Words by Jane Zhuk, Staff Writer
The United Nation’s (UN) Sustainable Development goals of 2015 were set with high hopes, yet clear intentions. Among them, we see statements such as “clean water and sanitation”, “responsible consumption and production”, and “climate action”. Agriculture has definitely been one of the top industries that required urgent transformation, representing 70% of worldwide freshwater use and draining global resources at an unsustainable rate. Moreover, large-scale monoculture farming that uses pesticides, chemical fertilisers and exhausts the soil has caused lasting ecological damage. But how else do we feed the growing population?
Introducing underwater farms – an underwater agricultural system that addresses the issues of water management and pesticide overuse. The miniature biosphere enclosed within an underwater greenhouse protects the plants inside from any kind of dangerous parasites. This eliminates the need for pesticides, making the greenhouses completely safe for the surrounding aquatic environment!
When it comes to fertilisers, the products used by the ocean farmers are of natural origin. Furthermore, the project researchers are now looking into making the greenhouses even more self-sufficient by developing an algae-based fertiliser.
Water management is optimised by using natural condensation: since the surrounding ocean is much colder than the inside of the biosphere, water aggregates on internal surfaces of the greenhouse bubble and eventually falls down onto the plants. In fact, external water supply is only needed to help the seedlings grow at the very start of the project, which makes these farms ideal for places located far from bodies of water. The plants themselves are grown without soil in a nutrient-rich solution that delivers water and minerals to their roots.
The idea for the project was born in 2012 in Italy and realised with the help of researchers from Ocean Reef Group. A single farm comprises 6 plastic bubbles filled with air and anchored to the bottom of the sea. Each pod contains sensors that monitor carbon dioxide and oxygen levels, as well as humidity, illumination and the temperature of the water outside. The farm is overlooked by a control tower located on the surface and is tended to by divers that communicate with the land via ultrasonic devices.
During the COVID-19 pandemic, the farm faced an incredible challenge and was on the verge of being shut down – it had to be abandoned for months with no one to look after and guard it. Luckily, it survived and has now returned to normal operation. Now that the project is getting more publicity, we can only hope that the world will take up the idea and expand it into more units across the planet!