Did you know that oceans cover 71 percent of the Earth's surface, yet they provide less than 2 percent of our food? 

As we think about how to feed a growing global population, we're looking to the sea as a largely untapped resource for food. Why? Fish have one big advantage over land animals: They need a lot less food to grow.

Different sources of animal protein that we eat place different demands on our natural resources. One way to measure these demands is the feed conversion ratio, an estimate of the feed required for different animals to gain one pound of body mass. By this measure, farming salmon is about seven times more efficient than raising beef.

Fish need fewer calories to live because they’re cold-blooded, and they live in a buoyant environment, so they waste fewer calories fighting gravity. As a source of animal protein that puts the least demand on Earth’s resources, aquaculture—particularly for omnivores like tilapia, carp, and catfish—looks like a good way to help the world feed 9 billion people.

Share this infographic on social media using #futureoffood to spread the word about the benefits of aquaculture.

Find out more about the sea's role in helping feed our growing planet in National Geographic's latest feature on aquaculture, "How to Farm a Better Fish".