As rising seas and saltwater intrusion threaten fertile farmland, scientists are turning to the ocean for solutions. A groundbreaking study in Ambio highlights the potential of seagrass cultivation, particularly Zostera marina (nicknamed “sea-rice”), as a viable grain crop for the future. Projections show that by 2100, up to 620,000 km² of land worldwide could be lost to flooding, while around 80,000 km² of new brackish coastal zones could be transformed into seagrass farms. Unlike conventional crops, Z. marina thrives without freshwater, fertilisers, or pesticides—resources that are becoming increasingly scarce due to climate stress.
Wild Z. marina already yields 3–6.5 tons of grain per hectare, often surpassing the global rice average of 4.7 tons/ha, making it one of the few marine crops capable of competing with staple cereals. Beyond its food potential, seagrass meadows deliver major ecological benefits: they store up to 1,900 kg of CO₂ per hectare annually, act as nurseries for fish, and buffer shorelines from erosion. Indigenous communities in Mexico’s Baja California have traditionally harvested seagrass seeds as food, showing its cultural as well as nutritional relevance. Researchers stress that scaling up will require careful domestication, ecological safeguards, and sustainable harvesting practices to avoid damaging fragile wild meadows—ensuring this “ocean grain revolution” strengthens both food security and marine ecosystems. More