Ocean farmers use a ruler to check how much the seaweed has grown.

Smith’s New Farm

The scientist suggested that Smith try growing a large kind of seaweed called sugar kelp. Smith was sold. He would become an ocean farmer. He wouldn't be fishing, but he could still be on the water. He would own his own businessand feed people!

But Smith wasn’t satisfied with growing only kelp. He wanted to produce a variety of food. How much could he produce within the 40-acre plot of ocean that he rented in Long Island Sound?

sugar kelp

Smith wondered if he could farm the entire depth of the water. There was a lot to consider. How do you grow kelp? What other kinds of food crops can be raised along with kelp? How should everything be arranged in a small ocean plot? And, how can the farm be run so that it actually helps the ocean instead of harming it?

After 15 years, Smith came up with a farming method called 3D ocean farming. Let’s see how it works.

Explore 3D ocean farming.

3D Ocean Farming

Take a look at one version of a 3D ocean farm. Now you can see the purpose of those black buoys. They hold up ropes that form an underwater framework. The ropes support kelp that grows downward in long, wavy ribbons. Scallops and mussels grow in nets that hang between the kelp. And below it all, oysters grow in cages on the seafloor.

Ropes are suspended 2.4 meters (8 feet) underwater.

Kelp grows fast. It’s no longer than the width of a coin when planted in December. By spring harvest, it’s 5.4 meters (18 feet) long.

Anchors keep the buoys and ropes in place.

How Do They Start?

Crops on land begin as seeds planted in the ground. How do kelp, mussels, and other ocean farm “crops” get their start? It depends.

For kelp, the farmer collects some kelp each fall and brings it to a nursery. There the kelp produce tiny round spores. The spores are attached to a string that is then rolled around a tube. The seeds continue to grow on the string until harvest.

It’s different with mussels. Young mussels called larvae swim in the ocean. They attach themselves to parts of the kelp. There the larvae grow small, hard shells. The farmer removes these baby mussels and loads them into mussel socks. They poke through the mesh as they grow.

Kelp spores grow around a tube in a nursery.

Other shellfish usually start out life in a nursery before being moved to the 3D farm to continue growing.