A farm under the sea

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A decade ago, Sergio, Luca Gamberini’s father, decided to pursue what seemed like a crazy plan to Luca to grow crops under the sea.

Family owned and operated by Gamberini, Ocean Reef Group specializes in scuba and diving equipment. Farming was not part of the picture. But after the idea of ​​growing underwater plants came up over a dinner between Sergio – who had a passion for gardening and diving – and a farmer friend, he decided to give it a try.

“It was kind of a bet, a funny joke,” says Gamberini. “And my dad said, ‘Hey, you know what, I’m actually going to try that.’ And he did. And it worked.”

In the beginning, they used small, curved, transparent balloons that were submerged underwater and filled with air, forming an underwater dome. First, the family kept a plant alive underwater, and then attempted to plant a basil seed, which germinated and grew.

But Gamberini says he didn’t see a good reason to do so at first. “I was the number one hater. I resisted it so much,” he says.

He also opposed the decision to implement the program off the coast of Noli, Italy – the family’s usual vacation spot – as it would mean they would always be working, not relaxing, on their vacations.

Luca Gamberini takes care of plants in one of the biospheres © Giacomo d’Orlando

But when he first visited one of the new, larger, rigid underwater domes the family had been developing about five years ago, he changed his mind.

“For my first minute in one of these big environments, I was like, ‘Ah, okay, that’s pretty cool,'” he says. “These rigid domes are so much more beautiful and incredibly easy to maintain. They make a lot more sense and make the technology work. That’s when I went from being the biggest hater and opponent of the project to my biggest fan.”

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Today, Nemo’s Garden – the start-up that grew out of that dinner conversation – has six domes, each holding around 2,000 liters of air, located at depths of between five and eleven metres.

To tend to the plants, divers enter the domes from below, their legs still floating in the water, while their torsos emerge into the air of the biosphere. When crops are harvested, they are placed in reusable bags or containers that are sealed and brought to the sea surface for collection.

Harvested plants are brought to the surface

Once harvested, the plants are placed in sealed sacks or containers before being brought to the surface © Giacomo d’Orlando

The company has grown a wide variety of crops underwater at its site in Italy, from its trademark basil to other medicinal and culinary herbs, strawberries, lettuce, tomatoes, beans, quinoa and even tobacco (for vaccine purposes, Gamberini says).

Aside from being suitable for plants that require a high-humidity environment, the dome’s limitations are primarily size, Gamberini says. “Due to the geometry of the dome, we can’t grow big stuff. We need to grow high-quality and high-demand products.”

Plants are grown in a nutrient-rich solution (a method known as “hydroponics”), eliminating the need for soil. Meanwhile, the domes meet the water needs of plants by extracting fresh water from sea water. The domes are slightly hotter than the sea outside temperature, meaning that water from the seawater ‘floor’ inside the dome evaporates and condenses as fresh water on its curved inner surface. This then “rains” on the plants.

Basil grows in a dome in Nemo's garden

Basil begins to grow from the hydroponic cones in one of the biospheres © Giacomo d’Orlando

This setup also allows for an exchange of CO2 from the ocean inside the dome, adds Gamberini. “We’ve found that this environment doesn’t need to be filled in all that much,” he says.

In many ways, the technology is similar to vertical farming systems: it’s a soil-free, controlled and carefully monitored environment, remote from the farmer, with live cameras in each pod. But in the subsea system, the surrounding sea provides an incredibly stable thermal environment for the plants, reducing energy use.

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Even the sunlight that penetrates underwater is enough for the plants to grow, Gamberini adds, compared to LED lights in vertical farms, which in turn consume energy. He also says the plants grow faster and have higher essential oil content.

There might even be an environmental benefit. A 2019 grant survey concluded that the structure of Nemo’s Garden is likely to have positive impacts on the area’s local ecology. “The amazing thing about the ocean is that whenever you put something under water that looks like an artificial reef, the ecosystem thrives,” says Gamberini.

Biosphere in Nemo's garden

The biospheres are located off the coast of Noli, Italy, at depths of five to eleven meters © Giacomo d’Orlando

So could this form of farming ever really be scaled to compete with conventional farming? dr George Littlejohn, associate professor of plant and fungal biology at the University of Plymouth, says he thinks niche production is more likely.

He notes that the technology is not yet at a stage where it is a viable way to produce high crop yields and, in particular, cannot currently provide the high-calorie and high-protein foods needed to form the basis of our diets. “That is [also] is common in many vertical farming systems,” he adds.

While underwater growing has the advantage of not taking up space on land, Littlejohn says, it also comes with some pitfalls, including the extra energy input required to keep plants nourished, the inconvenience of planting and harvesting, and the high maintenance the whole system.

He also notes that plants are already well adapted to thrive in the conditions found here solid groundwhere they have access to the full light spectrum, time of day information on light and temperature cues, and nutrients and CO2.

Tree of Life in Nemo's Garden

At the center of Nemo’s garden is the “Tree of Life” through which cables are run to the biospheres to power the cameras © Giacomo d’Orlando

However, Littlejohn says developing controlled growth environments in difficult locations, like Nemo’s Garden is doing, is “essential” to future space exploration. “It may be that knowledge gained through underwater cultivation will bring further benefits to exploration than we have seen so far,” he says.

Of course, Nemo’s Garden isn’t the only project pushing the boundaries of where we can grow plants. Others include the University of Arizona’s Prototype Lunar Greenhouse, the plant growth experiments currently being conducted on the International Space Station, and NASA’s OMEGA system, which floats on the sea surface and grows algae.

Despite the spacey look of the pods in Nemo’s Garden, Gamberini says it’s “far superior to imagine the technology being used on another planet like Mars [his] pay grade”.

There could be an application in space travel, he says. The intense flavors of plants grown in the high-pressure underwater habitats could be helpful in flavoring foods eaten in low-pressure environments — like space — where our taste buds can go wrong.

Nemo's Garden team

The team celebrates one last harvest on the beach © Giacomo d’Orlando

But perhaps more useful for the foreseeable future are the potential impacts of underwater farming here on Earth. Gamberini says he sees underwater farms as an option, particularly for coastal communities outside the western world, like the Maldives, which have no farmland for agriculture but have many experienced divers. “I think it’s a really viable option to put it alongside all the other technologies that are coming,” says Gamberini.

After being selected for the acceleration program for Neom, Saudi Arabia’s controversial mega-project to build a futuristic smart city from the ground up in the desert, the company is now aiming for the next level of scale. This fall, Nemo’s Garden will present business and feasibility studies to build 30 biospheres for the project, which could produce 3.1 tons of basil per year using current technology.

Gamberini hopes they could set up a project at Neom next year to become the world’s first true underwater farm.

By 2030, he wants the company to employ hundreds of people and implement the underwater domes around the world. “No one has ever done that,” he says. “We can only learn through experience.”

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