According to our most accurate measurements, about 40% of the earth’s landmass is devoted to agricultural activity. Much of the remaining territory isn’t suitable for farming and ranching.

This is creating a challenge for agricultural productivity, which will need to double by 2050 to feed a population that will soon eclipse 10 billion.

That’s turned experts’ attention to new frontiers — everything from greenhouse growing to hydroponics.

But perhaps the most promising opportunity lies not on earth’s landmass, but under the oceans, lakes, and seas that comprise roughly 70% of the earth’s surface.

Undersea farming started as a fantasy of an Italian scuba diver and amateur gardener named Sergio Gamberini. The Ligurian had an epiphany one day, dreaming of an oceanic garden enclosed in a transparent bubble.

He couldn’t shake the vision, so he started assembling his undersea farm. Gamberini began on a small scale, installing a single pot of basil enclosed in a clear balloon about 20 feet under the surface of the water. 

Today, his dream has become a business venture. “Nemo’s Garden” and its parent company Ocean Reef now grows 700 different crops under the sea, including everything from tomatoes to mint. Gamberini patented the technology, positioning himself to profit handsomely from further development of his blueprint.

There have been challenges to navigate. Italian law forbids permanent, underwater fixtures anchored to the sea floor, so the greenhouses are fully removable. Heavy storms unmoored earlier iterations of Nemo’s Garden on a few occasions. Ocean Reef is still working to develop better transparent enclosures for the garden.

Others have raised alarms about the potential threat underwater agriculture poses for fragile marine ecosystems. Although little evidence exists to support these fears, scaling Nemo’s Garden to industrial proportions could cause serious disruptions. 

But the benefits of Gamberini’s experiment are hard to argue with. Opening the vast resources of the sea to agricultural development enlarges the possibilities for farming beyond lands that are suffering the effects of soil depletion and climate change. The environment is minutely controlled, with few fluctuations in light (amplified by LED lights powered by renewable generators offshore), temperature, or air quality. There are no pests, eliminating the need for pesticides.

Most intriguing is the way Gamberini uses natural desalination processes to water the gardens. Nemo’s Garden is not fully enclosed, and allows a controlled flow of seawater in. When this saltwater hits the warmer air of the greenhouse, it evaporates. The water that condenses and hydrates the plants is freshwater; salt residue removed by evaporation is collected and repurposed within the structures.

Growing undersea has also changed the biochemistry of the plants in interesting ways. Repeated tests of Gamberini’s harvests of basil, for example, have revealed intensified concentrations of eugenol and chlorophyll. This makes for more potent, flavorful foods. Further studies are being done to understand the mechanisms of the advantageous quality, and engineer its results.

What started as a personal fantasia may be creating a new path forward for sustainable agriculture. With the earth’s terrestrial surface consumed with farming, we may want to delve into an untapped reservoir for food production – an area that takes up most of our planet.