
Basil plants grown underwater, for example, have higher concentrations of eugenol (a substance contained in basil essential oils) and more chlorophyll (the substance that allows for photosynthesis to take place) compared with plants grown on land. “For plants that have a medicinal or cosmetic use, this could translate into heightened therapeutic effects,” Fontanesi says.
But the ultimate goal of the project remains to turn underwater farming into a viable option, especially in areas where water scarcity is an issue. “Eventually we want to create a system that is cost-efficient and energy-sufficient to offer a sustainable alternative to land farming,” Fontanesi explains.
The biggest issue the project has faced is weather. In October 2019, Nemo’s Garden suffered serious storm damage. Before the team was able to complete repairs on the biospheres, Covid-19 lockdowns and other restrictions kept the researchers away from Nemo’s Garden, leaving the habitats unguarded and untended for months. However, Nemo’s Garden successfully fended for itself and is under full operation once again. You can check out a livestream from inside the biospheres HERE. Learn more about Nemo’s Garden HERE. (Sources: World Economic Forum, Atlas Obscura, Business Insider)