It may look like we've led you into a squishy green minefield, but don't worry, these clustered oysters will only explode with flavor. In honor of Oyster Day, August 5 of each year, we're getting a glimpse of just one method of oyster mariculture, or farming in open seawater. The briny bivalves may be grown on beds, rods, racks, or—in this case—ropes, but the basic process is simple: Growing surfaces are 'seeded' with whole or ground oyster shells before oyster larvae are introduced. The shells attract the larvae, which attach themselves and soon grow into a new layer of mature oysters. Humans have been doing this at least since the days of ancient Rome, but wild-picked oysters have been an important food source to many cultures since prehistory.