Can underwater farms help avert the world’s looming food crisis?
- 27 Mar
- 4 dakikada okunur
With millions facing food insecurity and traditional agriculture straining under climate pressure, scientists and entrepreneurs are experimenting with a surprising frontier: farming beneath the sea.
The idea sounds like science fiction: vegetables growing in glass domes anchored to the seabed, nourished by desalinated seawater and sunlight filtering through the waves.
But in the waters off Italy’s Riviera, it is already a reality.
The project, known as Nemo's Garden, began with a simple question posed by Italian entrepreneur Sergio Gamberini in the summer of 2012. While on holiday and discussing gardening after a dive, Gamberini wondered whether basil—the key ingredient in pesto—could be grown underwater.
The idea combined his two passions: diving and horticulture. The result was the world’s first underwater cultivation system.
Today, spherical underwater greenhouses—called biospheres—are anchored between 4.5 and 11 metres below the sea surface, creating controlled microclimates where a wide range of plants can thrive.
Each biosphere consists of a transparent dome filled with air. Inside are seed beds and a spiral irrigation tube roughly 10 metres long.
At the base of the system, clean water and nutrients are stored and pumped upward to the plants. Solar panels and fans regulate humidity inside the dome, while seawater evaporates and condenses to produce fresh water used for irrigation.
The result is a self-contained ecosystem.
Because the domes are sealed, parasites and pests cannot enter—meaning pesticides are unnecessary. Divers can access the structures through small openings, while most monitoring and control is done remotely from the surface.
The small experimental farm currently operates six biospheres, each holding between 800 and 2,000 litres of air space. Within them researchers have successfully grown herbs and vegetables including basil, thyme, mint, tomatoes, strawberries, radishes, beans, mushrooms, lavender and even aloe vera.
The basil that inspired the project now grows inside the domes—and is used to make pesto served with salads grown in the same underwater greenhouses.
Why underwater agriculture matters
The experiments are not just technological curiosities.
According to the World Food Programme, 155 million people in 55 countries are currently facing food crises. In 2020 alone, the number of people confronting acute hunger rose by 20 million.
Meanwhile, agriculture places enormous pressure on the planet’s resources. Data from the World Bank shows that around 70% of the world’s freshwater supply is used for farming.
With global population rising and climate change increasing the risk of drought and crop failure, scientists and entrepreneurs are increasingly exploring alternative food production systems.
One possibility lies beneath the ocean’s surface.
According to Vincent Doumeizel, an adviser on ocean-based solutions at the United Nations, cultivating just 2% of the world’s oceans could produce enough protein to feed 12 billion people.
Doumeizel points in particular to seaweed as a potential game changer.
“Seaweed requires no land, freshwater or pesticides,” he said. If livestock were fed with seaweed-based products instead of soy, methane emissions could fall by up to 90%. Countries such as Scotland and Iceland are already experimenting with such systems.
Building ecosystems under the sea
While Nemo’s Garden focuses on growing vegetables for human consumption, other companies are developing broader underwater farming systems.
One of the best known is the US-based startup GreenWave, founded by former fisherman Bren Smith.
GreenWave promotes a form of vertical ocean farming, where ropes suspended in the water column support the growth of seaweed, mussels and scallops.
The system requires no fresh water, fertilisers or artificial feed. Instead, it creates a small marine ecosystem where each organism supports the others.
Seaweed plays a particularly important role: it absorbs carbon dioxide from seawater, helping to reduce ocean acidification.
According to estimates by the World Bank, cultivating seaweed across less than 5% of US coastal waters could help absorb 10 million tonnes of nitrogen and 135 million tonnes of carbon.
GreenWave says an underwater farm can be started with around 4,000 square metres of ocean space, a small boat and an investment of roughly $20,000 to $25,000.
The idea has attracted global attention, earning Smith a place on Rolling Stone magazine’s list of “25 People Shaping the Future.”
Seaweed forests and carbon capture
Elsewhere in the world, underwater farming is also being explored as a tool to combat climate change.
Off the coast of Lüderitz in Namibia, the company Kelp Blue plans to establish a vast kelp forest farm beginning in 2021.
Kelp—a type of large brown seaweed—is one of the fastest-growing organisms on Earth. Some species can grow up to 60 centimetres per day and reach lengths of 40 metres.
Because of this rapid growth, kelp absorbs enormous amounts of carbon dioxide through photosynthesis.
The company’s long-term goal is ambitious: by 2029, it aims to operate a farm capable of absorbing one million tonnes of carbon dioxide each year.
Products derived from kelp could be used in industries ranging from textiles and animal feed to aquaculture and organic fertilisers.
A new frontier for food
From underwater basil gardens in the Mediterranean to seaweed forests off the African coast, ocean farming is still in its early stages.
Yet as food demand grows and environmental pressures intensify, the world’s oceans are increasingly being seen not just as ecosystems to protect—but as a potential frontier for sustainable food production.
Whether underwater agriculture can scale enough to address global hunger remains uncertain.
But the experiments already underway suggest that the future of farming may extend far beyond the land—and deep beneath the waves. 🌊🌱
(This article was first published in Independent Turkish on July 28, 2021)
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