The future of protein is blue

In the future, most of our protein will come from the ocean.

This might sound far-fetched, but first principles make it inevitable. Here’s why.

1. Seaweeds are extremely good at photosynthesis.

Seaweeds are faster and more efficient than land plants at turning sunlight and carbon dioxide into useful molecules, including proteins. Never water limited, and not needing a vascular system, this diverse group of organisms are fundamentally advantaged over terrestrial crops like corn and soy in their potential for productivity.

2. Free inputs

Two critical things for growing plants are free for seaweeds. They are 1) nitrogen and 2) water.

Nitrogen is the building block of protein. It’s why it’s the most important component of fertilizer. The atmosphere holds most of the nitrogen in the part of the earth we inhabit, but it’s inaccessible to most living things because of its chemical form as nitrogen gas. When you look at where the pool of chemically reactive nitrogen lies, it’s mostly in the ocean in the form of nitrate. Pouring into the ocean from rivers and streams, and upwelling from deeper waters onto continental shelves, this liquid nitrogen compound flows along out coastlines and just below the ocean’s surface at high concentration.

Water has historically been a cheap and reliable resource for farmers, but it won’t continue to be. As climate change makes droughts and floods more severe, and as groundwater aquifers are pumped dry, freshwater supplies will become even more unreliable and expensive. The crops that can grow in saltwater will be the future of our agricultural production systems.

3. Biggest scale

The ocean covers 71% of the earth’s surface. Maybe we should take a look at it for growing crops? Not that we need anywhere even close to the whole ocean to feed the world. Much less than 1%, actually. But it helps to have a lot of options for where to put those seaweed farms.

Seaweeds are already a huge industry. Every year, more than 35 million tons are harvested for food and chemicals. More than oats. More than green beans. It’s big, but can get a lot, lot bigger.

We don’t need any new scientific breakthroughs to build the technology to make seaweed the most abundant, lowest cost, and most sustainable source of protein on earth. We just need to apply basic engineering to build scalable, modern farming systems that are safe for ocean creatures. Our ARPA-E project is doing just this. Technologies like passive, deep water upwelling will open up the open ocean to high productivity farming.

We’ll need new, high protein varieties of seaweed. Sushi-grade nori has more protein than soybeans, but most cultivated seaweeds (like sugar kelp) have generally been selected for varieties with high sugars and low protein. Traditional breeding techniques can change that balance and push protein levels much higher.

What does this mean for our food system? Seaweeds are destined to supply a major fraction of our future foods. With basic advances in marine engineering and biology, seaweed will soon be a contender as a bulk protein source. Finally, with technology opening up the ocean to autonomous farming systems for seeding and harvesting, and ocean transport being the most fuel efficient way to move goods, seaweed will eventually outcompete soy as a protein source on both cost and scale.