Lucy Biggers visits Stonington Kelp Company in Connecticut to explore how small-scale seaweed farming can serve as both a food source and a carbon sequestration tool.
Key insights:
Sugar kelp grows from millimeter-sized seedlings to over a meter long in a single season with zero fertilizer inputs, absorbing carbon and nitrogen from the water as it grows.
Carbon can be sequestered long-term by sinking harvested seaweed to the deep ocean floor where decomposition is minimal, with one study finding that sinking just 14–25% of current global seaweed production could make the entire aquaculture sector carbon neutral.
Seaweed farming occupies only 0.05% of suitable ocean area globally, leaving enormous room for expansion across 132 countries with viable coastlines.
Farming seaweed on just 5% of US territorial waters could sequester the equivalent of 20 million cars annually while generating protein equivalent to 2.3 trillion hamburgers.
And the US currently has no federal seaweed farming policy, leaving the industry far behind Asia in scale and commercialization.