Nemo’s Garden – The Underwater Greenhouse
There may be some interesting upgrade coming soon to a menu near you, with new, exotic dishes like Atlantic strawberries on a bed of ocean lettuce with a dollop of sea pesto. While it may sound a bit odd, these dishes are the literal fruit of experiments with underwater greenhouses that have been going on for years off the coast of Noli 70 kilometers from the Italian port city Genoa. Now the project is ready to start producing vegetables in large quantities.
Passionate diver Sergio Gamberini’s pet project is called Nemo’s Garden. The greenhouses look a bit like balloons or giant jellyfish. Open at the bottom, they work like diving bells underwater, trapping air that is not displaced by sea water. Over time, sea water evaporates into the greenhouse, where it condenses as fresh water and drips onto the seedbeds placed all around the walls, creating a kind of automatic irrigation system. The balloons are anchored to the ocean floor at around eight meters where the plants inside the biosphere still have enough light to grow.
It is a model with great future potential. Unlike on land, underwater growing conditions for plants are constant and almost optimal. The coast of the Mediterranean is practically ideal, as the water is warm and varies very little in temperature. Underwater greenhouses require hardly any outside energy and no irrigation, so they could allow for agriculture in coastal regions with little or no farmland. They could also be a viable option for coastal regions subject to extreme weather conditions that make farming difficult. Unlike conventional cultivation methods where workers need little formal training, Nemo’s Garden requires experienced divers to harvest the crops and maintain the balloons.
Gamberini and his team began their experiment with basil. It is very easy to grow, seems to feel right at home in Nemo’s Garden, and has yielded quite a few jars of sea pesto thus far. Working with basil helped the team determine the best underwater conditions for plant growth, as they observed the basil’s progress via webcam. The team soon expanded their test phase to include beans, strawberries, garlic, lettuce and, most recently, marigolds. The farming technique could easily be expanded to work with any type of vegetable that does not require intense sunshine.