🏭CommercialAgriculture & Food • Aquaculture

Regenerative Ocean Farming

Regenerative Ocean Farming grows seaweed and shellfish together in vertical underwater farms that sequester carbon, reduce ocean acidity, and produce sustainable food with negative environmental impact. These polyculture systems can sequester 20 tons of CO₂ per hectare annually while producing 25-50 tons of seaweed and 200-500 tons of shellfish. Companies like GreenWave and Ocean Approved operate farms with production costs of $2-5 per kg for seaweed and $3-8 per kg for shellfish.

How It Works

Vertical rope farming systems suspend seaweed lines from surface buoys to ocean floor anchors, creating three-dimensional growing structures. Shellfish including oysters, mussels, and scallops are grown on additional lines within the same system. Seaweed absorbs CO₂ and nutrients from seawater while shellfish filter water and build calcium carbonate shells. Integrated systems require no inputs of freshwater, fertilizer, or feed while improving local water quality.

Advantages

Sequesters carbon and reduces ocean acidification while producing sustainable protein and biomaterials, requires no freshwater, fertilizer, or pesticides unlike terrestrial agriculture, and improves marine biodiversity and water quality. Ocean farming provides coastal economic opportunities and climate resilience. Products include food, fertilizer, biofuels, and biomaterials.

Challenges

Limited to suitable coastal areas with appropriate water conditions, faces regulatory barriers for ocean use permits and food safety approval, and vulnerable to climate impacts including storms and temperature changes. Market development needed for seaweed food products in Western markets. Equipment and maintenance costs can be substantial for offshore operations.