In transparent plastic bubbles 20 feet beneath the surface of the Mediterranean Sea, an experimental garden grows. The strawberries, basil, beans and tomatoes within these air-filled biospheres thrive in their submerged homes. Surrounding water provides the constant temperature and humidity elusive at most terrestrial farms, and freshwater trickles down the spheres' interiors after the seawater below evaporates and then condenses.

These marine greenhouses, located off the coast of Italy, represent a foray into underwater farming by Ocean Reef Group, a diving and scuba gear company. Company president Sergio Gamberini chose to grow his crops hydroponically after noticing, during an early trial, that soil brought along stowaway insect pests. He hopes to introduce this gardening approach to coastal developing countries with arid lands. In fact, Gamberini has received requests for biospheres from nations ranging from the Maldives to Saudi Arabia. His son, Luca Gamberini, admits a long path lies ahead: “Our dream is, on a large scale, utopic.”