Underwater Farming

In areas both urban and rural, our land is becoming dirt-poor, lacking the moisture and microbes needed to grow healthy food. In fact, according to an article published on November 19th, 2018 in Earth Island Journal, a third of the world’s land surface is no longer as productive as it once was. This rapid rate of decline in our soil quality is known as topsoil erosion: the wearing away of a field’s surface layer of soil by the natural forces of water and wind. So, what if instead of growing our food on the surface, we started utilizing the vast area below the waves?

Nemo’s Garden is an underwater farming project that uses transparent bubbles, or biospheres, to house edible plants. It began in 2012, so it is still a fairly new idea, but its long-term goal is to help humankind overcome the problems associated with topsoil erosion and the lack of fertile land. Nemo’s Garden is anchored to the floor of the sea just 100 meters off the coast of Noli, Italy. While the actual cost of this project has not been made public, Nemo’s Garden’s official Kickstarter page has received $31,000 of their $30,000 goal to continue the further development of their biospheres. 

Currently, Nemo’s Garden has six air-filled clear plastic biospheres located 20 feet underwater and, according to a March 19th, 2018 article from Euronews, each biosphere can hold up to approximately 2,000 liters of air, three divers at a time, and house at least 60 plants. The article continues to note that the plants are grown hydroponically, meaning that they are grown without soil in a controlled environment. Instead, a nutrient rich solution is used to deliver water and minerals to their roots, allowing them to be harvested at a much faster rate. Since Nemo’s Garden began, they’ve successfully grown 26 different kinds of plants including basil, garlic, lettuce, strawberries, beans, oak, turnip tops, and red cabbage. In the future, the group would like to build a few more biospheres to experiment with other crops, such as mushrooms, which should thrive in the humid environment.

A March 13, 2018 article from Business Insider reports that at the center of Nemo’s Garden stands, what they call, the Tree of Life: a 12-foot-tall, 10-foot-wide metal structure that conceals the cables running to each biosphere and allows the divers to monitor the area from above, controlling the light levels through a live camera feed.

The Nemo’s Garden official website, last updated in 2019, explains the functions of the Tree of Life in more detail. Each biosphere, is equipped with sensors for CO2, O2, humidity, air temperature, and illumination. The Tree of Life utilizes an underwater communication system so that all divers may communicate with each other, as well as the surface. Basically, the Tree of Life acts as the central hub for all the input and output of biosphere data.

Even with all this technology the system devised does not need the power, temperature regulation tools, or LED lighting involved in standard surface farming. In an August 26, 2016 interview from ABC, Nemo’s Garden’s President Sergio Gamberini stated, “the seawater acts like a filter, so all the useless and non-beneficial frequencies of light are actually cut off.” With the ability to obtain sunlight necessary for crop development, Gamberini and his team needed to figure out a watering system so the plants could receive the nutrients needed to survive. A July 27, 2018 article from Atlas Obscura reports that they were able to do this hydroponically by creating a 10-meter (400-inch) spiral tube which they installed into the dome housing the seed beds. The irrigation water and fertilizer are kept in a tank at the lowest part of the spiral and, as a water pump pushes the water from the tank to the top of the spiral, it descends by gravity, providing nourishment to the plants. The previously mentioned article from Business Insider adds that this design ensures much-needed fresh water for the topmost area with plants because when the salt water evaporates within the biosphere, it condenses on top of the dome, then trickles back down salt-free, and nurtures the herbs and vegetables.

Nemo’s Garden is a unique alternative we are using to combat issues regarding topsoil erosion. A 2017 article from the Nature Communications Journal expresses that continents such as Africa, Asia, and Europe have clocked in with the most eroded soil to date, making their topsoil practically useless for crop production. Nemo’s Garden has created the technology to potentially aid these countries. This is great, except that Nemo’s Garden is still very much in a research and developmental stage. A June 5th, 2018 article from Basmati explains that, due to permit limitations and harsh weather conditions, Gamberini and his team can only operate these biospheres from May to September, limiting the amount of research, production, and technological advancement they can achieve to four months.

When considering Nemo’s Garden’s potential disruption to the aquatic ecosystems they are built in, the biospheres are actually attracting several endangered species of underwater wildlife, rather than harming them. According to a 2018 article from the Energy Observer, the biospheres are acting like artificial reefs, attracting aquatic life such as octopi that take shelter under the structures, many species of fish, and endangered seahorses, which gather beneath the biospheres to develop nurseries. Crabs have also been known to crawl up the anchors and into the greenhouses, and, so far, none of the animals have posed a threat to the plants.

Even though Nemo’s Garden still has a long way to go in solving the world’s topsoil erosion problems, it is a start that has the potential of becoming something big. In the words of a famous fish named Dory from the Disney movie that inspired the name of Gamberini’s operation, we may have to… just keep swimming… in order to find out.

 

Written by Michelle Johnson

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