An underwater garden
The biospheres of Nemo’s Garden, submerged off the Ligurian coast, are home to a new form of organic farming.
In the future, perhaps some farming will be carried out underwater. ©Ocean Reef Group/Nemo's Garden 2018
Growing strawberries and basil under the sea may sound like something straight out of a Jules Verne novel, but it is in fact the brainchild of Sergio Gamberini, an Italian entrepreneur. Nemo’s Garden is an underwater farm created off the coast of Liguria in 2012, currently producing around forty different species of herbs and vegetables inside air-filled ‘pods’ using hydroponics. With this cultivation technique, plants do not need soil – it is replaced with an inert substrate, irrigated by a solution containing all the nutrients the plants need.
This underwater greenhouse comprises six biospheres but, as each pod can only contain between 80 and 100 small plants, the yield remains somewhat limited. However, Gianni Fontanesi, coordinator of the Nemo’s Garden project explains, “If the parent company Ocean Reef Group could resolve the issues related to the pod size, the logistics and the profitability of the project, it could offer a solution to the shortage of farmland and to the other major problems raised by traditional farming.” Gianni Fontanesi joined the project in 2015. He is one of six people authorised to access the garden.
Nina Schroeder, hydroponics project manager for the World Food Programme (WFP) says, “I think this project is really cool. In our Innovation Accelerator, we are always looking for more interesting, innovative ideas to help solve hunger. Nemo’s Garden is in its early stages, but looks very promising, especially in terms of temperature stability, a challenge we are facing in lots of our contexts, and the automated production of freshwater.”
A simple and ecologically promising concept
Sergio Gamberini came up with the idea of creating an underwater farm in 2012, after talking with a farmer friend while holidaying in Noli, 60 km from Genoa. The concept was simple: A plant covered by a protective film and submerged in the sea could be watered by collecting the condensation formed inside the plastic film. The results of initial experiments were conclusive so, in 2013, he rallied engineers and agronomists to help him reproduce it on a larger scale on the seabed. A keen scuba diver, Sergio Gamberini has always had a close connection with the sea. He has presided as CEO of the Ocean Reef Group, specialised in the production and sale of diving equipment and services since the 1950s. In fact, you can only access the garden with a scuba tank and wetsuit.
This futuristic garden prospers at 50 metres from the shore, at a depth ranging from 6 to 10 metres, in conditions that are actually hostile to humans: Hence, nobody is allowed to enter the pods, where the quantity of oxygen is likely to be too low and the CO2 levels too high for anyone without the right equipment. However, these conditions seem to suit the plants’ needs. Gianni Fontanesi points out that, “The average pressure inside the biospheres is 1.8 bars, which is thought to stimulate the growth of certain plants. We’re currently studying which plants grow best. For basil, for example, we have observed higher levels of essential oils and chlorophyll.”
Another advantage of underwater farming is the absence of parasites. No insects means there’s no need for pesticides, so Nemo’s Garden can be sure its production is 100% organic. Nonetheless, the growth of algae on the walls of the biospheres can limit the amount of sunlight passing through, and the currents and rough sea can endanger the system. Hence, the pods are equipped with cameras and sensors to constantly monitor the temperature, humidity, amount of sunlight, etc. Ocean Reef Group produces all this technology, and the live data is recorded on open-source software and shared on the internet.1
As there are no insects in the pod, there’s no need for pesticides! ©Ocean Reef Group/Nemo's Garden 2018
The project does not allow for economies of scale, hence it is currently for research purposes only. Partnerships have been established with the University of Pisa (to determine which plants are best suited to this type of farming) and with the University of Genoa (for aspects related to evaporation and the consequent production of fresh water inside the biospheres). “We are often asked why we don’t build bigger pods,” says Giann Fontanesi. “The problem is that, with a diameter of 2 metres, the biospheres’ anchoring system has to withstand pressure equivalent to 2 tonnes. If we increased the diameter to 5 metres, we would have to secure them with 32 tonnes of concrete! Given the cost, for the moment pods of this size can only be produced to order.”
Nonetheless, the relatively small size of the project is advantageous when it comes to sustainability, as Nemo’s Garden only uses clean energy, produced by solar panels and wind turbines. Such expertise and eco-awareness is a legacy from the Ocean Reef Group, which uses biodegradable packaging for its products, while its American offshoot Ocean Reef Inc. generates 130% of its energy needs from sustainable sources.
Italy presented this project to over 22 million visitors at Expo 2015. The benefits of this meticulous scientific research are not limited to the production of vegetables. The team has observed that the biospheres also play a role in protecting marine life. Gianni Fontanesi is keen to point out that, “As well as the wide variety of fish in Nemo’s Garden, we also find squid, moray eels, octopuses, sea horses, starfish and mussels. We’ve been witnessing a repopulation of the surrounding marine area, year after year.”
A solution to the shortage of farmland?
According to the scientist David Obura, director of Coastal Oceans Research and Development in the Indian Ocean (CORDIO) and an expert in coastal ecosystems, making use of the vast area offered by the sea while so few resources are available on land is the greatest asset of Nemo’s Garden. He explains, “Having worked in remote areas, islands in particular, I find that this project has very interesting potential: It could offer a sustainable ‘package’ to compensate the lack of soils and fresh water.”
Agriculture has already shown that it can adapt to extreme conditions, from polar permaculture2, to the growing of plants in space.3 As with these examples, however, Nemo’s Garden also has a very limited scope of application. Ocean Reef has already spent almost 250 000 euros on the project, but the revenues do not cover this outlay. For 40 000 euros, it is possible to buy a full size biosphere, a ‘pod’ equipped with the same technology as that of the Italian underwater garden, but sales are rare, indicating that the challenges ahead are mainly financial. Some big corporations such as Volvo or Sky are on board as official partners, while others have contributed less overtly.
“Land plants depend on red light for their growing energy. The limited quantity of red light that can get inside the spheres and their reduced surface mean that Nemo’s Garden needs to improve productivity,” explains Brian Von Herzen, founder and executive director of the Climate Foundation. The future of the project therefore now depends on the development of new commercial and technological partnerships. In terms of the technology, Brian Von Herzen is optimistic: “Utilising seaweed’s ability to convert green light to red, thereby increasing the amount of red light available, and finding new ways to produce fresh water is something we are working on. This, combined with the expertise of Nemo’s Garden, could revolutionise the way vegetables are grown in Italy.” Sergio Gamberini’s dream lives on.
